HomeMy WebLinkAbout11/05/1991, 3 - ENVIRONMENTAL IMPACT REPORT (EIR) FOR STENNER CANYON WATER TREATMENT PLAN UPGRADE MEETING DATE
m��i I�IIIII��Pn � U city of San LUIS OBISPO -
COUNCIL AGENDA REPORT ITEM NUMBER
b '
FROM: Arnold B. Jonas, Community Development Director
PREPARED BY: Glen Matteson, Associate Planner
SUBJECT: Environmental Impact Report (EIR) for Stenner
Canyon Water Treatment Plan Upgrade
CAO RECOMMENDATION
Adopt a resolution to certify the. final EIR.
DISCUSSION
Before approving a project which may significantly affect the
environment, the Council must complete environmental review. An
initial study on this project, to improve effectiveness and
expand capacity at the City's primary water treatment plant in
Stenner Canyon, found that energy consumption could be
significant, especially in combination with other approved and
proposed City utility projects.
In May 1991, Council approved consultant services to prepare an
EIR focused on energy consumption. The draft EIR was published
in July, and the public review period ended September 16. No
comments were received from the general public or from 'State
agencies. Comments were received from the County Air Pollution
Control District and from the City's Public Works Director. None
of the comments concerned energy usage or significant, new
environmental issues. Responses to comments have been prepared.
The EIR concludes that the upgraded plant will use additional
energy (mainly electricity) , to treat the same amount of water as
the current plant, equivalent to the usage of about 400
households. Staff is recommending that Council determine that
this increased energy usage will not be significant, considering
overall energy consumption in the City (which contains about
17 , 000 households and many other energy users) . The EIR
recommends mitigation measures which will make existing and
proposed treatment plant features as efficient as any new water
treatment plant in the State producing an equivalent water
quality. Separately, cost-effective energy efficiency
improvements recommended in the 1989 Newcomb-Anderson audit of
other City facilities are being pursued by the energy
conservation coordinator in the Public Works Department. While
these other measures will help contain City energy usage, they
are not considered mitigation for the proposed project since they
would be undertaken anyway.
Water conservation is perhaps the most effective energy
conservation measure for both water treatment and wastewater
treatment activities.
3-1
��� �1111111�P ��d�N crty of san ' s oaispo
i COUNCIL AGENDA REPORT
FISCAL IMPACTS
An energy audit of the existing water treatment plant, conducted
to help prepare the EIR, identified 40 conservation measures with
modest initial costs, which would save about $28, 500 annually.
Any features that would reduce operating costs, but which would
substantially increase the construction cost of the upgrade, will
be evaluated when Council is asked to approve plans and
specifications. None are anticipated.
ALTERNATIVES
The Council may make findings or require mitigation measures
other than those identified in the draft resolution. The Council
may continue action'.
RECOMMENDATION
Adopt a resolution certifying the draft EIR, comments, and
responses as adequate for a final EIR.
ATTACHMENTS
Draft resolution certifying EIR
Comments and responses
ENCLOSED
Draft EIR
gmD: STNREIR.WP
3-�
RESOLUTION NO. (1991 SERIES)
A RESOLUTION OF THE SAN LUIS OBISPO CITY COUNCIL
CERTIFYING THE ENVIRONMENTAL IMPACT REPORT FOR
THE WATER TREATMENT PLANT UPGRAD4 (ER 34-90)
The Council of the City of San Luis Obispo resolves as follows:
Findings ,
1. The City has published and made available for public review
a Draft Environmental Impact Report (EIR) for the proposed
upgrade of its water treatment plant, in accordance with the
California Environmental Quality Act and the City's
Environmental Impact Procedures and Guidelines.
2 . On November 12 , 1991, the City Council conducted a public
hearing on the EIR.
Actions
1. The Council certifies that the EIR is adequate, provided
that it includes the comments, responses, and additional
information concerning mitigation and monitoring fully
contained in the attached Exhibit A. A Final EIR
incorporating Exhibit A is to be published within 60 days,
and will be made available to any responsible agency.
2 . The Council determines that there will .be no significant,
adverse impacts, since increased energy consumption will be
mitigated to an insignificant level.
•
On motion of seconded by ,
and on the following roll call vote:
AYES:
NOES:
ABSENT:
the foregoing resolution was passed and adopted this
day of , 1991.
Mayor
ATTEST:
City Clerk
3-3
Resolution No. (1991 Series)
Water treatment EIR
.Page 2
APPROVED:
City A inistrative Officer
r
t tt,c �(n�e
Community De pment Director
gmD: eir-res.wp
•
Exhibit A
STENNER CANYON WATER TREATMENT PLANT EIR
COMMENTS AND RESPONSES
Following are summaries of comments received, and responses. Numbers. key to
topics in the following correspondence.
San Luis Obispo County Air Pollution Control District (APCD)
1. More information and an APCD permit will be required for a diesel-powered
peaking generator.
Response: Use of an on-site diesel-powered generator to replace utility-
provided electricity could reduce the City's electricity bills, but not
energy consumption. It is not recommended mitigation, though
the city may decide to pursue it. If the City pursues this option,
additional environmental review will occur and APCD permitting
procedures will be followed.
A diesel generator will be provided for emergency power only. It
will be able to supply chemical feed systems (other than ozone
generation), but not full plant operation. Except for tests to
assure its readiness, it would be run only when utility power fails..
2. Air pollution from construction equipment, particularly grading, should be
addressed through conditions on building permits for this project. •
Response: There will be no expansion or recontouring of the site, which was
graded for the original treatment plant construction. However, there will be
excavation and minor fill for building foundations:
Ozone generator building - cut 700 cubic yards, fill 30 cubic yards;
Ozone contact basins - cut 950 cubic yards, fill 70 cubic yards.
Construction equipment likely to be used includes skip loaders, dump trucks,
back hoes, concrete-mix trucks and concrete pumpers, and compressors for
various pneumatic equipment. When the duration of use of this equipment is
known, that information will be provided to the APCD for any required review
prior to construction.
3. If population growth enabled by the increase in treatment capacity exceeds the
projections in the Clean Air Plan, air quality impacts of additional induced
growth should be evaluated.
3-5
Water Treatment EIR - Response to Comments 2
Response: The adopted general plan's build-out capacity is about 53,000
people. The nine percent additional capacity enabled by the
treatment plant expansion would lead to a total service capacity of
about 57,800 people. This capacity would be reached sometime
between 2015 and 2020, if water supply and other. resources are
adequate. The Clean Air Plan (June 1991 draft) contains two
population projection series for San Luis Obispo. The lower
series shows a population of 57,465 in the year 2015 and 60,657
in 2020. Therefore, the general plan and water treatment
capacities are within the Clean Air Plan growth projections, and
no further analysis of air quality impacts due to population growth
is required for this project.
4. Address the fate of the ozone not vented to the destruction unit.
Response: The ozone contact basin will have several features to contain the
ozone gas and to minimize the amount of dissolved ozone in
water leaving the contact basin.
A. The contact basin will be fully covered. It will be
maintained at a negative pressure, so any leak would result
in atmospheric air flowing into the basin, rather ozone-rich
air flowing out.
B. After ozone has been introduced to the water, it will flow
slowly through enclosed cells where there is no further
ozonation, to allow the ozone (which is unstable in water)
to decompose.
C. Before the water leaves the contact-basin system, it will
flow over a weir to remove most of any remaining ozone.
According to Black & Veatch, the engineering firm designing the
plant upgrade, "Our experience indicates that facilities designed
with these features will operate with very low ozone residuals in
the water exiting the basin and [concentrations will] comply with
air quality regulations."
David F. Romero. Public Works Director
5. The executive summary should clearly state that the plant's capacity is 11-5
mgd, following the 1977 upgrade.
Response: Noted.
3-tC2
Water Treatment EIR - Response to Comments 5
Other energy conservation and water conservation measures which the City is pursuing
will mitigate energy usage, though they are not listed as mitigation for this project.
Monitoring
Implementation of the mitigation measures will be monitored by the City's Energy
Conservation Coordinator, assisted by the City's Water Division Manager, as
construction drawings and specifications for the project are prepared and presented
for City Council approval.
3 . 9
Yec\3
AIR POLLUTICuJ CONTROL DISTRICiL
COUNTY OF SAN LUIS OBISPO
2156 SIEBBA WAY,SUITE B—SAN LUIS OBISPO,CAI.immu 93401 —(805) 549-5912
5 September 1991
SEP 2 31991
Mr. Glenn Matteson, Associate Planner C"y a,San Vu's oms•-
Community Development Department
City of San Luis Obispo
P.O. Box 8100
San Luis Obispo, CA 93403-8100
SUBJECT: Draft Environmental Impact Report (EIR) for the Stenner
Canyon Water Treatment Plan Upgrade
Dear Mr. urtogos on;
The District has reviewed the information contained in the Draft EIR for
the above-mentioned project. The City of San Luis Obispo is proposing to
upgrade the Stenner Canyon Water Treatment Plant to provide an ozone-based
process in place of the traditional chlorine-based process in order to
meet present and future water quality regulations for a capacity of 16
million gallons per day (16 mgd) .
In general, the Focused EIR provides a good discussion of the impacts of
the increased energy use resulting from the Stenner Canyon Water Treatment
Plant and its upgrade. The following comments pertain to sections which
the District feels should be expanded further:
1. Section D - Mitigation Measures, Potential Measures in Design and
Operation (Page 18) : The section discussing identification of
potential energy conservation measures includes the recommendation to
study the option of having a diesel-generator operate as a
peak-shaving generator.
In evaluating the air quality impacts associated with the use of a
diesel generator, it is necessary to determine the size of the
generator needed (horsepower rating) , and extent of use
(hours/day) . In addition, this generator (and other equipment
installed at this facility) may be subject to District permitting
requirements . The City should contact the APCD Engineering
Department for further information regarding the permitting
process.
2. Section F - Unavoidable Adverse Impacts (Page 21) : Short-term
unavoidable impacts occur as a result of construction traffic and
activities; however, it is believed that these potential impacts are
minor.
3"/0
reevnetl oaoer
G. Matteson
. DEIR for Stenner Canyon Water Treatment Plant
Page 2
The District has been designated a nonattainment area for the state
ozone standard and is required to reduce emissions of nonattainment
pollutants (or their precursors) by at least 58 per year until the
standards are achieved. State law requires that emissions of
nonattainment pollutants countywide will have to be decreased by at
least 408 from the 1987 levels in order to meet clean air
standards.
Pursuant to state law, the District has developed guidelines for
air quality impacts from project construction (see attached) . In
O accordance with those guidelines, it will be necessary for the City
to provide a construction and grading plan identifying the proposed
amount of cut and fill required for the project, proposed grading
equipment to be used and duration of use. That information should
be provided to the District when it becomes available so that APCD
construction mitigations may be included as conditions on the
building permits.
3. Section I - Growth Inducing Impacts (Page 24) : 'The existing water
treatment facility was designed to treat a maximum of 8 mgd. Due to
modifications, it has been able to treat up to 11.5 mgd at a lower
quality of treatment. The upgraded facility will have the capacity
to treat 16 mgd at a relatively high quality of treatment.
This increase will not automatically lead to additional growth. The
added capacity will raise one of the thresholds which could constrain
growth.
The correction sheet to the initial study (dated 7-26-91) indicates
that the proposed project would establish a treatment capacity
level approximately 98 higher than is needed for build-out of the
City's adopted General Plan. If the population projections in the
General Plan are consistent with those presented in the District's
O 1991 Clean Air Plan (CAP) , then the air quality considerations are
adequately addressed. However, if treatment capacity and the
resultant growth projections exceed that presented in the CAP, the
potential air quality impacts associated with growth inducement
should be evaluated further.
