HomeMy WebLinkAbout03.a. Review draft Position Paper to approve the Outfall Improvements, Phase 7, District Project 7353, for California Environmental Quality Act (CEQA) and regulatory permitting purposes Page 1 of 7
Item 3.a.
CENTRAL SAN BOARD OF DIRECTORS
POSITION PAPER
DRAFT
MEETING DATE: OCTOBER 29, 2019
SUBJECT: REVIEW DRAFT POSITION PAPER TO APPROVE THE OUTFALL
IMPROVEMENTS, PHASE 7, DISTRICT PROJECT 7353, FOR CALIFORNIA
ENVIRONMENTAL QUALITYACT (CEQA)AND REGULATORY PERMITTING
PURPOSES
SUBMITTED BY: INITIATING DEPARTMENT:
RITA CHENG AND MARK WENSLAWSKI, ENGINEERING AND TECHNICAL SERVICES-
ASSOCIATE ENGINEERS ERC-REGULATORY COMPLIANCE
RUSS LEAVITT, ENGINEERING ASSISTANT III
REVIEWED BY: DANEA GEMMELL, PLANNING AND DEVELOPMENT SERVICES DIVISION
MANAGER
EDGAR J. LOPEZ, CAPITAL PROJECTS DIVISION MANAGER
LORI SCHECTEL, ENVIRONMENTALAND REGULATORY COMPLIANCE
DIVISION MANAGER
JEAN-MARC PETIT, DIRECTOR OF ENGINEERINGAND TECHNICAL
SERVICES
ISSUE
Board approval of the Outfall Improvements, Phase 7, District Project 7353, is required prior to the filing
of a Notice of Exemption under the California Environmental Quality Act Guidelines.
BACKGROUND
The National Pollutant Discharge Elimination System (NPDES) Permit CA0037648, Order No. R2-2017-
0009 (Permit) requires Central Contra Costa Sanitary District (Central San)to properly operate and
maintain its 3.5 mile, 72-inch reinforced concrete outfall pipeline. Every five to ten years, Central San
drains and inspects the outfall pipeline, verifies the alignment and assesses the physical integrity of the
pipe joint seals, and makes any necessary repairs. Central San's NPDES Permit, Attachment F, Section
I I.B states that Central San plans to conduct an outfall inspection and necessary repairs during the current
permit cycle ending in May 2022. During the outfall inspection and repairs, treated effluent is diverted to a
holding basin for discharge to Lower Walnut Creek via the overflow weir structure at the treatment plant in
accordance with permit requirements.
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During normal operation, Central San discharges treated wastewater effluent to Suisun Bay through the
72-inch outfall pipeline. Constructed in 1958, the outfall pipeline runs primarily underground for nearly
19,000 feet and the submarine section of the outfall is about 1,700 feet in length. Above the underground
pipeline, an unvegetated, tidal mudflat extends approximately 1,000 feet from the shoreline edge into the
Suisun Bay. The end of the submarine section of the outfall consists of 11 diffusers and three manhole
access structures that rise above the water surface, which are used to identify the location of the
submerged manholes and provide a working maintenance platform.
As part of the 2012 Outfall Improvements, Phase 6 Project, the outfall was dewatered, inspected,
repaired, and surveyed. Additionally, over 1,500 pipe joint seals were inspected, 368 joints were repaired
with new seals, and ballast rocks were deployed in Suisun Bay to stabilize the submarine portion of the
pipeline. Of the total 1,500 joints, approximately 950 joints have been repaired since the construction of
the pipeline.
In 2017, Central San hired divers to perform an external inspection of the submarine diffuser lines and
wooden manhole access structures straddling the outfall pipeline. The 11 diffusers and the piles were all
found to be in good working conditions; however, some of the braces, platforms, and ladders on the
manhole access structures are missing or in need of repair to ensure structural integrity. In July 2019,
corrosion consultants conducted a condition assessment on the manhole risers of the land portion of the
outfall and found moderate corrosion on many of the risers. Installation of galvanic anodes and test
stations, as well as a new anti-corrosive coating system on the manhole risers, was recommended by the
consultants to ensure the structural integrity of the manhole risers and prevent outfall leakages.
This project will allow for the inspection of the land portion of the outfall, and to make any repairs that are
identified during the inspection. The project will retest the joints of the land portion of the outfall in a similar
fashion to the work performed in 2012, and install newjoint seals, as necessary. Repairs on the three
wooden trestle structures over the submarine portion of the outfall will be performed via boat in Suisun
Bay. Galvanic anodes and test stations will be installed at each of the 23 manhole risers on the land portion
for corrosion control. The pipeline will be surveyed to monitor the outfall alignment. Since the outfall will be
out of service, this project will also replace two 60-inch valves, install two standby effluent valves, perform
Structure D concrete repairs, install a new 30-inch flowmeter at the 9000 Valve Structure, and perform
seismic improvements to the 9000 Valve Structure.
