HomeMy WebLinkAbout07/05/1988, 4 - WASTEWATER MANAGEMENT PLAN - BENEFICIAL USE OPTIONS �IIRIII��IIIII^IIIAIIIII�I "1 MEETING DATE:
II I�Null C� 0 Sdn IU�S �B�SpO July 5, 1988
COUNCIL AGENDA REPORT ITEM NUMBER
From: David F. Romero / Prepared By: William T. Hetland
Director of Public Works Utilities Manager
Subject: Wastewater Management Plan - Beneficial Use Options
CAO
Recommendation: By motion direct staff to proceed with the development o
the stream enhancement and irrigation project alternativ
2 . Also direct staff to submit findings of this report
to the Regional Board and request changes in waste
discharge requirements.
BENEFICIAL USE OPTIONS
* SUMMARY
As part of the City's wastewater Management Plan the City council
supported the idea of reuse of the City's wastewater. The Wastewater
Reclamation/Beneficial Use Investigation study reviewed four major
reclamation/beneficial use options: 1. ) stream enhancement; 2. ) landscape
irrigation; 3. ) agricultural irrigation; and 4. ) indirect discharge to
Laguna Lake. Specific alternative projects were developed for the first
three options. Recommendations are to implement the stream enhancement
and landscape irrigation project and submit these findings to the Regional
Water Quality Control Board with a request for changes to the City's wast
discharge requirements.
* BACKGROUND
In 1987 the City Council adopted the Wastewater Management Plan. In the
Plan a brief investigation of beneficial use options was made which
resulted in a letter report to the Council on September 22, 1987. the
Council then directed that the four beneficial use options be evaluated
during the wastewater treatment plant predesign studies. The Wastewater
Reclamation/Benedicial Use Investigation study is the result of that
direction. The report is a "working draft" which presents initial
findings and conslusions. It is anticipated that changes in the
recommendations may occur due to Council and Community input.
In addition, discussions with the Regional Water Quality Control Board
regarding the City's inability to meet certain receiving water
requirements indicated that beneficial use options represented a total
resource management effort. This approach would help mitigate the City's
inability to meet those requirements.
* BENEFICIAL USE OPTIONS
The four beneficial use options evaluated were:
1. Stream Enhancement - This option includes the reestablishment of
riparian vegetation, construction of instream structures to improve
steelhead habitat and terracing of the bank slope to provide for flood
flows.
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Wastewater Management Plan
Page 2
2 . Landscape Irrigation - This option would develop reclaimed water
for irrigation of golf courses, parks, commerical and road side
landscaping. A higher level of treatment than being recommended would
be required.
3. Agricultural Irrigation - This option includes the use of
reclaimed water for irrigation of agriculture crops. Different level
of treatment are required for agricultural irrigation depending on the
type of crop. The City has in essence been doing agricultural
irrigation for a number of years by its continued discharge to San
Luis Creek and the withdrawal of water by the downstream property
owners.
4. Indirect Discharge to Laguna Lake - this option involves the
discharge of reclaimed water to holding ponds above Laguna Lake and
allowing the water to percolate into the lake. This would provide
increased flow into the lake during the summer time to maintain a
higher lake level.
* ALTERNATIVE PROJECTS AND ANALYSIS
After review of the above options, alternative projects were developed fo
evaluation. The most feasible options included stream enhancement,
landscape and agricultural irrigation. Laguna Lake discharge was
determined to be infeasible due to the impact that the addition of
nutrient-laden effluent would have on lake algae growth.
Five alternative projects were then developed.
Stream Enhancement - This project is to provide improved habitat for
steehead trout, improve habitat for wildlife, and provide a visually
pleasing riparian corridor. It would also demonstrate the feasibility of
stream enhancement projects and be the groundwork for further projects in
the area. The costs for this project can vary significantly but it is
estimated to range from $200,000 to $4008000.
Landscape and Agricultural Irrigation - Four irrigation alternatives
were developed. Each involve several irrigation elements requiring the
same treatment level and located in a given geographic area to minimize
transmission costs.
Alternative 1 Landscape irrigation of 177 acres in Laguna Lake area;
treatment level A. (Figure 3-5)
Alternative 2 Landscape irrigation of 180 acres in the airport area;
treatment level B. (Figure 3-6)
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COUNCIL AGENDA REPORT
Wastewater Management Plan
Page 3
Alternative 3 Landscape irrigation of 75 acres in the Central City
area and agricultural irrigation of 140 acres at Cal Poly; treatment
level A. (Figure 3-7)
Alternative 4 Agricultural irrigation of 300 acres of pasture
northwest of Laguna Lake; treatment level B. (Figure 3-8)
Capital costs for these alternatives range form $2 .9 million to $9.1
million with unit costs per acre foot of water ranging form $322 to $1200
per acre foot. (Table 3-4)
An evaluation matrix based on six weighted criteria was used in rating the
different alternatives. Though there is some subjectivity to this process
it does provide a framework for development of a consensus on the
alternative projects. The criteria used involved financial
considerations, savings on potable water, operation and maintenance
considerations (noncost) , construction impacts, environmental benefits an
ease of implementation. Table 4-1 shows the matrix evaluation. Based on
the evaluation, irrigation alternative 2 and stream enhancement projects
are the highest rated alternatives.
* RECOMMENDATION
The recommendations are summarized into three areas, irrigation, stream
enhancement, and request for Regional Board action.
A. Irrigation
1. Select as a "base project", Alternate 2 in the draft
reclamation/beneficial use report.
2. Select additional project components to be included in recommended
plan (focus on Caltrans and on "greenbelt area west of highway) .
3 . Determine whether additional treatment is desired to be able to use
the reclaimed water for close-public-contact irrigation applications
such as parks. (A final decision can be deferred, but if it is
considered, the impact on financing should be addressed early. )
4. Develop a strategy to (1) implement reclamation in conjunction with
development in the area, (2) finance construction of the project, and
(3) obtain revenues for the project.
B. Stream Enhancement
1. Develop an agreement-in-principle with Mr. David Pereira to
implement a stream enhancement project on his property. This should
include (1) a description of the proposed project, including one or
more typical cross sections and a plan view of the project; (2) a
description of the time frame over which the project will be
conducted; (3) a description of the short-term (construction and
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Wastewater Management Plan
page 4
establishment of vegetation) and long-term (maintenance)
responsibilities of each party; and (4) a description of access
rights and responsibilities. The agreement should also acknowledge
the potential impact of regulatory agencies on the project, including
the agreed-upon elements cited above.
2. Approach regulatory agencies for input and required permits.
These are likely to include (1) the California Department of Fish and
Game, (2) the Regional Water Quality Control Board, and (3) the
California Department of Health Services. Flood control authorities
may also become involved.
3. Once permitting requirements are identified, develop a formal
agreement between the City and Mr. David Pereira to implement the
project. Revise and refine the agreement elements as necessary and
appropriate.
C. Request for Regional Board Action
1. Direct staff to submit the findings of Council's review and
request the Regional Water Quality Control Board for a modification t
the City waste discharge requirements.
2. Also Request the Regional Water Quality Control Board to support
and submit the City's request for a change in its waste discharge
requirements to the State Board, the Environmental Protection Agency
and any other body necessary for their approval.
Approvals:
ity A inistrative Officer
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City Ati<: rney
Attachments
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