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HomeMy WebLinkAbout10-24-2017 Item 06 - Mitigatged Negative declaration of Environmental Impacts for the Laguna Lake Dredging and Sediment Management Project (Item Continued from 10-17-17) Meeting Date: 10/24/2017 FROM: Derek Johnson, City Manager Prepared By: Robert A. Hill, Natural Resources Manager SUBJECT: MITIGATED NEGATIVE DECLARATION OF ENVIRONMENTAL IMPACTS FOR THE LAGUNA LAKE DREDGING AND SEDIMENT MANAGEMENT PROJECT (CONTINUED FROM OCTOBER 17, 2017) RECOMMENDATION Approve a Resolution (Attachment A) to adopt a Mitigated Negative Declaration of Environmental Impacts for the Laguna Lake Dredging and Sediment Management Project. DISCUSSION Due to a noticing error, this item has been continued from the October 17, 2017 City Council hearing. Background The City of San Luis Obispo owns the 344 -acre Laguna Lake Natural Reserve (the “Reserve”) that includes most of the lake itself, portions of Prefumo Creek and its outlet into the lake, and adjacent upland areas. The City Council adopted the Laguna Lake Natural Reserve Conservation Plan (“Conservation Plan”) on July 15, 2014 to guide future management of the Reserve by offering a framework for conservation, restoration, recovery, and scenic recreational use. La guna Lake is primarily a naturally occurring lake, although the lake and its watersheds have been altered and manipulated, to include the re-routing of Prefumo Creek into the lake in the early 1960s. This has resulted in increased sediment deposition rates. Recent bathymetric surveys indicate accelerated changes in lake depth and morphology resulting in decreased water quality and aquatic habitat functions, as well as diminished aesthetic and recreational values associated with the lake. As a result, dredging and sediment management strategies are among the primary recommendations of the Conservation Plan. The City’s Financial Plan for 2015-17 identified implementation of the Conservation Plan as an “Other Important Council Objective” and included a work plan that contains all of the necessary steps to make a dredging and sediment management project “shovel ready”. In January 2016, the City retained the firm MNS Engineers (“MNS”) to assist the City with the work plan that was adopted by the City Council that included the following main tasks: 1.) Prepare Design Plans and Engineering Specifications; 2.) Environmental Studies and Project Permitting; and 3.) Public Outreach and Financing Options. The 2017-19 Financial Plan includes a work plan and budgets funding in order for the City to establish a basic dredging maintenance regime for the lake. To accomplish this, the City will remove modest amounts of sediment with the lake commensurate with annual deposition rates (i.e. 3,000-4,000 cubic yards per year), as well as utilize a small weed harvester to effectively manage aquatic vegetation that has been problematic for water quality. Packet Pg 39 6 Next Steps At this time, the City anticipates completing final planning and receiving regulatory agency permits in 2017-18. Adoption of a Mitigated Negative Declaration pursuant to the California Environmental Quality Act (CEQA), as contemplated herein and further described below under the Environmental Review section of this Council Agenda Report, is a key procedural step leading towards project implementation. Following the CEQA process, regulatory agency permits will be filed with the United States Army Corps of Engineers, which will trigger biological consultation with the U.S. Fish and Wildlife Service and National Oceanic and Atmospheric Administration Fisheries Division. The project will also require a Clean Water Act section 401 certification from the Central Coast Regional Water Quality Control Board and a section 1602 permit from the California Department of Fish and Wildlife. Staff anticipates having completed plans, specifications, and engineering (PS&E) suitable for contractor bidding purposes by winter of 2017-18, and issuing a Request for Proposals in the spring / early summer of 2018. Once regulatory agency permits are in hand, and a qualified contractor has been selected, the City will be in position to begin implementation of the project following July 1, 2018 at which time construction funds would be available in the 2018 -19 Budget, if approved as anticipated in the 2017-19 Financial Plan. CONCURRENCES The City Biologist and the City Engineer have provided their concurrence for the recommendation set forth in this Council Agenda Report. ENVIRONMENTAL REVIEW An Initial Study and Environmental Review has been prepared for the Laguna Lake Dredging and Sediment Management Project that concludes that potentially significant impacts on the environment could occur, but these impacts will be reduced to less than significant with mitigation measures incorporated. Potentially significant impacts that will be mitigated were identified in the areas of Air Quality, Biological Resources, Cultural Resources, Geology / Soils, Hazards and Hazardous Materials, and Hydrology / Water Quality. Other less than significant impacts were also identified in the areas of Aesthetics, Air Quality, Biological Resources, Geology and Soils, Greenhouse Gas Emissions, Hazards and Hazardous Materials, Hydrology / Water Quality, Land Use and Planning, Noise, Public Services, and Transportation / Traffic. It should be noted that most all of the impacts identified through the environmental review process are temporary in nature, as the project is ultimately expected to have beneficial environmental effects. A variety of technical studies were completed to support the environmental review of the project, including: 1.) Preliminary Dredging Report (MNS Engineers, 2016); 2.) Geotechnical Characterization Report (Leighton, 2016); 3.) Biological Resources Assessment (Rincon, 2016); and, Cultural Resources Study (Rincon, 2016). These studies are all available on the City’s website. Packet Pg 40 6 A “Human Health Risk Assessment of Sediment Dredging and Dewatering Activities for Laguna Lake” was recently completed by Langan Engineering and Environmental Services to help inform the conclusions of the Hazards and Hazardous Materials section of the environmental review. The objectives of the Human Health Risk Assessment were to determine whether concentrations of constituents in soil may pose unacceptable risks to human health under site- specific exposure conditions, and to provide information to support decisions concerning the need for further evaluation or action of these media based on the proposed dredging activities. The inhalation of fugitive dust exposure pathway was evaluated for the off-site resident receptor. The risk assessment supports the following conclusions: 1.) No unacceptable cancer risks are posed to the off-site resident. The incremental lifetime cancer risk is estimated to be within the EPA’s risk management range at 2E-05, primarily attributable to background concentrations of [naturally-occurring] asbestos. 2.) No unacceptable non-carcinogenic risks are posed to the off-site resident. As a new study that has not been previously available to the public, the complete Human Health Risk Assessment is included as Attachment B to this Council Agenda Report. FISCAL IMPACT Funding is identified in the 2017-18 Budget and 2017-19 Financial Plan to support final environmental review, permitting, and to begin project implementation (see pages E2-47 and E2- 48). Adequate staff resources to support the project have also been identified within the Natural Resources Program and Public Works CIP Engineering Division. ALTERNATIVES 1. The City Council could request additional information or make changes to the proposed project. Depending on the extent of changes that might be requested, it may be necessary to recirculate the required 30-day Notice of Intent to Adopt a Mitigated Negative Declaration. 2. The City Council could elect not to proceed with the proposed project at this time. Attachments: a - Resolution b - Extended Notice of Intent to Adopt MND 9-15-17 c - Human Health Risk Assessment - Langan Engineering and Environmental 2017 Packet Pg 41 6 R ______ RESOLUTION NO. ________ (2017 Series) A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF SAN LUIS OBISPO, CALIFORNIA, ADOPTING A MITIGATED NEGATIVE DECLARATION FOR THE LAGUNA LAKE DREDGING AND SEDIMENT MANAGEMENT PROJECT WHEREAS, the City of San Luis Obispo has adopted policies for protection, management, and public use of open space lands and cultural resources acquired by the City; and WHEREAS, the City of San Luis Obispo owns and manages fourteen Open Space properties totaling approximately 3,850 acres, as well Open Space or Conservation Easements totaling approximately 3,400 acres; and WHEREAS, one of the City of San Luis Obispo’s Open Space properties is the 344-acre Laguna Lake Natural Reserve, the management and stewardship of which is guided by the Council-adopted Laguna Lake Natural Reserve Conservation Plan that calls for dredging and sediment management strategies, among other goals and policies; and WHEREAS, members of the public provided continuous testimony to the City Council requesting implementation of dredging and sediment management strategies, and City staff have identified a project to begin implementation of maintenance dredging regime for Laguna Lake, following a Council-directed process. NOW, THEREFORE, BE IT RESOLVED by the City Council of the City of San Luis Obispo as follows: The City Council hereby adopts a Mitigated Negative Declaration of environmental impact for the Laguna Lake Dredging and Sediment Management Project based on the following findings and subject to the following mitigation measures: 1. The Laguna Lake Dredging and Sediment Management Project considered a “Project” under the California Environmental Quality Act (CEQA) as defined in Public Resources Code §21065 because it represents an activity which may cause either a direct physical change in the environment, or a reasonably foreseeable indirect physical change in the environment, and because it is an activity directly undertaken by a public agency. 2. An Initial Study and Environmental Review has been prepared for the pilot program that concludes that significant impacts on the environment could occur, but these impacts will be reduced to less than significant with mitigation measures incorporated. Potentially significant impacts were identified in the areas of Air Quality, Biological Resources, Cultural Resources, Geology / Soils, Hazards and Hazardous Materials, and Hydrology / Water Quality. These potentially significant impacts are reduced to less than significant with the following mitigation measures, which are incorporated herein: Packet Pg 42 6 Resolution No. _____ (2017 Series) Page 2 R ______ Air Quality AQ-1 During construction/ground disturbing activities, the applicant shall implement the following particulate (dust) control measures. These measures shall be shown on grading and building plans. In addition, the contractor shall designate a person or persons to monitor the dust control program and to order increased watering, modify practices as necessary, to prevent transport of dust off site. Their duties shall include holiday and weekend periods when work may not be in progress. The name and telephone number of such persons shall be provided to the Community Development and Public Works Departments prior to commencement of construction. a. Reduce the amount of disturbed area where possible. b. Use water trucks or sprinkler systems in sufficient quantities to prevent airborne dust from leaving the site and from exceeding the APCD’s limit of 20% opacity for no greater than 3 minutes in any 60-minute period. Increased watering frequency will be required whenever wind speeds exceed 15 m.p.h. and cessation of grading activities during periods of winds over 25 m.p.h. Reclaimed (non-potable) water is to be used in all construction and dust control work. c. All dirt stock pile areas (if any) shall be sprayed daily and covered with tarps or other dust barriers as needed. d. Permanent dust control measures identified in the approved project revegetation and landscape plans shall be implemented as soon as possible, following completion of any soil dist urbing activities. e. Exposed grounds that are planned to be reworked at dates greater than one month after initial grading shall be sown with a fast germinating, non-invasive, grass seed and watered until vegetation is established. f. All disturbed soil areas not subject to revegetation shall be stabilized using approved chemical soil binders, jute netting, or other methods approved in advance by the APCD. g. All roadways, driveways, sidewalks, etc. to be paved shall be completed as soon as possible. In addition, building pads shall be laid as soon as possible after grading unless seeding or soil binders are used. h. Vehicle speed for all construction vehicles shall not exceed 15 m.p.h. on any unpaved surface at the construction site. i. All trucks hauling dirt, sand, soil, or other loose materials, are to be covered/tarped in accordance with California Vehicle Code Section 23114 to prevent the escape of soil or dust. j. Install wheel washers where vehicles enter and exit unpaved roads onto streets, or wash off trucks and equipment leaving the site. k. Sweep streets at the end of each day if visible soil material is carried onto adjacent paved roads. Water sweepers shall be used with reclaimed water where feasible. Roads shall be pre- wetted prior to sweeping when feasible. l. All PM10 mitigation measures required shall be shown on grading and building plans. m. The contractor or builder shall designate a person or persons to monitor the fugitive dust emissions and enhance the implementation of the measures as necessary to minimize dust Packet Pg 43 6 Resolution No. _____ (2017 Series) Page 3 R ______ complaints, reduce visible emissions below the APCD’s limit of 20% opacity for no greater than 3 minutes in any 60-minute period. Their duties shall include holidays and weekend. AQ 2 Prior to any construction activities at the site, the project proponent shall ensure that all equipment and operations are compliant with California Air Resource Board and APCD permitting requirements, by contacting the APCD Engineering Division at (805) 781-5912 for specific information regarding permitting requirements. AQ 3 To reduce sensitive receptor emissions impact of diesel vehicles and equipment used to construct the project and export soil from the site, the applicant shall implement the following idling control techniques: I. California Diesel Idling Regulations a. On-road diesel vehicles shall comply with Section 2485 of Title 13 of the California Code of regulations. This regulation limits idling from diesel-fueled commercial motor vehicles with gross vehicular weight ratings of more than 10,000 pounds and licensed for operation on highways. It applies to California and non-California based vehicles. In general, the regulation specifies that drivers of said vehicles: 1. Shall not idle the vehicle’s primary diesel engine for greater than 5 minutes at any location, except as noted in Subsection (d) of the regulation; and, 2. Shall not operate a diesel-fueled auxiliary power system (APS) to power a heater, air conditioner, or any ancillary equipment on that vehicle during sleeping or resting in a sleeper berth for greater than 5.0 minutes at any location when within 1,000 feet of restricted area, except as noted in Subsection (d) of the regulation. b. Off-road diesel equipment shall comply with the 5 minute idling restriction identified in Section 2449(d)(2) of the California Air Resources Board’s In-Use Off-Road Diesel regulation. c. Signs must be posted in the designated queuing areas and job sites to remind drivers and operators of the state’s 5 minute idling limit. II. Diesel Idling Restrictions Near Sensitive Receptors (residential homes). In addition to the State required diesel idling requirements, the project applicant shall comply with these more restrictive requirements to minimize impacts to nearby sensitive receptors: a. Staging and queuing areas shall not be located within 1,000 feet of sensitive receptors. b. Diesel idling within 1,000 feet of sensitive receptors shall not be permitted. c. Use of alternative fueled equipment is recommended. d. Signs that specify the no idling areas must be posed and enforces at the site. III. Soil Transport. The final volume of soil that will be hauled off-site, together with the fleet mix, hauling route, and number of trips per day will need to be identified for the APCD. Specific standards and conditions will apply. Monitoring Program: These measures shall be incorporated into project grading and building plans for review and approval by the City Community Development Department. Packet Pg 44 6 Resolution No. _____ (2017 Series) Page 4 R ______ Compliance shall be verified by the City during regular inspections, in coordination with the County of San Luis Obispo Air Pollution Control District, as necessary. Biological Resources BIO-1 Special Status Plant Species Avoidance: Avoid impacts to occurrences of special status plants listed under ESA and/or CESA. As part of the design of the projects, biological surveys shall be conducted by a qualified Biologist to identify specimens in the project area. If total avoidance of CRPR species is not feasible, minimize impacts to less than 10 percent of onsite populations. BIO-2 Special Status Plant Species Mitigation. Should it be determined that more than 10% of onsite population of Special Status Plants be impacted, the City shall develop a Habitat Mitigation and Monitoring Plan (HMMP) to develop adequate mitigation to offset impacts to species. The HMMP shall quantify the impacts associated with operations and specify restoration practices and enhancement of species habitat. The HMMP shall be reviewed, as applicable by the California Department of Fish and Wildlife for consistency with State requirements. BIO-3 Special Status Wildlife-Birds Avoidance. To avoid take of nesting birds, and raptor nests at any time of year (including inactive nests), activities requiring vegetation disturbance would occur outside the nesting season, which is approximately February 1 through September 15. If activities must begin within the bird breeding season, then no more than two weeks prior to initiation of ground disturbance and/or vegetation removal, a nesting bird pre-construction survey will be conducted by a qualified biologist within the disturbance footprint plus a 100-foot buffer. Pre-construction nesting bird surveys will be conducted during the time of day when birds are active and will be of sufficient duration to reliably conclude presence/absence of nesting birds and raptors onsite and within the designated vicinity. If no nests are observed no further mitigation is required. BIO-4 Special Status Wildlife-Birds Nesting. If nests are found, their locations will be flagged and then mapped onto an aerial photograph of the project site at a scale no less than 1”=200’ and/or recorded with the use of a Global Positioning System (GPS) unit. An appropriate avoidance buffer ranging in size from 50 to 500 feet from the nest, depending upon the species and the proposed work activity, will be determined and demarcated by a qualified biologist with bright orange construction fencing or other high-visibility delineators. No ground disturbance will occur within this buffer until the qualified biologist confirms that the breeding/nesting is completed and all the young have fledged. If buffer zones are determined to be infeasible, a full- time qualified biological monitor can monitor project activity within the buffer zones to ensure active nests and nesting birds are not impacted. BIO-5 Special Status Animals Badger. Prior to activities that disturb native habitats in upland areas, a qualified biologist should complete a survey for badger dens. In order to avoid the potential direct take of adults and nursing young, no grading should occur within 50 feet of an active badger den between March 1 and June 30. Activities during July 1 and March 1 should comply with the following measures to avoid direct take of adult and weaned juvenile badgers. Packet Pg 45 6 Resolution No. _____ (2017 Series) Page 5 R ______ o Conduct a biological survey of the anticipated development areas between 2 weeks and 4 weeks of the start of ground clearing or grading activity. The survey should cover the entire area proposed for disturbance. Surveys should focus on both old and new den sites. If dens are too long to see the end, a fiber optic scope (or other acceptable method) can be used to assess the presence of badgers. o Inactive dens shall be excavated by hand with a shovel to prevent badgers from reusing them during construction. o Badgers should be discouraged from using currently active dens prior to the grading of the site by partially blocking the entrance of the den with sticks, debris and soil for 3 to 5 days or through use of a 1-way door. After badgers have stopped using active dens within the development area, the dens shall be hand excavated with a shovel to prevent re-use. BIO-6 Special Status Animals Pallid Bat. Prior to activities that require tree removal, a qualified biologist should inspect trees proposed for removal to ensure bats are not roosting. If bats are observed, the biologist shall determine if the roost is a hibernaculum or a maternity colony. If so, removal of the tree would be postponed until outside wintering or maternity seasons. If not, the bat(s) would be evicted using appropriate one-way devices and the tree inspected again prior to tree removal. BIO-7 Special Status Animals Coast Horned Lizard. During new grading activities in upland habitats, a qualified biologist should be on-site to recover any coast horned lizards that may be excavated/unearthed with native material or found under vegetation. If the animals are in good health, they should be immediately relocated to a designated release area. If they are injured, the animals shall be turned over to an approved wildlife rehabilitator until they are in a condition to be released into the designated release area. BIO-8 Special Status Animals Vernal Pool Fairy Shrimp. The project would be designed to avoid impacts to the basins and wetland depressions (adjacent to but not abutting Laguna Lake), and would avoid altering hydrology of these features. Work areas would be flagged, resources to be avoided would be flagged, and no work would occur upslope and within 250 feet of vernal pool fairy shrimp habitat. BIO-9 Special Status Animals Western Spadefoot Toad . During new grading activities in upland habitats, a qualified biologist should be on-site to recover any spadefoot toads that may be excavated/unearthed with native material or found under vegetation. If the animals are in good health, they should be immediately relocated to a designated release area. If they are injured, the animals shall be turned over to an approved wildlife rehabilitator until they are in a condition to be released into the designated release area. BIO-10a Special Status Animals California Red-Legged Frog. Prior to initiation of construction activities (including staging and mobilization), all personnel associated with project construction would attend a Worker Environmental Awareness Program (WEAP) training, conducted by a qualified biologist, to aid workers in recognizing special status resources that may occur in the project area. The specifics of this program would include identification of the sensitive species and habitats, a description of the regulatory status and general ecological Packet Pg 46 6 Resolution No. _____ (2017 Series) Page 6 R ______ characteristics of sensitive resources, and review of the limits of construction and avoidance measures required to reduce impacts to biological resources within the work area. A fact sheet conveying this information would also be prepared for distribution to all contractors, their employers, and other personnel involved with construction of the project. BIO-10b Special Status Animals California Red-Legged Frog. Ground disturbing activities associated with dry portions of Prefumo Creek should be conducted between May 1 and October 31 during dry weather conditions, which are periods of low activity for these species in dry habitats, to minimize the potential for encountering CRLF. Work should be restricted to daylight hours to the extent feasible. o If activities must occur between November 1 and April 30, the qualified biologist should conduct a pre‐activity clearance sweep each morning prior to start of project activities after any rain events of 0.1 inch or greater. o All trash should be removed from the site daily and disposed of properly to avoid attracting potential predators to the site. o Non-automated operational activities (i.e. truck trips), shall not be conducted during rain events occurring at night to the extent feasible. If project activities requiring movement of equipment are to occur at night during rain events, a qualified biologist should conduct a pre-construction survey of the site each night. BIO-10c Special Status Animals California Red-Legged Frog. A qualified biologist should conduct a survey of work areas associated with the lake and creek within 48 hours of initial ground disturbing activities. The survey area would include the proposed disturbance area and all proposed ingress/egress routes, plus a 100-foot buffer. A biologist authorized to relocate frogs should be present for activities that require movement or placement of equipment into the lake, stream, and wetlands along the lake to monitor for frogs. If a frog is observed in the work area, the biologist would relocate it, with prior authorization from USFWS, out of the work area. BIO-10d Special Status Animals California Red-Legged Frog. If drying basins are used to remove water from the sediment, appropriate exclusion fence should be placed around the basins to prevent access by frogs. BIO-11 Special Status Animals Southwestern Pond Turtle. A qualified biologist should conduct a survey of work areas associated with the lake and creek within 48 hours of initial ground disturbing activities. The survey area would include the proposed disturbance area and all proposed ingress/egress routes, plus a 100-foot buffer. Turtles within work areas should be relocated outside the work area. A biologist authorized to relocate turtles should be present for activities that require movement or placement of equipment into the lake, stream, and wetlands along the lake to monitor for turtles. If a turtle is observed in the work area, the biologist would relocate it out of the work area. BIO-12 Habitat Enhancement Fisheries. During project design, including options to stabilize banks along the lake, the following habitat parameters would be considered and incorporated as feasible: Packet Pg 47 6 Resolution No. _____ (2017 Series) Page 7 R ______ o The lake should provide abundant cover including woody debris, boulders, and undercut banks. Woody debris is very important to provide needed shelter for juvenile fish especially in low velocity refuges. Having appropriate cover and shelter would be imperative for steelhead to survive in Laguna Lake. o Depths greater than 0.5 meter are generally deep