4. Additional Information: In the letter from David Dixon dated January
8, 1991 a concern was raised regarding the proposed system's ability
Oto release greater than 0.09 ppm ozone to the atmosphere. A
�- suggestion to redesign the system in order to vent less ozone to the
atmosphere was also made. Please address the fate of the ozone not
vented to the destruction unit.
3-ll
G. Matteson
DEIR for Stenner Canyon Water Treatment Plant
Page 3
We appreciate the opportunity to provide input into this project. Please
contact the District at (805) 549-5912 if you have any questions
concerning these comments.
Respectfully,
LARRY R. ALLEN
Senior Air Qu ity Specialist
DIANA GOULD
Air Quality Specialist, Planning
cc: D. Dixon, APCD
eir/dsg91/90228c.doc
enc. (1)
3-/Z
AIR POLLUTI N CONTROL DISTRICT
C0UNW OF SAN LUIS OBISPO _.
2156 SmexA WAY,SUrn B -SAN LUIS OBISPO.CALIFORNIA 93401 -(805) 549-5912
MITIGATION GUIDELINES FOR AIR QUALITY IMPACTS FROM CONSTRUCTION
Heavy construction generates dust and combustion emissions that may have
substantial temporary impacts on local air quality. Building and road
construction are the prevalent construction categories with the highest
emissions potential. Emissions during the construction of buildings and roads
are associated with land clearing, blasting, ground excavation, cut and fill
operations, and the construction of the particular facility itself. Emissions
vary substantially from day to day depending on the level of activity, the
specific type of operation and, for dust, t$e prevailing weather conditions. A
large portion of fugitive dust emissions result from equipment traffic over
temporary roads at the construction site.
Calculation of emissions from construction activities should include peak hour,
daily and total construction phase emissions of nitrogen oxides (NOx) , reactive
organic gases (ROG) , sulfur dioxide (SO2) , carbon monoxide (CO) and fine
particulate matter (PM10) . Sources of emissions primarily include heavy-duty
mobile construction equipment, non-vehicular equipment such as compressors and
portable generators, and fugitive dust. The appropriate emission factors for
off-highway mobile construction equipment (such as bulldozers, scrapers, etc.)
and non-vehicular equipment (such as generators) are contained in the federal
Environmental Protection Agency publication, Compilation of Air Pollutant
Emission Factors. AP-42 (latest edition) . Tables II-7.1 and II-7.2 in volume
II of that document list the AP-42 emission factors for construction vehicles.
Those tables are provided at the end of this document for your convenience.
In calculating emissions from construction equipment, it is important to use
the most accurate equipment scenarios possible, including estimates of the
number and type of equipment that may be operating simultaneously. If that
information is not available , however, it is possible to estimate emissions
wirholit knowing the specific cquipment that will used. Although each project
will vary, an average of 0. 27 gallons of diesel fuel are burned for each cubic
yard of earth moved. Based on that estimate, the following emissions rates
would apply:
TABLE 1
DIESEL CONSTRUCTION EQUIPMENT EMISSION RATES
(Grams Per Cubic Yard of Material Moved)
Pollutant G/Cu, Yd.
Particulate 2,6
CO 11.2
ROG 5.6
NOx 42.9
Sox 4,9
PM10 1.2 tons/acre of construction
activity per month
-1- 3-/3 �
(SOURCE: Bay Area AQMD: Guidelines for Assessing Impacts of Projects and Plans
- November 1985. )
MITIGATION THRESHOLDS
Mitigation of construction activities is required when the following emission
thresholds are equalled or exceeded:
1. ROG or NOx
- Greater than 185 lbs/day requires BACT.
- 2.5 - 6.0 tons/quarter requires BACT.
- Over 6.0 tons/quarter requires BACT plus further mitigations, including
emission offsets.
2. PM10
- 2.5 tons/quarter requires mitigation
Using emission estimates from Table 1 and the mitigation thresholds identified
above, the following table shows the approximate level of construction activity
that would require mitigation for each pollutant of concern:
TABLE 2
ROG EMISSIONS AMT. MATERIAL MOVED
TONS/OTR. LBS DAY CU. YDS. /OTR, CU, YDS. /DAY
2.5 185 405,080 15,000
6.0 972,776
NOx EMISSIONS AMT. MATERIAL MOVED
TONS/OTR, LBS/DAY CU. YDS. /OTR. CU. YDS./DAY
2.5 185 52,884 1950
6.0 126,984
PM10 EMISSIONS
Any project with a grading area greater than 2.0 acres will generate 2. 5
tons of PM10 per quarter and will thus require PM10 mitigation
measures
(All calculations assume working conditions of 8 hours per day, 5 days per
week, for a total of 65 days per quarter. )
NOx emissions will Ve the controlling factor in determining the application of
control strategies for combustion-related emissions. In the absence of
project-specific emission calculations, any project requiring grading of>1950
cubic yards/day or ;iP50,000 cubic yards within a three-month period will need to
apply BACT combustion controls. Projects requiring X125,000 cubic yards of
grading in a three month period will need to apply BACT plus offsets and/or
other mitigation. Applicable mitigation measures are defined- below.
23-��
NOx AND ROG MITIGATION MEASURES
The following measures are considered Best Available Control Technology (SACT)
for construction equipment:
1. Use of Caterpillar prechamber diesel engines (or equivalent) together with
proper maintenance and operation to reduce emissions of oxides of nitrogen
(NOx) .
2. Electrify equipment where feasible.
3. Maintain equipment in tune per manufacturer's specifications, except as
required in condition 5.
4. Install catalytic converters on gasoline-powered equipment.
5. Implement engine timing retard (four degrees) for diesel-powered
equipment.
6. Substitute gasoline-powered for diesel-powered equipment, where feasible.
PM-10 MITIGATION MEASURES
1. Reduce the amount of the disturbed area.
2. Use of water trucks or sprinkler systems in sufficient quantities to
prevent airborne dust from leaving the site. Increased watering frequency
would be required whenever wind speeds exceed 15 mph.
3. All dirt stock-pile areas should be sprayed daily as needed.
4. Permanent dust control measures identified in the approved project
revegetation and landscape plans should be implemented as soon as possible
following completion of any soil disturbing activities.
5. Exposed ground areas that are planned to be reworked at dates greater than
one month after initial grading should be sora with a fast-germinating
native grass seed and watered until vegetation is established.
6 . All disturbed soil areas not subject to revegetation should be stabilized
using approved chemical soil binders, jute netting, or other methods
approved in advance by the APCD.
7. All roadways, driveways, sidewalks, etc. to be paved should be completed
as soon as possible. In addition, building pads should be laid as soon as
possible after grading unless seeding or soil binders are used.
8. Vehicle speed for all construction vehicles shall not exceed 25 mph on any
unpaved surface at the construction site..
-3-
3-15
ACTIVITY MANAGEMENT TL_rfNIOUES
1. Development of a comprehensive construction activity management plan
designed to minimize the amount of large construction equipment operating
during any given time period.
2. Scheduling of construction truck trips during non-peak hours to reduce
peak hour emissions.
3. Limiting the length of the construction work-day period, if necessary.
4. Phasing of construction activities , if appropriate.
®eir®dsg®cetsum
dsg®lra 1-4-91
-4-
3-1�
Table 11 -7 . 3 r-miss:on Factors Cor Heavy-Duty . Diesel -Powered
Construction Equipment° it
Emission Factor Rating: C
Track-type wheeled wheeled Motor
roloutant tractor tractor dozer° Scraperrq ader
CARBON MONOXIDE
o/hr 157.01 1622 . 77 568. 19 68 .46
lb/hr 0.346 3. 59 1. 257 0. 151
9/kWh 2.88 9.84 3 . 28 2 .06
g/hphr - _2. 15 7 . 34 2 .45 1.54
kg/103 liter 9.4 32 . 19 10. 16 6.55
lb/103 qal 78.5 268.5 1. 84. 6 54.65
EXHAUST HYDROCARBONS
g/hr 55.06 85.26 128. 15 18.07
lb/hr 0. 121 0. 188 0. 282 0.040
g/kWh 1.01 2.36 0. 74 0.48
g/hphr 0.75 1.76 0. 55 0. 36
k.g/103 liter 3.31 7 .74 2. 28 1.53
lb/103 qal 27.6 64.6 19.0 12.73
NITROGEN OXIDES
(NO, as N01 )
g/hr 570.70 575.84 1740.74 324 .43
lbihr 1. 26 1.269 . 3 . 840 0.713
9/kWh 10.47 15.96 10.00 9. 57
g/hphr 7.81 11.91 7 .46 7 . 14
kg%ld liter 34.16 52.35 30.99 30.41
lb/103 qal 28A .92 436.67 258. 6 253.84
ALDEHYDES
(RCHO as HCHO)
g/hr 12 .4 13. 5 29.5 65. 5. 54
lb/hr 0.027 0.030 0.065 0. 143 0.012
g/kWh 0.228 0. 378 0.215 0. 375 0. 162
g/hphr 0. 170 0. 282 0. 160 0. 280 0. 121
kg/103 liter 0.745 1. 23 0.690 1 . 16 0. 517
1b%103 aal 6 . 22_ 10. 3 5.76 9. 69 4 . 31
SULFUR OXIDES
(SC. as SO,
(;/'r,. 62 . 3 30. 9 158. 210 . 39 .0
1b/`.; 0. 137 0.090 0. 348 0.463 0.056
g 'vWh 1 . 1; 1. 14 l. It. 1 . 21 1 . 17
a/".;hr 0.851 0. 351 0.817 0. 901 0. 874
lir.c- 3 .'3 3 . 73 3 . 7; 3 . 74 3 . 73
31 :.1 31 . 1 31 . 2 31. 2 31. 1
_ - -----
50.7 131 . 5 75. 184 . 27 . 7
0. 112 0. 136 0. 165 0.406 0.061
0. 928 1 . 70 0 . 551 1 . 06 0 . 83E
y,...:.nhr 0 . ;;2 1 . 27 0 . 411 0. 789 0. o25
,.) • : i'.?: 3 .03 5. 57 1 . 77 3 . 27 2 . 66
25. 3 b... 5. _...14 .8 27 . 3 22 _2 .
-.efe: h YC/CO,4O. emissions , and
eCe en: 1 arc _' Cc: SSiOnS.
