HomeMy WebLinkAboutMINUTES - 10271998 - C68 TO: BOARD OF SUPERVISORS COl1tC
5
FROM: DENNIS M. BARRY, AICD Costa'
COMMUNITY DEVELOPMENT DIRECTOR County
DATE: OCTOBER 27, 1908
SUBJECT: REPORT ON CONTRA COSTA WATER DISTRICT GRANT REQUEST FOR FUNDS
TO ADDRESS IMPACTS OF RUNOFF INTO ROCK SLOUGH
SPECIFIC REQUEST(S) OR RECOMMENDATION(S) & BACKGROUND AND JUSTIFICATION
RECOMMENDATIONS
AUTHORIZE the Chair to sign a letter from the Board of Supervisors to the State
Water Resources Control Board in support of a grant application submitted by the
Contra Costa Water District for planning funds to ameliorate the water quality
impacts of local runoff near the District's drinking water intake at Rock Slough.
FISCAL IMPACT
None.
BACKGRO ND/REASONS FOR RECOMMENDATIONS
The Contra Costa Water District ("CCWD") has applied to the State Water
Resources Control Board ("SWRCB") for a grant to fund the "Rock Slough
Watershed Management Project". The specific grant program from which funds
were requested is the Delta Tributary Watershed Program, a component of
Proposition 204 which was approved by the voters in 1996. The intent of the Dock
Slough project is to provide additional monitoring to pinpoint and quantify local
sources of salt and other contaminants into bock Slough and to develop a feasibility
study of options for ameliorating this water quality problem. Agricultural runoff from
Veale Tract is currently believed to be a major local source of salt runoff. CCWD
has requested a grant in the amount of $200,000.
CONTINUED ON ATTACHMENT: _XL YES SIGNATURE .
-- -R RECOMMENDATION OF CMNTY ADMINISTRATOR _ RECOMMENDATION OF BOARft CIOMMITTEE
APPROVE OTHER
SIGNATURE(S):
ACTION OF BOARD ON trtoba; 27, i99a APPROVED AS RECOMMENDED X__ OTHER
VOTE OF SUPERVISORS
I HEREBY CERTIFY'THAT THIS IS A TRUE
UNANIMOUS (ABSENT AND CORRECT COPY OF AN ACTION TAKEN
AYES: NOES: AND ENTERED ON THE MINUTES OF THE
ABSENT: ABSTAIN: BOARD OF SUPERVISORS ON THE DATE
SHOWN.
Contact: John Kopchik, CDD (925-335-1227) ATTESTED October 27, 1998
cc: Community Development Department (CDD} PHIL BATCHELOR, CLERK OF
County Administrator THE BOARD OF SUPERVISORS
Agricultural Commissioner AND COUNTY ADMINISTRATOR
BY , DEPUTY
j.lkopctrocksigh.bo
Report on CCWD Grant Application to Address Runoff to Rock Stough
October 27, 1998
Page 2
The grant application submitted by CCWD identifies four potential methods for addressing
the water quality impacts of local runoff which it expects to consider in the feasibility study.
These four method's are. 1) relocating discharges to nearby water bodies other than Rock
Slough; 2)changing the timing of discharges; 3)treating discharges; and 4) isolating the
CCWD intake from discharges by constructing a flow barrier. CCWD has notified local
landowners of the grant request. The monitoring and feasibility project will involve the
voluntary participation of property owners in the Rock Slough watershed.
CCWD supplies drinking water, both treated and untreated, to approximately 400,000
people in Contra Costa County. A significant portion of this water is diverted at Rock
Slough. Reducing salts and other contaminants in the CCWD drinking water supply is an
important long-term undertaking, and a number of very large efforts: have been and
continue to be made to address this issue, including construction of the Los Vaqueros
Reservoir-and advocacy of increased freshwater flows through the Delta. Improvement of
local sources of contamination constitutes an additional means to address drinking water
quality which may offer significant and cost-effective benefits.
Attachments: 1) Draft letter of support
2) Grant application submitted by CCWD
JAikopcVocksigh,bo
AUG-18-96 TUE 06:27 PM CCWD WATER RESOURCES FAX NO, 510 688 8142 P. 02
PROJECT APPLICATION TO THE .