enough to avoid wading birds. Depth alone is not the determining factor in water temperature, but lake which has a depth to create a thermocline cold enough to support the fish during periods of higher water temperatures is desirable. o The lake should contain a regular and pronounced slope along its banks. o DO concentrations affect the migration and swimming performance of steelhead at all temperatures. Low DO levels decrease the rate of metabolism, swimming speed, growth rate, food consumption rate, efficiency of food utilization, behavior, and survival. Steelhead does best where DO concentration is at least 7.0 mg/L. DO concentrations should remain at or near saturation levels with temporary reductions no lower than 5.0 mg/L, which has been documented to result in severe production impairment (Carter, 2005). o Suspended and deposited fine sediment can directly affect steelhead by clogging gills, indirectly causing reduced feeding, destruction of food supplies, and changed rearing habitat. Silt loads of less than 25 mg/L permit good rearing conditions for juvenile steelhead. Controlling sediment loads into the creek and lake will improve conditions for steelhead. BIO-13 Project Monitoring Fisheries. During project implementation, a biologist with fisheries experience should be present during activities movement or placement of equipment into the lake, stream, and wetlands along the lake to monitor for fish. If feasible, the active dredge area would be screened to reduce likelihood of aquatic vertebrate species in the active dredging area (e.g. intakes will be screened). If steelhead is observed, activities would cease until NMFS can be consulted. While dredging is underway, a biologist will monitor activities at least weekly. BIO-14 Needlegrass Habitat Avoidance. To the maximum extent feasible, project activities would be designed to avoid needlegrass grassland habitat. If needlegrass grassland habitat areas cannot be avoided in temporary impact areas, purple needlegrass will be incorporated into the revegetation plant palette to functionally replace the impacted habitat. BIO-15 Needlegrass Enhancement. If permanent impacts remove needlegrass grassland habitat areas greater than 0.5 acre in size, an equivalent amount of this habitat type must be created within a City-designated and -approved needlegrass grassland habitat mitigation area onsite. Pertinent and logistic details regarding the creation of needlegrass grassland habitat would be outlined in a HMMP. The needlegrass grassland habitat mitigation areas will be monitored annually for at least five years to ensure successful establishment and that no-net-loss of this sensitive habitat has been achieved. BIO-16 Wetlands Restoration. Jurisdictional areas that cannot be avoided will acquire all applicable regulatory permits. Temporary impact areas will be restored at a one to one (1:1) ratio (one acre of restoration for each acre of impact) to offset temporary losses in wetland, stream, or riparian function. Permanent impacts will be offset through creation, restoration, and/or enhancement of in-kind habitats at a minimum ratio of 2:1 to mitigate unavoidable permanent Packet Pg 48 6 Resolution No. _____ (2017 Series) Page 8 R ______ impacts to jurisdictional areas. Note the resource agencies may require a higher mitigation ratio. A Mitigation and Monitoring Plan will likely be required, and would be prepared by a biologist familiar with restoration and mitigation techniques. The plan will include, but not be limited to the following components: o Description of the project/impact site, o Goal(s) of the compensatory mitigation project, o Description of the proposed compensatory mitigation-site, o Implementation plan for the compensatory mitigation-site, o Maintenance activities during the monitoring period, o Monitoring plan for the compensatory mitigation-site, o Success criteria and performance standards, o Reporting requirements, and o Contingency measures and funding mechanisms. BIO -17 Erosion Control. Erosion control and landscaping specifications shall allow only natural-fiber, biodegradable meshes and coir rolls, (i.e. no plastic-mesh temporary erosion control measures) to prevent impacts to the environment and to fish and terrestrial wildlife. BIO-18 Habitat Improvement. Where feasible, aquatic habitat improvements such as root wads and downed logs will be incorporated into bank stabilization and sediment control efforts to enhance aquatic habitat in perennial waterways. BIO-19 State/Federal Consultation. Prior to commencement of operations, consultations with applicable federal and state agencies shall be completed per the provisions of the Clean Water Act and Porter Cologne Act. Monitoring Program: These conditions and measures shall be noted on all grading and construction plans. The City Community Development Department and Natural Resources Manager shall verify compliance. Cultural Resources CULT-1: If cultural resources are encountered during ground-disturbing activities, work in the immediate area should be halted and an archaeologist meeting the Secretary of the Interior’s Professional Qualifications Standards for archaeology (National Park Service 1983) should be contacted immediately to evaluate the find. If necessary, the evaluation may require preparation of a treatment plan and archaeological testing for National Register of Historic Places eligibility. If the discovery proves to be significant under the National Historic Preservation Act and cannot be avoided by the project, additional work such as data recovery excavation may be warranted to mitigate any adverse effects to historic properties. CULT-2: The discovery of human remains is always a possibility during ground disturbing activities; if human remains are found, State of California Health and Safety Code Section 7050.5 states that no further disturbance shall occur until the County Coroner has made a determination of origin and disposition pursuant to Public Resources Code Section 5097.98. In Packet Pg 49 6 Resolution No. _____ (2017 Series) Page 9 R ______ the event of an unanticipated discovery of human remains, the San Luis Obispo County Sherriff- Coroner must be notified immediately. If the human remains are determined to be prehistoric, the coroner will notify the Native American Heritage Commission, which will determine and notify a most likely descendant (MLD). The MLD shall complete the inspection of the site within 48 hours of notification and may recommend scientific removal and nondestructive analysis of human remains and items associated with Native American burials. Monitoring Program: These conditions shall be noted on all grading and construction plans. The City Community Development Department shall verify compliance, including preparation and implementation of the Monitoring Plan, and review and approval of cultural resources monitoring reports documenting compliance with required mitigation measures. Geology / Soils GEO-1 Grading and erosion and sediment control plans shall be designed to minimize erosion during operations and shall be implemented for the duration of the grading period and until regraded areas have been stabilized. The City shall prepare Erosion Control Plan using Best Management Practices (BMPs) that are designed to stabilize the site and protect natural watercourses. GEO-2 The City shall revegetate graded areas upon completion of grading activities with deep rooted, native, drought-tolerant species to minimize slope failure and erosion potential. Use of hydro-seed, straw blankets, other geo-textile binding fabrics or other P&D-approved methods as necessary to hold slope soils until vegetation is established. Monitoring Program: These measures shall be incorporated into project grading plans for review and approval by the City Community Development and Public Works Departments. Compliance shall be verified by the City during regular inspections. Hazardous Materials HAZ-1 Excavated sediment must be covered/tarped when transported outside of the project area. HAZ-2 Excavated sediment shall be tested according to a soil sampling protocol to ensure that the soils are acceptable to the desired disposal site. If it is determined that the sediments contain hazardous constituents and are unacceptable to the desired disposal site, the sediments shall be disposed at a licensed hazardous waste disposal site. HAZ-4 Water sprays or other adequate measures will be applied each day that work activities occur to all disturbed areas with the potential to emit fugitive dust. At a minimum, water will be applied to exposed areas three times per day with increasing watering frequency required whenever the wind speed exceeds 15 miles per hour. Reclaimed water should be used whenever possible. HAZ-5 Sediments/soil stockpiles will be covered, kept moist, or treated with soil binders to prevent dust generation at the end of each work day. Packet Pg 50 6 Resolution No. _____ (2017 Series) Page 10 R ______ HAZ-6 On site vehicle speeds will be limited to 15 miles per hour or less. Loose dirt and dust shall be removed from all vehicular wheels using brushes, rumble strips, or water prior to leaving the site. HAZ-7 The contractor will designate a person(s) to monitor the dust control program and to order increased watering, as necessary, to prevent transport of dust offsite. The contractor will stop project activities immediately if visible dust emissions are detected at the property boundary and will implement additional dust mitigation measures. HAZ-8 After work activities are completed, all disturbed areas will be re-vegetating or otherwise developed so that dust generation will not occur. HAZ-9 A worker health, safety and education plan will be developed and required, as well as emergency and remedial procedures. Hydrology / Water Quality HYDRO-1. For dredging operations the use of a turbidity curtain will be employed as applicable. Sediment basins to be used for dewatering should be located at least 200 feet ways from the lake shoreline. Implementation of Mitigation Measure HYDRO-1 would mitigate impacts to water quality to less than significant. HYDRO-2. Upon conclusion of operations, creek banks would be regraded as necessary and laid back to 2H:1V to 2.5H: 1V and reinforced to stabilize banks. Slopes will be revegetated with native riparian species and ground cover. Monitoring Program: These measures shall be incorporated into project grading and building plans for review and approval by the City Community Development, Public Works, and Utilities Departments. Compliance shall be verified by the City during regular inspections. 3. Other less than significant impacts were also identified in the areas of Aesthetics, Air Quality, Biological Resources, Geology and Soils, Greenhouse Gas Emissions, Hazards and Hazardous Materials, Hydrology / Water Quality, Land Use and Planning, Noise, Public Services, and Transportation / Traffic. Upon motion of _______________________, seconded by _______________________, and on the following roll call vote: AYES: NOES: ABSENT: The foregoing resolution was adopted this _____ day of _____________________ 2017. Packet Pg 51 6 Resolution No. _____ (2017 Series) Page 11 R ______ ____________________________________ Mayor Heidi Harmon ATTEST: ____________________________________ Carrie Gallagher City Clerk APPROVED AS TO FORM: _____________________________________ J. Christine Dietrick City Attorney IN WITNESS WHEREOF, I have hereunto set my hand and affixed the official seal of the City of San Luis Obispo, California, this ______ day of ______________, _________. ____________________________________ Carrie Gallagher City Clerk Packet Pg 52 6 Packet Pg 53 6 lower dissolved oxygen levels, decreased recreational use due to presence of microcystins, and more frequent dry cycles on the banks or lake-wide that create vegetation and fish die-offs, with associated decomposition odors and increased nitrate levels. 3. The Lake provides some natural flood protection as a natural water body, but is not maintained or operated as a flood control facility. The ability of the Lake to continue to perform its natural, limited function of flood control and water storage will be restored with dredging. 4. Deeper waters may support and enhance salmonid and other fish populations. The maintenance dredging regime is expected to be ongoing, but comprised of at least four construction seasons, avoiding the winter months between November 1 and April 15 to: 1) Avoid impacts during the wettest seasons on local wildlife and 2) Complete work outside the bird nesting season. To minimize impacts on local structures and citizens: 1. There will be no downstream releases of water. 2. Most access for work shall be from the north (park) side of the lake utilizing the park entrance on Madonna Road. 3. All dewatering of the dredged slurry soil will be performed by the following method: a. Semi-Passive Dewatering. Dredged slurry will be pumped onshore into geotextile bags or “tubes” that serve to decant the water through the fabric leaving the solids inside the geotextile bags. Flocculating polymer agents will also be used in conjunction with this process to more thoroughly remove turbidity. The geotextile bags will be placed into a sediment basin constructed a minimum of 100 feet away from the lake surface to allow for capture of materials and filtrated recharge into the soil profile. During this dewatering process, water quality will be improved from that of the existing lake water; nitrates and biocides (pesticides) tend to adhere to sediments. To assure that water quality meets established standards, a water quality testing program will be implemented during dredging. Trailer mounted activated carbon filters will be available for initial operations as a confidence measure for compliance, but will only continue to be used if on-going dredging operations and proposed dewatering equipment cannot satisfy permitting agency water quality requirements without them. 4. Water quality impacts by the dredging process will be mitigated by: a. Use of sediment screens to reduce migration of turbidity caused by the hydraulic dredging process, b. Dewatering processes designed and proven to treat the return water to an equivalent, or better water quality as proscribed in final permits. c. Sediment management plan with best management practices implemented at the dewatering and bank restoration and protection sites. The dewatering and sediment handling area will be as small as practical (approximately 3 to 4 acres), and contained within the area shown on Attachment 3. Material shall be loaded on haulers or dump trucks, and hauled to the disposal site via City and County streets, as well as Highway 227. Equipment may include any or all of the following:  One (1) tracked high-capacity (4-7 CY) excavator used to prepare the sediment basin area. Caterpillar 325 Excavators or equivalent (Diesel).  Two (2) front-end loaders (4-7 CY) (Diesel) used to load dewatered sediment into dump trucks. Packet Pg 54 6  Two (2) three–axle dump trucks, Cat CTC660 or equivalent (Diesel).  One (1) Oiler Truck, on a one ton Ford Frame, or equivalent (Diesel).  One (1) Water Truck/Trailer, on a one ton Ford Frame, or equivalent (Diesel).  Pontoon-boat mounted hydraulic 6” or 8” dredge that can be launched from the existing boat ramp, and associated floating 6” or 8” dredge pipe leading from the dredge to the dewatering site. Hours of operations will be between 7:00AM-7:00PM Monday through Friday and, if required, Saturday between 8:00AM-5:00PM. Once dredging activities conclude, the impacted areas of the park will be planted and/or seeded per pre-construction conditions and in accordance with final permits. With the exception of periodic sediment removal from the sedimentation basin on Prefumo Creek north of Los Osos Valley road, a sediment removal project has not been performed in the Lake since the early 1960s. Based on historic sediment flows and accumulation, and the anticipated development and maintenance of the sedimentation basin, it is estimated that a maintenance dredging regime project will need to remove approximately 3,000 to 4,000 cubic yards of sediment on an annual basis. The dredging priority area will be near the outlet of Prefumo Creek into the Lake where sediment deposition has been the greatest. Reference copies of the Mitigated Negative Declaration are available at the City’s Clerk’s Office, at 990 Palm Street, or by calling Robert Hill at 805-781-7211. These documents will also be available on the City’s website at www.slocity.org. The required 30-day public review period for the Mitigated Negative Declaration will be extended from Friday September 15, 2017 to Tuesday October 24, 2017. Anyone interested in commenting on the document should submit a written statement to the City of San Luis Obispo, 990 Palm Street, San Luis Obispo, CA 93401, Attention: Robert Hill, Natural Resources Manager, or by email to rhill@slocity.org by 5:00 p.m., October 24, 2017. The San Luis Obispo City Council will hold a public hearing on October 24, 2017 to consider the adoption of the Mitigated Negative Declaration. Interested persons can access the City Council agenda at http://www.slocity.org/government/mayor-and-city-council/agendas-and-minutes to locate the dates of the public hearings for this project.   Packet Pg 55 6 Packet Pg 56 6 Packet Pg 57 6 Packet Pg 58 6 INITIAL STUDY ENVIRONMENTAL CHECKLIST FORM 1. Project Title: Laguna Lake Dredging and Sediment Management Project 2. Lead Agency Name and Address: City of San Luis Obispo 990 Palm Street San Luis Obispo, CA 93401 3. Contact Person and Phone Number: Robert Hill, Natural Resources Manager 805-781-7211 Prepared By: Brian A. Tetley, Senior Planner Rural Planning Services 4. Project Location: 504 Madonna Road 5. Project Sponsor’s Name and Address: City of San Luis Obispo 919 Palm Street San Luis Obispo, CA 93401 6. General Plan Designations: Park 7. Zoning: Public Facility Packet Pg 59 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 2 8. Description of the Project: The City of San Luis Obispo proposes to implement a maintenance dredging regime that will remove sediment impacting the function and operation of Laguna Lake (the “Lake”) as a recreational facility within the Parks and Recreation Department and as a wildlife and natural reserve overseen by the City’s Natural Resources Program. This work will be performed by hydraulic dredging methods without draining the Lake. The project also includes some elements of bank restoration and stabilization on the northern shore adjacent to the Park, emptying and restoring of the sedimentation basin on Prefumo Creek between Los Osos Valley Road and Laguna Lake, and future construction of a new sedimentation basin within the City owned golf course on the south side of Los Osos Valley Road on Prefumo Creek. The project will remove a sediment layer averaging approximately 3-4 feet deep in the area shown on Attachment 2 for a total removal of between 3,000 CY and 4,000 CY of material. The material will be disposed of at a local off-site location in a legal and lawful manner. Sediments will be transported to the disposal site in covered trucks/trailers. Although there may be one or more local ranches or development project sites that may desire and receive some or all of the sediment, the guaranteed or default disposal site will be the Cold Canyon Landfill, located at 2268 Carpenter Canyon Rd, San Luis Obispo, CA 93401. The landfill has reviewed the soils reports and determined they can receive the sediment for disposal, and possibly for use as daily cover dirt. The project will only dispose of sediment at other, closer locations if, at project bid time, these locations have appropriate and required environmental documentation and permitting in place. The area to be dredged extends from the outlet of Prefumo Creek downstream approximately 1,200 feet (see Attachment 2). The work will be performed within the Lake while it retains the water in it at the time of construction. The necessity for dredging and the associated public benefits of dredging include: 1. Restoring recreational use of Laguna Lake. Formerly a popular kayaking, canoeing, sailing and windsurfing lake, the Lake is now shallow and limited in its ability to support these activities. 2. Restore lake water quality and health of the lake to support birds and wildlife. The shallow lake creates a warm-water environment that is susceptible to seasonal algae blooms resulting in lower dissolved oxygen levels, decreased recreational use due to presence of microcystins, and more frequent dry cycles on the banks or lake-wide that create vegetation and fish die- offs, with associated decomposition odors and increased nitrate levels. 3. The Lake provides some natural flood protection as a natural water body, but is not maintained or operated as a flood control facility. The ability of the Lake to contin ue to Packet Pg 60 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 3 perform its natural, limited function of flood control and water storage will be restored with dredging. 4. Deeper waters may support and enhance salmonid and other fish populations. The maintenance dredging regime is expected to be ongoing, but comprised of at least four construction seasons, avoiding the winter months between November 1 and April 15 to: 1) Avoid impacts during the wettest seasons on local wildlife and 2) Complete work outside the bird nesting season. To minimize impacts on local structures and citizens: 1. There will be no downstream releases of water. 2. Most access for work shall be from the north (park) side of the lake utilizing the park entrance on Madonna Road. 3. All dewatering of the dredged slurry soil will be performed by the following method: a. Semi-Passive Dewatering. Dredged slurry will be pumped onshore into geotextile bags or “tubes” that serve to decant the water through the fabric leaving the solids inside the geotextile bags. Flocculating polymer agents will also be used in conjunction with this process to more thoroughly remove turbidity. The geotextile bags will be placed into a sediment basin constructed a minimum of 100 feet away from the lake surface to allow for capture of materials and filtrated recharge into the soil profile. During this dewatering process, water quality will be improved from that of the existing lake water ; nitrates and biocides (pesticides) tend to adhere to sediments. To assure that water quality meets established standards, a water quality testing program will be implemented during dredging. Trailer mounted activated carbon filters will be available for initial operations as a confidence measure for compliance, but will only continue to be used if on-going dredging operations and proposed dewatering equipment cannot satisfy permitting agency water quality requirements without them. 4. Water quality impacts by the dredging process will be mitigated by: a. Use of sediment screens to reduce migration of turbidity caused by the hydraulic dredging process, b. Dewatering processes designed and proven to treat the return water to an equivalent, or better water quality as proscribed in final permits. c. Sediment management plan with best management practices implemented at the dewatering and bank restoration and protection sites. Packet Pg 61 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 4 The dewatering and sediment handling area will be as small as practical (approximately 3 to 4 acres), and contained within the area shown on Attachment 3. Material shall be loaded on haulers or dump trucks, and hauled to the disposal site via City and County streets, as well as Highway 227. Equipment may include any or all of the following: • One (1) tracked high-capacity (4-7 CY) excavator used to prepare the sediment basin area. Caterpillar 325 Excavators or equivalent (Diesel). • Two (2) front-end loaders (4-7 CY) (Diesel) used to load dewatered sediment into dump trucks. • Two (2) three–axle dump trucks, Cat CTC660 or equivalent (Diesel). • One (1) Oiler Truck, on a one ton Ford Frame, or equivalent (Diesel). • One (1) Water Truck/Trailer, on a one ton Ford Frame, or equivalent (Diesel). • Pontoon-boat mounted hydraulic 6” or 8” dredge that can be launched from the existing boat ramp, and associated floating 6” or 8” dredge pipe leading from the dredge to the dewatering site. Hours of operations will be between 7:00AM-7:00PM Monday through Friday and, if required, Saturday between 8:00AM-5:00PM. Once dredging activities conclude, the impacted areas of the park will be planted and/or seeded per pre-construction conditions and in accordance with final permits. With the exception of periodic sediment removal from the sedimentation basin on Prefumo Creek north of Los Osos Valley road, a sediment removal project has not been performed in the Lake since the early 1960s. Based on historic sediment flows and accumulation, and the anticipated development and maintenance of the sedimentation basin, it is estimated that a maintenance dredging regime project will need to remove approximately 3,000 to 4,000 cubic yards of sediment on an annual basis. The dredging priority area will be near the outlet of Prefumo Creek into the Lake where sediment deposition has been the greatest. 9. Project Entitlements Required: None. 10. Surrounding Land Uses and Settings: Existing uses surrounding the site area are as follows: West: Rural lands (C/OS-40); single-family residential neighborhood (R-1) Packet Pg 62 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 5 North: Rural lands (C/OS-40); city park (PF) East: Rural lands (C/OS-40); city park (PF); single-family residential neighborhood (R-1) South: Single-family residential neighborhood 11. Have California Native American tribes traditionally and culturally affiliated with the project area requested consultation pursuant to Public Resources Code Section 21080.3.1? If so, has consultation begun? No consultation required as no tribe has requested consultation in writing. 