-he - !.,-lied in the
nff
II-7-4 ��/
Table II-7. 1 ( C'd) Emission Factors for He -Duty
Diesel-Powered
Construction Equipmenta
Emission Factor Rating: C
Off-
Wheeled Tracktype Highway Miscel-
Pollutant loader loader truck° Roller laneous
CARBON MONOXIDE
g/hr 259.58. 91. 15 816.81 137.97 306.37
lb/hr 0.572 0.201 1.794 0. 304 0:675
9/kWh 3.63 3.03 4.70 _8.08 6. 16
g/hphr 1 2.711 2.26 --- 2.28- - 6.034.60_
kg/10 liter 14.73 22.64 18.41
lb/103 gal 98_66 82.85 123.46 188.37 153. 51
EXHAUST HYDROCARBONS
9/hr 113.17 44.55 86.84 30.58 69. 35
lb/hr 0.25 0.098 0.192 0.067 0. 152
9/kWh _ 1.59 1.49 0.50 1.30 1.35
gAphr 0.97 1.11 0..37_- _ 0..97 1.01_
g-71-003 (ite 5.17 4.85 1.58 3.60 4.04
lb/103 qal 43.16 40. 55 13.16 30.09 33.70
NITROGEN OXIDES
(N0: as NOz)
g/hr 858.19 375. 22 1889.16 392.90 767. 30
lb/hr 1.89 0. 827 4.166 0.862 1.691
g/kWh 11.81 12.46_ 10_92-_17.49
9/hphr - - - 8.81 _ 9. 30 8.15_____ 13_05 11.0.1 .
kq/10� liter 38.5 40.78 34.29 48.49 44. 10
lb/10' qal 321.23 339. 82 286.10 404 . 51 368.01
ALDEHYDES
(RCHO as HCHO)
g/hr 18.8 4.00 51.0 7.43 13.9
lb/hr 0.041 0.009 0. 112 0.016 0.031
9/kWh 0.264 0. 134 0:295 0. 263 0. 272
9/hphr 0.197 0. 100 0.220 0. 196 0. 203
kg/103 liter 0.859 0.439 0.928 0.731 0.813
lb/10' qal 7.17 3.66 7 .74 6. 10 6.78
SULFUR OXIDES
(SO. as SOz)
g/hr 82.5 34.4 206. 30.5 64 .7
lb/hr 0.182 0.076 0.454 0.067 0. 143
g/kWh 1...1,5 1. 14 1.19 _ ._ _ 1. 34 1. 2r.
q/h hr_ 0.857 __ . 0.,853 0.887. .. .__._1_0.0...-.....-.0..9.32-
kg 0 liter 3.74 3.74 3.74 3.73 3 .73
lb/10' cal 31.2 31. 2 31.2 31. 1 31 . 1
PARTICULATE
9/hr 77.9 26.4 116. 22 .7 63 . 2
lb/hr 0.172 0. 058 0.256 0.050 0. 139
9/kWh _--. 1.08 0. 878 0.673 1.04 1 . 21
/hphr 0.805 0. 6550.502 0. 778 0.902
_ -- - - -
kg/10' liter 3.51 2. 88 2. 12 2.90 •3 .61
lb/10'ga1 29. 3 24 . 0 17.7 24. 2 30. 1
a References 3 and 4 for the HC/CO/NO, emissions and
references 1 and 2 for other emissions.
The off-highway truck category incudes HC/CO/NO„
emissions fron,-the wheeled dozer.
11-7-5 3-/S
Table II -7 . . fission Factors for Heavy-Dut; gasoline-Powered
Construction Equipment°
Emission Factor Rating: C
Wheeled Motor Wheeled Miscel-
Pollutant tractorrq ader loader Roller laneous
CARBON MONOXIDE
9/hr 4320. 5490. 7060. 6080. 7720.
lb/hr 9.52 12 . 1 15.6 13 .4 17 .0
g/kWh 190. 251. 219. 271 . 2.66.
g/hphr 142. 187 . 163. 202 198.
kq/10' liter 389. 469. 435. 460. 475.
lb/10' gal 3250. 3910. 3630. 3840. 3960.
EXHAUST HYDROCARBONS
g/hr 164. 186. 241. 277 . 254.
lb/hr 0.362 0.410 0.531 0.611 0. 560
q/kWh 7.16 8.48 7.46 12 .40 8.70
g/hphr 5.34 6. 32 5.56 9. 25 6.49
kg/10' liter 14.6 15.8 14. 9 21. 1 15. 6
lb/10' gal 122. 132. 124. 176. 130.
EVAPORATIVE
HYDROCARBONS°
9/hr 30.9 30.0 29.7 28.2 25.4
lb/hr 0.0681 0. 0661 0.0655 0.0622 0.0560
CRANKCASE
HYDROCARBONS°
g/hr 32.6 37 . 1 48.2 55.5 50.7
lb/hr 0.0719 0.0818 0.106 0. 122 0. 112
NITROGEN OXIDES
(NO. as NO2 )
g/hr 195. 145. 235. 164 . 187 .
lb/hr 0.430 0. 320 0.518 0. 362 0.412
g/kWh 8. 54 6. 57 7 .27 7.08 6.48
g/hphr 6.37 4 . 90 5.42 5. 28 4 .79
kg/10' liter 17 .5 12 . 2 14 . 5 12.0 11 . 5
lb/10' qal 146. 102__ 121._ 100. 95. 8
ALDEHYDES
(RCHO as HCHO)
g/hr 7 .97 8 . 80 9.65 7 . 57 9.00
lb/hr 0.0176 0.0194 0.0213 O.C167 0.0198
0.0198
g/kAh 0. 341 0 . 386 0. 298 0. 34"s• 0. 298
g/hphr 0. 254 0. 288 0. 222 0. 256 0. 222
kg/10' liter 0.697 0.721 0.593 0. 582 0. 532
lb/10' gal 5. 82 6. 02 4 .95 _ 4 . 86 4 .44
SULFUR OXIDES
(sox as SO2 )
g/hr 7 .03 7 . 59 10.6 8. 38 10. 6
lb/hr 0.0155 0.0167 0.0234 0.0185 0. 0234
g/kWh 0. 304 0 . 341 0. 319 0. 373 0. 354
g/hphr 0. 227 0. 25; 0. 239 0.. 278 0. 264
kg/10' liter 0.623 0. 636 O. 536 0. 633 0 . 633
lb/101 gal 5.20 _5 . 31 5. 31 5. 28 _ 5. 28
11_7_6 3_�9
����������►�iifl��illllllllillllli@11°""°►i III
city osAn tuis oBispo
Noffimm
955 Morro Street • San Luis Obispo, CA 93401
August 5, 1991
MEMORANDUM
TO: Glen Matteson, Community Development Department
FROM: David F. Romero, Public Works Director
SUBJECT: Stenner Canyon EIR
Although I have no involvement in the proposed modification and
expansion of the Water Treatment Plant, I am quite familiar with
the history. I submit the following suggestions for changes in
the EIR.
Executive Summary, first paragraph
I believe it should be made clear in the executive summary that
Othe 1977 upgrade to the plant provided a treatment capacity of
11. 5 MGD. This was made clear in the body of the report but not
corrected in the executive summary.
In the initial study of environmental impact, there was a two
paragraph correction made to a discussion regarding population
growth. I question a couple of statements within both the
initial study and the correction. I do not believe that water
treatment is really a bonafide "threshold which now constrains
growth" . Our current process treats something in the magnitude
of 8 MGD, with an 11.5 MGD treatment capacity for emergency or
peak periods. Under current operations, this does not constrain
growth in any way. In addition, it is relatively easy to
increase the capacity should this be seen as a constraint on
growth.
The second paragraph of both the initial study and the correction
imply that as of the year 2015 the City will be built out and
growth will cease. Can anyone really believe that 2015 is a
Omagic year when growth would or could be stopped? I believe that
7 year is just a planning year to give us direction for upgrading
City facilities. In actuality the proposed expansion of the
Water Treatment facilities will probably be in operation in 1993 ,
thus giving only a 22 year increment for this improvement. This
is a relatively short service period for a major plant upgrade. '
c: Bill Hetland
growth/dfrr#31 3-zO
STATE OF CALIFORNIA PETE WILSON, Governor
GOVERNOR'S OFFICE OF PLANNING AND RESEARCH
1400 TENTH STREET '
"'CRAMENTO,CA 95814
Sep 16, 1991 $EQ 1 9199►
o1 San Lu+s OVE-"
GLEN MATTESON -
CITY OF SAN LUIS OBISPO
990 PALM STREET (BOX 8100)
SAN LUIS OBISPO, CA 93403-8100
. Subject: STENNER CANYON WATER TREATMENT PLANT UPGRADE
SCH # 91081011
Dear GLEN MATTESON:
The State Clearinghouse submitted the above named environmental
document to selected state agencies for review. The review period is
closed and none of the state agencies have comments. This letter
acknowledges that you have complied with the State Clearinghouse review
requirements for draft environmental documents, pursuant to. the
California Environmental Quality Act.
Please call Tom Loftus at (916) 445-0613 if you have
any questions regarding the environmental review process: When
contacting the Clearinghouse in this matter, please use the eight-digit
State Clearinghouse number so that we may respond promptly.
Sincerely,
David C. Nunenkamp
Deputy Director, Permit Assistance
Notice of Completion Appendix F}fadto:SlaneClwnaghouse•1400TcooSueaL memo•C4 95814 916/445-0613ProJeetTltlos 5ternzr Can on Water fitment Plant Upgrade SCH:03:�
Lead AleocY: City of San Luis Obispo Cont�Pe. , Glen t4atteson
Seen Addrar 990 Palm Street (PO lox 8100) Phone 805 549-7165
Gtr: San i 'e n�icgo 93403-8100
Zip: County-
-----------------------------------------
ounty. can � iiie Obispo
PrejeotLoeadps
--— ------------------------------
County. -San I'li c Q i Dc
Cuy/Nso Commmtity San Luis Obispo
Cross steeera: Hi Chway 1 and Stenner Canyon Road
.averse's Patcel No. Tout Ate: n.a.
Section: 10 Top, 30S Range 12E Base:MOSM
Widbm'.M,ls Sum Hwy S.- 1 Waoesaye Stenner Creek
Ate¢ ^-a- SPTCO
Rdr Schools: a O y
NOp
CEO&- ❑❑8017 Cons ❑s ay, NEPA: ❑NOI OtherC]EDl(Prior SCH Nos ❑Joint Doamenn
aDDs�Dec ❑ O Drat EM O oNvFinal DR+mtnu
❑FONSi
-----------------------------------------
- --
Local Actloerype - —_— �----------
❑Gena)Roo Updaa ❑Slow,&Plat
r�-General Plum ❑M
r2 C esel Plan E3, 0M. Plan Q � ❑ Anneauum
L Ceao®min Plan 13De
planned Unit rebpmen, ❑use Penns ❑ Redevelopment
[3 Sim Plancontai permit
❑Land Diviemt(Subdivlsba Otho3,,e1l�r.
Panod Map.Trap Map.sea) -'Foe
Davellopeated Types
❑ ReethessuL Univ Acaa _
❑ OQics: S94L=AonW+na Fadi u : Type Yh vn t.-}v a•..m&MGD f 6
❑ COmmeeak s9/►• Acer ❑Trattsporut� Type
Ml,d,neiaL S9ft- Aac F vbveQ ❑ MiRM& Mind
Educ conal E-111,1eyea ❑ Pover. r
ve.77: Retreacmw ❑Wasm Truanent T;P, wen:�
Cl Hazardous Wute:Type
—rl
w.
Projoat[sues olacussood in Doeumeed -------
----
C] A=MwNlsud C]Flood Pldtt/Floodbtg 13 SclsooWU,tivenitia
•�sr'I W ❑Foaest LandrFuv Hamed ❑Septic Spaces 11
WNW Quaa9'
❑ [3Gaob•:'1e_:m - ❑Sawa�1' ❑Ware SWNYremmdraos
12 coa"_Arclsociopol ❑ Afmmsts ❑ Wildlife poiot
❑ �RdAbsoepoes ❑popdau Baloee ❑Solid Waste NO= 0 sadB ❑ WildH[a g .
Eooeomie/loba ❑ ❑ oaicMazodom a Grawth
❑ Aacal ❑ BrR�obn/Parb ❑❑ Veoeuoonottculauon ❑eumWauve Effeeu
*(Other =•/20'•ek V
------
.7
Peraesst Lard llse/ZoMegfGeeerd Plea Use -----------
Public facility
Project Dsoeripwon ---_--- ---
-T-77
�.:
Upgrade treatment process with ozonation and expand cm
m 11.° to 16 million gallons per day, for
capacity fro
the city's main rater treatment plant. I !�I,�t'y �•a t
.EARINC•HOUSE OONTACT: Ruse colllau t
(916) 445-0617 '
8 „ . air sir otT atrr
ATE REVIEW DLGANt Resources Stets/Conaumer Svcs
'
s
:PT REV TO ACEMM �.