STATE WATER RESOURCES CONTROL BOARD
SAPS,CLEAN RELIABLE WATER SUPPLY ACT(PROPOSITION 204)
DELTA TRIBUTARY WATERSHED PROGRAM(DELTA PROGRAM)
COVER PAGE
APPLICANT: Contra Costa Water District
ADDRESS: 1331 Concord Avenue,P.O.Box H2O,
California,CA 94524.2099
PROJECT DIRECTOR: Walter J.Bishop, General Manager
Telephone: (925)688.8117
PROJECT TITLE: Rock Slough Watershed Management Project
APPLICANT ELIGIBILITY:
Local Public Agency not represented by County Government pursuant to Section 3'.a.(l)(b). The
Contra Costa Water District(CCWD)contacted Contra Costa County(County)to discuss the
Rock Slough Watershed Management Project. The County and CCWD agreed that the County
would not apply for funds under this program and that CCWD should do so instead and tape the
lead for the project. A letter from the County is included with this application as Attachment 1.
PROJECT ELIGIBILITY:
The Rock Slough watershed is located in Contra Costa County within the statutory Delta defined
in Water Code See. 12200. The intake to the Contra Costa Canal(Canal),which is located at the
western end of Rock Slough,is the source of drinking water for CCWD.Thera is a net flow toward
the intake when the Canal pumping plants are operating;as such,the Reck Slough watershed,for
the purpose of this application,is defined as the arca draining into Rock Slough between Old River
and the first Canal pumping plant near Highway 4 in Oakley. The entire watershed falls within the
Delta Program area described in Section 3.b.(l)of the Request for Proposals(RPP).
The bock Slough Watershed Management Project is eligible for funding under requirement
3.b.(2)(a)of this program because the primary objective of the project is to ttduce contaminants in
the CCWD raw water supply. CCWD provides drinking water to a total population of
approximately 400,000,partly through its own treatment plants and partly by supplying raw water
to the Diablo Water District(serving Oakley),the Southern California Water Company(serving
.Bay Point)and the cities of Antioch,Pittsburg,and Martinez.
t
AUG-18-98 TUE 06:28 PM CCWD WATER RESOURCES FAX NO, 510 686 8142 P. 03,._
This project will involve voluntary participation of property owners in the Rock Slough watershed,
We have received verbal approval and have requested letters of support for the project.
FISCAL SUMMARY:
Total Delta Program Funds Requested $200,000
The Budget Summary Sheet(page 3)provides a breakdown of costs into the categories required
by the State Water Resources Control Board(SWRCB), This cost is for(1)water,quality
monitoring to pinpoint the sources and magnitudes of contaminant loading and(2)consultant
assistance in preparing a feasibility study to identify and quantify the costs and benefits of
mitigation alternatives. Administrative costs and personnel costs from CCWD will not be
charged to the project.
SUNMAR"Y PROJECT D:RSCRIMON:
Background
The Rock Slough intake to the Contra Costa Canal is located in the west-central Delta in the
vicinity of Ktightsen in eastern Contra Costa County. The land surrounding Rock Slough is
primarily agricultural. Peaces in Rock Slough salinity are typically caused by seawater intrusion
from the San Francisco Bay during periods of low Delta outflow,or by agriculturaldrainage
discharges from the Delta and San Joaquin River. Agricultural drainage during wet winters can
lead to significant increases in the concentrations of dissolved solids,total organic carbon(TQC),
and possibly pathogens,in CCWD's drinking water supply from Rock Slough and at other urban
drinking water intakes in the Delta.
Additional Monitoring
To pinpoint and quantify the sources of salt and other contaminants into Rock Slough and the
Canal,simultaneous measurements along a number of locations(up to twelve)between Pumping
Plant No. 1 and the junction with Old River are planned for the late fall/winter of 1998-99. The
first set of measurements will obtain EC and other water quality.parameters at 1-hour intervals
over a one week period. Subsequent sampling will focus on the locations where significant water
quality degradation is observed.