12. Other public agencies whose approval is required: U.S. Army Corps of Engineers, California Department of Fish and Wildlife, Regional Water Quality Control Board, United States Fish and Wildlife Service, National Marine Fisheries Service. Packet Pg 63 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 6 ENVIRONMENTAL FACTORS POTENTIALLY AFFECTED: The environmental factors checked below would be potentially affected by this project, involving at least one impact that is a “Potentially Significant Impact” as indicated by the checklist on the following pages. Aesthetics Greenhouse Gas Emissions Population / Housing Agriculture Resources X Hazards & Hazardous Materials Public Services X Air Quality X Hydrology / Water Quality Recreation X Biological Resources Land Use / Planning Transportation / Traffic X Cultural Resources Mineral Resources Tribal Cultural Resources X Geology / Soils Noise Utilities / Service Systems Mandatory Findings of Significance FISH AND WILDLIFE FEES The Department of Fish and Wildlife has reviewed the CEQA document and written no effect determination request and has determined that the project will not have a potential effect on fish, wildlife, or habitat (see attached determination). X The project has potential to impact fish and wildlife resources and shall be subject to the payment of Fish and Game fees pursuant to Section 711.4 of the California Fish and Game Code. This initial study has been circulated to the California Department of Fish and Wildlife for review and comment. STATE CLEARINGHOUSE X This environmental document must be submitted to the State Clearinghouse for review by one or more State agencies (e.g. Cal Trans, California Department of Fish and Wildlife, Department of Housing and Community Development). The public review period shall not be less than 30 days (CEQA Guidelines 15073(a)). Packet Pg 64 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 7 DETERMINATION (To be completed by the Lead Agency): On the basis of this initial evaluation: I find that the proposed project COULD NOT have a significant effect on the environment, and a NEGATIVE DECLARATION will be prepared. I find that although the proposed project could have a significant effect on the environment, there will not be a significant effect in this case because revisions in the project have been made, by or agreed to by the project proponent. A MITIGATED NEGATIVE DECLARATION will be prepared. X I find that the proposed project MAY have a significant effect on the environment, and an ENVIRONMENTAL IMPACT REPORT is required. I find that the proposed project MAY have a “potentially significant” impact(s) or “potentially significant unless mitigated” impact(s) on the environment, but at least one effect (1) has been adequately analyzed in an earlier document pursuant to applicable legal standards, and (2) has been addressed by mitigation measures based on the earlier analysis as described on attached sheets. An ENVIRONMENTAL IMPACT REPORT is required, but it must analyze only the effects that remain to be addressed I find that although the proposed project could have a significant effect on the environment, because all potentially significant effects (1) have been analyzed adequately in an earlier EIR or NEGATIVE DECLARATION pursuant to applicable standards, and (2) have been avoided or mitigated pursuant to that earlier EIR or NEGATIVE DECLARATION, including revisions or mitigation measures that are imposed upon the proposed project, nothing further is required. 9/15/17 Signature Date Robert A. Hill Natural Resources Manager Printed Name Title Packet Pg 65 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 8 EVALUATION OF ENVIRONMENTAL IMPACTS: 1. A brief explanation is required for all answers except “No Impact” answers that are adequately supported by the information sources a lead agency cites in the parentheses following each question. A “No Impact” answer is adequately supported if the referenced information sources show that the impact simply does not apply to projects like the one involved (e.g. the project falls outside a fault rupture zone). A “No Impact” answer should be explained where it is based on project-specific factors as well as general standards (e.g. the project will not expose sensitive receptors to pollutants, based on a project-specific screening analysis). 2. All answers must take account of the whole action involved, including off-site as well as on-site, cumulative as well as project-level, indirect as well as direct, and construction as well as operational impacts. 3. Once the lead agency has determined that a particular physical impact may occur, then the checklist answers must indicate whether the impact is potentially significant, less than significant with mitigation, or less than significant. "Potentially Significant Impact' is appropriate if there is substantial evidence that an effect may be significant. If there are one or more "Potentially Significant Impact" entries when the determination is made, an EIR is required. 4. “Negative Declaration: Less Than Significant with Mitigation Incorporated” applies where the incorporation of mitigation measures has reduced an effect from "Potentially Significant Impact" to a "Less than Significant Impact." The lead agency must describe the mitigation measures, and briefly explain how they reduce the effect to a less than significant level (mitigation measures from Section 19, "Earlier Analysis," as described in (5) below, may be cross- referenced). 5. Earlier analysis may be used where, pursuant to the tiering, program EIR, or other CEQA process, an effect has been adequately analyzed in an earlier EIR or negative declaration (Section 15063 (c) (3) (D)). In this case, a brief discussion should identify the following: a) Earlier Analysis Used. Identify and state where they are available for review. b) Impacts Adequately Addressed. Identify which effects from the above checklist were within the scope of and adequately analyzed in an earlier document pursuant to applicable legal standards, and state whether such effects were addressed by mitigation measures based on the earlier analysis. c) Mitigation Measures. For effects that are “Less than Significant with Mitigation Measures Incorporated,” describe the mitigation measures which were incorporated or refined from the earlier document and the extent to which they addressed site-specific conditions for the project. 6. Lead agencies are encouraged to incorporate into the checklist references to information sources for potential impacts (e.g. general plans, zoning ordinances). Reference to a previously prepared or outside document should, where appropriate, include a reference to the page or pages where the statement is substantiated. 7. Supporting Information Sources: A source list should be attached, and other sources used or individuals contacted should be cited in the discussion. 8. The explanation of each issue should identify: a) the significance criteria or threshold, if any, used to evaluate each question; and b) the mitigation measure identified, if any, to reduce the impact to less than significance Packet Pg 66 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 9 1. AESTHETICS. Would the project: a) Have a substantial adverse effect on a scenic vista? 8 --X-- b) Substantially damage scenic resources, including, but not limited to, trees, rock outcroppings, open space, and historic buildings within a local or state scenic highway? 8 --X-- c) Substantially degrade the existing visual character or quality of the site and its surroundings? 8 --X-- d) Create a new source of substantial light or glare which would adversely affect day or nighttime views in the area? 8 --X-- Evaluation In the local area, Laguna Lake serves as a substantial public scenic resource as the immediate backdrop for Laguna Lake Park. Views have been somewhat degraded in the recent past due to siltation and drought effects that have resulted in little or no water in areas historically covered in water. Unobstructed public views of Laguna Lake are also found from the Let It Be Nature Reserve. Secondary and partially obscured public views into Laguna Lake can also be seen from Laguna Middle School, Smith Elementary School, Smith Park, Laguna Hills park and as viewed from Madonna and Los Osos Valley Roads. a) The project purpose to remove silt and deepen Laguna Lake in key areas would improve the visual character of the lake in the long-term. Since Laguna Lake serves as a local visual resource, the operational project would therefore improve local scenic vistas. Active dredging activities, however, would temporarily introduce heavy equipment and associated materials that would degrade the scenic vistas in the short-term during the dredging project. b) There are no designated scenic highways near the project area. Therefore, there would be no impact to scenic resources visible from a scenic highway. c) The project purpose to remove silt and deepen Laguna Lake in key areas would improve the visual charac ter of the lake in the long-term. The operational project would therefore improve local scenic vistas. Active dredging activities, however, would temporarily introduce heavy equipment and associated materials that would degrade the scenic vistas in the short- term during the dredging project. d) The dredging project would be performed during daylight hours. No lighting is proposed. No impacts to nighttime views would result. Conclusion: The project would have a less than significant impact on aesthetics. 2. AGRICULTURE RESOURCES. Would the project: a) Convert Prime Farmland, Unique Farmland, or Farmland of Statewide Importance (Farmland), as shown on the maps pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency, to non-agricultural use? --X-- b) Conflict with existing zoning for agricultural use or a Williamson Act contract? --X-- c) Involve other changes in the existing environment which, due to their location or nature, could result in conversion of Farmland to non-agricultural use? --X-- Evaluation a) The project site is not designated as Prime or Unique Farmland or Farmland of Statewide Importance on the maps prepared pursuant to the Farmland Mapping and Monitoring Program of the California Resources Agency. Therefore, the proposed project would not result in conversion of these agricultural resources to nonagricultural use. Packet Pg 67 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 10 b) The project site is not located on farmland, nor is it under a Williamson Act contract. The Project site is designated for conservation/open space in the General Plan and is zoned C/OS-40 (Conservation/Open Space-40 acres minimum lot size). The project site is surrounded by open and park space to the north and established single-family neighborhoods to the south. Therefore, the proposed project would not conflict with existing zoning for agricultural use or a Williamson Act contract. c) The proposed dredging project will not contribute to conversion of farmland. No impacts to existing on site or off site agricultural resources are anticipated. Conclusion: No impact. 3. AIR QUALITY. Where available, the significance criteria established by the applicable air quality management or air pollution control district may be relied upon to make the following determinations. Would the project: a) Conflict with or obstruct implementation of the applicable air quality plan? 8 --X-- b) Violate any air quality standard or contribute substantially to an existing or projected air quality violation? 8 --X-- c) Result in a cumulatively considerable net increase of any criteria pollutant for which the project region is non-attainment under an applicable federal or state ambient air quality standard (including releasing emissions which exceed quantitative thresholds for ozone precursors)? 8 --X-- d) Expose sensitive receptors to substantial pollutant concentrations? 8 --X-- e) Create objectionable odors affecting a substantial number of people? 8 --X-- Evaluation a), b), c), d) Both the US Environmental Protection Agency (EPA) and the California A ir Resources Board (CARB) have established ambient air quality standards for common pollutants. These ambient air quality standards are levels of contaminants representing safe levels that avoid specific adverse health effects associated with each pollutant. The ambient air quality standards cover what are called “criteria” pollutants because the health and other effects of each pollutant are described in criteria documents. Areas that meet ambient air quality standards are classified as attainment areas, while areas that do not meet these standards are classified as nonattainment areas. The City of San Luis Obispo is currently designated as nonattainment for the state and federal ambient air quality standards for ground-level ozone and PM2.5 as well as the state standards for PM10. CEQA Appendix G states the significance criteria established by the applicable air quality management or air pollution control district may be relied upon to make significance determinations. In April 2012, the San Luis Obispo Air Pollution Control District (SLO APCD) adopted The Clean Air Plan (CAP) for San Luis Obispo County. The CAP is a comprehensive planning document identifying thresholds of significance to assist local jurisdictions during the review of projects that are su bject to CEQA, and is designed to reduce emissions from traditional industrial and commercial sources, as well as from motor vehicle use. Under CEQA, the SLO County APCD is a responsible agency for reviewing and commenting on projects that have the potential to cause adverse impacts to air quality. Due to the nature of the proposed dredging project, the are no “operational” emissions, per se. All emissions would be during the dredging and hauling phase utilizing internal combustion engine pumps and diesel trucks, respectively. Construction Significance Criteria: Temporary impacts from the project, including but not limited to dredging and hauling activities, vehicle emissions from heavy duty equipment, has the potential to create dust and emissions that exceed air quality standards for temporary and intermediate periods. Construction and earth-moving activities can generate fugitive dust, which could be a nuisance to local residents and businesses in close proximity to the proposed construction site. Because the project is within 1,000 feet of sensitive receptors a Packet Pg 68 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 11 mitigation measure (AQ 1) has been recommended to manage fugitive dust emissions such that they do not exceed the APCD’s 20% opacity limit (APCD Rule 401) or prompt nuisance violations (APCD Rule 402). Construction equipment itself can be the source of emissions, and may be subject to California Air Resources Board or APCD permitting requirements. This includes portable equipment, 50 horsepower (hp) or greater or other equipment listed in the APCD’s 2012 CEQA Handbook, Technical Appendices, page 4-4. Truck trips associated with the soils that will be exported from the site may also be a source of emissions subject to APCD permitting requirements, subject to specific truck routing selected. The specific requirements and exceptions in the regulations can be reviewed at the following web sites: www.arb.ca.gov/msprog/truck-idling/2485.pdf and www.arb.ca.gov/react/2007/ordiesl07/frooal.pdf. A mitigation measure (AQ 2) has been recommended to ensure proper use of subject equipment. Additionally, because the project is in close proximity to nearby sensitive receptors, an additional mitigation measure (AQ 3) is recommended to ensure that public health benefits are realized by reducing toxic risk from diesel emissions. e) The project would not include the development of any potential land uses which would have the potential to produce objectionable odors in the area. Mitigation Measures: Mitigation Measure AQ-1: During ground disturbing activities, the applicant shall implement the following particulate (dust) control measures. These measures shall be shown on grading and building plans. In addition, the contractor shall designate a person or persons to monitor the dust control program and to order increased watering, modify practices as necessary, to prevent transport of dust off site. Their duties shall include holiday and weekend periods when work may not be in progress. The name and telephone number of such persons shall be provided to the City prior to commencement of construction. a. Reduce the amount of disturbed area where possible. b. Use water trucks or sprinkler systems in sufficient quantities to prevent airborne dust from leaving the site and from exceeding the APCD’s limit of 20% opacity for no greater than 3 minutes in any 60-minute period. Increased watering frequency will be required whenever wind speeds exceed 15 m.p.h. and cessation of grading activities during periods of winds over 25 m.p.h. Reclaimed (non-potable) water is to be used in all construction and dust control work. c. All dirt stock pile areas (if any) shall be sprayed daily and covered with tarps or other dust barriers as needed. d. Permanent dust control measures identified in the approved project revegetation and landscape pla ns shall be implemented as soon as possible, following completion of any soil disturbing activities. e. Exposed grounds that are planned to be reworked at dates greater than one month after initial grading shall be sown with a fast germinating, non-invasive, grass seed and watered until vegetation is established. f. All disturbed soil areas not subject to revegetation shall be stabilized using approved chemical soil binders, jute nettin g, or other methods approved in advance by the APCD. g. All roadways, driveways, sidewalks, etc. to be paved shall be completed as soon as possible. In addition, building pads shall be laid as soon as possible after grading unless seeding or soil binders are used. h. Vehicle speed for all construction vehicles shall not exceed 15 m.p.h. on any unpaved surface at the construction site. i. All trucks hauling dirt, sand, soil, or other loose materials, are to be covered/tarped in accordance with California Vehicle Code Section 23114 to prevent the escape of soil or dust. j. Install wheel washers where vehicles enter and exit unpaved roads onto streets, or wash off trucks and equipment leaving the site. k. Sweep streets at the end of each day if visible soil material is carried onto adjacent paved roads. Water sweepers shall be used with reclaimed water where feasible. Roads shall be pre-wetted prior to sweeping when feasible. l. All PM10 mitigation measures required shall be shown on grading and building plans. m. The contractor or builder shall designate a person or persons to monitor the fugitive dust emissions and enhance the implementation of the measures as necessary to minimize dust complaints, reduce visible emissions below the APCD’s limit of 20% opacity for no greater than 3 minutes in any 60-minute period. Their duties shall include holidays and weekend periods when work may not be in progress. The name and telephone number of such persons shall be provided to the APCD Compliance Division prior to the start of any grading, earthwork or demolition. Mitigation Measure AQ-2: Prior to any construction activities at the site, the project proponent shall ensure that all equipment Packet Pg 69 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 12 and operations are compliant with California Air Resource Board and APCD permitting requirements, by contacting the APCD Engineering Division at (805) 781-5912 for specific information regarding permitting requirements. Mitigation Measure AQ-3: To reduce sensitive receptor emissions impact of diesel vehicles and equipment used to construct the project and export soil from the site, the applicant shall implement the following idling control techniques: I. California Diesel Idling Regulations a. On-road diesel vehicles shall comply with Section 2485 of Title 13 of the California Code of regulations. This regulation limits idling from diesel-fueled commercial motor vehicles with gross vehicular weight ratings of more than 10,000 pounds and licensed for operation on highways. It applies to California and non-California based vehicles. In general, the regulation specifies that drivers of said vehicles: 1. Shall not idle the vehicle’s primary diesel engine for greater than 5 minutes at any location, except as noted in Subsection (d) of the regulation; and, 2. Shall not operate a diesel-fueled auxiliary power system (APS) to power a heater, air conditioner, or any ancillary equipment on that vehicle during sleeping or resting in a sleeper berth for greater than 5.0 minutes at any location when within 1,000 feet of restricted area, except as noted in Subsection (d) of the regulation. b. Off-road diesel equipment shall comply with the 5-minute idling restriction identified in Section 2449(d)(2) of the California Air Resources Board’s In-Use Of-Road Diesel regulation. c. Signs must be posted in the designated queuing areas and job sites to remind drivers and operators of the state’s 5 minute idling limit. II. Diesel Idling Restrictions Near Sensitive Receptors (residential homes). In addition to the State required diesel idling requirements, the project applicant shall comply with these more restrictive requirements to minimize impacts to nearby sensitive receptors: a. Staging and queuing areas shall not be located within 1,000 feet of sensitive receptors. b. Diesel idling within 1,000 feet of sensitive receptors shall not be permitted. c. Use of alternative fueled equipment is recommended. d. Signs that specify the no idling areas must be posed and enforces at the site. III. Soil Transport. The final volume of soil that will be hauled off-site, together with the fleet mix, hauling route, and number of trips per day will need to be identified for the APCD. Specific standards and conditions will apply. Conclusion: Implementation of Mitigation Measures AQ-1, AQ-2, and AQ-3 would mitigate impacts to Air Quality to less than significant 4. BIOLOGICAL RESOURCES. Would the project: a) Have a substantial adverse effect, either directly or through habitat modifications, on any species identified as a candidate, sensitive, or special status species in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? 9, 12, 13, 14, 15 --X-- b) Have a substantial adverse effect, on any riparian habitat or other sensitive natural community identified in local or regional plans, policies, or regulations, or by the California Department of Fish and Game or U.S. Fish and Wildlife Service? 9, 12, 13 --X-- c) Have a substantial adverse effect on federally protected wetlands as defined in Section 404 of the Clean Water Act (including, but not limited to, marsh, vernal pool, coastal, etc.) through direct removal, filling, hydrological interruption, or other means? 9, 12, 13 --X-- d) Interfere substantially with the movement of any native resident or migratory fish or wildlife species or with established native resident or migratory wildlife corridors, or impede the use of native wildlife nursery sites? 9, 13, 15 --X-- e) Conflict with any local policies or ordinances protecting 9, 12 --X-- Packet Pg 70 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 13 biological resources, such as a tree preservation policy or ordinance? f) Conflict with the provisions of an adopted habitat Conservation Plan, Natural Community Conservation Plan, or other approved local, regional, or state habitat conservation plan? 9, 13 --X-- Evaluation The site consists of a section of Laguna Lake, Laguna Lake Park, and Prefumo Creek inlet and upstream reach 300 feet upstream of Los Osos Valley Road and its outlet from Laguna Lake to 150 feet downstream of Madonna Road. It contains diverse habitat types indicative of riparian and wetland interrelations with non-native grasslands and urban interfaces. The existing condition of the Laguna Lake project area consists of degraded capacity of hydrologic function due to sedimentation, which allows for succession of non-native plant material. Biologically, the lack of maintenance and deposition of sediment material has resulted in lowering the ecological function of the project area. Rincon Consultants prepared a Biological Resources Assessment (BRA) dated May 2016 that quantifies existing habitat values. a) Eighteen special status plant species may occur onsite based on the presence of suitable habitat; five of which, Cambria morning-glory (Calystegia subacaulis ssp. episcopalis), San Luis Obispo owl’s-clover (Castilleja densiflora ssp. obispoensis), Congdon’s tarplant (Centromadia parryi ssp. congdonii), adobe sanicle (Sanicula maritima) and saline clover (Trifolium hydrophilum), were documented in the Study Area. However, these species are not expected to be impacted whatsoever as project activity will not occur where they are located. Of the numerous wildlife species reported from the vicinity of the Study Area, nineteen species may occur onsite based on the presence of suitable habitat, including golden eagle, white-tailed kite , tricolored blackbird, burrowing owl, purple martin, Cooper's hawk, grasshopper sparrow, California horned lark, merlin, prairie falcon, American badger, pallid bat, Blainville’s horned lizard, California red-legged frog, Coast Range newt , spadefoot toad, Southern western pond turtle, vernal pool fairy shrimp, and steelhead – South Central California Distinct Population Segment. The upper reach of Prefumo Creek upstream of the project site is designated as critical habitat for south-central California coast steelhead. For eventual design, quantified impacts to species identified on the site that are listed in the Federal and State Endangered Species Act and/or identified as sensitive or species of concern may require consultation with the US Fish and Wildlife Service and California Department of Fish and Wildlife. Subsequent impact assessment will determine the level of review as applicable. Mitigation Measures: BIO-1 Special Status Plant Species Avoidance: Avoid impacts to occurrences of special status plants listed under ESA and/or CESA. As part of the design of the projects, biological surveys shall be conducted by a qualified Biologist to identify specimens in the project area. If total avoidance of CRPR species is not feasible, minimize impacts to less than 10 percent of onsite populations. BIO-2 Special Status Plant Species Mitigation. Should it be determined that more than 10% of onsite population of Special Status Plants be impacted, the City shall develop a Habitat Mitigation and Monitoring Plan (HMMP) to develop adequate mitigation to offset impacts to species. The HMMP shall quantify the impacts associated with operations and specify restoration practices and enhancement of species habitat. The HMMP shall be reviewed, as applicable by the California Department of Fish and Wildlife for consistency with State requirements. BIO-3 Special Status Wildlife-Birds Avoidance. To avoid take of nesting birds, and raptor nests at any time of year (including inactive nests), activities requiring vegetation disturbance would occur outside the nesting season, which is approximately February 1 through September 15. If activities must begin within the bird breeding season, then no more than two weeks prior to initiation of ground disturbance and/or vegetation removal, a nesting bird pre-construction survey will be conducted by a qualified biologist within the disturbance footprint plus a 100-foot buffer. Pre-construction nesting bird surveys Packet Pg 71 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 14 will be conducted during the time of day when birds are active and will be of sufficient duration to reliably conclude presence/absence of nesting birds and raptors onsite and within the designated vicinity. If no nests are observed no further mitigation is required. BIO-4 Special Status Wildlife-Birds Nesting. If nests are found, their locations will be flagged and then mapped onto an aerial photograph of the project site at a scale no less than 1”=200’ and/or recorded with the use of a Global Positioning Sy stem (GPS) unit. An appropriate avoidance buffer ranging in size from 50 to 500 feet from the nes t, depending upon the species and the proposed work activity, will be determined and demarcated by a qualified biologist with bright orange construction fencing or other high-visibility delineators. No ground disturbance will occur within this buffer until the qualified biologist confirms that the breeding/nesting is completed and all the young have fledged. If buffer zones are determined to be infeasible, a full- time