Staff will coordinate with and obtain necessary approval and/or permits from the San Francisco Bay
Regional Water Quality Control Board, United States Army Corps of Engineers, San Francisco Bay
Conservation and Development Commission, California Department of Fish and Wildlife, and any other
applicable agencies. Some of these permits will require proof of CEQA determination.
CEQA
Staff has concluded that this project is exempt from CEQA under CEQA Guidelines in the California
Code of Regulations Section 15301, since it involves repairs to an existing sewage facility with no
increase in capacity. Approval of this project will establish the Board of Directors' independent finding that
this project is exempt from CEQA.
ALTERNATIVES/CONSIDERATIONS
Alternatives to this project, such as deferment or reduction of project scope, are not recommended by
Staff because proper maintenance of the outfall pipeline is required by the NPDES permit and the outfall
pipeline is critical to operations. A reduced scope would pose high operational and regulatory risks, which
could lead to more costly repairs in the future.
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FINANCIAL IMPACTS
The total estimated cost for the project is $5,500,000; however, this Position Paper only approves the
project for CEQA and permitting purposes and does not award a construction contract. The Outfall
Improvements, Phase 7, District Project 7353 is included in the Fiscal Year(FY) 2019-20 Capital
Improvement Budget on page 186 of the FY 2019-20 Budget.
COMMITTEE RECOMMENDATION
The Engineering and Operations Committee has reviewed this subject at its meeting on October 29, 2019
and recommended
RECOMMENDED BOARD ACTION
Approve the Outfall Improvements, Phase 7, District Project 7353 for CEQA and permitting purposes and
direct staff to file a Notice of Exemption.
Strategic Plan Tie-In
GOAL TWO: Strive to Meet Regulatory Requirements
Strategy 1 - Strive to achieve 100%permit compliance in air, water, land, and other regulations, Strategy 2- Strive to
minimize the number of sanitary sewer overflows, Strategy 3- Comply with all federal, state, and local regulations
related to District administration
GOAL FIVE: Maintain a Reliable Infrastructure
Strategy 1 - Manage assets optimally throughout their lifecycle, Strategy 2- Facilitate long-term capital renewal and
replacement, Strategy 3- Protect District personnel and assets from threats and emergencies
ATTACHMENTS:
1. Presentation
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APPROVE OUTFALL IMPROVEMENTS,
PHASE 7, DISTRICT PROJECT (DP) 7353
FOR CEQA AND PERMITTING PURPOSES
October 29,2019
Engineering and Operations Committee Meeting
_ Rita Cheng
-- Regulatory Compliance Associate Engineer
Russ Leavitt
Planning and Development Services Engineering Assistant III
Mark Wenslawski
Capital Projects Associate Engineer
I
CENTRAL SAN'S OUTFALL PIPELINE
• Constructed in 1958, 3.5 mile, 72-inch outfall pipeline that
conveys treated effluent to Suisun Bay
• 19,000 feet of buried pipeline and 1,700 feet of submarine
section in Suisun Bay
• NPDES Permit requires proper operation and maintenance of
the outfall
`1 z
CENTRALSAN
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OUTFALL IMPROVEMENTS HISTORY
• 2012 Outfall Improvements
• 1,500 pipe joints inspected y .
• 368 joints repaired
• Ballast rocks deployed in
Suisun Bay to stabilize
pipeline
• Flow meter and structure
installed at the plant
• 950 out of 1 ,500 joints have
been repaired
CENTRALSAN
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PROJECT SCOPE
OUTFALL IMPROVEMENTS, PHASE 7, DP 7353
• Drain,inspect,and survey the land Seismically improve 9000 valve
portion of the outfall pipeline structure and install a new flowmeter
• Test pipe joints and install new joint seals, Replace 9001 and 9002 valves
as needed Install two standby effluent valves
• Install galvanic anodes and test stations Repair Structure D concrete
at all manhole risers for corrosion control Operations will bypass treated final
• Repair three wooden trestle structures in effluent to Lower Walnut Creek
the Suisun Bay
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PERMITS NEEDED FOR OUTFALL
IMPROVEMENTS, PHASE 7, DP 7353
• Staff will obtain permits from the following agencies:
CALIFO NNI0.� '
WATER BOARDS
J
US Army Corps
of Engineersg
• Ecological firm Zentner is under contract to complete
these assessments required for permitting
• Wetland Jurisdictional Evaluation
• Special Status Habitat and Species Assessment
t
CEQA CATEGORICAL EXEMPTION
• This project is exempt from CEQA under CEQA
Guidelines Section 15301 since it involves repairs to
an existing sewage facility with no increase in
capacity.
• Previous Outfall Improvements, Phase 6 Project, in
2012 and other phases were exempt from CEQA.
• Approval of this project will establish the Board of
Directors' independent finding that this project is
exempt from CEQA.
CENTRALSAN
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RECOMMENDATION
Approve Outfall Improvements, Phase 7,
District Project 7353 for CEQA and permitting
purposes
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CENTRALSAN
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