E= ility Study
The major portion of the requested funding will be used for consultant services to analyze the
feasibility of various options to reduce the impacts of agricultural drainage on CCWD's water
supply. The alternatives would be screened for potential water quality improvements and
environmental,economic,and other impacts. Alternatives may include,but are not limited to:
(1)relocation,(2)changing timing of discharge,(3)treatment,and(4)isolation of intake to
Contra Costa Canal from drait&ge source.
2
AUG-16-98 TUE 08:29 PM CCWD WATER RESOURCES FAX NO. 510 688 8142 P. 04.
BUDGET SUMMARY SHEET
S'L'ATE WATER RESOURCES CONTROL BOARD
DELTA TRIBUTARY WATIERSHED PROGRAM
AGENCY: Contra Costa Water District
Total funds
requested
A. Personnel Services
B. Operating Expenses 20,000
C. Property Aquisitions
- Equipment
- Furniture
- Portable assets
- Electronic data.,processing equip.
- Miscellaneous,other
D. Professional and Consulting Services 180,000
E. Construction Expenses
F. Administration
TOTAL BUDGET 200,040
Motes:
Operating expenses are for rental of water quality monitoring equipment.
Professional and Consulting Services are for the feasibility study.
3
A11C-18-98 TUE 06:29 Ptd CCWO WATER RESOURCES FAX NO, 514 688 8142 P105
PROJECT APPLICATION
I. Project Name: Rock Slough Watershed Management Project
2. Lead Agency: Contra Costa Water District
Address: 1331 Concord Avenue
P.O.Box H2O
Concord,CA 94524-2099
Project Director: Walter J.Bishop Phone: (925)688-8117
3. Project Description:
Background
High salinity at CCWD's Delta intakes is due to sea water and/or agricultural drainage. Whereas
high salinity caused by sea water intrusion can be reduced only by costly measures such as
increasing Delta outflow or major changes in Delta channels,salinity impacts due to agricultural
drainage can be mitigated to a significant extent by pretreatment or by relocating those discharges
that have the greatest impacts on CCWD.
Salinity duo to agricultural drainage can be distinguished from that due to sea water by the
different relationship between its electrical conductivity(SSC)and chloride(or the concentrations
of other dissolved solids). Agricultural drainage at interior Delta stations such as Rock Slough
can also be identified when the salinity at an interior station is higher than that at more seaward
stations(e.g. at Jersey Point).
The major sources of agricultural drainage reaching CCWD's intakes are farmlands on Delta
islands and in the watershed of San Joaquin River. The salinity of these drainage varies
considerably,both seasonally and geographically. Typically,discharges from Delta islands have
the highest salinity when the fields are leached in winter months. Salinity in the San Joaquin
River decreases as the flow increases.
Most of the agricultural drainage discharges are well mixed in the channel water by the time they
reach CCWD's intakes,and only a small fraction of the agricultural drainage from distant sources
is actually diverted at CCWD's intakes. Results from numerical simulations suggest that distant
sources of agricultural drainage constitute a few percent in CCWD's water supply. However,a
number of discharges in the immediate vicinity of CCWD's Rock Slough intake have a major
influence on the quality of CCWD's water supply,leading to significant increases in salinity and
other contaminants. Mitigation of these sources could lead to substantial improvements in
CCWD's water quality.
The following description of the water quality impacts of agricultural drainage on CCWD's
drinking water supply provides the basis for the Rock Slough Watershed Management Project
(RSWMP)which is described below.
4
AUG-18-98 TUE 06:30 PSS CCWD WATER RESOURCES FAX NO. 510 688 8142 P, 06
Drainage Impact
The Flock Slough intake to the Canal is located in the west-central Delta in the vicinity of
Knightsen in eastern Contra Costa County. The land surrounding Rock Slough is primarily
agricultural. Water levels in Rock Slough are subject to tidal variations,and a typical daily
Yt2NWl' is ro
about 3.5 if:.et. -i ouk SSLUugn salinity is high when there is seawater intrusion from
San Pablo Bay during periods of tow Delta outflow,or when agricultural drainage discharges
from the Delta and the San Joaquin River are high(in Muth volume and salinity,typically during
leaching in wet periods when Delta outflow is high). Seawater intrusion typically occurs during
the summer months in dry years and fall months in most years. Local drainage has historically
increased the salinity at the intake by up to 130 mg/L chloride,clone to the 150 mg/L chloride
objective in the May 1995 Water Quality Control Plan for the Bay-Delta. The main impact of
agricultural drainage is to increase dissolved solids,TOC,and possibly pathogens at the intake.