qualified biological monitor can monitor project activity within the buffer zones to ensure active nests and nesting birds are not impacted. BIO-5 Special Status Animals Badger. Prior to activities that disturb native habitats in upland areas, a qualified biologist should complete a survey for badger dens. In order to avoid the potential direct take of adults and nursing young, no grading should occur within 50 feet of an active badger den between March 1 and June 30. Activities during July 1 and March 1 should comply with the following measures to avoid direct take of adult and weaned juvenile badgers. o Conduct a biological survey of the anticipated development areas between 2 weeks and 4 weeks of the start of ground clearing or grading activity. The survey should cover the entire area proposed for disturbance. Surveys should focus on both old and new den sites. If dens are too long to see the end, a fiber optic scope (or other acceptable method) can be used to assess the presence of badgers. o Inactive dens shall be excavated by hand with a shovel to prevent badgers from reusing them during const ruction. o Badgers should be discouraged from using currently active dens prior to the grading of the site by partially blocking the entrance of the den with sticks, debris and soil for 3 to 5 days or through use of a 1-way door. After badgers have stopped using active dens within the development area, the dens shall be hand excavated with a shovel to prevent re- use. BIO-6 Special Status Animals Pallid Bat. Prior to activities that require tree removal, a qualified biologist should inspect trees proposed for removal to ensure bats are not roosting. If bats are observed, the biologist shall determine if the roost is a hibernaculum or a maternity colony. If so, removal of the tree would be postponed until outside wintering or maternity seasons. If not, the bat(s) would be evicted using appropriate one-way devices and the tree inspected again prior to tree removal BIO-7 Special Status Animals Coast Horned Lizard. During new grading activities in upland habitats, a qualified biologist should be on-site to recover any coast horned lizards that may be excavated/unearthed with native material or found under vegetation. If the animals are in good health, they should be immediately relocated to a designated release area. If they are injured, the animals shall be turned over to an approved wildlife rehabilitator until they are in a condition to be released into the designated release area. BIO-8 Special Status Animals Vernal Pool Fairy Shrimp. The project would be designed to avoid impacts to the basins and wetland depressions (adjacent to but not abutting Laguna Lake), and would avoid altering hydrology of these features. Work areas would be flagged, resources to be avoided would be flagged, and no work would occur upslope and within 250 feet of vernal pool fairy shrimp habitat. BIO-9 Special Status Animals Western Spadefoot Toad. During new grading activities in upland habitats, a qualified biologist should be on-site to recover any spadefoot toads that may be excavated/unearthed with native material or found under vegetation. If the animals are in good health, they should be immediately relocated to a designated release area. If they are injured, the animals shall be turned over to an approved wildlife rehabilitator until they are in a condition to be released into the designated release area. BIO-10a Special Status Animals California Red-Legged Frog. Prior to initiation of construction activities (including staging and mobilization), all personnel associated with project construction would attend a Worker Environmental Awareness Program (WEAP) training, conducted by a qualified biologist, to aid workers in recognizing special status resources that may occur in the project area. The specifics of this program would include identification of the sensitive species and habitats, a description of the regulatory status and general ecological characteristics of sensitive resources, and review of the limits of construction and avoidance measures required to reduce impacts to biological resources within the work area. A fact sheet conveying this Packet Pg 72 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 15 information would also be prepared for distribution to all contractors, their employers, and other personnel involved with construction of the project. BIO-10b Special Status Animals California Red-Legged Frog. Ground disturbing activities associated with dry portions of Prefumo Creek should be conducted between May 1 and October 31 during dry weather conditions, which are periods of low activity for these species in dry habitats, to minimize the potential for encountering CRLF. Work should be restricted to daylight hours to the extent feasible. o If activities must occur between November 1 and April 30, the qualified biologist should conduct a pre‐activity clearance sweep each morning prior to start of project activities after any rain events of 0.1 inch or greater. o All trash should be removed from the site daily and disposed of properly to avoid attracting potential predators to the site. o Non-automated operational activities (i.e. truck trips), shall not be conducted during rain events occurring at night to the extent feasible. If project activities requiring movement of equipment are to occur at night during rain events, a qualified biologist should conduct a pre-construction survey of the site each night. BIO-10c Special Status Animals California Red-Legged Frog. A qualified biologist should conduct a survey of work areas associated with the lake and creek within 48 hours of initial ground disturbing activities. The survey area would include the proposed disturbance area and all proposed ingress/egress routes, plus a 100-foot buffer. A biologist authorized to relocate frogs should be present for activities that require movement or placement of equipment into the lake, stream, and wetlands along the lake to monitor for frogs. If a frog is observed in the work area, the biologist would relocate it, with prior authorization from USFWS, out of the work area BIO-10d Special Status Animals California Red-Legged Frog. If drying basins are used to remove water from the sediment, appropriate exclusion fence should be placed around the basins to prevent access by frogs. BIO-11 Special Status Animals Southwestern Pond Turtle. A qualified biologist should conduct a survey of work areas associated with the lake and creek within 48 hours of initial ground disturbing activities. The survey area would include the proposed disturbance area and all proposed ingress/egress routes, plus a 100-foot buffer. Turtles within work areas should be relocated outside the work area. A biologist authorized to relocate turtles should be present for activities that require movement or placement of equipment into the lake, stream, and wetlands along the lake to monitor for turtles. If a turtle is observed in the work area, the biologist would relocate it out of the work area. Implementation of Mitigation Measures BIO-1 through BIO-11 would mitigate impacts to Special Status Species to less than significant. b) The project area maintains eight different types of vegetative communities including several sensitive habitat types such as 5.95 acres of Needlegrass grasslands, 6.85 acres of Riparian habitat, 2.97 acres of freshwater wetlands, 55.34 acres of open water habitat. Other habitats include non-native grasslands, developed and ornamental landscaping, and planted groves due to the close proximity of the urbanized landscape. The project would result in temporary impacts during dredging operations of habitat types. The following mitigation measures are recommended to be implemented during the design phase and subsequent implementation to minimize impacts to natural communities. Mitigation Measures: BIO-12 Habitat Enhancement Fisheries. During project design, including options to stabilize banks along the lake, the following habitat parameters would be considered and incorporated as feasible: o The lake should provide abundant cover including woody debris, boulders, and undercut banks. Woody debris is very important to provide needed shelter for juvenile fish especially in low velocity refuges. Having appropriate cover and shelter would be imperative for steelhead to survive in Laguna Lake. o Depths greater than 0.5 meter are generally deep enough to avoid wading birds. Depth alone is not the determining factor in water temperature, but lake which has a depth to create a thermocline cold enough to support the fish during periods of higher water temperatures is desirable. o The lake should contain a regular and pronounced slope along its banks. o DO concentrations affect the migration and swimming performance of steelhead at all temperatures. Low DO levels decrease the rate of metabolism, swimming speed, growth rate, food consumption rate, efficiency of food utilization, Packet Pg 73 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 16 behavior, and survival. Steelhead does best where DO concentration is at least 7.0 mg/L. DO concentrations should remain at or near saturation levels with temporary reductions no lower than 5.0 mg/L, which has been documented to result in severe production impairment (Carter, 2005). o Suspended and deposited fine sediment can directly affect steelhead by clogging gills, indirectly causing reduced feeding, destruction of food supplies, and changed rearing habitat. Silt loads of less than 25 mg/L permit good rearing conditions for juvenile steelhead. Controlling sediment loads into the creek and lake will improve conditions for steelhead. BIO-13 Project Monitoring Fisheries. During project implementation, a biologist with fisheries experience should be present during activities movement or placement of equipment into the lake, stream, and wetlands along the lake to monitor for fish. If feasible, the active dredge area would be screened to reduce likelihood of aquatic vertebrate species in the active dredging area (e.g. intakes will be screened). If steelhead is observed, activities would cease until NMFS can be consulted. While dredging is underway, a biologist will monitor activities at least weekly. BIO-14 Needlegrass Habitat Avoidance. To the maximum extent feasible, project activities would be designed to avoid needlegrass grassland habitat. If needlegrass grassland habitat areas cannot be avoided in temporary impact areas, purple needlegrass will be incorporated into the revegetation plant palette to functionally replace the impacted habitat. BIO-15 Needlegrass Enhancement. If permanent impacts remove needlegrass grassland habitat areas greater than 0.5 acre in size, an equivalent amount of this habitat type must be created within a City-designated and -approved needlegrass grassland habitat mitigation area onsite. Pertinent and logistic details regarding the creation of needlegrass grassland habitat would be outlined in a HMMP. The needlegrass grassland habitat mitigation areas will be monitored annually for at least five years to ensure successful establishment and that no-net-loss of this sensitive habitat has been achieved Implementation of mitigations Measures BIO-12 through BIO-15 would mitigate impacts to Habitat Communities to less than significant (Class II). c) The project site maintains 4.72 acres of wetlands and 56.77 acres of other waters that are potentially under USACE and RWQCB jurisdiction. A jurisdictional delineation was completed by Rincon Consultants and the results are identified in the BRA for this project. According to the study, the jurisdictional area applicable to the Clean Water Act (404/401) consisted of 4.72 acres of wetlands and 56.77 acres of other waters below the ordinary high-water mark (OHWM) area subject to the Porter Cologne Act and CDFW Section 1602 consisted of 65.89 acres. The project would consist of temporary impacts to areas due to dredging under jurisdiction of the regulatory agencies requiring 404/401/1602 permits. Mitigation Measures: BIO-16 Wetlands Restoration. Jurisdictional areas that cannot be avoided will acquire all applicable regulatory permits. Temporary impact areas will be restored at a one to one (1:1) ratio (one acre of restoration for each acre of impact) to offs et temporary losses in wetland, stream, or riparian function. Permanent impacts will be offset through creation, restoration, and/or enhancement of in-kind habitats at a minimum ratio of 2:1 to mitigate unavoidable permanent impacts to jurisdictional areas. Note the resource agencies may require a higher mitigation ratio. A Mitigation and Monitoring Plan will likely be required, and would be prepared by a biologist familiar with restoration and mitigation techniques. The plan will include, but not be limited to the following components: o Description of the project/impact site, o Goal(s) of the compensatory mitigation project, o Description of the proposed compensatory mitigation-site, o Implementation plan for the compensatory mitigation-site, o Maintenance activities during the monitoring period, o Monitoring plan for the compensatory mitigation-site, o Success criteria and performance standards, o Reporting requirements, and Packet Pg 74 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 17 o Contingency measures and funding mechanisms. BIO -17 Erosion Control. Erosion control and landscaping specifications shall allow only natural-fiber, biodegradable meshes and coir rolls, (i.e. no plastic-mesh temporary erosion control measures) to prevent impacts to the environment and to fish and terrestrial wildlife. BIO-18 Habitat Improvement. Where feasible, aquatic habitat improvements such as root wads and downed logs will be incorporated into bank stabilization and sediment control efforts to enhance aquatic habitat in perennial waterways. BIO-19 State/Federal Consultation. Prior to commencement of operations, consultations with applicable federal and state agencies shall be completed per the provisions of the Clean Water Act and Porter Cologne Act. Implementation of Mitigations Measures BIO-16 through BIO-19 would mitigate impacts to wetlands to less than significant. d) Laguna Lake is indicative urban water resource benefiting the community with multiple uses such as flood control, recreation, and cultural enhancement. The lake itself is surrounded on two sides to the south and east by existing urban and agricultural development. Additional development is also envisioned with the future San Luis Ranch project located to the east. North and west of the site lies non-native grasslands and open space that provide ample movement potential for wildlife. The proposed project would potentially result in temporary short-term impacts to wildlife movement due to increased vehicle trips, equipment access and staging, temporary spoils and settling basins, soil disturbance, and dredging equipment. Upon completion of the project, wildlife movement conditions are expected to return to pre-project conditions. Mitigation Measures and Conclusion: No mitigation measures are required, significant impacts to fish or wildlife movement are not anticipated. e) Management of sediment issues in Laguna Lake and Prefumo Creek are identified in local conservation and management plan documents for Laguna Lake, and proposed project alternatives would be consistent with conservation goals in the Laguna Lake Natural Reserve Conservation Plan, where applicable. The project will also require the removal of some trees which is regulated by the City. Tree removal will be required per the local ordinances to be processed via a tree removal permit. Adherence to the city’s removal policies the project would be consistent with local requirements. Mitigation Measures and Conclusion: No mitigation measures are required, significant impacts to local policies or ordinances are not anticipated. f) The City, assisted by technical experts, prepared the Laguna Lake Natural Reserve Conservation Plan (Plan) for the LLNR in 2014. As previously noted, a portion of the LLNR is within the Study Area. Th e document provides a summary of the history of the site, including Laguna Lake, and the natural resources present in the LLNR. No adopted Habitat Conservation Plan or Natural Community Conservation Plan is in effect within the Study Area so there is no conflict on other local, regional, or state levels Mitigation Measures and Conclusion: No mitigation measures are required, significant impacts to adopted conservation plans is not anticipated Conclusion: With implementation of the above listed Mitigation Measures, the project would have a less than significant impact on Biological Resources. 5. CULTURAL RESOURCES. Would the project: a) Cause a substantial adverse change in the significance of a historic resource as defined in §15064.5. 11 --X-- b) Cause a substantial adverse change in the significance of an archaeological resource pursuant to §15064.5) 11 --X-- c) Directly or indirectly destroy a unique paleontological resource or site or unique geologic feature? 11 --X-- Packet Pg 75 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 18 d) Disturb any human remains, including those interred outside of formal cemeteries? 11 --X-- Evaluation a) There are no historic structures associated with the proposed dredging of Laguna Lake. b-d) The property does not contain any known prehistoric or historic archaeological resources identified on City maintained resource maps. A cultural resources study was prepared to determine the presence or likelihood of archaeological historical resources. The surface survey resulted in no evidence of prehistoric or historic archaeological materials. However, there is the limited potential that materials (including but not limited to bedrock mortars, historical trash deposits, and human burials) could be encountered during operation of the project. Two mitigation measures (CULT 1 and CULT 2) are recommended to ensure that any materials discovered during construction activities be appropriately handled. Mitigation Measure CULT-1: If cultural resources are encountered during ground-disturbing activities, work in the immediate area should be halted and an archaeologist meeting the Secretary of the Interior’s Professional Qualifications Standards for archaeology (National Park Service 1983) should be contacted immediately to evaluate the find. If necessary, the evaluation may require preparation of a treatment plan and archaeological testing for National Register of Historic Places eligibility. If the discovery proves to be significant under the National Historic Preservation Act and cannot be avoided by the project, additional work such as data recovery excavation may be warranted to mitigate any adverse effects to historic properties. Mitigation Measure CULT-2: The discovery of human remains is always a possibility during ground disturbing activities; if human remains are found, State of California Health and Safety Code Section 7050.5 states that no further disturbance shall occur until the County Coroner has made a determination of origin and disposition pursuant to Public Resources Code Section 5097.98. In the event of an unanticipated discovery of human remains, the San Luis Obispo County Sherriff-Coroner must be notified immediately. If the human remains are determined to be prehistoric, the coroner will notify the Native American Heritage Commission, which will determine and notify a most likely descendant (MLD). The MLD shall complete the inspection of the site within 48 hours of notification and may recommend scientific removal and nondestructive analysis of human remains and items associated with Native American burials. Conclusion: With implementation of CULT-1 and CULT-2, the project will have a less than significant impact on cultural resources. 6. GEOLOGY AND SOILS. Would the project: a) Expose people or structures to potential substantial adverse effects, including the risk of loss, injury or death involving: 7,8 --X-- I. Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? Refer to Division of Mines and Geology Special Publication 42. --X-- II. Strong seismic ground shaking? --X-- III. Seismic-related ground failure, including liquefaction? --X-- IV. Landslides? --X-- b) Result in substantial soil erosion or the loss of topsoil? 7,8 --X-- c) Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in on or off site landslide, lateral spreading, subsidence, liquefaction or collapse? 7,8 --X-- d) Be located on expansive soil, as defined in Table 1802.3.2 of the California Building Code (2013), creating substantial risks 7,8 --X-- Packet Pg 76 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 19 to life or property? e) Have soils incapable of adequately supporting the use of septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of waste water? 7,8 --X-- Evaluation The project site is located along the southern end of Los Osos Valley between the San Luis Range and Santa Lucia Range which are part of the southern coast Ranges. The Range is typified by Mesozoic-age to recent materials composed of sedimentary, volcanic, igneous, and metamorphic rocks. The older formations, Jurassic to Cretaceous age bedrock of the Franciscan Formation were intruded by younger volcanic/igneous rocks forming volcanic plugs. These plugs formed the current peaks along the ridges of the hills found in the valley. The Los Osos Valley fault lies on a northwest-southeast axis and Laguna Lake is described as a sag pond within the fault zone. The lake itself is located in the floodplain with alluvium deposited by area streams that overlay Franciscan age metamorphic greenstones. Geological Mapping Units of the site indicate the suite to consist primarily of fine grained alluvial flood-plain deposits and pervasively sheared serpentine greenstone. Soils onsite primarily consist of relatively loose to medium silts (MH) and stiff clay layers (CL/CH). a) The project does not propose any structural development or result in a situation where it would create a situation placing people permanently on site exposed to earthquake activity. Mitigation Measures: No impacts are associated with potential fault and earthquake impacts. b) The project requires some disturbance and equipment being placed within watercourses resulting in impacts to stream banks. The project also proposes potential creek bank restoration and stabilization along Prefumo Creek and a sediment settling basin. In order to protect habitat and creek function it will be necessary to manage sediment and erosion control. Once the dredging plan is finalized an erosion and sediment control plan will be required to stabilize potentially erosive soils. Mitigation Measures: GEO-1 Grading and erosion and sediment control plans shall be designed to minimize erosion during operations and shall be implemented for the duration of the grading period and until regraded areas have been stabilized. The City shall prepare Erosion Control Plan using Best Management Practices (BMPs) that are designed to stabilize the site and protect natural watercourses. GEO-2 The City shall revegetate graded areas upon completion of grading activities with deep rooted, native, dr ought-tolerant species to minimize slope failure and erosion potential. Use of hydro-seed, straw blankets, other geo-textile binding fabrics or other P&D-approved methods as necessary to hold slope soils until vegetation is established. Conclusion: With implementation of GEO-1 and GEO-2, the project will have a less than significant impact in relation to soil erosion. c-e) Activities are focused on the alluvial flood plain and not on the slopes adjacent to the lake. Likewise, no structural development is proposed that could potentially be constructed in unstable areas. No wastewater systems are proposed, sediment is proposed to be transported and used as landfill top cover. No impacts are anticipated to geology and soils from developmen t on unstable soils or inadequate wastewater system disposal. With implementation of GEO-1 and GEO-2, the project will have a less than significant impact on geology and soils. 7. GREENHOUSE GAS EMISSIONS. Would the project: Packet Pg 77 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 20 a) Generate greenhouse gas emissions, either directly or indirectly, that may have a significant impact on the environment? --X-- b) Conflict with an applicable plan, policy or regulation adopted for the purpose of reducing the emissions of greenhouse gases? --X-- Evaluation a,b) In addition to the criteria pollutants discussed in the above air quality analysis, the state of California’s Assembly Bill 32, the California Global Warming Solution Act of 2006 and California Governor Schwarzenegger Executive Order S -3-05 (June 1, 2005), both require reductions of greenhouse gases in the State of California. City policies recognize that compact, infill development allow for more efficient use of existing infrastructure and Citywide efforts to reduce greenhouse gas emissions. The City’s Climate Action Plan (CAP) also recognizes that energy efficient design will result in significant energy savings, which result in emissions reductions. The proposed project, however, does not include structural development subject to the efficiency measure typically applied in those cases. SLOAPCD states that GHGs (CO2 and CH4) from all projects subject to CEQA must be quantified and mitigated to the extent feasible. The California Office of Planning and Research has provided the following direction for the assessment and mitigation of GHG emissions: • Lead agencies should make a good-faith effort, based on available information, to calculate, model, or estimate the amount of CO2 and other GHG emissions from a project, including the emissions associated with vehicular traffic, energy consumption, water usage and construction activities; • The potential effects of a project may be individually limited but cumulatively considerable. Lead agencies should not dismiss a proposed project’s direct and/or indirect climate change impacts without careful evaluation. All available information and analysis should be provided for any project that may significantly contribute new GHG emissions, either individually or cumulatively, directly or indirectly (e.g., transportation impacts); and, • The lead agency must impose all mitigation measures that are necessary to reduce GHG emissions to a less than significant level. CEQA does not require mitigation measures that are infeasible for specific legal, economic, technological, or other reasons. A lead agency is not responsible for wholly eliminating all GHG emissions from a project; the CEQA standard is to mitigate to a level that is “less than significant.” The emissions from dredging engines/generators and haul vehicle exhaust comprise the total project CO2eq emissions; see Air Quality discussion is Section 3 (above) for discussion. Mitigation Measures AQ 2 and AQ 3 address vehicle and equipment exhaust, and include provisions for reducing those impacts to below a level of significance. Due to the lack of any long-term operational emissions, the threshold for reactive organic gases (ROG) and oxides of nitrogen (NOx) would not be exceeded by the proposed project. Therefore, the APCD is not requiring any operational phase mitigation measures for this project. Conclusion: Less than significant impact. 