REPORT TO COUNCIL
SUBJECT
Title
Accept Addendum 5 to the Program Environmental Impact Report (PEIR) for the Sunnyvale Water Pollution Control Plan (WPCP) Master Plan and Approve the Plan for the Secondary Effluent Pipeline Replacement Project in Accordance with the California Environmental Quality Act (CEQA)
Report
BACKGROUND
The City of Sunnyvale owns and operates the Donald M. Somers Water Pollution Control Plant (WPCP), located at 1444 Borregas Avenue in Sunnyvale, Santa Clara County. The WPCP provides treatment of wastewater flows and loads from domestic, commercial, and industrial sources in Sunnyvale, Rancho Rinconada, and Moffett Field. The WPCP was originally constructed in 1956. With the enactment of the Clean Water Act in 1972, more restrictive water quality standards were established, requiring expansion of and process upgrades to the WPCP.
The City was the lead agency for the Sunnyvale WPCP Master Plan Program Environmental Impact Report (PEIR); State Clearinghouse No. 2015062037). The City adopted and certified the PEIR and approved implementation of the WPCP Master Plan on August 23, 2016. The PEIR evaluated potential environmental impacts that could occur as a result of implementing the Master Plan and included mitigations to reduce the intensity of potential environmental impacts. As part of Master Plan approval, the City adopted a Mitigation Monitoring and Reporting Program.
As part of the WPCP Master Plan process, the City identified the need to rehabilitate two existing pipelines. The first is an existing 60-inch primary effluent pipeline from the main plant to the pond recirculation channel (also called the pond return channel). The second is an existing 36‐inch secondary effluent pipeline from the oxidation ponds to the fixed growth reactor distribution structure. The Master Plan noted that rehabilitation of the existing primary effluent pipeline would include either sliplining or placing cure‐in‐place pipe within the existing pipeline. Sliplining was conservatively assumed as the rehabilitation method in the analyses because it requires a more extensive footprint. Following certification of the Master Plan PEIR and approval of the Master Plan, the City proceeded with design of the projects.
In 2020, WPCP operators observed an active boil in the Cargill Channel. The secondary effluent pipeline was leaking partially treated wastewater from the oxidation ponds (treatment ponds) into the channel, which required immediate action by the City. Emergency repair activities were completed and were intended to be temporary while a long-term solution was designed.
Completing an appropriate environmental review under the California Environmental Quality Act (CEQA) is precedent to securing the permits required to construct this project (U.S. Army Corps of Engineers Clean Water Act 404 Nationwide Permit, California Department of Fish and Wildlife Lake or Streambed Alteration Agreement, San Francisco Bay Regional Water Quality Control Board Clean Water Act 401 Water Quality Certification, and Bay Conservation and Development Commission Permit). Staff is requesting Council accept Addendum 5 to the PEIR (Attachment 1) at this time, in advance of the award of the construction contract.
EXISTING POLICY
General Plan, Chapter 7 Environmental Management
Policy Goal EM-7: Continue to operate and maintain the Water Pollution Control Plant, using cost effective methods, so that all sewage and industrial wastes generated within the City receive sufficient treatment to meet the effluent discharge and receiving water standards of regulatory agencies.
Policy EM-7.1: Monitor water pollution control plant operations and maintenance to meet regulatory standards.
ENVIRONMENTAL REVIEW
CEQA Guidelines Section 15164(a) provides that “The lead agency or a responsible agency shall prepare an addendum to a previously certified EIR if some changes or additions are necessary but none of the conditions described in CEQA Guidelines Section 15162 calling for preparation of a subsequent EIR have occurred.” Under Section 15162, a subsequent EIR is required if substantial changes are proposed to the project, or to the circumstances under which the project is undertaken, which require major revisions to the EIR due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects. An addendum does not need to be circulated for public review, but must be considered by the decision-making body prior to approving the project.
As discussed in the Addendum, the project, as amended from the PEIR, would not result in new or more severe significant impacts than those attributable to the project described in the WPCP Master Plan PEIR.
The analyses and discussion in the Addendum demonstrate that the changes in the project do not involve new significant environmental effects or a substantial increase in the severity of previously identified significant effects. There have been no changes in circumstances under which the project is undertaken that would result in new significant environmental impacts or substantially more severe impacts. No new information has become available that would indicate the potential for new significant impacts or substantially more severe impacts than were discussed in the PEIR. Therefore, no further evaluation is required, and no Subsequent EIR is needed pursuant to CEQA Guidelines Section 15162. Because the changes or additions related to the project do not trigger conditions requiring preparation of a Subsequent EIR, no public notice is required, and the addendum does not need to be circulated for public review.
DISCUSSION
After implementing the temporary emergency pipeline repairs, the City proceeded with design of the Secondary Effluent Pipeline Replacement Project (the project). It will provide a long-term solution that replaces the existing buried inoperable secondary effluent pipeline and allows for removal of the temporary emergency pipelines. The project would remove and replace the pond return pipeline and inoperable secondary effluent pipeline. It would also repair the primary effluent pipeline. While replacing the pond return pipeline was not proposed in the Master Plan, due to the City’s interest in maintaining the redundancy provided by the pond return pipeline, the age of the pipeline, and the fact that the pipeline is physically connected to the secondary effluent pipeline, the replacement of the pond return pipeline is now included in this project.
In March 2023, the City of Sunnyvale prepared an addendum to the PEIR for the Sunnyvale WPCP Master Plan - Secondary Effluent Pipeline Replacement Project. The City certified the PEIR for the WPCP Master Plan and adopted the WPCP Master Plan on August 23, 2016. The addendum evaluates environmental impacts of the pipeline replacement project as currently developed in comparison to the impacts disclosed in the PEIR.
CEQA Guidelines (Sections 15162 and 15164) provide that a lead agency may prepare an addendum to a previously certified EIR under certain conditions. The addendum revisited the evaluations in the PEIR to determine whether any changes to the analyses were warranted based on refinements to the project. The addendum documents that the project, as modified subsequent to the Master Plan, would not result in new or more severe significant impacts than those attributable to the project as described in the PEIR. Therefore, no further evaluation is required, and no Subsequent EIR is needed pursuant to CEQA Guidelines Section 15162.
FISCAL IMPACT
No budget modifications are expected at this time. Staff will return to City Council should additional budget appropriations be needed.
PUBLIC CONTACT
Public contact was made by posting the Council meeting agenda on the City's official-notice bulletin board at City Hall, at the Sunnyvale Public Library and in the Department of Public Safety Lobby. In addition, the agenda and this report are available at the NOVA Workforce Services reception desk located on the first floor of City Hall at 456 W. Olive Avenue (during normal business hours), and on the City's website.
RECOMMENDATION
Recommendation
Accept Addendum 5 to the Water Pollution Control Plant Master Plan Program Environmental Impact Report (Attachment 1 to the report) and Approve the Plan for the Secondary Effluent Pipeline Replacement Project.
Staff
Prepared by: Allison Boyer, Assistant City Engineer
Reviewed by: Chip Taylor, Director, Public Works
Reviewed by: Jaqui Guzmán, Deputy City Manager
Approved by: Kent Steffens, City Manager
ATTACHMENTS
1. Addendum 5 to the Program Environmental Impact Report (PEIR) for the Sunnyvale Water Pollution Control Plan (WPCP) Master Plan - Secondary Effluent Pipeline Replacement Project