ENCY REV TO SCH : 12Bd
�conwr�etlon-&Fish came CA Yuts Hgmt Bd
_ i
X COMPLIANCE t _�
GS R I cO — y
_ t--Vtr Rights
YD/APCDI (Resources,_/ ) _ -&DyR �Re6• VQCB f
n•
Wcalrsnt /��
Roar Co®
State Lands Comm
t• Sen •a• sent b /��n
MEETING AGENDA
DATE w�Z-6-11 ITEM # ,
Draft Environmental Impact Report
on
Stenner Canyon Water Treatment Plant Upgrade
for
City of San Luis Obispo
P.O. Box 8100
San Luis Obispo, California 93403
by
Technical Analysis Corporation
282 Second Street, Third Floor
San Francisco, California 94105
July 25, 1991
List of Acronyms and Abbreviations
B&V . . . . . . . . . . Black and Veatch
BLCC . . . . . . . . . Building Life Cycle Cost
CEQA . . . . . . . . . California Environmental Quality Act
EIR . . . . . . . . . . Environmental Impact Report
ft2 . . . . . . . . . . . square feet
gpm . . . . . . . . . . gallons per minute
kW . . . . . . . . . . . kilowatt
kWh . . . . . . . . . . kilowatt -hour
1 . . . . . . . . . . . . liter
lb . . . . . . . . . . pound
LCC . . . . . . . . . . Life Cycle Cost
mg . . . . . . . . . . . milligram
Mgal . . . . . . . . . . Mega gallons, million gallons
mgd . . . . . . . . . . million gallons per day
MW . . . . . . . . . . Megawatt
PG&E . . . . . . . . . Pacific Gas & Electric
SLO . . . . . . . . . . The City of San Luis Obispo
TAC . . . . . . . . . . Technical Analysis Corporation
Table of Contents
Executive Summary
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Environmental Procedures and Intended Use of the EIR . . . . . . . . . . . . . 1
Initial Study and Focused EIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
A. Project Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1. Upgrades in Equipment and Processes . . . . . . . . . . . . . . . . . . . . . . . 7
2. Fuel Type and End Use . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3. Energy Conservation Equipment and Design . . . . . . . . . . . . . . . . . . . 8
4. Initial and Life Cycle Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
B. Environmental Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
C. Environmental Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
1. Energy Requirements and Efficiencies . . . . . . . . . . . . . . . . . . . . . . 11
2. Local and Regional Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3. Peak and Base Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4. Comparison to Existing Standards . . . . . . . . . . . . . . . . . . . . . . . . 15
5. Effects on Energy Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6. Transportation Energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
D. Mitigation Measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
1. Potential Measures in Design and Operation . . . . . . . . . . . . . . . . . . 17
2. Potential Measures of Siting, Orientation . . . . . . . . . . . . . . . . . . . . 19
3. Potential for Reducing Peak Demand . . . . . . . . . . . . . . . . . . . . . . . 19
4. Alternate Fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5. Recycling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
E. Alternatives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
F. Unavoidable Adverse Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
G. Irreversible Commitment of Resources . . . . . . . . . . . . . . . . . . . . . . . 22
H. Short-term Gains vs. Long-Term Impacts . . . . . . . . . . . . . . . . . . . . . 23
I. Growth Inducing Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
List of Figures
Figure 1 Regional Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Figure 2 Plant Vicinity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Figure 3 Plant Layout and Proposed Changes . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 4 Schematic Flow Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Figure 5 Monthly Water Demand for the City of San Luis Obispo . . . . . . . . . . . . 13
Figure 6 Monthly Energy Usage of the Stenner Canyon Facility . . . . . . . . . . . . . 14
Figure 7 Monthly Energy Cost for the Stenner Canyon Facility . . . . . . . . . . . . . . 14
List of Thbles
Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
List of Attachments
Attachment 1. Initial SWdy of Environmental Im=tt(City of San Luis Obispo, December
1990, Updated January 15, 1991).
Attachment 2. Letter from Ronald E. Henderson, Black & Veatch, to David Dietrich,
Technical Analysis Corporation, dated June 25, 1991, one attachment.
Attachment 3. Life Cycle Cost Program BLCC 3.0 Summary.
Attachment 4. Nomogram for Converting mgd to Acre-Feet per year.
Executive Summar
The City of San Luis Obispo provides water service to businesses, agencies, Cal Poly, and
about 42,000 residents. The existing water treatment plant in Stenner Canyon was built
in 1963 and was designed to treat about eight million gallons per day (8 mgd, equivalent
to about 9,000 acre-ftlyr). At times of peak demand, the plant has treated water at the
rate of up to 11.5 mgd, The City of San Luis
Obispo has proposed to upgrade the facility to provide an ozone-based process in place of
the traditional chlorine-based process in order to meet present and future water quality
regulations for a capacity of sixteen million gallons per day (16 mgd, or about 18,000
acre-ftlyr).
An Initial Study of Environmental Impact on the proposed upgrade to the Stenner Canyon
Water Treatment Plant reviewed sixteen potential impacts of the proposed upgrade and
determined that the only impact to warrant an Environmental Impact Report was the
increased energy use resulting from the upgrade.
Technical Analysis Corporation (TAC) was contracted by the City of San Luis Obispo to
prepare a Focused Environmental Impact Report on the energy use of the water treatment
plant and its proposed upgrade. Because the energy efficiency of the plant is dependent
on the volume of water treated per day, we have evaluated the energy use of both the
existing and the upgraded plant at a specific rate of water treatment. Although the future
supply and demand of water are largely indeterminate, a volume rate of treatment of 8
mgd was chosen as a comparison point because it is very close to the level of pre-drought
water treatment at Stenner Canyon.
At a water treatment rate of 8 mgd, the existing plant consumes approximately 1.2 million
kilowatt hours (kWh) of electricity per year. At that same rate of water treatment, the
upgraded plant is expected to use approximately 3.7 million kWh per year. This is
approximately a 210% increase in energy use.
An average single family residential customer in San Luis Obispo uses about 6,300 kWh
of electricity per year. The increased energy use of the upgraded plant is therefore
equivalent to the electrical usage of about 400 households. The overall energy use of the
upgraded plant will be equivalent to that of about 590 single-family dwellings.
Under contract to San Luis Obispo, Technical Analysis Corporation carried out an energy
audit of the pre-upgrade and post-upgrade facility, and presented recommendations to the
City in a formal report. These recommendations would reduce the energy costs of the
existing plant by about$28,500 per year and would reduce those of the upgraded plant by
a larger amount.
Introduction
Envirommental Procedures and Intended Use of the EIR
The California Environmental Quality Act (CEQA) requires the city to prepare an
environmental impact report (EIR) when it considers an action that could significantly
affect the environment. The purpose of an EIR is to help the parties understand the
consequences of the action, to consider possible alternatives, and to include features that
will nuinhimize harmful effects. Actions of the City of San Luis Obispo that are subject to
this environmental review requirement include approving public projects such as the
Stenner Canyon-water treatment plant upgrade.
Initial Study and Focused EIR
The Initial Study of Environments Impar (City of San Luis Obispo, December 1990,
Updated January .15, 1991, Attachment 1) reviewed sixteen potential impacts. The
conclusions of the Initial Study were that, with the exception of energy/resource use, none
of the issues resulted in significant impacts requiring further evaluation in an EIR.
The initial study described increased energy use as an apparently "significant impact for
which no mitigation is available". To ensure that all practical mitigation measures were
evaluated, the City of San Luis Obispo contracted with Technical Analysis Corporation
for a technical energy audit. The purpose of this audit was to provide mitigation in the
form of energy conservation both at the existing plant and in the design of the upgraded
plant.
The City of San Luis Obispo also contracted with TAC to prepare a focused EIR. This
document was written in strict accordance with the content and format requirements of the
California Environmental Quality Act (CEQA Law and Guidelines, January 1984,
Appendix F). It addresses only that item identified in the Initial Study as requiring further
evaluation, namely, energy/resource use. The report that follows is the Draft EIR which
is open to public comment. Following the t;ompletion of the comment period, TAC will
take all comments into account before revising this report It will then be published as the
Final Environmental Impact Report for the proposed upgrade to the Stenner Canyon Water
Treatment Plant.
1
A. Project Description -
The City of San Luis Obispo proposes to modify treatment processes and capacity at its
existing water treatment plant in Stenner Canyon north of the city. Figure 1 shows the
regional setting and Figure 2 shows the plant vicinity. Figure 3 shows the plant layout
and proposed changes. Figure 4 shows a schematic flow diagram.
The changes are intended to meet anticipated stricter requirements for drinking water
quality.
The plant treats water from Salinas Dam (Santa Margarita Reservoir) and Whale Rock
Reservoir. Salinas Dam can store about 23,300 acre-feet of waterl and provides a safe
annual yield of 4,800 acre-feet. Whale Rock Reservoir can store about 40,660 acre-feet
of water and has a safe annual yield of about 4,400 acre-feet (4 mgd), of which the City
is entitled to 2,057 acre-feet(1.8 mgd). These two sources combined can provide enough
water to supply the needs of 20 to 27 thousand single-family homes. The quality of the
water from the two sources differs, and seasonal variations are also usual. Groundwater
from wells is treated at smaller package units close to the wells and not at the main plant.
The monthly aggregate demand for water is illustrated in Figure 5 (see section C.3).
1 An acre-foot of water would cover one acre to a depth of one foot(about 326,000 gallons). One
acre-foot of water will supply the needs of three to four single-family homes for one year.
2
�o
u
v,
u
0.'
H
0
' c
is
0
a
O
. H
0 o Ju ..
V
e7 a C
U 3 e7
A m
s
e
n
G
c ■
U
C
u
F
011
A ..
� > n
1 o
u
m o
A U
0 0
"q
DID cp
m a m
a s r v
3 m
� u
N
bll
-A
Gy
3
Figure .2 . Plant Vicinity
6 - ir :y__
Oct
/il I ✓ SO ' \ i1 �'•.%. li \M - lio°%+ 797
g,,r 1 /, ... \ rla` ` ( n4 �' 1 `l0 720_ s� li I '�a xex
' (•�i SOI I \ I III I.•e95 1 qq' i Cl lerIt, `
—�'—
-.j01' .a�.. _�:` �.In a� e_,_-' n _D .E ro
ip
n
at
/ ' '.,•l I It '� - 'Opp 7arrks L600
BM599
am
awn• �$� /�\ ��� � ,1�� g� g \ �\` ri�30I1^O -/� ��600/ °
LIF t
e
io I
14 39 EN C ONY I - 1 'k •- 1; -'
•Filtratl�'
Plan
-SM 3d I -r bstatloe
'- .�., - Mlrle,• r .
ice:\ c i• .i _ ) lies.
it
� qp4`• 00 I i^�/l�� � I 466
m \ Q
It
L- 472r\
L '�•r r .� • California State
�Il-• /1-_I��� '�----- t I _`.' 324 _ �' — Polrtechnic College c,.., f:u`y� 0 ■--r,�t
__' "'�- °Alr ort 'a. I \��_`^•
300
C1 __ Wa
Well .ao ° .7a1
302 QD�o ■ ■ `0
22;` \. ,Nat
_1111_1
See 1 r
t°n,sett,_ TCz
1 I. y-
$Y7--%1' � ., rr `: - :r --T Th n 1♦ .I .< stpY
in Ila I J a
`Gravel _ L. c . .. e�r
lI
l `. _ _-..-I i:� _ — r_t •�r F TI%!LL BLVD 6
I U 8 AMO R 'aaBO v� RR rCKS
S a'':Viri 1
.2000 .
'/ -_ _—_—__ •� Santa Rosq. M
\ / k r
1 _ a.....').