8. HAZARDS AND HAZARDOUS MATERIALS. Would the project: a) Create a significant hazard to the public or the environment through the routine transport, use, or disposal of hazardous materials? 7,8,9 --X-- b) Create a significant hazard to the public or the environment through reasonably foreseeable upset and accident conditions involving the release of hazardous materials into the environment? 7,8,9 --X-- c) Emit hazardous emissions or handle hazardous or acutely hazardous materials, substances, or waste within one-quarter mile of an existing or proposed school? 7,8,9 --X-- Packet Pg 78 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 21 d) Be located on a site which is included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 and, as a result, would it create a significant hazard to the public or the environment? --X-- e) For a project located within an airport land use plan or, where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project result in a safety hazard for people residing or working in the project area? 7,8,9 --X-- f) For a project within the vicinity of a private airstrip, would the project result in a safety hazard for people residing or working in the project area? 7,8,9, 10 --X-- g) Impair implementation of or physically interfere with an adopted emergency response plan or emergency evacuation plan? 8,9 --X-- h) Expose people or structures to a significant risk of loss, injury, or death involving wildland fires, including where wildlands are adjacent to urbanized areas or where residences are intermixed with wildlands? 8,9 --X-- Evaluation a) Under Title 22 of the California Code of Regulations (CCR), the term “hazardous substance” refers to both h azardous materials and hazardous wastes. Both of these are classified according to four properties: toxicity, ignitability, corrosiveness, and reactivity (CCR Title 22, Chapter 11, Article 3). A hazardous material is defined as a substance or combination o f substances that may cause or significantly contribute to an increase in serious, irreversible, or incapacitating illness, or may pose a substantial presence or potential hazard to human health or the environment when improperly treated, stored, transported, disposed of, or otherwise managed. Hazardous wastes are hazardous substances that no longer have practical use, such as materials that have been discarded, discharged, spilled, or contaminated or are being stored until they can be disposed of properly (CCR Title 22, Chapter 11, Article 2, Section 66261.10). Soil that is excavated from a site containing hazardous materials is a hazardous waste if it exceeds specific CCR Title 22 criteria. Public health is potentially at risk whenever hazardous materials are or would be used. It is necessary to differentiate between the “hazard” of these materials and the acceptability of the “risk” they pose to human health and the environment. A hazard i s any situation that has the potential to cause damage to human health and the environment. The risk to health and public safety is determined by the probability of exposure, in addition to the inherent toxicity of a material. Factors that can influence the health effects when human beings are exposed to hazardous materials include the dose the person is exposed to, the frequency of exposure, the duration of exposure, the exposure pathway (route by which a chemical enters a person’s body), and the individual’s unique biological susceptibility. A geotechnical study (Leighton, 2016) was performed for the project. Based on review of previous studies, background literature, site geology and the presence of exposed serpentine and greenstone bedrock in the drainages surrounding Laguna Lake, elevated levels of select metals, primarily chromium and nickel, were anticipated. Previous studies indicated lake sediments contained elevated levels of total chromium, nickel and manganese. The studies determined that: 1) metals were below US EPA Region 9 Regional Screening Levels established for residential and industrial/ commercial settings, and 2) the sediment samples do not require management as California or Federal RCRA hazardous waste. Chromium +6 is a known human carcinogen, tetragen, and mutagen and is mainly a concern via inhalation and to a lesser degree via ingestion. Chromium +3 is not a carcinogen and is a common human essential nutrient. Chromium +3 can convert to chromium +6 in oxidizing environments. Sediment conditions at Laguna Lake are generally anoxic or reducing and fa vor chromium +3. However, the studies reviewed by Leighton and subsequent conferring with authors of these studies, indicated that there was a potential for naturally occurring chromium +6 to be present in the soils and sediment within the lake due to Packet Pg 79 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 22 presence of serpentinite rock outcrops near Laguna Lake. There is potential for the chromium +3 in the sediment to revert to chromium +6 when dredged from the lake and deposited in an oxygen-rich setting (e.g., on Laguna Lake Park slopes adjacent to the northeast side of the lake). Leighton performed a sampling and analytical testing program to include surface soil and sediment sampling from Prefumo Creek and selected ephemeral drainages that flowed into the lake from the northeast slopes and originated the nearby serpentinite outcrop. In addition, Leighton collected a soil sample (i.e., soil sample LS-2) from coarse sandy soil located in a serpentinite outcrop. To evaluate concerns with nickel and other metals in the sediment, analytical testing of discrete and composite soil and sediment samples included the 17 metals listed in the California Code of regulations, Title 22, Article 11 (CAM-17 Metals) as well as chromium +6 in selected samples that exhibited elevated total chromium concentrations. Additional testing was performed to evaluate the levels of chromium in the sediment to assess if it may require management as California Hazardous Waste and/or Federal RCRA waste. Based on the presence of serpentinite rock outcrops near the lake and professional articles regarding the presence of natural chromium +6 under similar regimes, Leighton concluded that the presence of chromium +6 in the soil and sediment samples is naturally occurring. In addition, no man-made sources of the chromium +6 (e.g., plating and manufacturing facilities) found in the Laguna Lake area are evident and reinforces the likelihood that the prevalence of chromium +6 in the soil and sediment samples is of a natural origin. Review of the analytical test data for the Lake Laguna sediment samples suggests the sediment does require management as California or Federal RCRA hazardous waste. The sediment, once dredged, would be managed as a nonhazardous waste. It meets the landfill acceptance criteria, and should be acceptable for use as ground cover for a local municipal landfill. The proposed dredging project would not create a significant hazard to the public or to the environment through the routine transport, use, or disposal of hazardous materials. However, intermittent hauling or other movement of dredged material during active dredging or associated post-dredging operations could present a potential risk of exposure to chromium +6. This is only true for the time that dredged materials would be exposed to the air during the dewatering process and/or during hauling to the disposal site if significant wind events create fugitive dust from deposited sediments or during hauling. To formally assess this risk, a Human Health Risk Assessment (HHRA) was conducted for Laguna Lake and the surrounding area by Langan Engineering and Environmental Services, Inc. (2017) to determine if constituents in sediment and dried sediment (soil) pose unacceptable risks to human health under site-specific exposure conditions and support decisions concerning the need for further evaluation or mitigation. Previous investigations have indicated the presence of naturally occurring nickel, trivalent chromium (Cr+3) and hexavalent chromium (Cr+6) in exceedance of various risk -based human health screening levels. In addition, asbestos is naturally occurring in the local geologic formations. The technical approach for the HHRA consisted of data analysis, exposure assessment, toxicity assessment, risk characterization, and an assessment of the uncertainty associated with each stage of the HHRA process. The inhalation of fugitive dust exposure pathway was evaluated for the off -site resident receptor using reasonable maximum exposure point soil concentrations to derive exposures and risks. Incomplete pathways were not considered in the HHRA. Cancer risk results were compared to the United States Environmental Protection Agency’s cumulative risk management range for multiple carcinogens of one in one million (1E-06) to one in ten thousand (1E-04). Non- cancer hazards were compared to a non-cancer hazard index of 1. The HHRA supported that no unacceptable cancer risks are posed to the off-site resident. The incremental lifetime cancer risk was estimated to be within the EPA’s risk management range at 2E-05, primarily attributable to naturally occurring asbestos concentrations. In addition, the HHRA also supported that no unacceptable non-carcinogenic risks are posed to the off-site resident. The complete risk assessment is available for public review. Dredging and hauling activities would use hazardous materials such as fuels (gasoline and diesel), oils, and lubricants. The amount of these materials used would be small, so the project would not create a significant hazard to the public or to the environment. The following mitigation measures are recommended to be implemented during the operation of the project to minimize risks associated with potentially hazardous materials. In addition, the transport, use, or disposal of hazardous materials shall comply with applicable federal, state, and local regulations, including but not limited to Titles 8 and 22 of the CCR, the Uniform Fire Code, and Chapter 6.95 of the California Health and Safety Code. HAZ-1 Excavated sediment must be covered/tarped when transported outside of the project area. Packet Pg 80 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 23 HAZ-2 Excavated sediment shall be tested according to a soil sampling protocol to ensure that the soils are acceptable to the desired disposal site. If it is determined that the sediments contain hazardous constituents and are unacceptable to the desired disposal site, the sediments shall be disposed at a licensed hazardous waste disposal site. HAZ-3 The dewatering and sediment handling area will be as small as practical (3 to 4 acres). Sediments will be removed from Laguna Lake in a wet state (i.e. the water will be retained in the lake during dredging). The dredged slurry will be pumped into geotextile bags that will contain the sediments as water is decanted. HAZ-4 Water sprays or other adequate measures will be applied each day that work activities occur to all disturbed areas with the potential to emit fugitive dust. At a minimum, water will be applied to exposed areas three times per day with increasing watering frequency required whenever the wind speed exceeds 15 miles per hour. Reclaimed water should be used whenever possible. HAZ-5 Sediments/soil stockpiles will be covered, kept moist, or treated with soil binders to prevent dust generation at the end of each work day. HAZ-6 On site vehicle speeds will be limited to 15 miles per hour or less. Loose dirt and dust shall be removed from all vehicular wheels using brushes, rumble strips, or water prior to leaving the site. HAZ-7 The contractor will designate a person(s) to monitor the dust control program and to order increased watering, as necessary, to prevent transport of dust offsite. The contractor will stop project activities immediately if visible dust emissions are detected at the property boundary and will implement additional dust mitigation measures. HAZ-8 After work activities are completed, all disturbed areas will be re-vegetating or otherwise developed so that dust generation will not occur. HAZ-9 A worker health, safety and education plan will be developed and required, as well as emergency and remedial procedures. b) As discussed in Impacts a and c, the proposed project would not result in the routine transport, use, disposal, handling, or emission of any hazardous materials that would create a significant hazard to the public or to the environment. However, intermittent hauling or other movement of dredged material during active dredging or associated post-dredging operations could present a potential risk of exposure to chromium +6. This is only true for the time that dredged materials would be exposed t o the air during the dewatering process and/or during hauling to the disposal site if significant wind events create fugitive dust from deposited sediments or during hauling. The implementation of proposed mitigation measures and implementation of Title 49, Parts 171–180, of the Code of Federal Regulations would reduce any impacts associated with the potential for accidental release during the proposed project or by transporters picking up or delivering hazardous materials to the project site. These regulations establish standards by which hazardous materials would be transported, within and adjacent to the proposed project. Where transport of these materials occurs on roads, the California Highway Patrol is the responsible agency for enforcement of regulations. c) The proposed dredging project site project is within a quarter mile of Laguna Middle School and CL Smith Elementary School. As discussed in Impacts a and b, the proposed dredging project would not result in the routine transport, use, disposal, handling, or emission of any hazardous materials that would create a significant hazard to the public or to the environment, including at the existing nearby schools. However, intermittent hauling or other movement of dredged material during active dredging or associated post-dredging operations could present a potential risk of exposure to chromium +6. This is only true for the time that dredged materials would be exposed to the air during the dewatering process and/or during hauling to the dispos al site if significant wind events create fugitive dust from deposited sediments or during hauling. The HHRA, described above, determined that there is no unacceptable off-site risk. The implementation of proposed mitigation measures would further reduce any impacts associated with the potential for exposure to hazardous materials. d) The project site is not on a parcel included on a list of hazardous materials sites compiled pursuant to Government Code Section 65962.5 (DTSC 2012). The closest listed site is located about one mile distant near the intersection of Los Osos Valley Packet Pg 81 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 24 Road and Highway 101. That site is listed on the Cortese list due to the presence of a PCE plume. The distance and type of site would not present a significant hazard to the public or to the environment related to an existing hazardous materials site. e,f) The project site is not located within an airport land use plan area or within 2 miles of a public use airport or airstr ip. There are no private airstrips in the vicinity of the project site that would result in a safety hazard for people residing or working in the project area. g) The dredging project would not be subject to the requirements contained in the City’s emergency response and evacuation plans. Therefore, impacts related to impaired implementation or physical interference with an adopted emergency response or evacuation plan are considered less than significant. h) The dredging project would not result in the inducement of new resident populations subject to wildland hazards. Therefore, the proposed project will have no impact on the placement of people or structures next to wildland areas that could result in loss, injury, or death involving wildland fires. Conclusion: With implementation of HAZ-1 through HAZ-9, the project will have a less than significant impact in relation to hazardous materials. 9. HYDROLOGY AND WATER QUALITY. Would the project: a) Violate any water quality standards or waste discharge requirements? 7,8 --X-- b) Substantially deplete groundwater supplies or interfere substantially with groundwater recharge such that there would be a net deficit in aquifer volume or a lowering of the local groundwater table level (e.g. the production rate of pre-existing nearby wells would drop to a level which would not support existing land uses or planned uses for which permits have been granted)? 8 --X-- c) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, in a manner which would result in substantial erosion or siltation on or off site? 7,8,9 --X-- d) Substantially alter the existing drainage pattern of the site or area, including through the alteration of the course of a stream or river, or substantially increase the rate or amount of surface runoff in a manner which would result in flooding on or off site? 8 --X-- e) Create or contribute runoff water which would exceed the capacity of existing or planned storm water drainage systems or provide substantial additional sources of polluted runoff? 8 --X-- f) Otherwise substantially degrade water quality? 8 --X-- g) Place housing within a 100-year flood hazard area as mapped on a federal Flood Hazard Boundary or Flood Insurance Rate Map or other flood hazard delineation map? 8 --X-- h) Place within a 100-year flood hazard area structures which would impede or redirect flood flows? 8 --X-- i) Expose people or structures to significant risk of loss, injury or death involving flooding, including flooding as a result of the failure of a levee or dam? 7,8 --X-- j) Inundation by seiche, tsunami, or mudflow? --X-- Packet Pg 82 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 25 Evaluation Laguna Lake, part of the 344-acre Laguna Lake Natural Reserve, is a 100-acre naturally occurring Lake that maintains a normal high water level of between two to six feet in depth with isolated deeper spots. Laguna Lake has an approximate capacity of 428.5 AF but has lost substantial capacity due to sedimentation deposition. The lake is fed by Prefumo Creek, a 2nd order stream which has been diverted in the past from its original route and is consistent with a typical urban watercourse, heavily impacted by adjacent urban uses, and eventually drains into San Luis Obispo Creek, a 1st Order stream, to the Pacific Ocean. Laguna Lake is fed by three sub-basins totaling 13.2 square miles of watersheds; Prefumo Canyon, Sycamore Canyon and Los Valley. Each sub basin maintains acreage of urban and/or agricultural development resulting in advanced acceleration of sedimentation and pollutants into the lake. A preliminary dredging report prepared by MNS Engineers August 2016 fully assessed existing setting and project parameters. a,f) Dredging and dewatering operations could result in increased impacts to water quality due to increased turbidity. Dredged slurry will be pumped onshore into geotextile bags or “tubes” that serve to decant the water through the fabric leaving the solids inside the geotextile bags. Flocculating polymer agents will also be used in conjunction with this process to more thoroughly remove turbidity. The geotextile bags will be placed into a sediment basin constructed a minimum of 100 feet away from the lake surface to allow for capture of materials and filtrated recharge into the soil profile. During this dewatering process, water quality will be improved from that of the existing lake water; nitrates and biocides (pesticides) tend to adhere to sediments. To assure that water quality meets established standards, a water quality testing program will be implemented during dredging. Trailer mounted activated carbon filters will be available for initial operations as a confidence measure for compliance, but will only continue to be used if on-going dredging operations and proposed dewatering equipment cannot satisfy permitting agency water quality requirements without them. Mitigation Measures. Mitigation Measure HYDRO-1. For dredging operations the use of a turbidity curtain will be employed as applicable. Dewatering will be via geotextile bags placed in sediment basins located at least 100 feet away from the lake shoreline. Implementation of Mitigation Measure HYDRO-1 would mitigate impacts to water quality to less than significant. b) The project would not result in the expanded use of groundwater resources. No impacts are anticipated to groundwater resources. c-d) The project proposes to conduct sedimentation removal operations via hydraulic dredging of approximately 3,000 to 4,000 cubic yards per year for at least four years. 404/401 Permitting Applicability. A Jurisdictional Waters and Wetlands Delineation Report was prepared by Rincon consultants May 2016. Delineation of the project site indicated approximately 4.72 acres of wetlands and approximately 61.49 acres of jurisdictional waters are subject to Sections 401 and 404 of the Clean Water Act and approximately 56.77 acres subject to the Porter Cologne Act to regulate the discharge of fill and dredged material directly into the waters of the United States. Such actions require necessary permitting from applicable agencies such as the US Army Corps of Engineers, Regional Water Quality Control Board, and California Department of Fish and Wildlife, respectively. Hydraulic dredging would result in the placement of fill within jurisdictional waters so all applicable state and federal permitting would be required. Likewise, alteration of the lake bed would require a streambed Alteration Agreement with the California Department of Fish and Wildlife. The project would temporarily impact the stream morphology of Prefumo Creek due to moving equipment and upstream sediment removal. Creek bank restoration would be required per Section 1602 of the State Fish and Wildlife Code. Mitigation Measures: Packet Pg 83 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 26 Mitigation Measure HYDRO-2. Upon conclusion of operations, creek banks would be re-graded as necessary and laid back to 2H:1V to 2.5H: 1V and reinforced to stabilize banks. Slopes will be revegetated with native riparian species and ground cover. Consultation with all applicable federal and state agencies and any conditions developed under that permitting process would ensure impacts associated with dredging operations are minimized. Implementation of Mitigations Measure GEO-1 and GEO-2 will minimize erosion and further sedimentation deposition into the lake and accompanying creeks. e) Dewatering operations will be done in vacant fields and all waters are to be percolated into the soil profile. No water will be discharged into city storm drains. No impacts are anticipated with storm drain public infrastructure. g-j) The proposed project is not associated with the construction of housing or other structures or would result in increased probability of flooding impacts. No impacts are associated with structural development. Conclusion: With implementation of Mitigation Measures BIO-16, BIO-19, HYDRO-1, GEO-1 and GEO-2, and HYDRO-2 impacts to hydrology would be less than significant. 10. LAND USE AND PLANNING. Would the project: a) Physically divide an established community? 7,8,9, 10,13 --X-- b) Conflict with any applicable land use plan, policy, or regulation of an agency with jurisdiction over the project (including, but not limited to the general plan, specific plan, local coastal program, or zoning ordinance) adopted for the purpose of avoiding or mitigating an environmental effect? 8, 12 --X-- c) Conflict with any applicable habitat conservation plan or natural community conservation plan? 9, 14, 15 --X-- Evaluation a) The proposed dredging project will not physically divide an established community or conflict with any applicable habitat conservation plan or natural community conservation plans. b) The proposed project will not conflict with applicable land use plans, policies, or regulations for the purpose of avoidin g or mitigating an environmental effect. The proposed project is consistent with the City General Plan Designation and zoning for the project site, regulations and development standards. c) As discussed in subsection 4, Biological Resources, with incorporation of the recommended mitigation measures the proposed project would not conflict with the provisions of an adopted habitat conservation plan, natural community conservation plan, or other approved local, regional, or state habitat conservation plan or natural community conservation plan. Conclusion: Less than significant impact. 11. MINERAL RESOURCES. Would the project: a) Result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the state? --X-- Packet Pg 84 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 27 b) Result in the loss of availability of a locally-important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan? --X-- Evaluation a,b) No known mineral resources are present at the project site. Implementation of the proposed project would not result in the loss of availability of a known mineral resource. The project site is not designated by the general plan, specific plan, or other land use plans as a locally important mineral recovery site. Conclusion: No impact. 12. NOISE. Would the project result in: a) Exposure of persons to or generation of noise levels in excess of standards established in the local general plan or noise ordinance, or applicable standards of other agencies? 8 --X-- b) Exposure of persons to or generation of excessive groundborne vibration or groundborne noise levels? 4,8 --X-- c) A substantial permanent increase in ambient noise levels in the project vicinity above levels existing without the project? --X-- d) A substantial temporary or periodic increase in ambient noise levels in the project vicinity above levels existing without the project? --X-- e) For a project located within an airport land use plan, or where such a plan has not been adopted, within two miles of a public airport or public use airport, would the project expose people residing or working in the project area to excessive noise levels? f) For a project within the vicinity of a private airstrip, would the project expose people residing or working in the project area to excessive noise levels? 