Dispersion of the discharge is dominated by two processes governing the flow in Rock Slough
and the Canal. Tidal effects induce an oscillatory flow which carries a portion of the Veal*Tract
discharge into Indian Slough and Sandmound Slough. At the same time,CCWD's diversion
induces a mean flow in Rock Slough towards the Contra Costa Canal and carries the rest of the
Veale Tract discharge to CCWD`s intake. At times of high CCWD diversion.a major portion of
the Veale Tract drainage is drawn into the+Canal. However,this drainage is diluted by the time it
reaches Pumping Plant No.I at the Canal.
Two measurements of the water quality of the drainage from Veale Tract are available. The total
dissolved solids concentration was 2,160 mg/L in a December 1981 grab sample and 3,560 ingiL
in a January 1982 sample, The January 1982 measurement also showed a chloride concentration
of 1,014 mg/L and sodium concentration of 770 mg/L. This volume of drainage is not known,
but even a limited discharge(e.g. 5 million-gallons-per-day)can lead to a substantial increase in
chloride in CCWD`s water supply.
A number of rapid and sharp increases in chloride at Pumping Plant No.t at times of relatively
good water quality in the Delta have boon attributed to agricultural drainage into Rock Slough.
For example,chloride concentration at Pumping Plant No. 1 increased from 57 mg&on January
12, 1981 to 105 mg/L on January 15 when that in Old River at Holland Tract remained in the
307s. Simultaneous measurements on January 20, 1982 showed that the chloride concentration
increased from 27 mg/L in Old River at Holland Tract to 91 mg/L in Rock Slough near the
Sandmound Slough junction,to 131 mg1L,at Pumping Plant No.I-
More recent measurements are shown in Figure 1 for the calendar years 1995-97. Mean daily
electrical conductivity(BC)at Pumping Plant No. i is compared to those at Old River at Bacon
Island(near Santa Pe Railway Cut)and Holland Tract(near the junction of Sand Mound Slough
and Piper Slough). The two latter stations give an estimate of the salinity in hock Slough at Old
River. In all four years of record,EC at Pumping Plant No.1 was higher than that in Old River in
the winter.months. The periods of maximum salinity difference correlated with periods of high
precipitation,when the farmlands in the Delta are usually leached and discharge high salinity
return.flows Tato Dolts channels.
s
AUG-18-98 TUE 06:31 PM CCWD WATER RESOURCES FAX NO, 510 688 8142 P. 07
Figure 1. Salinity increase along Rock Slough and Contra Costa
Canal
1.50
1.25 Puniphg Plant No. 1
/�(� -- - -0�i(�,River
ya,�t Bacon Island
r 1.00 ....... Rolland Tract
0.75
fry
0.30 f '
f
• _ at
0.25j'n tw ',
t yyCC
w .t v rrti.f � .Alta r'
0.00
95 96 97 98
Calendar Year
Nate. Rock Slough pumping Is small In November and December of 1997.
Water quality data on the Veale Tract drainage suggest that the discharge can increase chloride
concentration at the intake by tons of mg/L. For example,if 5 MCD(7.7 cfs)was being
discharged from Veale Tract with a chloride concentration of 750 mg/L and most of the .
discharge reached the intake,and if CCWD was diverting at 100 MGD(155 cis)from Rack
Slough which had a salinity of 50 mg/L chloride,the chlorides in Rock Slough would increase to
85 mg/L,an increase of 35 mg/L. The actual drainage from Veale Tract could be much higher.