28- i Water.,
lank 1,. Il• .l. �I ` :r/
fi�1' -�' -. yr ..•yF,•-•��,f'
-``e. ...` 'ti�-5�:_;- ~r�M1._ y aVF a'.P.j����S'ra^'°A.Fr �.w�a:�P:�L�t'�''',.-'T TJ' .'C.':1'• O
�r v Z•s '`-Y sy.;., .� a�. '� •"�•R.a Jya n � _. �E�' b�� *zw, y •:.
�< a ryv. .dt^F s L� berg .' Z�• Nf
c.7�-
;.r tr_� �xX ��-``.: v1.��..,tl�'�'ra.."h'R. 1, �,�� �� "'t� �R\•I•. "a'`'�`Tt"_ 'T •i�" :i
.y4z• +a fH y: V
� �.n+-y%���" C'�4' �,"�-ti.,��J ,•ya,L:vj.. r � �r��ti" ,• ��{ ���'' �y {:. `�� 'd y
�_i•:i..'r<..c --v.�-�•i+.�.y>y���- �c ,� `h-�,,.r - r.• }y��,•1�4''yC3.1�h
y-sv ... ,...,lif° � �• .M1 •�{l'r�'`�'.' :a` �F
Ar,
VA
S'�:•'�� 4':.'t/�'.-�.:'. Cs��y . _ - .!�-.re's!xY-..?.'.vI
Tom, A3 -.I
fa
...f ?C� (`,c - ~ '. •'?•4:y.rte alb�•�4y"''.'• $4
ME
fd
4-3
va
'��J?'.�.yy,�c 4' `s�urq�•-••��v aha i�..tla i.. P+� _ � �h: '�1r �i
•�,..N ^wTL•^r���. .i
41
a
. y r.'4• 'J' ..W'.l 1 i b
.a,_ f ice. ,Y . : :• O
i..i:_ � •pr ^ � '�4".f,�"�' .a'R - 171
O
_ ' ,�..�.�,r•� •yam ':;m,�.t.t�. ,y
.Eta - _ - t�-..,, ted.�ri� ,•^��.'. 7•.:v�, ..'. pp r. y�+";"cae+ �rvYa' a ' b1
Wit-
- -�by Ev JS�� •� .E.:+-•j .w { ��V r+� �r .„a�2. r�� �1
Ll
� " �: .^E a r -..�}., pc ya..n „S-+�'1"ze 1 . jYl•+�. r �r, ,
[r .,,+� :wee: .,.• .f,' ° `"�t',s'�y a�'r$�i�.oi ria .'rn � s:i v .+s ,'P'?�.
L'. a'��•:t'� '+ 7 �~ ,r'C.°f�,.�.�fv `tea- 'xr 1J 4`T. S �Tegf'a: �'tii'r t.,n;.;
.{ "ail 04. . • �. '.'{` i, l;�i�'F..�J+7-�5.�1"{'-i � l .� f� f vr•�.
O
V O
O 0 O
�i W o
N2
o �
30000
W
8
w
ON
ro
a
3
P4
ro
e
ti � ti z x
b
G4
6�L 2
N ti
0
vi 3
fRQAI SACIIWLS fXOAI Wl'14Lf fnOCX
6
1. Upgrades in Equipment and Processes
Some proposed changes were evaluated in the Environmental Impact Reoort for the Water
Management Element and Water Management Plan (City of San Luis Obispo, February
1987). That EIR concluded that the previously proposed changes would have no impacts
and could be considered "categorically exempt," since they would be changes to an existing
facility with no substantial expansion of capacity. Additional changes are now proposed.
These are:
a. Use ozone rather than chlorine as the primary disinfectant. Equipment
includes ozone generators and an ozone contact basin. (Improve water quality.)
b. Provide a two-story, 7,000-fr building to house the ozone generators, new
chemical feed systems, control room, and additional office space. Eliminate a
smaller existing building.
c. Replace the initial flash mixing facilities with a larger, two-stage facility.
(Improve introduction of chemicals to raw water.)
d. Replace the flocculation equipment in the existing basin. (Improve particle
aggregation and settling.)
e. Replace filter media and repair drains and outflow pipe. (Improve effective-
ness of filters and filter backwashing.)
L Add a tank and pumps. (Reduce the time between backwashing cycles.)
g. Modify equipment and flow path for recycling filter backwash water.
(Improve accessibility, improve water quality.)
h. Use liquid sodium hypochlorite (bleach) rather than chlorine gas for residual
disinfection. (Improves safety on-site and water quality.)
i. Provide standby metering pumps for each of several chemical feed systems.
(Improve reliability.)
j. . Upgrade electrical systems, replacing 208-Volt service with 120- and 480- .
Volt services. (Improve safety, reliability.)
k. Provide new controls for new and existing equipment. (Improve process
control.)
7
1. Remodel the existing laboratory and office. (Improve ability to monitor
performance.)
2. Fuel Type and End Use
Electricity will be virtually the only source of energy during normal operations. An
emergency diesel generator is included to provide for orderly shutdown of the plant in the
case of a loss of off-site power, and will use fuel only during regular maintenance and
testing, or in the event of a power failure. Electrical resistance heating is currently used
for space heating at the plant, but is not allowed-under California code Title 24. Since
natural gas is not available at the site, space heating will be provided by propane fueled
furnaces.
3. Energy Conservation Equipment and Design
The architect/engineering firm of Black & Veatch (B&V) has designed the plant upgrade
under contract to San Luis Obispo. B&V incorporated energy conservation into the design
and described these measures in a letter, Attachment 2, which is summarized here.
Reduced voltage starters are specified for all motors 75 horsepower and larger.
Power factor correction capacitors are specified for all motors 25 horsepower
and larger. High efficiency motors are specified with all equipment in Division
11 of the specification.
Variable Frequency Drives have been specified on six small motors for the
purpose of process control; these will conserve a small amount of energy.
Electrical interlocks are specified to prevent the simultaneous operation of two
service water pumps and of two air backwash blowers.
Lighting has been designed to meet or exceed Title 24. Administrative areas
include a tandem wired system.
The present electrical resistance heating will be replaced by two propane fueled
furnaces (Reznor CRPB400 and Reznor CRPB250), one in each building.
The air preparation system-provides cool, dry air to increase ozone generator
efficiency. Rotary lobe compressors, a type with high efficiency, were specified
8
for the system. Multiple compressors (3 x 50% of capacity)2 were selected to
increase efficiency at partial load.
Ozone contact basins are deep and will have fine bubble diffusers to achieve a
transfer efficiency of 95%.
To destroy ozone not transferred to the water,catalytic units are provided,a more
efficient type than thermal units.
4. Initial and Life Cycle Casts
The initial capital cost of the upgrade, $8,685,000 is taken from the B&V Pilot Plant Study
for Alternative 50B. Energy and power requirements for the plant were based on
assumptions of processing eight million gallons per day, roughly the pre-drought demand
of the city of San Luis Obispo. For 30 years of ozone plant and auxiliaries operation,
from start of construction in 1991, startup in 1993, and operation through 2020, the life
cycle cost (LCC) of the encgy used is calculated to be $3,921,804 (in 1991 dollars).
Nominal amounts were included for maintenance and replacements. Non-ozone opera-
tional costs would be incurred regardless of the upgrade and have been omitted from our
calculations. These calculations were performed with the National Institute of Standards
and Technology code BLCC 3.04,Type 5 Generic LCC without tax analysis as appropriate
for state and local governments. The life cycle cost is thus about $12,463,000 (in 1991
dollars) in total, equivalent to $811,000 annually from 1991 to 2020.
Any 30-year financial calculation, such as the one described above, is subject to significant
assumptions. Assumptions and results are documented in the TAC workpapers, which are
available from Technical Analysis Corporation upon request.
2 Telecon, W. McCullough, B&V, to D.Dietrich, TAC,July 8, 1991.
3 Black&Veatch, City of S „a T n;c Obi=Water Treatment Plant Modifications jnd Ozone Pilot
Stud, Final Report,June 1990,p. 27�
4 Building Life Cycle Cost Program, Version 3.0, U.S. Dept. of Commerce, National Institute of
Standards and Technology, Computing and Applied Mathematics Laboratory, Office of Applied
Economics, Gaithersburg, MD,January 1991.
9
B. Environmental Setting
The environmental setting in this section refers to the existing energy supplies in the San
Luis Obispo region and locality.
The water treatment plant gets its electricity from the PG&E electrical network which
carries approximately 5000 MW of power. This network is supplied by a mixture of
electrical generating stations controlled by PG&E's network dispatcher. The generating
stations that supply the network generate electricity from a variety of sources including
nuclear, natural gas, oil, hydroelectric and geothermal.
The upgrade in the Sterner Canyon water treatment plant will result in an increase in
energy use that will have an insignificant impact on PG&E's electrical network.
10
C. Environmental Impacts
This section discusses the consequences of the plant design and operation in terms of energy
consumption.
1. Energy Requirements and Efficiencies
The following table summarizes the overall power consumption of the proposed Stenner
Canyon ozone-based water treatment plant. The data were provided by Black & Veatch
based on the design that B&V will use to request bids for the equipment to be purchased.
Table 1 Projected Power Consumption and Relevant Information for Upgraded Plant
Demand Half Full Load Type
Load Load
Water Treated (mgd) 8 16 continuous
Ozone (lb/day) 250 500 continuous
Compressors (kW) 41 82 continuous
Generators (kW) 77 154 continuous
Off-Gas Equipment(kW) 3 3 continuous
65 hp Svc Water Pumps 54 54 continuous
150 hp Process Blowers 124 124 intermittent
Max. connected load (kW) 940 arithmetical
Max. plant demand (kW) 840 intermittent
Avg. plant demand (kW) 420 continuous
The proposed interior lighting consists primarily of standard 4 ft. fluorescent lights. The
outdoor lighting consists of high pressure sodium fixtures. Overall the currently specified
lighting will draw approximately 7.8 kW.
11 -
Two air conditioning units are specified in the upgrade (Payne 584ANO30040 and Payne
580BPV0480074), one for each building.
Two furnaces are specified (Reznor CRPB400 and Reznor CRPB250), one for each
building. These are propane fueled.
Currently chlorine is shipped to the plant in loads of 10,000 pounds and used as a
disinfectant. Energy is expended during its collection, compression, storage, and delivery
to SLO. This hidden energy use is approximately 1.42 kWh per pound of chlorine or
about 321 kWh per day(at 8 mgd treatment). The upgraded plant,by using ozone produced
on site instead of importing chlorine, avoids these indirect energy expenditures.
2. Local and Regional Effects
All electricity is supplied by PG&E; this increase in power demanded will not significantly
affect their operation. There will therefore be no significant local or regional effects in
terms of energy resources.
3. Peak and Base Loads
The existing facility used 1,207,179 kWh on site during the year 1987 to process a volume
of 8,400 acre-feet (about 7.5 mgd). To process that same amount, the upgraded facility
would consume approximately 3,440,000 kWh over the course of one year.
Estimates of average water demand for treated water by the completion of this proposed
upgrade are 8 mgd, dependent on drought forecasts and continued water conservation
estimates. The treatment of this throughput by the upgraded plant would consume an
estimated 3,670,000 kWh yearly.
Figure 5 presents the historical demand for water over the past five years. This period
was selected in order to show the pre-drought demand and the subsequent effects of water
conservation.
Currently average demand is approximately 4 mgd with a peak demand of 4.5 mgd, as
compared to the pre-drought values of 7 mgd and 9.5 mgd respectively. Note that this is
total water demand, which, since July 1989, has been satisfied by filtered and chlorinated
groundwater in addition to treated water from Stenner Canyon.