8,10 --X-- --X-- Evaluation a) Table 2 in the Noise Guidebook includes distances from the centerline of roads to noise contours on sites along roadways with heavier traffic volumes. A comparison of a map of Laguna Lake and Table 2 indicates that the small portion of Laguna Lake adjacent to Madonna Road are exposed to existing noise levels between 60 and 70 decibels (dB) Ldn. Although parks are considered a noise sensitive use, nothing about the proposed dredging project would lead to the worsening of operational nois e levels or introduce additional populations to areas of increased ambient noise. b) Long-term operational activities would be absent with the proposed dredging project. Increases in groundborne vibration levels attributable to the proposed project would be associated with short-term dredging and hauling related activities. Since dredging activities are restricted to the days, hours, and sound levels allowed by City ordinance, impacts associated with groundborne vibration and noise would be less than significant. c) There would be no permanent increase in ambient noise and the proposed project will be short-term and seasonal. d) Noise generated by the project would occur during short-term dredging and hauling activities. Noise levels during dredging would be higher than ambient noise levels, but only for the duration of dredging and hauling. Noise impacts would be less than significant because the dredging would be short term and restricted to the hours and noise levels allowed by City ordinance. e, f) The project site is not located within an airport land use plan area or within 2 miles of a public use airport or private Packet Pg 85 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 28 airstrip. Implementation of the proposed project would not expose individuals to excessive noise levels associated with aircr aft operations. Conclusion: Less than significant impact 13. POPULATION AND HOUSING. Would the project: a) Induce substantial population growth in an area, either directly (for example, by proposing new homes and businesses) or indirectly (for example, through extension of roads or other infrastructure)? 8 --X-- b) Displace substantial numbers of existing housing, necessitating the construction of replacement housing elsewhere? c) Displace substantial numbers of people, necessitating the construction of replacement housing elsewhere? 8 --X-- 8 --X-- Evaluation a) The proposed dredging project would not directly add to the population of the city. Any new employment generated by the project would not be considered substantial. Considering the project area will remain park space and the proposed project would utilize existing infrastructure at the subject location, the project would not induce additional growth that would be considered significant. No upgrades to the existing infrastructure would be required to serve the project. The proposed pro ject would not involve any other components that would induce further growth. b,c) No existing housing or population would be displaced as a result of the proposed dredging project. Conclusion: Less than significant impact. 14. PUBLIC SERVICES. Would the project result in substantial adverse physical impacts associated with the provision of new or physically altered governmental facilities, the construction of which could cause significant environmental impacts, in order to maintain acceptable service ratios, response times or other performance objectives for any of the public services: a) Fire protection? 8 --X-- b) Police protection? 8 --X-- c) Schools? 8 --X-- d) Parks? 8 --X-- e) Other public facilities? 8 Evaluation a) The proposed project site is served by the City of San Luis Obispo Fire Department. Implementation of the proposed dredging project would not increase the intensity of use of the site and would, therefore, not increase the demand for fire protection services over existing conditions. The project would not alter the number of housing units or population in the city and would not result in the need for new fire protection facilities to serve the site. There would be no physical impacts related to the construction of new fire protection facilities and impacts related to fire protection would be less than significant. b) The project site is served by the City of San Luis Obispo Police Department for police protection services. The proposed dredging of the site would not result in the need for increased patrols or additional units such that new police facilities would need to be constructed. There would be no physical impacts related to the construction of new police facilities, and impacts related to police protection would be less than significant. c) Implementation of this project would not generate additional student population or result in other impacts to local schools. Packet Pg 86 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 29 d) The proposed dredging project would not result in an increase in the number of people utilizing park facilities relative to the city’s existing population, and no deterioration or accelerated deterioration at parks and recreation-oriented public facilities from possible increased usage is expected. The proposed project would have a less than significant impact on parks. e) As noted above, because of the proposed use, no increase in users relative to the city’s existing population, deterioration or accelerated deterioration of transportation infrastructure and other public facilities from possible increased usage is not expected. The proposed project would have a less than significant impact on transportation infrastructure and public facilities. Conclusion: Less than significant impact. 15. RECREATION. a) Would the project increase the use of existing neighborhood or regional parks or other recreational facilities such that substantial physical deterioration of the facility would occur or be accelerated? 1,2,8 --X-- b) Does the project include recreational facilities or require the construction or expansion of recreational facilities which might have an adverse physical effect on the environment? 1,2,8 --X-- Evaluation a,b) The proposed dredging project would not increase the use of, or draw additional populations to the existing park. Moreover, additional recreational facilities would not be constructed which might impact the environment. Therefore, no impact to recreational facilities would result from the proposed project. Conclusion: No impact. 16. TRANSPORTATION/TRAFFIC. Would the project: a) Conflict with an applicable plan, ordinance or policy establishing measures of effectiveness for the performance of the circulation system, taking into account all modes of transportation including mass transit and non-motorized travel and relevant components of the circulation system, including but not limited to intersections, streets, highways and freeways, pedestrian and bicycle paths, and mass transit? --X-- b) Conflict with an applicable congestion management program, including, but not limited to level of service standards and travel demand measures, or other standards established by the county congestion management agency for designated roads or highways? --X-- c) Result in a change in air traffic patterns, including either an increase in traffic levels or a change in location that results in substantial safety risks? 8 --X-- d) Substantially increase hazards due to a design feature (e.g., sharp curves or dangerous intersections) or incompatible uses (e.g. farm equipment)? 8 --X-- e) Result in inadequate emergency access? 8 --X-- f) Conflict with adopted policies, plans, or programs regarding public transit, bicycle, or pedestrian facilities, or otherwise decrease the performance or safety of such facilities? 8,10 --X-- Packet Pg 87 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 30 Evaluation a, b) Regional access to the project site is provided by Highway 101, located east of the project site. Local access to the project site is provided by Madonna Road and Los Osos Valley Road. All roadways in the immediate project vicinity have curbs, gutters, sidewalks, and on-street parking. The project does not conflict with any applicable circulation system plans and does not add to demand on the circulation system or conflict with any congestion management programs or any other agency’s plans for congestion management. No new trips will result from completion of the proposed dredging project. However, the project will generate approximately 18 new short-term daily vehicle truck trips on the street system during the dredging and hauling phase. Several likely haul routes of cover material to Cold Canyon Landfill are available on adequate streets that do not travel through residential neighborhoods. The proposed project would not result in a significant impact with regard to increased vehicular trips and does not conflict with performance standards provided in City adopted plans or policies. c) The project is not located in the vicinity of any public or private airports and will not result in any changes to air tra ffic patterns, nor does it conflict with any safety plans of the Airport Land Use Plan. d,e) The project would not modify existing intersections or roadways. The project would not alter the existing travel flow of vehicles, bicyclists, or pedestrians. The proposed dredging project would also not introduce any i ncompatible uses or hinder emergency access. e) The project would not modify existing intersections or roadways. The project would not alter the existing travel flow of vehicles, bicyclists, or pedestrians. The proposed dredging project would also not introduce any incompatible uses. f) The project would not conflict with adopted policies, plans, or programs regarding public transit, bicycle, or pedestrian facilities, or otherwise decrease the performance or safety of such facilities. Conclusion: Less than significant impact. 17. TRIBAL CULTURAL RESOURCES. Would the project cause a substantial adverse change in the significance of a tribal cultural resource, defined in Public Resources Code Section 21074 as either a site, feature, place, cultural landscape that is geographically defined in terms of the size and scope of the landscape, sacred place, or object with cultural value to a California Native American tribe, and that is: a) Listed or eligible for listing in the California Register of Historical Resources, or in a local register as defined in Public Resources Section 5020.1(k)? --X-- b) A resource determined by the lead agency, in its discretion and supported by substantial evidence, to be significant pursuant to criteria set forth in subdivision (c) of Public Resources Code Section 5024.1? In applying the criteria set forth in subdivision (c) of Public Resources Code Section 5024.1, the lead agency shall consider the significance of the resource to a California Native American tribe. --X-- Evaluation a,b) The cultural resources study prepared for the project determined that no historical or other cultural resources exist on the project site. Therefore, there would be no potential impacts to historical or tribal cultural resources. Conclusion: No impact. Packet Pg 88 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 31 18. UTILITIES AND SERVICE SYSTEMS. Would the project: a) Exceed wastewater treatment requirements of the applicable Regional Water Quality Control Board? --X-- b) Require or result in the construction or expansion of new water or wastewater treatment facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? --X-- c) Require or result in the construction of new storm water drainage facilities or expansion of existing facilities, the construction of which could cause significant environmental effects? --X-- d) Have sufficient water supplies available to serve the project from existing entitlements and resources, or are new and expanded entitlements needed? --X-- e) Result in a determination by the wastewater treatment provider which serves or may serve the project that it has adequate capacity to serve the project’s projected demand in addition to the provider’s existing commitments? --X-- f) Be served by a landfill with sufficient permitted capacity to accommodate the project’s solid waste disposal needs? --X-- g) Comply with federal, state, and local statutes and regulations related to solid waste? --X-- Evaluation a), b), c), e) The proposed dredging project would not result in an increase in demand on City infrastructure, including water, wastewater and storm water facilities. The proposed dredging project would improve the stormwater capacity of Laguna Lake. d) The proposed dredging project would not result in an increase in demand on water supplies. f), g) The proposed project does not require municipal solid waste disposal. Dewatered dredg ed material is intended for beneficial reuse as landfill cover. Conclusion: No impacts to utilities and service systems 19. MANDATORY FINDINGS OF SIGNIFICANCE. a) Does the project have the potential to degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife species, cause a fish or wildlife population to drop below self-sustaining levels, threaten to eliminate a plant or animal community, reduce the number or restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of California history or prehistory? --X-- The project has the potential to significantly impact special status plants and wildlife and habitat communities. Mitigations are proposed to minimize impact to species and to consult with federal and state agencies tasked to protect the species and habitats. b) Does the project have impacts that are individually limited, but cumulatively considerable? ("Cumulatively considerable" means that the incremental effects of a project are considerable when viewed in connection with the effects of the past projects, the effects of other current projects, and the effects of probable --X-- Packet Pg 89 6 Issues, Discussion and Supporting Information Sources Sources Potentially Significant Issues Less Than Significant with Mitigation Incorporated Less Than Significant Impact No Impact CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 32 future projects)? There are no other lake dredging projects planned in the San Luis Obispo area, that combined with the proposed project, would result in a situation that is cumulatively considerable. c) Does the project have environmental effects which will cause substantial adverse effects on human beings, either directly or indirectly? --X-- All aspects of the project that could have a substantial adverse effect on human being, particul arly hazardous materials, have been evaluated and are either less than significant, or less than significant with mitigation incorporated. Packet Pg 90 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 33 20. EARLIER ANALYSES. Earlier analysis may be used where, pursuant to the tiering, program EIR, or other CEQA process, one or more effects have been adequately analyzed in an earlier EIR or Negative Declaration. Section 15063 (c) (3) (D). In this case a discussion should identify the following items: a) Earlier analysis used. Identify earlier analyses and state where they are available for review. n/a b) Impacts adequately addressed. Identify which effects from the above checklist were within the scope of and adequately analyzed in an earlier document pursuant to applicable legal standards, and state whether such effects were addressed by mitigation measures based on the earlier analysis. n/a c) Mitigation measures. For effects that are "Less than Significant with Mitigation Incorporated," describe the mitigation measures which were incorporated or refined from the earlier document and the extent to which they address site- specific conditions of the project. n/a 21. SOURCE REFERENCES. 1. Final EIR - Laguna Lake Management Program; City of San Luis Obispo (1981) 2. Laguna Lake Management Program; City of San Luis Obispo (1981) 3. Wildlife of Laguna Lake Park Relationship to Proposed Dredging; Michael T. Hanson (1992) 4. Geotechnical Report Laguna Lake Dredging Project; Earth Systems Consultants (1992) 5. Laguna Lake Park Master Plan; City of San Luis Obispo (1993) 6. Rare Plants, Vegetation, and Flora of Laguna Lake Park; Keil (1996) 7. Geotechnical Characterization Report; Leighton (2016) 8. Laguna Lake Dredging and Sediment Management Project Phase I Report; MNS (2016) 9. Biological Resources Assessment; Rincon (2016) 10. Airport Land Use Plan for SLO County Regional Airport; SLO County (as amended 2005) 11. Cultural Resources Study; Rincon (2016) 12. Conservation and Open Space Element; City of San Luis Obispo General Plan (2007) 13. Laguna Lake Natural Reserve Conservation Plan; City of San Luis Obispo (2014) 14. Recovery Plan for the California Red-legged Frog (Rana aurora draytonii); U.S. Fish and Wildlife Service (2002) 15. South-Central/Southern California Coast Steelhead Recovery Plan; NOAA Fisheries (2013) 16. Human Health Risk Assessment of Sediment Dredging and Dewatering Activities for Laguna Lake, San Luis Obispo, CA; Langan Engineering and Environmental Services, Inc. (2017) Attachments: All of the above documents are included by reference and are on file at the City. In particular, the Laguna Lake Dredging and Sediment Management Project Phase I Report (MNS, 2016) provides detailed information regarding the approaches and specifications for dredging activities, dewatering facilities, and reuse plans. The Biological Resources Assessment (Rincon, 2016) provides comprehensive analyses of the ecological receptors in the area on potential impacts and impact avoidance and minimization measures. 1. Location Map 2. Dredging Exhibit 3. Dewatering Area Exhibit Packet Pg 91 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 34 REQUIRED MITIGATION AND MONITORING PROGRAMS Air Quality AQ-1 During construction/ground disturbing activities, the applicant shall implement the following particulate (dust) control measures. These measures shall be shown on grading and building plans. In addition, the contractor shall designate a person or persons to monitor the dust control program and to order increased watering, modify practices as necessary, to prevent transport of dust off site. Their duties shall include holiday and weekend periods when work may not be in progress. The name and telephone number of such persons shall be provided to the Community Development and Public Works Departments prior to commencement of construction. a. Reduce the amount of disturbed area where possible. b. Use water trucks or sprinkler systems in sufficient quantities to prevent airborne dust from leaving the site and from exceeding the APCD’s limit of 20% opacity for no greater than 3 minutes in any 60 -minute period. Increased watering frequency will be required whenever wind speeds exceed 15 m.p.h. and cessation of grading activities during periods of winds over 25 m.p.h. Reclaimed (non-potable) water is to be used in all construction and dust control work. c. All dirt stock pile areas (if any) shall be sprayed daily and covered with tarps or other dust barriers as needed. d. Permanent dust control measures identified in the approved project revegetation and landscape plans shall be implemented as soon as possible, following completion of any soil disturbing activities. e. Exposed grounds that are planned to be reworked at dates greater than one month after initial grading shall be sown with a fast germinating, non-invasive, grass seed and watered until vegetation is established. f. All disturbed soil areas not subject to revegetation shall be stabilized using approved chemical soil binders, jute netting, or other methods approved in advance by the APCD. g. All roadways, driveways, sidewalks, etc. to be paved shall be completed as soon as possible. In addition, building pads shall be laid as soon as possible after grading unless seeding or soil binders are used. h. Vehicle speed for all construction vehicles shall not exceed 15 m.p.h. on any unpaved surface at the construction site. i. All trucks hauling dirt, sand, soil, or other loose materials, are to be covered/tarped in accordance with California Vehicle Code Section 23114 to prevent the escape of soil or dust. j. Install wheel washers where vehicles enter and exit unpaved roads onto streets, or wash off trucks and equipment leaving the site. k. Sweep streets at the end of each day if visible soil material is carried onto adjacent paved roads. Water sweepers shall be used with reclaimed water where feasible. Roads shall be pre-wetted prior to sweeping when feasible. l. All PM10 mitigation measures required shall be shown on grading and building plans. m. The contractor or builder shall designate a person or persons to monitor the fugitive dust emissions and enhance the implementation of the measures as necessary to minimize dust complaints, reduce visible emissions below the APCD’s limit of 20% opacity for no greater than 3 minutes in any 60 -minute period. Their duties shall include holidays and weekend. AQ 2 Prior to any construction activities at the site, the project proponent shall ensure that all equipment and operations are compliant with California Air Resource Board and APCD permitting requirements, by contacting the APCD Engineering Division at (805) 781-5912 for specific information regarding permitting requirements. AQ 3 To reduce sensitive receptor emissions impact of diesel vehicles and equipment used to construct the project and export soil from the site, the applicant shall implement the following idling control techniques: I. California Diesel Idling Regulations a. On-road diesel vehicles shall comply with Section 2485 of Title 13 of the California Code of regulations. This regulation limits idling from diesel-fueled commercial motor vehicles with gross vehicular weight ratings of more than 10,000 pounds and licensed for operation on highways. It applies to California and non-California based vehicles. In general, the regulation specifies that drivers of said vehicles: 1. Shall not idle the vehicle’s primary diesel engine for greater than 5 minutes at any location, except as noted in Subsection (d) of the regulation; and, 2. Shall not operate a diesel-fueled auxiliary power system (APS) to power a heater, air conditioner, or any ancillary equipment on that vehicle during sleeping or resting in a sleeper berth for greater than 5.0 minutes at any location when within 1,000 feet of restricted area, except as noted in Subsection (d) of the regulation. Packet Pg 92 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 35 b. Off-road diesel equipment shall comply with the 5 minute idling restriction identified in Section 2449(d)(2) of the California Air Resources Board’s In-Use Off-Road Diesel regulation. c. Signs must be posted in the designated queuing areas and job sites to remind drivers and operators of the state’s 5 minute idling limit. II. Diesel Idling Restrictions Near Sensitive Receptors (residential homes). In addition to the State required diesel idling requirements, the project applicant shall comply with these more restrictive requirements to minimize impacts to nearby sensitive receptors: a. Staging and queuing areas shall not be located within 1,000 feet of sensitive receptors. b. Diesel idling within 1,000 feet of sensitive receptors shall not be permitted. c. Use of alternative fueled equipment is recommended. d. Signs that specify the no idling areas must be posed and enforces at the site. III. Soil Transport. The final volume of soil that will be hauled off -site, together with the fleet mix, hauling route, and number of trips per day will need to be identified for the APCD. Specific standards and conditions will apply. Monitoring Program: These measures shall be incorporated into project grading and building plans for review and approval by the City Community Development Department. Compliance shall be verified by the City during regular inspections, in coordination with the County of San Luis Obispo Air Pollution Control District, as necessary. Biological Resources BIO-1 Special Status Plant Species Avoidance: Avoid impacts to occurrences of special status plants listed under ESA and/or CESA. As part of the design of the projects, biological surveys shall be conducted by a qualified Biologist to identify specimens in the project area. If total avoidance of CRPR species is not feasible, minimize impacts to less than 10 percent of onsite populations. BIO-2 Special Status Plant Species Mitigation. Should it be determined that more than 10% of onsite population of Special Status Plants be impacted, the City shall develop a Habitat Mitigation and Monitoring Plan (HMMP) to develop adequate mitigation to offset impacts to species. The HMMP shall quantify the impacts associated with operations and specify restoration practices and enhancement of species habitat. The HMMP shall be reviewed, as applicable by the California Department of Fish and Wildlife for consistency with State requirements. BIO-3 Special Status Wildlife-Birds Avoidance. To avoid take of nesting birds, and raptor nests at any time of year (including inactive nests), activities requiring vegetation disturbance would occur outside the nesting season, which is approximately February 1 through September 15. If activities must begin within the bird breeding season, then no more than two weeks prior to initiation of ground disturbance and/or vegetation removal, a nesting bird pre -construction survey will be conducted by a qualified biologist within the disturbance footprint plus a 100-foot buffer. Pre-construction nesting bird surveys will be conducted during the time of day when birds are active and will be of sufficient duration to reliably conclude presence/absence of nesting birds and raptors onsite and within the designated vicinity. If no nests are observed no further mitigation is required. BIO-4 Special Status Wildlife-Birds Nesting. If nests are found, their locations will be flagged and then mapped onto an aerial photograph of the project site at a scale no less than 1”=200’ and/or recorded with the use of a Global Positioning System (GPS) unit. An appropriate avoidance buffer ranging in size from 50 to 500 feet from the nest, depending upon the species and the proposed work activity, will be determined and demarcated by a qualified biologist with bright orange construction fencing or other high-visibility delineators. No ground disturbance will occur within this buffer until the qualified biologist confirms that the breeding/nesting is completed and all the young have fledged. If buffer zones are determined to be infeasible, a full-time qualified biological monitor can monitor project activity within the buffer zones to ensure active nests and nesting birds are not impacted. BIO-5 Special Status Animals Badger. Prior to activities that disturb native habitats in upland areas, a qualified biologist should complete a survey for badger dens. In order to avoid the potential direct take of adults and nursing young, no gra ding should occur within 50 feet of an active badger den between March 1 and June 30. Activities during July 1 and March 1 should comply with the following measures to avoid direct take of adult and weaned juvenile badgers. Packet Pg 93 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 36 o Conduct a biological survey of the anticipated development areas between 2 weeks and 4 weeks of the start of ground clearing or grading activity. The survey should cover the entire area proposed for disturbance. Surveys should focus on both old and new den sites. If dens are too long to see the end, a fiber optic scope (or other acceptable method) can be used to assess the presence of badgers. o Inactive dens shall be excavated by hand with a shovel to prevent badgers from reusing them during construction. o Badgers should be discouraged from using currently active dens prior to the grading of the site by partially blocking the entrance of the den with sticks, debris and soil for 3 to 5 days or through use of a 1-way door. After badgers have stopped using active dens within the development area, the dens shall be hand excavated with a shovel to prevent re-use. BIO-6 Special Status Animals Pallid Bat. Prior to activities that require tree removal, a qualified biologist should inspect