Finck Slough Wa=hed Management P'roiect
Task 1. Additional Monitoring
To identify and quantify the sources of salt load into Rock Slough and the Canal,simultaneous
measurements along a number of locations(up to twelve)between Pumping Plant No. 1 and the
junction with Old River are planned for the late fall/winter of 1998-99. The first set of
measurements would obtain EC and possibly other water quality parameters at 15-minute
intervals over one week. Based on there results,additional sampling will be performed. The
additional sampling will probably be limited to grab samples to test for contaminants and their
sources.
6
AUG-18-98 TUE 06:32 PM CCWD WATER RESOURCES FAX N0, 610 688 8142 P. 08
Recent monitoring by CCWD indicates that additional monitoring will yield interpretable results
and provide essential information for the feasibility study.
Task 2: Feasibility Study
Based on the findings of the monitoring program,CCWD proposes to conduct a feasibility study
to develop and-evaluate options to reduce the impacts of agrioultural discharge. The purpose of
the feasibility study is to define a comprehensive list of alternatives from which a preferred
solution can be chosen. The types of alternatives will include but not be limited to the following:
a) Relocation
The discharge from Veale Tract into Rock Slough could be relocated to several places,such as
Sand Found dough north of the one-way gates,No Name Cut(actual name)at the southern end
of Veale Tract,or Marsh Creek below the discharge location of the Brentwood wastewater
treatment plant. Issues to be considered include impacts on agricultural and other beneficial uses
adjacent to Rock Slough,including Holland Tract and Hotchkiss Tract.
b) Changing riming of Discharges
Modification of discharge configuration and/or timing the discharge of the drainage from Veale
Tract could reduce the impacts to drinking water quality. This could be achieved,e.g.,by
storing drainage water on Veale Tract and only discharging during the ebb tide(from west to
east). Issues to be considered include the need for storage and CCWD's pumping,which usually
causes the flow in this stretch of Rock Slough to not reverse on the ebb tide.
c) Treatment
Drainage from Veale Tract could be collected and conveyed to an urban wastewater treatment
facility. The nearest treatment plants are the Brentwood Wastewater Treatment Plant and the
henhouse Sanitary District facility in Oakley. The,drainage could also be discharged into
existing or created wetlands areas,which would remove some constituents before tilt water is
discharged into Delta channels, Issues to be addressed include the high cost of treatment and the
availability of land for constructed wetlands.
d) Isolation of Intake to Contra Costa Canal from Drainage Source
(ane potential project is a one-way flow barrier(west to east only)to be constructed at the Delta
Road Bridge which could cause water to be drawn into Rock Slough from Sandmound Slough,
i.e.,in the reverse direction of the existing tidal flap gate. Issues to be addressed include impacts
on navigation,recreation,and other beneficial uses.
7
AUG--18--98 TUE 06:33 PM CCWD WATER RESOURCES FAX NO. 510 688 8142 P. 09
Task 3. Stakeholder Involvement
A Watershed Stakeholder Group will be formed consisting of local property owners and others
interested in the watershed. CCWD will horst workshops to provide technical information on the
project and a forum for group members to discuss the options investigated in the feasibility study.
CCWD has successfully included stakeholder involvement in several significant projects,
including the Los Vaqueros Project,the Future Water Supply Study,the Los Vaqueros
Recreation Program.and the Facility Reserve Charge development.
4. Cooperating Agencies.
CCWD is in contact with various agencies about this project. However,there are no formal
agreements at this time.
5. Map
A snap of the project area is included with this application as Attachment 2.
G. Phased.Project
This project is a phased project. The first phase,the water quality monitoring program designed
to determine the sources of contaminants in Rock Slough, has been started by CCWD. The
second phase consists of a feasibility study for various alternative mitigation measures.
7. Schedule
4/99-Complete Phase 1 Monitoring
5/99-Complete RFP for Consultant Services
12/99-Complete Feasibility Study
8. Other Resource Management Plans
There are no existing Cather resource management plans in the area. Previous studies include the
But Knightsen Drainage Study of 1985,CCWD's Sanitary Survey for the Canal(1997)and
CC';'WD's Canal Drainage Study(1998).