12
Figure 5 San Luis Obispo Water Demand
u Average MGD by Month
10
9
8
A 7
.A
G6
5
3
2
1
0
1 3 Ili 5 111 3 5 7 9111 3 5i9I''lIl 1 W74 it 1 3
8602 6 8 10 8702 6 8 10 8802 6 8 10 8902 6 8 10 9002 6 8 10 9102
January 1986—March 1991
(YYMM)
Figure 6 (on the following page) presents historical demand for energy over the past five
years. It exhibits a declining trend similar to that of Figure 5. Compare Figure 5 to
Figure 6. The two curves have the same basic shape, but do differ slightly due to fixed
costs such as heating and lighting. Also, the energy consumed by the transfer pumps is
not directly related to the volume of water treated by the plant. The pumps are run at the
discretion of the plant personnel to store treated water and their use accounts for some of
the fluctuation in the historical energy use of the plant.
Figure 7 (on the following page) shows the monthly energy bills of Stenner Canyon for
the past five years. This figure differs from Figure 6 due to differences in seasonal rates
among the various rate schedules used by PG&E.
13
_ 1
1
1
1
1
VA
VW
XX �Am
AOAMA -OA
Amm AAM
:t.
' e. J
�.
AA
1
:i j
' : J
i
Munn
At
AA
1
1
A
•,�. AIM At-
:,
_ J ,t .J i • .iii
:YJ V:
tf ti .'JI J::
_ tI tti t J V
AAA
itt r AAA
1J
fAll A ..
t J. i
A. :. ! y
i ., ;•.
J j.
..t
The preceding data lead to the conclusion that energy conservation is a direct result of
water conservation, due to reduced volumes being treated.
There is a privately owned hydroelectric generator at the inlet to the forebay which sells
PG&E about 100 kW of power. Its direct use by Stenner Canyon as a peak load shaving
measure would have no adverse environmental consequences.
4. Comparison to Existing Standards
The amount of energy expended per million gallons of water treated (1,260 kWh in the
case of the upgraded Stenner Canyon plant) is dependent on the treatment process, on the
amount of pumping necessary to move that gallon to and from the treatment facility (which
is site-specific), and on the quality of incoming, as well as outgoing water(which are both
also site-specific); therefore, any direct comparisons of energy use between different
facilities would be misleading. For this reason we did not compare the energy use of the
Stenner Canyon Water Treatment Plant to other existing facilities.
5. Effects on Energy Resources
The ozone treatment process was chosen as an upgrade for technical reasons of water
quality, rather than for energy efficiency. The large organic load from the Salinas source
(Santa Margarita Lake) makes ozone a choice far superior to chlorine on a public health
basis.
The direct energy consumption figures (at 8 mgd) are as follows; the existing facility has
a ratio of energy use to water processed of 400 kWh/Mgal as compared to 1,260 kWh/Mgal
for the upgraded facility. For a more accurate comparison, though, the hidden energy
costs of the current plant's chemical use (as described in the following section) should be
taken into account, and result in an energy consumption of 439 kWh/Mgal for the current
plant.
15
6. Transportation Energy
The energy consumed processing and transporting the various inputs necessary to effec-
tively run the water treatment plant does not affect the plant's direct energy consumption
(as measured by PG&E), but does in fact affect overall (global) energy consumption; it
therefore warrants closer scrutiny.
Propane must be delivered to the upgraded facility to fuel the two furnaces which replace
the existing electric resistance heating. The furnaces will increase transportation energy
use by necessitating propane deliveries; but, due to their increased efficiency over electric
resistance heating, the furnaces will result in a net energy savings.
Currently chlorine is shipped to the existing plant in loads of 10,000 pounds and used as
a disinfectant. The upgraded plant, by using ozone produced on-site instead of importing
chlorine, avoids about eight deliveries of chlorine per year.
In its current state the plant must have a variety of chemicals(excluding chlorine)delivered
to it; the upgraded facility will need chemicals of a different variety to be delivered, but
in approximately the same quantity. These changes will not significantly affect the energy
expended during the transportation of chemicals.
16
D. Mitigation Measures
1. Potential Measures in Design and Operation
Potential mitigation measures were identified in an energy audit of the existing Stenner
Canyon plant. These are not technically within the scope of the EIR, since they deal with
existing facilities, but are discussed here for the sake of completeness. Thirteen general
and 24 lighting energy conservation measures were recommended for the existing plant.
These include:
• Run transfer pumps in preferred order using most efficient first.
• Run only one transfer pump at a time, especially on peak.
• Maintain finished water level as high as possible to minimize pumping costs.
• Install high efficiency motors immediately on three transfer pumps. (Planned
during upgrade.)
• Reduce size of pump and motor at reservoir #1.
• Reduce size of pump and motor at reservoir #2.
• Specify numerical minimum efficiencies for existing motors to be replaced
during the upgrade.
• Eliminate electrical resistance heating of office areas. (Planned during upgrade.)
• Optimize rate schedules.
• Replace T12 fluorescent lighting with T8 lamps and ballasts in 11 locations.
17
• Install electronic ballasts on existing eight-foot fluorescent lamps in two loca-
tions.
• Replace mercury vapor and incandescent lighting with high pressure sodium in
nine locations.
• Replace incandescent flood lights with halogen floods lamps in two locations.
Potential energy conservation measures have been included in the upgraded design by
Black& Veatch. These were discussed in Section A.3. above and are described in detail
by B&V in Attachment 2.
Potential energy conservation measures were also identified by TAC in its energy audit
for the plant upgrade. Because the design is not completed, these measures are necessarily
less detailed. Most of the recommendations take the form of advising the city to consider
the measures in detail when more information becomes available. The recommendations
are:
Select an operating schedule that gives adequate consideration to on-peak and
off-peak energy and demand charges. If possible, avoid the peak charge periods
from 12:00 noon to 6:00 p.m. on weekdays from May through October.
Consider variable frequency drives on 65-horsepower plant service water pumps
used for ozone process cooling.
Peak demand for water has been reduced from about nine mgd to about 4.5 mgd
during the current drought. Consider some appropriate long-term measures for
water conservation.
Consider operation of diesel-generator as peak-shaving generator. (There are
unknown factors including .availability of natural gas as fuel and air quality
'considerations. The recommendation is to study the concept.)
Operate the existing hydroelectric generator as a peak shaving device. (Unknown
factors include legal status and ownership of the generator, but this would be an
attractive option with no environmental impacts.)
Install T8 fluorescent lamps and electronic ballasts in place of planned T12s in
18
14 applications.
Install PL type fluorescent lamps instead of incandescent lamps in two applica-
tions.
2. Potential Measures of Siting, Orientation
The existing site at Stenner Canyon limits the option of choosing an alternative site. The
existing plant orientation takes advantage of gravity to move water through the treatment
process, and the upgrade maintains this advantage. No other potential measures were
considered.
3. Potential for Reducing Peak Demand
Peak load shaving measures were identified for both the existing plant and for the upgrade
to the plant. These measures are detailed in Section 1 above.
4. Alternate bels
The ozone process requires electricity and there is no alternative. B&V have specified
Number 2 diesel fuel as being necessary for the emergency diesel generator. Propane will
be supplied to furnaces, thus eliminating electrical resistance heating.
S. Recycling
The major opportunity for recycling at the Stenner Canyon site lies with the water used
.for filter backwashing. This water is recovered and treated with the raw water supply
rather than being discharged.
19
E. Alternatives
The decision to change from chlorination to ozonation as the primary disinfection method
for the treatment of water was made for public health reasons. We believe that no
acceptable alternatives to ozone treatment meet the objectives of compliance with the
disinfection requirements of the Safe Drinldng Water Act and the need to reduce the total
amount of Trihalomethanes created by treating the water with chlorine. No alternatives
were considered for purposes of this impact assessment.
20
R Unavoidable Adverse Effects
The upgraded facility, including the use of ozone for water treatment, requires approxi-
mately 210% more electricity than the existing water treatment plant to treat the same
volume of water (8 mgd). By using additional electricity, the project will add to demand
for generation, and may therefore increase air pollution to the extent that fossil fuels are
used by the serving utility, Pacific Gas and Electric. The relationship between this added
demand for electricity and plans for San Luis Obispo's or other air basins cannot be
determined at this time.
There will be minor, short-term impacts to the access routes and to the site itself due to
the construction traffic and activities. These impacts are believed to be short-term and
localized to the immediate access and site areas. The potential impacts are believed to be
minor.
21
G. Irreversible Commitment of Resources
Use of fuel for project construction and use of electricity and chemicals to operate the
upgraded plant will be irreversible. The amounts consumed are believed to be small in
comparison with demands and supplies for such items throughout the state and region.
22
H. Short-term Gains vs. Long-Term Impacts
The primary gains from converting to the ozone treatment of water are reducing potential
public health risks. The long-term impacts of changing to the ozone treatment process are
the potential impacts on air and water quality due to the increase in long-term energy use
for the purpose of ozone generation. These impacts are discussed in detail in this EER and
are not believed to be significant.
There will be a minor short-term impact on the site and the access road to it due to the
construction activities. These impacts are minor when compared to the long-term gains
to the public health from the change to ozone treatment process.
23
I. Growth Inducing Effects
The existing water treatment facility was designed to but a maximum of 8 mgd. Due to
modifications it has been able to treat up to 11.5 mgd at a lower quality of treatment. The
uprgaded facility will have the capacity to treat 16 mgd at a relatively high quality of
treatment.5
This increase will not automatically lead to additional growth. The added capacity will
raise one of the thresholds that could constrain growth. Other constraints include water
availability from reservoirs and ground water, waste water treatment capacity, air quality,
road capacity, and residents' desires for the size and pace of change within the community,
reflected in the general plan and growth management regulations.
5 The 500 lb/day of ozone generation is sufficient for treating 15 mgd at the maximum dose of 4 mg
ozone/liter of water(mg/1). If a lower concentration is required, more water could be treated.
Average is expected to be 3 mg/l and minimum 1.5 mg/l.
24
c
Attachment 1. Initial Study of EnvironmenW Imnact (City of San Luis Obispo, Decem-
ber 1990, Updated January 15, 1991)
MY O� San LUIS OBISp0
�����►I►lillliliil���l������I��I
a INITIAL STUDY OF ENVIRONMENTAL IMPACT
8
SITE LOCATION Stenner Canyon, north of San Lu i s Obispo APPLICATION NO. ER 34-90
PROJECT DESCRIPTION Upgrade the city's water treatment plant and expend tr +mo +
capacity.
APPLICANT City of San Lulc Obispo (Gary Henderson, Itiliti s Fnnineer)
STAFF RECOMMENDATION:
NEGATIVE DECLARATION _MITIGATION INCLUDED
EXPANDED INITIAL STUDY REQUIRED _X ENVIRONMENTAL IMPACT REPORT REQUIRED
PREPARED BY
DATE '17-13-Qn
COMMUNITY DEVELOPMENT DIRECTOR'S ACTION: DATE 17 30
FhV%jt ML Is p
SUMMARY OF INITIAL STUDY FINDINGS
s.DESCRIPTION OF PROJECT AND ENVIRONMENTAL SETTING
11.POTENTIAL IMPACT REVIEW POSSIBLE ADVERSE EFFECTS
A. COMMUNITY PLANS AND GOALS ............. YES*
B. POPULATION DISTRIBUTION AND GROWTH.......................................... YES*
C. LAND USE .....................................
D. TRANSPORTATION AND CIRCULATION .............................................._- YFS*
E. PUBLIC SERVICES ................................................................. nln*
F. UTILITIES............................
.................
G. NOISE LEVELS ..................................... yr-¢*
................