trees proposed for removal to ensure bats are not roosting. If bats are observed, the biologist shall determine if the roost is a hibernaculum or a maternity colony. If so, removal of the tree would be postponed until outside wintering or maternity seasons. If not, the bat(s) would be evicted using appropriate one-way devices and the tree inspected again prior to tree removal BIO-7 Special Status Animals Coast Horned Lizard. During new grading activities in upland habitats, a qualified biologist should be on-site to recover any coast horned lizards that may be excavated/unearthed with native material or found under vegetation. If the animals are in good health, they should be immediately relocated to a designated release area. If they are injured, the animals shall be turned over to an approved wildlife rehabilitator until they are in a condition to be released into the designated release area. BIO-8 Special Status Animals Vernal Pool Fairy Shrimp. The project would be designed to avoid impacts to the basins and wetland depressions (adjacent to but not abutting Laguna Lake), and would avoid altering hydrology of these features. Work areas would be flagged, resources to be avoided would be flagged, and no work would occur upslope and within 250 feet of vernal pool fairy shrimp habitat. BIO-9 Special Status Animals Western Spadefoot Toad. During new grading activities in upland habitats, a qualified biologist should be on-site to recover any spadefoot toads that may be excavated/unearthed with native material or found under vegetation. If the animals are in good health, they should be immediately relocated to a designated release area. If they are injured, the animals shall be turned over to an approved wildlife rehabilitator until they are in a condition to be released into the designated release area. BIO-10a Special Status Animals California Red-Legged Frog. Prior to initiation of construction activities (including staging and mobilization), all personnel associated with project construction would attend a Worker Environmental Awareness Program (WEAP) training, conducted by a qualified biologist, to aid workers in recognizing special status resources that may occur in the project area. The specifics of this program would include identification of the sensitive species and habitats, a description of the regulatory status and general ecological characteristics of sensitive resources, and review of the limits of construction and avoidance measures required to reduce impacts to biological resources within the work area. A fact sheet conveying this information would also be prepared for distribution to all contractors, their employers, and other personnel involved with construction of the project. BIO-10b Special Status Animals California Red-Legged Frog. Ground disturbing activities associated with dry portions of Prefumo Creek should be conducted between May 1 and October 31 during dry weather conditions, which are periods of low activity for these species in dry habitats, to minimize the potential for encountering CRLF. Work should be restricted to daylight hours to the extent feasible. o If activities must occur between November 1 and April 30, the qualified biologist should conduct a pre‐activity clearance sweep each morning prior to start of project activities after any rain events of 0.1 inch or greater. o All trash should be removed from the site daily and disposed of properly to avoid attracting potential predators to the site. o Non-automated operational activities (i.e. truck trips), shall not be conducted during rain events occurring at night to the extent feasible. If project activities requiring movement of equipment are to occur at night during rain events, a qualified biologist should conduct a pre-construction survey of the site each night. BIO-10c Special Status Animals California Red-Legged Frog. A qualified biologist should conduct a survey of work areas associated with the lake and creek within 48 hours of initial ground disturbing activities. The survey area would inclu de the proposed disturbance area and all proposed ingress/egress routes, plus a 100-foot buffer. A biologist authorized to Packet Pg 94 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 37 relocate frogs should be present for activities that require movement or placement of equipment into the lake, stream, and wetlands along the lake to monitor for frogs. If a frog is observed in the work area, the biologist would relocate it, with prior authorization from USFWS, out of the work area BIO-10d Special Status Animals California Red-Legged Frog. If drying basins are used to remove water from the sediment, appropriate exclusion fence should be placed around the basins to prevent access by frogs. BIO-11 Special Status Animals Southwestern Pond Turtle. A qualified biologist should conduct a survey of work areas associated with the lake and creek within 48 hours of initial ground disturbing activities. The survey area would incl ude the proposed disturbance area and all proposed ingress/egress routes, plus a 100-foot buffer. Turtles within work areas should be relocated outside the work area. A biologist authorized to relocate turtles should be present for activities that require movement or placement of equipment into the lake, stream, and wetlands along the lake to monitor for turtles. If a turtle is observed in the work area, the biologist would relocate it out of the work area. BIO-12 Habitat Enhancement Fisheries. During project design, including options to stabilize banks along the lake, the following habitat parameters would be considered and incorporated as feasible: o The lake should provide abundant cover including woody debris, boulders, and undercut banks. Woody debris is very important to provide needed shelter for juvenile fish especially in low velocity refuges. Having appropriate cover and shelter would be imperative for steelhead to survive in Laguna Lake. o Depths greater than 0.5 meter are generally deep enough to avoid wading birds. Depth alone is not the determining factor in water temperature, but lake which has a depth to create a thermocline cold enough to support the fish during periods of higher water temperatures is desirable. o The lake should contain a regular and pronounced slope along its banks. o DO concentrations affect the migration and swimming performance of steelhead at all temperatures. Low DO levels decrease the rate of metabolism, swimming speed, growth rate, food consumption rate, efficiency of food utilization, behavior, and survival. Steelhead does best where DO concentration is at least 7.0 mg/L. DO concentrations should remain at or near saturation levels with temporary reductions no lower than 5.0 mg/L, which has been documented to result in severe production impairment (Carter, 2005). o Suspended and deposited fine sediment can directly affect steelhead by clogging gills, indirectly causing reduced feeding, destruction of food supplies, and changed rearing habitat. Silt loads of less than 25 mg/L permit good rearing conditions for juvenile steelhead. Controlling sediment loads into the creek and lake will improve conditions for steelhead. BIO-13 Project Monitoring Fisheries. During project implementation, a biologist with fisheries experience should be present during activities movement or placement of equipment into the lake, stream, and wetlands along the lake to monitor for fish. If feasible, the active dredge area would be screened to reduce likelihood of aquatic vertebrate species in the active dredging area (e.g. intakes will be screened). If steelhead is observed, activities would cease until NMFS can be consulted. While dredging is underway, a biologist will monitor activities at least weekly. BIO-14 Needlegrass Habitat Avoidance. To the maximum extent feasible, project activities would be designed to avoid needlegrass grassland habitat. If needlegrass grassland habitat areas cannot be avoided in temporary impact areas, purple needlegrass will be incorporated into the revegetation plant palette to functionally replace the impacted habitat. BIO-15 Needlegrass Enhancement. If permanent impacts remove needlegrass grassland habitat areas greater than 0.5 acre in size, an equivalent amount of this habitat type must be created within a City-designated and -approved needlegrass grassland habitat mitigation area onsite. Pertinent and logistic details regarding the creation of needlegrass grassland habi tat would be outlined in a HMMP. The needlegrass grassland habitat mitigation areas will be monitored annually for at least five years to ensure successful establishment and that no-net-loss of this sensitive habitat has been achieved BIO-16 Wetlands Restoration. Jurisdictional areas that cannot be avoided will acquire all applicable regulatory permits. Temporary impact areas will be restored at a one to one (1:1) ratio (one acre of restoration for each acre of impact) to offset temporary losses in wetland, stream, or riparian function. Permanent impacts will be offset through creation, restoration, and/or enhancement of in-kind habitats at a minimum ratio of 2:1 to mitigate unavoidable permanent impacts to jurisdictional areas. Note the resource agencies may require a higher mitigation ratio. A Mitigation and Monitoring Plan will likely be required, and would be prepared by a biologist familiar with restoration and mitigation techniques. The plan will include, but not be limited to the following components: o Description of the project/impact site, Packet Pg 95 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 38 o Goal(s) of the compensatory mitigation project, o Description of the proposed compensatory mitigation-site, o Implementation plan for the compensatory mitigation-site, o Maintenance activities during the monitoring period, o Monitoring plan for the compensatory mitigation-site, o Success criteria and performance standards, o Reporting requirements, and o Contingency measures and funding mechanisms. BIO -17 Erosion Control. Erosion control and landscaping specifications shall allow only natural-fiber, biodegradable meshes and coir rolls, (i.e. no plastic-mesh temporary erosion control measures) to prevent impacts to the environment and to fish and terrestrial wildlife. BIO-18 Habitat Improvement. Where feasible, aquatic habitat improvements such as root wads and downed logs will be incorporated into bank stabilization and sediment control efforts to enhance aquatic habitat in perennial waterways. BIO-19 State/Federal Consultation. Prior to commencement of operations, consultations with applicable federal and state agencies shall be completed per the provisions of the Clean Water Act and Porter Cologne Act. Monitoring Program: These conditions and measures shall be noted on all grading and construction plans. The City Community Development Department and Natural Resources Manager shall verify compliance. Cultural Resources CULT-1: If cultural resources are encountered during ground-disturbing activities, work in the immediate area should be halted and an archaeologist meeting the Secretary of the Interior’s Professional Qualifications Standards for archaeology (National Park Service 1983) should be contacted immediately to evaluate the find. If necessary, the evaluation may require preparation of a treatment plan and archaeological testing for National Register of Historic Places eligibility. If the discovery proves to be significant under the National Historic Preservation Act and cannot be avoided by the project, additional work such as data recovery excavation may be warranted to mitigate any adverse effects to historic properties. CULT-2: The discovery of human remains is always a possibility during ground disturbing activities; if human remains are found, State of California Health and Safety Code Section 7050.5 states that no further disturbance shall occur until the County Coroner has made a determination of origin and disposition pursuant to Public Resources Code Section 5097.98. In the event of an unanticipated discovery of human remains, the San Luis Obispo County Sherriff-Coroner must be notified immediately. If the human remains are determined to be prehistoric, the coroner will notify the Native American Heritage Commission, which will determine and notify a most likely descendant (MLD). The MLD shall complete the inspection of the site within 48 hours of notification and may recommend scientific removal and nondestructive analysis o f human remains and items associated with Native American burials. Monitoring Program: These conditions shall be noted on all grading and construction plans. The City Community Development Department shall verify compliance, including preparation and implementation of the Monitoring Plan, and review and approval of cultural resources monitoring reports documenting compliance with required mitigation measures. Geology / Soils GEO-1 Grading and erosion and sediment control plans shall be designed to minimize erosion during operations and shall be implemented for the duration of the grading period and until regraded areas have been stabilized. The City shall prepare Erosion Control Plan using Best Management Practices (BMPs) that are designed to stabilize the site and protect natural watercourses. GEO-2 The City shall revegetate graded areas upon completion of grading activities with deep rooted, native, drought-tolerant species to minimize slope failure and erosion potential. Use of hydro-seed, straw blankets, other geo-textile binding fabrics or other P&D-approved methods as necessary to hold slope soils until vegetation is established. Packet Pg 96 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 39 Monitoring Program: These measures shall be incorporated into project grading plans for review and approval by the City Community Development and Public Works Departments. Compliance shall be verified by the City during regular inspections. Hazardous Materials HAZ-1 Excavated sediment must be covered/tarped when transported outside of the project area. HAZ-2 Excavated sediment shall be tested according to a soil sampling protocol to ensure that the soils are acceptable to the desired disposal site. If it is determined that the sediments contain hazardous constituents and are unacceptable to the desired disposal site, the sediments shall be disposed at a licensed hazardous waste disposal site. HAZ-4 Water sprays or other adequate measures will be applied each day that work activities occur to all disturbed areas with the potential to emit fugitive dust. At a minimum, water will be applied to exposed areas three times per day with increasing watering frequency required whenever the wind speed exceeds 15 miles per hour. Reclaimed water should be used whenever possible. HAZ-5 Sediments/soil stockpiles will be covered, kept moist, or treated with soil binders to prevent dust generation at the end of each work day. HAZ-6 On site vehicle speeds will be limited to 15 miles per hour or less. Loose dirt and dust shall be removed from all vehicular wheels using brushes, rumble strips, or water prior to leaving the site. HAZ-7 The contractor will designate a person(s) to monitor the dust control program and to order increased watering, as necessary, to prevent transport of dust offsite. The contractor will stop project activities immediately if visible dust emissions are detected at the property boundary and will implement additional dust mitigation measures. HAZ-8 After work activities are completed, all disturbed areas will be re-vegetating or otherwise developed so that dust generation will not occur. HAZ-9 A worker health, safety and education plan will be developed and required, as well as emergency and remedial procedures. Hydrology / Water Quality HYDRO-1. For dredging operations the use of a turbidity curtain will be employed as applicable. Sediment basins to be used for dewatering should be located at least 200 feet ways from the lake shoreline. Implementation of Mitigation Measure HYDRO-1 would mitigate impacts to water quality to less than significant. HYDRO-2. Upon conclusion of operations, creek banks would be regraded as necessary and laid back to 2H:1V to 2.5H: 1V and reinforced to stabilize banks. Slopes will be revegetated with native riparian species and ground cover. Monitoring Program: These measures shall be incorporated into project grading and building plans for review and approval by the City Community Development, Public Works, and Utilities Departments. Compliance shall be verified by the City during regular inspections. Packet Pg 97 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 40 This page intentionally left blank. Packet Pg 98 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 41 ATTACHMENT 1 Packet Pg 99 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 42 ATTACHMENT 2 Packet Pg 100 6 CITY OF SAN LUIS OBISPO INITIAL STUDY ENVIRONMENTAL CHECKLIST 2016 43 ATTACMENT 3 Packet Pg 101 6 Human Health Risk Assessment of Sediment Dredging and Dewatering Activities for Laguna Lake San Luis Obispo, CA Prepared For: Robert Hill City Administration Natural Resources 990 Palm Street San Luis Obispo, CA 93401 Prepared By: Langan Engineering and Environmental Services, Inc. 924 Anacapa Street, Suite 2X Santa Barbara, California 93101 Emily Strake, CEP Senior Project Chemist/Risk Assessor Eric Deaver, PG Project Manager September 11, 2017 270059901 Packet Pg 102 6 Human Health Risk Assessment Report of Sediment Dredging & Dewatering Activities Laguna Lake San Luis Obispo, CA Langan Project No: 270059901 11 September 2017 Page 1 of 9 TABLE OF CONTENTS INTRODUCTION ....................................................................................................................... 2 DATA ANALYSIS ...................................................................................................................... 2 EXPOSURE ASSESSMENT ...................................................................................................... 2 General Exposure Parameters ................................................................................................ 3 Route-Specific Exposure Parameters ..................................................................................... 3 Asbestos Time Weighting Factors ......................................................................................... 4 Exposure Point Concentrations .............................................................................................. 4 TOXICITY ASSESSMENT ......................................................................................................... 5 Non-Carcinogenic Toxicity Values ........................................................................................... 5 Carcinogenic Toxicity Values .................................................................................................. 6 Hexavalent Chromium Formation ........................................................................................... 6 RISK CHARACTERIZATION ...................................................................................................... 6 UNCERTAINTY ......................................................................................................................... 7 CONCLUSIONS ........................................................................................................................ 8 REFERENCES ............................................................................................................................ 8 TABLES Table 1 – Data Summary Table 2 – Calculation of Particulate Emission Factor Table 3 – Inhalation Toxicity Values Table 4 – Risk Characterization, Offsite Resident Table 5 – Risk Characterization with Chromium Adjustment, Offsite Resident FIGURES Figure 1 – Location Map & Soil Staging Area Packet Pg 103 6 Human Health Risk Assessment Report of Sediment Dredging & Dewatering Activities Laguna Lake San Luis Obispo, CA Langan Project No: 270059901 11 September 2017 Page 2 of 9 INTRODUCTION The City of San Luis Obispo has proposed a maintenance dredging regime at Laguna Lake (the Site) to mitigate ongoing sedimentation. The Lake is situated on the 344-acre Laguna Lake Natural Reserve (Figure 1). Previous investigations have indicated the presence of nickel, trivalent chromium (Cr[III]) and hexavalent chromium (Cr[VI]) in exceedance of various risk- based human health screening levels. Dredging will be completed intermittently across a four- year construction period with dredging cycles of approximately 2 to 3 weeks in duration each year. Dredged sediment will be staged and dried prior to off-site disposal on a 4-acre staging area located to the north of Lake Laguna (Figure 1). This Human Health Risk Assessment (HHRA) was conducted to determine whether constituents in sediment and dried sediment (soil) pose unacceptable risks to human health under site-specific exposure conditions and to support decisions concerning the need for further evaluation or mitigation. The technical approach for the HHRA consists of the following basic steps: data analysis, exposure assessment, toxicity assessment, and risk characterization, which includes an assessment of the uncertainty associated with each stage of the HHRA process. The HHRA uses reasonable maximum exposure point soil concentrations to derive exposures and risks to potentially exposed human populations for the inhalation pathway. Incomplete pathways are not relevant to human health risks and are not considered in the HHRA. Cancer risk results were compared to the United States Environmental Protection Agency’s (EPA) cumulative risk management range for multiple carcinogens of one in one million (1E-06) to one in ten thousand (1E-04). Non-cancer hazards were compared to a non-cancer hazard index of 1. DATA ANALYSIS Various investigations have occurred at Lake Laguna over the past 20 years, including collection of sediment vibracore samples, surface soil samples around the lake, and dredge sediment composite samples. Data from prior sampling events for samples collected within the dredging areas are presented in Table 1. The maximum detected concentrations of Cr[III], nickel, and Cr[VI] are also presented in Table 1. Given the prevalence of naturally occurring asbestos (NOA) in various areas of California, asbestos fibers are also considered a constituent of potential concern associated with the proposed dredging regime. Asbestos sampling has not been conducted at the Site. EXPOSURE ASSESSMENT An exposure pathway is the course a chemical takes from its source to the exposed receptor. In order for an exposure pathway to be complete, it must contain a source, a transport medium (e.g., soil, air), a point of contact (receptor), and an exposure route (e.g., inhalation). If any of these elements is missing, an exposure pathway is deemed incomplete and can be excluded from the quantitative evaluation of risk (EPA 1989). Consistent with EPA’s Summary of Exposure Scenario Characteristics and Pathways of Concern (Exhibit 1-1, EPA 2002), the off- site resident is assumed to be located at the site boundary and exposed only through inhalation Packet Pg 104 6 Human Health Risk Assessment Report of Sediment Dredging & Dewatering Activities Laguna Lake San Luis Obispo, CA Langan Project No: 270059901 11 September 2017 Page 3 of 9 of fugitive dust. Direct contact with soil through ingestion and dermal contact is not expected in the sediment staging area; however, if direct contact were to occur, the corresponding exposure pathways are considered insignificant. Consequently, this evaluation focused on one unique receptor population and pathway: inhalation of particulates by off-site residents. General Exposure Parameters Constituent concentration, exposure frequency (EF), exposure duration (ED), exposure time (ET), and averaging time (AT), are general parameters that are included in the intake calculations for the inhalation pathway. The EF describes the number of times per year an event is likely to occur. Variables such as weather, vacations, and institutional controls are considered when determining reasonable and realistic exposure frequencies. For the off-site resident, an EF of 28 days was assumed such that a resident would be exposed to fugitive dust at the Site each day for four weeks of the year. This number was selected based on the estimated project schedule of 2-3 weeks each year and best professional judgment. The ED parameter in the intake equation represents the number of years over which an event is likely to occur. Factors affecting this parameter include variables such as age of the receptor and population mobility. The off-site resident was assumed to be exposed for a period of four years, consistent with the four-year construction duration. For respirable soil, it is necessary to apply an ET to account for the number of hours a resident receptor spends at the home and to calculate an hourly inhalation rate. The off-site resident ET was set to 24 hours under the assumption that residents could be exposed to particulates at their home throughout an entire day. The AT parameter is the period over which exposure is averaged. For non-carcinogenic effects, ATn was used in calculating carcinogenic exposure concentration, and is calculated as the product of the receptor-specific exposure frequency and the 24 hours of the day. The ATn value for the resident is 35,040 hours (4 years X 365 days/year X 24 hours/day). Exposures to carcinogens were averaged over a lifetime. The carcinogen averaging time (ATc) is the product of a 365-day year, a 24-hour day, and a 70-year lifetime, or 613,200 hours. Route-Specific Exposure Parameters Based on the available data, a mathematical model was required for the inhalation pathway to convert the chemical concentration in soil to a corresponding concentration in ambient air. This was accomplished by calculating a soil-to-air particulate emission factor (PEF). The PEF converts concentrations of constituents in soil to concentrations on dust particles in the air (PM10) as a result of fugitive dust emissions from bare surfaces of fine-grained soils. In its Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites, the EPA (2002) provides the methodology required to calculate the PEF. Chemical-specific concentrations in soil are multiplied by the inverse of the PEF to derive chemical-specific concentrations of soil dust in the ambient air (Ca), as follows: Packet Pg 105 6 Human Health Risk Assessment Report of Sediment Dredging & Dewatering Activities Laguna Lake San Luis Obispo, CA Langan Project No: 270059901 11 September 2017 Page 4 of 9 ( ⁄ ) where: Cs = Concentration in soil (mg/kg); and PEF = Particulate emission factor (m3/kg). The PEF is based on fugitive dusts that may be generated as a result of soil dumping, dozing, and wind erosion. These operations may occur separately or concurrently, and the duration of each operation may be different. Therefore, the total unit mass emitted from each operation is calculated separately and the sum is normalized over the entire area of work. The equation used to derive the PEF for the off-site resident is as follows: ( ⁄ ) where: Q/Coff = Inverse of the ratio of the 1-hour geometric mean air concentration and the emission flux at the center of the square emission source (g/m2-s per kg/m3); and J’T = Total time-average PM10 unit emission