9. Actions Accomplished to Date
Monitoring of water quality has been performed by CCWD,DWR,and the Bureau over many
years. Intensive monitoring of Rock Slough was carried out on various occasions in 1998. tither
existing water quality data have been collected,processed,and analyzed.
8
AUG-18--98 TUE 06:33 PM CCWD WATER RESOURCES FAX NO. 510 688 8142 P. 10..
10. Educational dement
A Watershed Stakeholder Group will be formed consisting of local property owners and others
interested in the watershed to address drainage and flooding issues. One of the purposes for the
Watershed Stakeholder Group to be formed is to educate property owners about the project. The
formation and work of the Watershed Stakeholders Group will be according to the"Principles of
Watershed Community Involvement".
11. 'Volunteer Monitoring Element
Although not planned as part of the project,voluntary monitoring may result from the initiative
of the Watershed Stakeholder Group.
12. NPDES Permlt Requirements
An NpDES permit is not required for this project and this project is not conducted to fulfill the
requirements of an NPDES permit.
13. Milestones
The following milestones have been identified for this project
• Completion of Monitoring(ongoing)
• Formation of Watershed Stakeholder Group
• Completion of Feasibility Study
14. Commitments to Complete Project
CCWD has existing placeholders in its 10-year Capital Improvement Plan(CIP)for projects
which may be recommended by the consultant conducting the feasibility study. The feasibility
study is scheduled for completion in December of 1999 in order to allow identified projects to be
included in the updated CIP and the FY01/02 budget. Federal and state funding(as provided for
in the Clean Water Act and the Safe Drinking Water Act)will also be sought for part of the
funding for the implementation phase.
Rock Slough is a major source of drinking water for approximately 400,000 people. Old River
was recently developed as an alternative source as part of the Los Vaqueros project.' Old River
does not replace lock Slough. The use of Old River instead of hock Slough actually intensifies
the impact of drainage from the hack Slough watershed because,in the absence of pumping,
tidal flushing is very inefficient in diluting drainage inflow or carrying it out into the Bay.
CCWD and other drinking water agencies will be faced with meeting even more stringent
drinking water standards in the near future. The quality of the supply must be improved to meet
those standards. Watershed management has the potential to improve water quality at a
9
AUG--18-98 TUE 08:34 PM CCWD WATER RESOURCES FAX NO, 510 888 8142 P. 11
substantially lower cost than developing new supplies or adding advanced treatment. CoND is
committed to this project for the long-term.
15. Anticipated Future Work and Commitments
It is anticipated that this project will identify projects that will improve water quality in Rock
Slough. The implementation of these project will be the responsibility of CCWD CCWD has
committed substantial resources to this effort and will continue to seek supplementary funding
from other sources.
Attachment 1: better from County
Attachment 2: Project Map
10
AU.G-18-98 TUE 06.35 PM CCWD WATER RESOURCES FAX NO, 510 688 8142
P. 13
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October 27, 1998
Ms. Jean Ladyman
Division of Water Quality
State Water Resources Control Board
P.O. Box 944213
Sacramento,CA 042442130
Re: Grant Application from the Contra Costa Water District
Dear Ms. Ladyman:
The Contra.Costa County Board of Supervisors has authorized this letter to convey our support for
a grant application submitted by the Contra Costa Water District to the Delta Tributary Watershed
Program for$200,000 to fund the"Rock Slough Watershed Management Program." The intent of
the Rock Slough project is to provide additional monitoring to pinpoint and quantify local sources
of salt and other contamination, and to develop a feasibility study of options for ameliorating this
water quality problem. Contra Costa Water District supplies drinking water, both treated and
untreated, to approximately 400,000 people in Contra Costa County. Reducing salts and other
contaminants in this drinking water supply is an important long-term undertaking,and funding of
this project to develop a plan for reducing local sources of contamination is an excellent opportunity
to provide significant,cost-effective benefits to drinking water supplies in Contra Costa County.
Thank you for your consideration of this matter. Should you have any questions on this letter,
please feel free to contact John Kopchik in our Community Development Department at(925) 335-
1227.
Sincerely,
Jim Rogers, Chair
Contra Costa County Board of Supervisors
cc: Walter Bishop, CCWD
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