H. GEOLOGIC&SEISMIC HAZARDS&TOPOGRAPHIC MODIFICATIONS .................... nip
I. AIR QUAUTY AND WIND CONDITIONS................................................ yES*
J. SURFACE WATER FLOW AND QUALITY ................................................ NO
K. PLANTLIFE
L. ANIMAL LIFE......................................
M. ARCHAEOLOGICAL/HISTORICAL ................................................... NO
N. AESTHETIC ............................
.......................................... YES*
1. ENERGY/RESOURCEUSE ................. YQS*
................
1'. OT111"I1 ,••I�I II I I
I, '..I f n I Y.. ..I.f!�!.I•r•.'.,
. ... . .. .. . .. .. .................. ........ .. ... . . .... rlul
III.STAFF RECOMMENDATION
'SEE ATTACHED REPORT
seas
Correction to Initial Study
Page 3 - discussion of population growth Change first two paragraphs to read:
The existing plant was designed to treat about 8 million gallons per day (mgd). An upgrade
completed several years ago increased the rated treatment capacity to 11.5 mgd, which has
been approached at times of peak demand. The proposed project would increase the
treatment capacity to 16 mgd. The project would increase one threshold which now
constrains growth. Other growth-limiting resource thresholds are the amount of water
supply (the reason for the current moratorium on projects which increase water use),
wastewater treatment capacity, and air quality. The project would have -no effect on the
amount of water available for treatment: the safe yield of the existing reservoirs, or possible
new sources of water.
Considering peak demand experienced with existing population, and assuming that peak
treatment demands would increase approximately in proportion to city population, the
increased capacity could serve a city population of about 58,000. City population, consistent
with the general plan, is projected to increase from about 42,000 in 1991 to about 53,000
by the year 2015, assuming other resource thresholds are increased. Thus, the proposed
project would establish a treatment capacity level about nine percent higher than needed
for build-out of the adopted general plan. (Additional long-term water conservation would
allow additional development within this limit.) The excess capacity created by the project
is considered a reasonable margin of safety for potential differences in the future
composition of the community under the adopted plan, and is not seen as inducing
substantial growth beyond that allowed by the general plan.
gm
7-26-91
INITIAL ENVIRONMENTAL STUDY 34-90
Water Treatment Plant Upgrade
DESCRIPTION OF PROJECT & SETTING
The City of San Luis Obispo proposes to modify treatment processes at its existing water
treatment plant in Stenner Canyon. The changes are intended to make the treatment
process safer for employees and the public, and to help meet anticipated, stricter
requirements for drinking water quality. The changes will also double the. designed
treatment capacity, from about eight million gallons per day (mgd) to 16 mgd. All the
new facilities would be built within the existing treatment plant site.
The plant treats water from Salinas Reservoir and from Whale Rock Reservoir. The
quality of raw water arriving from the two reservoirs varies substantially throughout the
year, and differs between the two sources. The plant does not treat water from the city's
wells, which is treated in smaller "package plants" close to the wells.
The treatment plant is set into a gradually sloping hillside above Stenner Creek, and is
bordered by the Southern Pacific Railroad and grazing land. The nearest development; .
other than utility structures, is a dwelling about one-third mile to the northwest
Some proposed changes were evaluated in the Environmental Impact Report for the
Water Management Element and Water Management Plan (City of San Luis Obispo,
February 1987). That EIR concluded that the .previously proposed changes would have
no impacts; in fact, they could be considered "categorically exempt," since they would be
changes to an existing facility with no substantial expansion of capacity. Additional
changes are now proposed. They are:
1. Replace the initial ('flash") mixing facilities with a larger, two-stage facility. This
facility introduces chemicals to the incoming, raw water so that contaminating
particles will group together rather than repel each other. The city does not
propose changing the types of chemicals used in this stage.
2. Replace the flocculation equipment, in the existing basin. This step gently mixes
the water, encouraging larger clumps of particle to form so they will settle out
3. Replace filter media and rehabilitate drains and outflow pipes, to improve the
effectiveness of filtering and filter washing.
4. Add a tank and pumps to reduce the time between cycles of filter washing.
5. Make more accessible and modify the equipment which recycles water used to
wash the filters back to earlier treatment steps, to make removal of solids more
^ effective. The changes will help meet state standards for water treatment plants.
Water Treatment Plant Environmental Review 2
6. Use liquid sodium hypochlorite (bleach) rather than chlorine gas for residual
disinfection. Adding chlorine in an active form is the final step before treated
water is sent to storage tanks and distribution pipes throughout the city. The
chlorine inhibits growth of viruses and bacteria which survive the treatment
process or which enter the water system (a concern primarily in dead-end water
mains where water may stay for a long time before being used). The liquid
chemical is safer to store and handle, and far easier to contain if it leaks, than
the pressurized gas.
7. Provide a stand-by metering pump for each of several systems which feed
chemicals into the stream of water undergoing treatment.
8. Upgrade the electrical system, replacing the 208-volt service with 480- and 120-
volt services.
9. Provide new control equipment, which will be compatible with existing equipment
to be retained.
10. Remodel the existing laboratory and office to better provide for monitoring
requirements.
11. Use ozone rather than chlorine as the primary disinfectant, which will require an
ozone generator and a new ozone contact basin at the beginning of the treatment
process.
12. Provide a new building to house the ozone generator, new chemical feed systems,
control room, and additional office space. This building will be two stories, with
about 7,000 square feet of floor space.
POTENTIAL IMPACT REVIEW
A. Community lans andgols
Overall, the project is consistent with community goals.
With the exception of policies concerning energy use, discussed under item "O" below,
the project is consistent with the general plan Water and Wastewater Management
Element. The project raises no issues of consistency with other general plan elements.
B. Population distribution and growth
The project will raise one threshold which now constrains city growth, but this project
alone will not induce growth.
Water Treatment Plant Environmental Review 3
The existing plant was designed to treat about 8 million gallons per day (mgd). At times
of peak demand during summer and fall, it has treated at a rate of about 11 mgd for
short periods, though the'level of treatment was barely adequate. The proposed project
would increase the designed treatment capacity to 16 mgd. The project would increase
one threshold which now constrains growth. Other growth-limiting resource thresholds
are the amount of water supply (reason for the current moratorium on projects which
increase water use), wastewater treatment capacity, and air quality. The project would
have no effect on the amount of water available for treatment: the safe yield of the
existing reservoirs, or possible new sources of water.
Considering peak demand experienced with existing population, and assuming that peak
treatment demands would increase approximately in proportion to city population, the
increased capacity could serve a city population of about 59,000. City population,
consistent with the general plan, is projected to increase from about 42,000 to about
53,000 by the year 2015, assuming other resource thresholds are increased.
Constructing and installing the new facilities will increase construction employment in
the area by.roughly 50 people at a time, for up to one year. Probably, there will be
several specialized contractors working in sequence,.with insignificant impact on
migration to the area.
There are now eight permanent workers for the plant, with one to four on duty per shift.
With completion of the project, there would be nine or ten workers. The number of
additional workers which may be needed when the plant is running at full capacity
sometime in the future, if any, is not known at this time.
D. Transportation and circulation
The project will not significantly affect traffic in the vicinity.
Stenner Canyon Road is a paved county road, which is wide enough to accommodate
one vehicle travelling in each direction, though lanes are not marked. It connects the
site with Highway 1, about one mile to the south, at a "I" intersection with no signal.
(The Highland Drive entry to the Cal Poly campus provides an alternate connection to
Highway 1 at an intersection with signals and turn lanes.) Stenner Canyon Road also
serves a few dwellings in the area, and is a minor entrance to the north end of the Cal
Poly campus. It is lightly travelled.
Traffic from permanent employees at the plant will not change significantly. There may
be slightly less truck traffic for chemical supply, with use of ozone. Construction traffic,
both workers and material trucks, will be a substantialincrease over existing traffic
levels on Stenner Canyon Road, but will not significantly affect Highway 1.
Water Treatment Plant Environmental Review 4
E. Ppblic services
The project will not directly impact other public services. The estimated total capital
cost of about 8.7 million dollars is expected to be funded by water rates and connection
fees, and therefore will not affect the level of funding for other public services.
G. Noise levels
Noise impacts will not be significant.
Construction activity will temporarily increase noise at the plant and along the access
route. Operation of the ozone generator and blowers will cause more noise than current
plant operations, but the increase is not expected to be noticeable along Stenner Canyon
Road, and will not be detected from existing dwellings in the vicinity.
1. Air quality
The project will not significantly impact air quality.
Construction traffic will cause a minor increase in emissions for a few months.
The ozonation process raises air quality issues. Ozone is a highly chemically active form
of oxygen, which lasts about 20 to 30 minutes in the atmosphere before forming other
compounds. In the lower atmosphere, it is a major component of smog, causing
irritation of eyes and lungs, and damage to plants and some synthetic materials. County
air quality is in violation of state ozone standards, which have been exceeded several
times per year in recent years. The draft County Air Quality Attainment and
Maintenance Plan aims for a 40 percent reduction in ozone production from current
levels.
The ozone generation system would have a firm capacity of about 500 pounds per day.
The system would produce air that is about two percent ozone, by weight, which is far
higher than occurs even in smoggy air. This ozone-rich air would be brought into
contact with the water. The ozone generation equipment and pipes would be air tight,
and the chamber where water receives the ozone would be sealed. About 90 percent of
the ozone brought into contact with the water would be transferred to it. The ozone
that is not transferred would be held in an air space at the top of the chamber. The
pressure in the contact chamber would be kept below atmospheric pressure, to prevent
leaks. Air vented from the vacuum blower which provides the lower pressure would
pass through a catalytic converter, where nonhazardous manganese dioxide would
convert the ozone to elemental oxygen
If ozone is detected at 0.01 parts per million (ppm) or more in the ozone generation
building, indicating a leak, the generation system will shut down and the building
Water Treatment Plant Environmental Review 5
ventilation will stop, to contain leaks. A vent gas ozone analyzer will be provided to
assure that discharges stay below 0.10 ppm under all operating conditions.
The San Luis Obispo County Air Pollution Control District staff has conducted a
preliminary review of the proposed ozone system, and has concluded that impacts will
not be significant. However, the volume of air to be vented from the containment area
is not known at this time. A complete review of the discharge will occur when the
design is further refined. At that point, the district may require the city to obtain an
"authority to construct" and a "permit to operate," which would specify any additional
ozone control measures.
N. Aesthetic
The appearance of the plant will not change substantially.
The plant is visible from several hundred feet along the Southern Pacific Railroad
(Amtrak) line on the hillside above, on both approaches to the "horseshoe" curve. A
relatively small part of the plant is visible from Stenner Canyon Road near the plant
access road. The existing multistory building at the plant is visible from 100 to 200 feet
on the northbound lanes of Highway 1, near the Stenner Canyon Road intersection. It
is not visible from the southbound lanes unless one looks back (to the left rear) at that
short segment
Most of the proposed changes will be below ground or in existing structures. The new
building will be in the same area and about the same size as the existing building. No
specific design is proposed at this time.
O. Energy use
The cumulative impact of increasing energy use in city utility projects is significant.
The water treatment plant now uses about 1.6 million kilowatt hours (kwh) per year.
The ozone process will substantially increase electricity usage. Aber the upgrade, the
plant would use about 4.5 million kilowatt hours per year. This additional energy use is
an unavoidable consequence of the ozone process. While there will be a small, but
unknown, reduction in the amount of energy used to produce and transport chlorine, the
reduction would not nearly offset the increase due to ozone production.