flux for all dredging activities (g/m2-s). Site-specific values, such as total time over which dredging occurs and the areal extent of the dewatering area were incorporated into the off-site resident PEF. Default parameter values provided in the Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites (EPA 2002) were utilized where site-specific information was not available. The resulting PEF for the off-site resident is 5.56E+07 m3/kg (Table 2). Asbestos Time Weighting Factors For asbestos exposure evaluations, EPA utilizes time weighting factors (TWF) to determine the proportion of time over which receptor activities may occur. For the off-site resident, the TWF was calculated assuming a 24-hour ET across a 28-day dredging period. The resulting TWFs for the off-site resident is 0.08, calculated as [(24 hours exposure/24-hour day) X (28 days exposure/365-day year)]. Exposure Point Concentrations The exposure point concentration (EPC) is the concentration of a constituent in a medium (e.g., soil) that is expected to be contacted by an individual and is assumed to be universally present throughout an exposure area. For this HHRA, the maximum detected sediment concentration of Cr[III], Cr[VI], and nickel was utilized as the EPC in the inhalation models (Table 1). Packet Pg 106 6 Human Health Risk Assessment Report of Sediment Dredging & Dewatering Activities Laguna Lake San Luis Obispo, CA Langan Project No: 270059901 11 September 2017 Page 5 of 9 To establish an EPC for asbestos, a regional background concentration was used. The Department of Toxic Substances Control (DTSC) investigated NOA within two miles of Golden Sierra High School, located approximately 30 miles northeast of Sacramento (DTSC 2002). NOA in this area is associated with serpentine rock, which is a form of ultramafic rock. The local geology is similar at Laguna Lake such that sediment derived from ultramafic rock may be present in the lake and is generally known to be present in the area. In the DTSC study, soil samples were collected in August and September of 2000 and the reported the mean concentration of all the polarized light microscopy (PLM) samples was 1.1%. Chrysotile was the only asbestos type found during the PLM analysis. The concentration of asbestos in soil was expressed in terms of the weight of asbestos per unit weight of soil calculated on a dry weight basis. The 1.1% background concentration is equivalent to 11,000 (mg/kg), the standard units used for soil concentration data. TOXICITY ASSESSMENT Toxicity assessment involves the evaluation of available toxicity information to be used in the risk assessment process. Toxicity values derived from dose-response relationships can be used to estimate the potential for the occurrence of adverse effects in individuals exposed to various constituent levels. In accordance with recent EPA guidance, toxicity values specific to the inhalation pathway were obtained from the sources listed hierarchically below: • Integrated Risk Information System (IRIS) on-line database • California Office of Environmental Health Hazard Assessment (OEHHA) • Agency for Toxic Substances and Disease Registry (ATSDR) The toxicity values used to evaluate the potential for human health effects from exposure to Site-associated constituents are presented in Table 3. Non-Carcinogenic Toxicity Values Adverse effects can be caused by acute exposure, which is a single or short-term exposure to a toxic substance, or by chronic exposure to lower levels on a continuous or repeated basis over an extended period of time. “Acceptable” acute or chronic levels of exposure to non- carcinogens are considered to be levels without any anticipated adverse effects. Such exposure levels are commonly expressed as reference concentrations (RfCs). An acceptable exposure level is calculated to provide an adequate margin of safety. RfCs have been developed by the EPA for chronic (e.g., lifetime) exposure to constituents based on the most sensitive non-carcinogenic effects. Chronic RfCs, which have been derived for a number of chemicals, are used to evaluate exposures lasting 7 to 70 years (EPA 1989). Though a subchronic exposure scenario is expected to occur consistent with the 4-year project dredging schedule, only chronic RfCs were used in this HHRA. Packet Pg 107 6 Human Health Risk Assessment Report of Sediment Dredging & Dewatering Activities Laguna Lake San Luis Obispo, CA Langan Project No: 270059901 11 September 2017 Page 6 of 9 Trivalent chromium does not have a published RfC; therefore, the IRIS RfD (1.5 mg/kg-day) was converted to a RfC by multiplying by the ratio of the default adult body weight (70 kg) to a default inhalation rate (20 m3/day) (EPA 2009). Carcinogenic Toxicity Values Carcinogenic risk refers to the probability of developing cancer as a result of exposure to known or suspected carcinogens. A cancer slope factor (CSF) is a plausible upper-bound estimate of the probability of an individual developing cancer as a result of a lifetime of exposure to a particular level of a potential carcinogen. Consistent with the EPA’s inhalation dosimetry methodology, the inhalation unit risk (IUR) (i.e., the cancer slope factor expressed in risk per g/m3) was used to assess incremental lifetime cancer risks associated with site carcinogens. Consistent with EPA guidance (EPA 2008, EPA 2005), exposures that are shorter than a lifetime may be evaluated using concomitant IURs representing continuous, but less-than-lifetime exposures. Less-than-lifetime IURs (IURLTL) for asbestos were developed by the EPA for various exposure durations and receptor ages of first asbestos exposure. To evaluate the off-site resident, the IUR for a 5-year exposure duration and 0-year exposure age was selected to represent a child resident. The resulting IUR is 0.046 fibers per cubic centimeter (f/cc)-1. The mass conversion to fibers was taken from the OEHHA Air Toxics Hot Spots Program and is 0.003 g per 100 PCM fibers. Hexavalent Chromium Formation Oxidation of Cr[III] to Cr[VI] in soil is facilitated by the presence of organic substances, oxygen, manganese dioxide, moisture, and heat (Apte, et al., 2005). The rate and extent of chromium oxidation has been studied under various conditions, including suspension in aerobic media, addition of manganese dioxide, application of heat and adjustment of pH in chromium contaminated sludge (Apte, et al., 2005). The results indicate that Cr[III] could be converted to Cr[IV] under aerobic conditions. However, the transformation was found to be transitory, with the Cr[VI] formed being ultimately reduced back to Cr[III] due to the presence of various reducing agents in the sludge. Given that up to 17% conversion of Cr[III] to Cr[VI] occurred in sludge under aerobic conditions by 30 days, modeling was conducted assuming 17% of the maximum concentration of Cr[III] (850 mg/kg) was present as Cr[VI]. RISK CHARACTERIZATION The objective of the risk characterization is to determine potential risk to receptors by combining the results of the exposure and toxicity assessments. The potential for non-cancer health effects was evaluated by comparing the average daily intake with the RfC. This ratio of exposure to toxicity (intake/RfC) is called the hazard quotient (HQ). For evaluating the noncarcinogenic risks for multiple constituents, the HQs are summed to produce a hazard index (HI). If the site-specific exposure level exceeds the effects-based Packet Pg 108 6 Human Health Risk Assessment Report of Sediment Dredging & Dewatering Activities Laguna Lake San Luis Obispo, CA Langan Project No: 270059901 11 September 2017 Page 7 of 9 threshold (i.e., the HI exceeds a value greater than 1), there may be concern for potential non-carcinogenic effects. The product of the lifetime daily intake and the IUR was used to estimate the upper bound excess cancer risk for carcinogenic (or potentially carcinogenic) constituents. The EPA endorses a de minimis cancer risk threshold of 1E-06 for exposure to multiple carcinogens as the point of departure (POD) for risk management decisions. This value represents an incremental increase of 1 in 1,000,000 in the chance of developing cancer over a lifetime. The EPA’s Office of Solid Waste and Emergency Response directive instructs development of risk- based, site-specific action levels to determine if response actions for asbestos should be undertaken. For site assessments involving short term exposures, it is common practice to use the 1E-04 target risk for asbestos in air (EPA 2008). Using the maximum detected Cr[III], Cr[VI], and nickel concentrations, and the regional average asbestos concentration, the cumulative incremental lifetime cancer risk (ILCR) is estimated to be 2E-05 for the off-site resident. The ILCR is predominantly attributable to asbestos exposure, assuming average concentrations in northern California soils are present at the Site. The ILCR is within the EPA’s risk management range for cumulative cancer risk, and below the target risk for short term exposures. The hazard index is calculated to be below the threshold for non- cancer health effects at 0.02. The calculated non-cancer and cancer risks for all chemicals of concern are provided in Table 4. Increasing the modeled Cr[VI] concentration by 17% of the maximum Cr[III] concentration results in an increase in the Cr[VI] HQ from 0.00004 to 0.002, and an increase in the ILCR attributable to Cr[VI] from 2E-08 to 1E-06. The cumulative ILCR and HI remain the same at 2E- 05 and 0.02, respectively. UNCERTAINTY There are uncertainties associated with the quantitative risk estimates discussed above. These uncertainties are introduced because of: (1) the need to extrapolate below the dose range of experimental tests; (2) the variability of the receptor population (e.g., smoker vs. non-smoker, genetic predisposition); (3) assumed dose-response relationship between animals and humans; (4) differences in exposure routes (e.g., Cr[III]); (5) conservative assumptions; and (6) ignoring background risks. These recognized uncertainties are raised to point out the limitations of this type of study. The assumptions used to estimate exposure in this HHRA were consistently conservative in nature and biased toward protecting human health. The maximum detected concentration of chemicals in sediment were used as the exposure point concentration. It is unlikely that receptors would be simultaneously exposed to the maximum concentration of various constituents. Values assumed for exposure parameters (e.g., inhalation rate and exposure frequency) used in calculations of intakes were based primarily on agency guidance. These assumptions might Packet Pg 109 6 Human Health Risk Assessment Report of Sediment Dredging & Dewatering Activities Laguna Lake San Luis Obispo, CA Langan Project No: 270059901 11 September 2017 Page 8 of 9 result in underestimating or overestimating the intakes calculated for specific receptors, depending on the accuracy of the assumptions relative to actual site conditions. Uncertainty is inherent in the toxicity values utilized in evaluating the carcinogenic and non-carcinogenic risks. Such uncertainty is chemical-specific and is incorporated into the toxicity value during its development to ensure that the risk assessment provides a protective evaluation of potential toxicity. For example, an uncertainty factor may be applied for interspecies and intrahuman variability, for extrapolation from subchronic to chronic exposures, or for epidemiological data limitations. Application of uncertainty factors is expected to overestimate risks. The hazards and risks derived based on the data analysis, exposure assessment, and toxicity assessment steps of the risk assessment are inherently uncertain given the uncertainties within each step of the HHRA process. The uncertainty in the risk characterization may be compounded from the uncertainties at these prior stages. The reliance on conservative inputs for various exposure parameters are anticipated to result in overestimations of risks from Site- related chemical stressors. Summing hazard quotients values to derive an HI is a conservative approach given that different chemicals often exert their effects on distinct target organs (USEPA 1989). CONCLUSIONS A human health risk assessment was conducted for a portion of Laguna Lake, located in San Luis Obispo, California. The objectives of the HHRA were to determine whether concentrations of constituents in soil may pose unacceptable risks to human health under site- specific exposure conditions, and to provide information to support decisions concerning the need for further evaluation or action of these media based the proposed dredging activities. The inhalation of fugitive dust exposure pathway was evaluated for the off-site resident receptor. The risk assessment supports the following conclusions: • No unacceptable cancer risks are posed to the off-site resident. The incremental lifetime cancer risk is estimated to be within the EPA’s risk management range at 2E -05, primarily attributable to background concentrations of asbestos. • No unacceptable non-carcinogenic risks are posed to the off-site resident. REFERENCES Apte A.D., Tare V., Bose P, 2006. Extent of oxidation of Cr[III] to Cr[VI] Under Various Conditions Pertaining to Natural Environment. Journal of Hazardous Materials, Volume 128, Issues 2–3, 6 February 2006, Pages 164-174 DTSC 2002. Report on Surface Soil Sampling for Naturally Occurring Asbestos. October 2002. EPA 1989. Risk Assessment Guidance for Superfund. Volume I, Human Health Evaluation Manual (Part A). Interim Final. EPA/540/1-89/002. Office of Emergency and Remedial Response. Washington, DC. Packet Pg 110 6 Human Health Risk Assessment Report of Sediment Dredging & Dewatering Activities Laguna Lake San Luis Obispo, CA Langan Project No: 270059901 11 September 2017 Page 9 of 9 EPA 2005. Guidelines for Carcinogen Risk Assessment. Washington, DC, National Center for Environmental Assessment. EPA/630/P-03/001b. NCEA-f-0644b. OEHHA 2015. Air Toxics Hot Spots Program Risk Assessment Guidelines: Guidance Manual for Preparation of Health Risk Assessments. OEHHA. Air, Community, and Environmental Research Branch. February. EPA 2008. Framework for Investigating Asbestos-Contaminated Superfund Sites. OSWER Directive 9200.0-68. September 2008. EPA 2009. Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual (Part F, Supplemental Guidance for Inhalation Risk Assessment) EPA-540-R-070- 002 OSWER 9285.7-82. January 2009. Packet Pg 111 6 Table 1 Data Summary Laguna Lake, City of San Luis Obispo Sample ID Depth (feet)Cr[III] (mg/kg) Nickel (mg/kg) Cr[VI] (mg/kg) VC-1 0.1 140 210 1.4 VC-1 5 150 220 2.9 VC-1 10 140 190 3.1 VC-7 0.1 160 250 <2.2 VC-7 5 140 200 <2.0 VC-7 10 140 230 <1.6 VC-7 14 170 260 <2.0 LS-16-1 NA 67 63 1.4 VC-11 0.1 140 220 <1.5 VC-11 6 180 250 3 VC-11 12.5 210 280 <2 VC-3 0.1 140 210 <1.6 VC-3 5 170 260 2.3 VC-3 10 160 220 <1.7 VC-14 0.1 160 230 <1.8 VC-14 6 190 290 <2.2 VC-14 12.5 210 350 <1.3 GRAB 8,10,11 NA 150 280 NA GRAB 12,14,15,16 NA 64 120 NA LFR-01-04 NA 850 790 NA LFR-01-04 NA 360 1100 <2 LFR-01-04 NA 380 630 NA LFR-01-04 NA 430 840 <2 850 1100 3.1Maximum Concentration Packet Pg 112 6 Table 2 Calculation of Particulate Emission Factor Laguna Lake, City of San Luis Obispo 1)Mwind = 0.036*(1-V)*(Um/Ut)3*F(x)*Asurf*ED*8,760hr/yr Units Mwind - Unit mass emitted from wind erosion 287983 g Calculated V - Fraction of vegetative cover 0.25 unitless Site-Specific Um - Mean annual windspeed 5.2 m/sec http://www.usa.com/san-luis-obispo-ca-weather.htm Ut - Equivalent threshold value of windspeed at 7m 11.32 m/sec USEPA 1996 F(x) - Um/Ut-dependent function 0.194 unitless USEPA 1996 Asurf - Areal extent of site with surface soil contamination 16187 m2 Site-Specific, 4-Acre Dewatering Area ED - Exposure duration 4 year Site-Specific, 4-Year Construction Period 2)Mpile = PM10*0.0016*(Um/2.2)1.3/(M/2)1.4*rsoil*Apile*dpile*NA*1E+03 Mpile - Units mass emitted from pile soil dumping 12135 g Calculated PM10 - PM10 particle size multiplier 0.35 unitless USEPA 1985 Um - Mean annual windspeed 5.2 m/sec http://www.usa.com/san-luis-obispo-ca-weather.htm M - Gravimetric soil moisture content 12 %USEPA 1985 rsoil - In situ soil density (includes water)1.68 mg/m3 USEPA 1985 Apile - Area extent of pile 16187 m2 Site-Specific, 4-Acre Dewatering Area dpile - Average depth of pile 0.2 m Site-Specific, Calculated to equal 4,000 CY of material NA - Number of times soil is dumped 16 unitless Site-Specific, 7 days for a single load to be dewatered and transported 28 d/yr for 4 years 3)VKT = SQRT(Asite)/BL)*SQRT(Asite)*3/1000 m/km VKT - Vehicle Kilometers Traveled 19.902 km Calculated Asite - Areal extent of site 16,187 m2 Site-Specific BL - Length of dozing blades 2.44 m USEPA 2002 4)Mdoz = SF*(0.45s1.5)/(M)1.4)*(VKT/S)*1E+03 Mdoz - Unit mass emitted from dozing operations 1896 g Calculated SF - PM10 Scaling Factor 0.75 unitless USEPA 2002 s - Soil silt content 15 %Site-Specific M - Gravimetric soil moisture content 7.9 %USEPA 1985 VKT - Sum of dozing kilometers traveled 19.902 km Site-Specific S - Average dozing speed 11.4 kph USEPA 1985 Packet Pg 113 6 Table 2 Calculation of Particulate Emission Factor Laguna Lake, City of San Luis Obispo 5)Mpc wind = 0.036*(1-V)*(Um/Ut)3*F(x)*Asurf*ED*8,760hr/yr Mwind - Unit mass emitted from wind erosion 287983 g Calculated V - Fraction of vegetative cover 0.25 unitless Site-Specific Um - Mean annual windspeed 5.2 m/sec http://www.usa.com/san-luis-obispo-ca-weather.htm Ut - Equivalent threshold value of windspeed at 7m 11.32 m/sec USEPA 1996 F(x) - Um/Ut-dependent function 0.194 unitless USEPA 1996 Asurf - Areal extent of site with surface soil contamination 16,187 m2 Site-Specific, 4-Acre Dewatering Area ED - Exposure duration 4 year Site-Specific, 4-Year Construction Period 6)Q/Coff = A*(exp((lnAsite-B)2/C)) 74.742 g/m2-s per kg/m3 Calculated A - Constant Zone 2, Los Angeles 15.7133 unitless USEPA 2002 B - Constant Zone 2, Los Angeles 21.8997 unitless USEPA 2002 C - Constant Zone 2, Los Angeles 269.8244 unitless USEPA 2002 Asite - Areal extent of site 4 acres Site-Specific, 4-Acre Dewatering Area 7)JT off= Mwind + Mpile + Mdoz + Mpc wind/(Asite *ED * 3.1536E+07s/yr) JT off - Total time-averaged PM10 unit emission flux for the off-site receptor 2.89E-07 g/m2-s Calculated Mwind - Unit mass emitted from wind erosion 287983 g Calculated Mpile - Units mass emitted from excavation soil dumping 12135 g Calculated Mdoz - Unit mass emitted from dozing operations 1896 g Calculated Mpc wind - Post-construction unit mass emitted from wind erosion 287983 g Calculated Asite - Areal extent of site 16,187 m2 Site-Specific, 4-Acre Dewatering Area ED - Exposure Duration 4 years Site-Specific, 4-Year Construction Period 8)PEFoff = Q/Coff *JT off-1 PEFoff -Particulate emission factor for off-site resident 2.59E+08 m3/kg Calculated Notes: EPA 1985. Compilation of Air Pollutant Emission Factors, Volume I: Stationary Point and Area Sources, and Supplements. Office of Air Quality Planning and Standards, Research Triangle Park, NC. EPA 1996. Soil Screening Guidance: User’s Guide. Publication 9355.4-23. Office of Solid Waste and Emergency Response. Washington, DC. July 1996. EPA 2002. Supplemental Guidance for Developing Soil Screening Levels for Superfund Sites. Office of Solid Waste and Emergency Response. OSWER 9355.4-24. Washington, DC. USA.com, Mean Annual Wind Speed Data for San Luis Obispo, CA Q/Coff - Inverse ratio of the 1-h geometric mean air concentration and the emission flux at the site boundary Packet Pg 114 6 Table 3 Inhalation Toxicity Values Laguna Lake, City of San Luis Obispo Chemical CAS # Inhalation RfC mg/m3 Source Inhalation IUR (mg/m3)-1 Source Cr[III]16065831 5.25E+00 Calculated from IRIS RfD NA -- Cr[VI]18540299 1.00E-04 IRIS 8.40E-02 IRIS Nickel 7440020 9.00E-05 ATSDR 2.60E-04 CalEPA Chemical CAS # Inhalation RfC mg/m3 Source Inhalation IUR (f/cm3)-1 Source Asbestos NA NA --4.60E-02 EPA Notes: RfD = Reference Dose RfC = Reference Concentration IUR = Inhalation Unit Risk NA = Not Available Cr[III] RfD adjusted by a 70 kg body weight and 20 m3/day inhalation rate Sources: IRIS - Integrated Risk Information System CalEPA - California EPA ATSDR - Agency for Toxic Substances and Disease Registry EPA - EPA IUR of 0.046 (f/cc)-1 for early life exposure and a 5 year exposure duration Packet Pg 115 6 Table 4 Risk Characterization, Offsite Resident Laguna Lake, City of San Luis Obispo Exposure Concentration (mg/m3) =Ca × EF × ED × ET AT Parameter Unit Value Source Ca - Concentration in air =mg/m3 see below Calculated EF - Exposure frequency =days/year 28 Best professional judgment ED - Exposure duration =years 4 Site-Specific ET - Exposure time =hr/day 24 USEPA 2002 ATn - Averaging time - noncarcinogenic =hours 35040 Best professional judgment ATc - Averaging time - carcinogenic =hours 613200 USEPA 2002 TWF = Time Weighting Factor =unitless 0.08 Best professional judgment Ca - Concentration in air (mg/m3) =Cs * (1/PEF)see below Calculated Cs - Concentration in soil =mg/kg see below PEF - Particulate Emission Factor =m3/kg 5.56E+07 Calculated (see Table 2) Constituent Maximum Concentration in Sediment mg/kg Concentration in Air mg/m3 Non-Carcinogenic Exposure Concentration mg/m3 Inhalation RfC mg/m3 Hazard Quotient Carcinogenic Exposure Concentration mg/m3 Inhalation Unit Risk (mg/m3)-1 Cancer Risk Metals Cr[III]8.50E+02 1.53E-05 1.17E-06 5.25E+00 0.0000002 6.70E-08 NA -- Cr[IV]3.10E+00 5.57E-08 4.28E-09 1.00E-04 0.00004 2.44E-10 8.40E+01 2E-08 Nickel 1.10E+03 1.98E-05 1.52E-06 9.00E-05 0.02 8.67E-08 2.60E-01 2E-08 Hazard Index =0.02 Constituent Maximum Concentration in Sediment mg/kg Concentration in Air mg/m3 Concentration in Air f/cm3 Carcinogenic Exposure Concentration f/cm3 Inhalation Unit Risk (f/cm3)-1 Cancer Risk Asbestos fibers 1.10E+04 1.98E-04 6.59E-03 5.06E-04 4.60E-02 2E-05 Total Cancer Risk =2E-05 TWF [(24 hours/24 hours)*(28 days/365 days)] 7.67E-02 Packet Pg 116 6 Table 5 Risk Characterization with Chromium Adjustment, Offsite Resident Laguna Lake, City of San Luis Obispo Exposure Concentration (mg/m3) =Ca × EF × ED × ET AT Parameter Unit Value Source Ca - Concentration in air =mg/m3 see below Calculated EF - Exposure frequency =days/year 28 Best professional judgment ED - Exposure duration =years 4 Best professional judgment ET - Exposure time =hr/day 24 USEPA 2002 ATn - Averaging time - noncarcinogenic =hours 35040 Best professional judgment ATc - Averaging time - carcinogenic =hours 613200 USEPA 2002 TWF = Time Weighting Factor =unitless 0.076712329 Best professional judgment Ca - Concentration in air (mg/m3) =Cs * (1/PEF)see below Calculated Cs - Concentration in soil =mg/kg see below PEF - Particulate Emission Factor =m3/kg 5.56E+07 Calculated (see Table 2) Constituent Maximum Concentration in Sediment mg/kg Concentration in Air mg/m3 Non-Carcinogenic Exposure Concentration mg/m3 Inhalation RfC mg/m3 Hazard Quotient Carcinogenic Exposure Concentration mg/m3 Inhalation Unit Risk (mg/m3)-1 Cancer Risk Metals Cr[III]8.50E+02 1.53E-05 1.17E-06 5.25E+00 0.0000002 6.70E-08 NA -- Cr[IV]1.48E+02 2.65E-06 2.04E-07 1.00E-04 0.002 1.16E-08 8.40E+01 1E-06 Nickel 1.10E+03 1.98E-05 1.52E-06 9.00E-05 0.02 8.67E-08 2.60E-01 2E-08 Hazard Index =0.02 Constituent Maximum Concentration in Sediment mg/kg Concentration in Air mg/m3 Concentration in Air f/cm3 Carcinogenic Exposure Concentration f/cm3 Inhalation Unit Risk (f/cm3)-1 Cancer Risk Asbestos fibers 1.10E+04 1.98E-04 6.59E-03 5.06E-04 4.60E-02 2E-05 Total Cancer Risk =2E-05 TWF [(24 hours/24 hours)*(28 days/365 days)] 7.67E-02 Packet Pg 117 6 © 2017 Langan 924 Anacapa Street, Suite 2XSanta Barbara, CA 93101T: 1.800.9LANGAN x6890 www.langan.comPacket Pg 1186 Newspaper of the Central Coast RCr-7�rf ? y WI 20 ?W r 3825 South Higuera • Post Office Box 112 • San Luis Obispo, California 93406-0112 • (805) 781-7800 In The Superior Court of The State of California Arf& CITY Op In and for the County of San Luis Obispo W San LUIS oalspo SAN LUIS OBIVO CITY COUNCIL NOTICE OF PUBLIC MEL=TING AD #3338712 CITY OF SAN LUIS OBISPO The San Luis Obispo City Council invites all interested persons to attend a public OFFICE OF THE CITY CLERK meeling on Tuesday, October 24, 2017, at 6:00 p.m. in the City Hall Council Chambers, 990 Palm Street, San Luis Obispo, California, relative to the follow - STATE OF CALIFORNIA mg. ss. LAGt1N _LAKE County of San Luis Obispo TFIe City of San Luis Obispo has complet- ed the Draft Initial Study/Mittgated Nega- live Declaration (IS/MND) for the proposed I am a citizen of the United States and a resident of the " uaa Lake Dredgfng_snd Sed€men[ Countyaforesaid; I am over the age of eighteen and not , g g lowing. Pro ect. The ISIMND found thefogn the following environmental factors to be interested in the above entitled matter; I am now, and at less than significant with mitigation incorpo- all times embraced in the publication herein mentioned rated: Air Quality,Biological Resources, CWtural Resources, Geology/Soils, Hazard - was, the principal clerk of the printers and publishers of tysTeOland ater Oual- lthproecis located at he Laguna THE TRIBUNE, a newspaper of general Circulation, Lake Natural Reserve at 504 Madonna Road, San Luis Obispo, 93401. The printed and published daily at the Ci of San Luis p p y City ed project site is not included on any of the Obispo in the above named county and state; that notice lists enumerated under Section 65962.5 of the Government Code. at which the annexed clippings is a true copy, was published in the above-named newspaper and not in an py Advance reference copies of the Mitigated Negative Declaration are available in the supplement thereof — on the following dates to wit; City Clerk's Office at 990 Palm Street. The required 3o-daypublic review period for OCTOBER 17 2017 that said newspaper was duly and the Mitigated NBgaiive Declarationwill be regularly ascertained and established a newspaper of extended from Friday September 15„2017 to Tuesday October 24, 2017. Anyone inter general circulation by Decree entered in the Superior ested in commenting on the document Court of San Luis Obispo County,State of California, on p submit a written statement to the ity ooff San Luis Obispo, 990 Palm Street, City June 9, 1952, Case #19139 under the Government Code San Luis Obispo, CA 93401, Attention: of the State of California. Robert Hill, Natural Resources Manager, or by email to!NLiQ !gg11y.M by 5:00 p.m., October 24, 2017. 1 certify (or declare) under the penalty of perjury that the The San Luis Obispo City Council will con - foregoing is true and correct. tiv er the adoption of the Mitigates Nega- tive Declaration. Interested persons can - Auxcily-councillanandas-and-minuias access the City Council agenda at htto:// www.slocit ,ar ovemman m.axp� a Ltd to locate (S1g1 ure of Principal Clerk) the dates of Lite public hearings for this project. DATE: OCTOBER 17, 2017 AD COST: $204.16 Council Agenda Reports for this meeting will be available for review in the City Cler- k's Office and online at www.slocity.org on Wednesday, October 18, 2017. Please call the City Clerk's Office at (805) 781-7400 for more information. The City Council meeting will be televised live on Charter Cable Channel 20 and live streaming on VVWA1q lty_org, Carrie Gallagher City Clerk City of San Luis Obispo October 17. 2017 3338712