The general plan Water and Wastewater Management Element says, "Water operations
will minimize energy use and will incorporate all cost-effective energy production
facilities" (Policy 53). The Energy Conservation Element says, "The city will set an
example for energy conservation and the use of renewable sources in its own facilities
and operations."
* 1-15-91 update: the project will be designed to limit vent gas ozone concentration
to 0.09 ppm or less, in compliance with State ambient standa0d. gm
Water Treatment Plant Environmental Review 6
The engineers who recommend the proposed project concluded, after evaluating six
alternative treatment processes, including pilot plant evaluations, that ozone treatment
was the most desirable due to treatment effectiveness and safety (Water Treatment Plant
Modifications and Ozone•Pilot Study,. Final Report; Black and Veatch, June 1990). Four
of the six alternatives involved ozone at some stage of treatment, while two did not.
The cumulative impact of increasing energy use in city utility systems is significant. In
addition to this proposed project, the recently approved upgrade of the city's wastewater
treatment plant will increase energy use, from about 1.75 million to about 5 million kwh
per year (Final EIR for Wastewater Treatment Plant Upgrade and Sewer Line
Replacement, City of San Luis Obispo, March 1990). That increase was determined to
be significant, adverse, and unavoidable, but justified by the overriding concern of
meeting water quality standards.' Further, the city proposes a seawater desalination
plant at Morro Bay which would use between 19.5 million and 32.6 million kilowatt
hours per year (EIR 45-90, forthcoming). Energy use in the area would be further
increased if the proposed wastewater treatment plant is built in Los Osos (not a city
Project), and if additional water transmission lines are built in connection with the State
Water Project Coastal Branch or other regional water projects.
An average single-family residential customer in San Luis Obispo uses about 6,300 kwh
per year of electricity. The increased electricity usage due to the proposed project is
therefore equivalent to the usage of about 460 households. The combined additional
electricity usage of the three utility projects, 38.7. million kwh per.year, would equal the
usage of about 6,100 households in the San Luis Obispo area.
California Energy Commission policy favors accommodating added electricity demands
of new customers or new uses by increased efficiency in energy use (conservation) of
existing customers. Assuming that the average residential customer can still reduce
electricity usage by 25 percent through more efficient lighting and motors on appliances,
the added usage by the water treatment upgrade would cancel out the savings of about
1,800 households, while the increased usage of all three city utility projects would cancel
out the savings of about 25,000 households.
The secondary effects of increased energy use are major environmental concerns.
Pacific Gas & Electric Company, the utility serving this area, generates electricity from
oil-fired and natural-gas fired plants, hydropower, nuclear, wind, and geothermal (to be
eliminated) sources at many stations throughout central and northern California. At
times, California power demand is met by purchases from out-of-state sources, including
coal-fired plants. The impacts of increased electricity production, depending on power
sources, include: air pollution (including acid-rain and acid-fog contributors); greenhouse
gases; radioactive waste; water pollution from petroleum spills; land disturbance from
mining; inundation of free-flowing streams, forests, and farmland; noise,.appearance, and
bird mortality due to wind generators; and soil or water pollution from geothermal
brine.
Water Treatment Plant Environmental Review 7
The increased energy usage of the proposed project would represent about 0.1 percent
of the 1987 output of Pacific Gas & Electric Company's fossil-fueled Morro Bay power
plant, which was about 3.5 billion kwh (primarily to meet peak demands in other parts
of the state); the three projects' usage combined would be about one percent of that
year's output.
P.P. Public safM
There will be no adverse impacts; hazards will be reduced by the proposed project.
Chlorination has been the conventional means of disinfecting public drinking water,
including San Luis Obispo's. Chlorine (the active component of household bleach) kills
microorganisms. However, it does not remove all tastes and odors from the water. In
fact, in relatively high concentrations, it adds its own taste and odor (as found in
swimming pools, which have. far higher chlorine concentrations than drinking water).
Also, chlorine reacts with some natural or synthetic organic compounds often found in
water to produce trihalomethanes (THMs), a group of compounds which have been
shown to cause cancer. While the city's treated water has met current standards for
THMs on average, there have been occasional, short-term exceedances. Further, the
chlorine treatment methods will not be able to consistently meet new federal standards,
which will allow about one-half the THM concentration which has been allowed, or
potential federal standards which would again reduce by one-half the allowed
concentration.
The ozone system will use an electrical current to produce a stream of air rich in this
chemically active form of oxygen, which will be brought in contact with the water.
Ozonation will remove tastes and odors, as well as avoiding formation of THMs.
Further, it will eliminate the need for pretreatment using both powdered activated
carbon and potassium permanganate, which is a potentially explosive combination.
STAFF RECOMMENDATION
To comply with CEOA, an EIR should be prepared even though it would address only
one issue: energy consumption. The city has already determined that an increase in
electricity usage about the same as that caused by the proposed project is individually
significant. The cumulative energy impact of the three currently proposed major water
and wastewater projects also would be significant. Increased energy use appears to be a
significant impact for which no mitigation is available. No other impacts will be
significant.
�` gm3: ER34.90.WP
M/ N. &—LU1 PO il
AL �U' V. ;iQNI "I 1\(l; ,.(�' :.
. 7� �\1 1 � •� - �a�. �1 \., :.:•.:r: j ar7'i'7:�n\ 1 1'`. 1cr\\.�.- II Lr'
Chi:: },'.rll! „ \\ )111 /
/, 1,..;:
1, .al` 1 I+�.' 1 1 11.1 BM
j 1 , ,-
JI� Q" J(/ j l `I 1 1 ^6 M .. ;v \, i,.,.l lift
797 a
8 r lel ,r{Fl \ 72d , .. I:t•` ' I ( ;.
W,.rBr 'eq1
155 �i ( //• BM 599 ' \', . �. / -,�..l l`'- •\. I i' ! / 1 / .
j m °
�o? 8 //\\ \ \ ., •♦. \I 11.81;`e ` ,� Oryo i'i. / .
BM SIS ��I�I`` .� •ii. ,- .11\ ,j 7�. -1'/ _ __CS �r/, `�\\� '�i (1..
ONY 1 ( i• / / \` �'' �f
-1 .j
C UM.3 '! I -' •bslatio~ =�.\1 ` �. � •' :_J�•. M1r�e� -�\` ', . .I)res, 1'
- . r Q .�. •� / ,1,. .\ \ . ._ 1 ♦V .'/�
lb co /Q '11 /. awe \ _ I' 1 / .-_: ( Ifi ,. I/•l
�\�\'•::: I !I -_•. -� __ 1 ri' I.a
;-16. r_ ,Q6r0'�� \�I g - � :. �6"• ^
1-'� �6p0�.Iti\! �^�~) ,(.'„- -•. \��'��.' ,`` ` 115 \s l'\ .'`-\_', �'I.,..- 1 /+ ,I'li ! � 1 •
f 11 31 W
v
California State
•.,�i�� r�`�I 4' �J`"��_r:` .r ..i. ,r.: \ I . 32a Js; Polytechnic ColleHe .\ -VO, s�.ou •t� �,�•,tiC
1"--7 -T —r^+"—t-- _._%`'; ---- nnl ,lro-
G �;I 1b•,
\. ',r. �� S(jr � � .;,.,, ��._ �(' �•//.. ._. \ `\ � 1 U i D ate` :.eJ��i, :r
_,`�,� ��(, /��•,.•`. 0.: ,'i ,!. F_'ia \) WlII �aa 300 .A t-.13J ♦ °,:' Wale/ `
• �- ::.; .::_ ,. :I` )o7 a I Y ° •Tank
:�),-�1/ �r (_����• L;`i/r�.. 1 C` ` — — 22/ .....:�\1 id_i ui
Nal I\ QSelle
La
I Qn _ ?7B •rpt•. .,t, _--.�.- �- L•t ,'�9, i' - ,.
ll - 1 �. �` �, � :' oaru.Loo Parp o in �t➢a \ ` I
` _`__n — --r }�� Gnrel �;:: ..,--... a .... ! r .""I' •J • 1.
cm
�. --'\ �• iNILL BLVD •�� '.t,_, � 1
` f \� ,` ,\ •r••: "R �t Irl• CD �� FR O GR6 -/Sf
• I � f
.I 600 `•` ( , \♦I 1 ♦ LJ \ uwR 6r .➢
oo / — -�I�: 9 Santa Fosr{. ?
28 �n� I . Wath• �! 1�•_.•-..`� 1�D'_._. .. � ' n // �a�,1�\`.
Attachment 2. Letter from Ronald E. Henderson, Black & Veatch, to David Dietrich,
Technical Analysis Corp., dated June 25, 1991, one attachment.
BLACK & V EATCH
ENGINEERS-ARCHITECTS
2300 CLAYTON ROAD.SUITE 1200
CONCORD.CALIFORNIA 94520-2100
TEL (415) 246-8000
FAX: 14151 674.9458
San Luis Obispo, California B&V Project 17432.200
Mater Treatment Plant Modifications June 25, 1991
Mr. David Dietrich, P.E.
Associate
Technical Analysis Corporation
282 Second Street, Third Floor
San Francisco, CA 94105
Dear Mr. Dietrich:
Enclosed for your use, as requested, is a list of energy conservation
measures that are incorporated into our design.
we are pleased to help expedite the EIR process. If you have any
additional questions or comments, do not hesitate to contact us.
Very truly yours,
BLACK & VEATCH
rRnald E. Henderson, P.E.
Project Engineer
Mit
Enclosure
cc: K. Earing, SLI
G. Henderson, SLO
W. Hetland, SLO
Mal
Black & Veatch
SAN LUIS OBISPO, CALIFORNIA
ENERGY CONSERVATION DESIGN MEASURES
I . Specifications will require high-efficiency motors be supplied for
Division 11 equipment.
2. Electrical interlocks have been provided to prevent the simultaneous
operation of the two service water pumps.
3. Electrical interlocks have been provided to prevent the simultaneous
operation of the two air backwash blowers.
4. Reduced-voltage starters have been provided for all motors
75 horsepower and larger.
5. Adjustable frequency drives have been provided for all variable speed
applications.
6. Power factor correction capacitors have been provided for all motors
25 horsepower and larger that operate continuously.
7. Lighting design in the administrative areas of the ozone building
utilizes a "master/slave" tandem-wired system.
8. Lighting design in the ozone building meets or exceeds the
requirements of California Title 24.
9. Rotary lobe compressors were selected for the ozone generation air
preparation system. The rotary lobe is a very high efficiency unit.
10. Multiple compressors were used in the air preparation system to
increase efficiency during turndown (reduced capacity).
11 . Deep (>20 foot) ozone contact basins with fine bubble diffusers.
This will provide an ozone transfer efficiency of greater than
95 percent.
12. The design incorporates catalytic type ozone destruct .units in lieu
of thermal types. Catalytic units require less power.
13. Ozone air preparation system is designed to provide cool , dry air
which will increase ozone generator efficiency.
L1Oa2
Attachment 3. Life Cycle Cost Program BLCC 3.0 Summary.
BLOC SUMMARY FOR SLO Run 03
----------------------------------------------------------------
PRESENT VALUE ANNUAL VALUE
INITIAL COST (AT OCCUPANCY) $8,273 , 989 $538 , 235
ANNUALLY RECURRING O&M COSTS $135, 130 $8,790
NON-AN. RECURRING O&M COSTS $10,595 $689
ENERGY COSTS $31921,804 $255, 119
REPLACEMENT COSTS $121,205 $7, 885
LESS: REMAINING VALUE ( $0) ( $0)
--------------------------------------------------------- -------
TOTAL LCC $12,462,723 $810,718
[\BLCC San Luis \SLORUN03 .SUM]
Attachment 4. Nomogram for converting mgd to Acre-Feet per year.
r
. n
e �
a
1000
I