REPORT TO COUNCIL
SUBJECT
Title
Receive a Report of an Emergency Repair Project for the Water Pollution Control Plant Oxidation Pond Levees
Report
BACKGROUND
The City of Sunnyvale’s Water Pollution Control Plant (WPCP) has two large ponds located north of the Plant that provide biological treatment of wastewater. The west pond is approximately 300 acres in size and the smaller east pond is approximately 100 acres in size. These ponds are protected by approximately 6.6 miles of levees. The levees recently experienced leaks at three separate locations. The leaks in the west pond’s west levee allowed partially treated wastewater to enter a basin owned by U.S. Fish and Wildlife Service. The leak on the east pond’s north levee allowed tidal water from the Guadalupe Slough into the east pond.
Emergency repairs on the west pond’s west levee were needed to stabilize the levee and prevent leakage of partially treated wastewater from the pond into the waters of the United States, an unpermitted release. Emergency repairs on the east pond’s north levee were needed to prevent tidal water from leaking into the treatment pond and compromising biological treatment of the wastewater and prevent partially treated wastewater leaking from the pond into the Guadalupe Slough.
Recognizing the urgency of the situation, the City Manager authorized repairs on an emergency basis. The City Manager also informed the City Council via email regarding the need for emergency repairs.
EXISTING POLICY
Sunnyvale Municipal Code Section 2.08.190 (Emergency Procurements) - The city manager, the purchasing officer or a department head, or a designee of such individual, may make or authorize others to make emergency procurements, regardless of the cost, if there is an urgent necessity to do so for the preservation of life, health, or property. Such emergency procurements shall be made with such competition as is practical under the circumstances and shall be limited to those goods and services necessary to satisfy the emergency need. In such circumstances, the purchasing officer or department head shall provide a written report of the procurement to the city manager, including a description of the emergency and the basis for selection of the particular contractor; and a copy of this report shall be included in the procurement records maintained by the purchasing officer. In the event that such emergency action is necessary, and the procurement cost is greater than one hundred thousand dollars in any one transaction, the city manager shall make a full and complete report to the city council at its next regularly scheduled meeting.
ENVIRONMENTAL REVIEW
Emergency repairs to publicly or privately owned service facilities necessary to maintain service essential to the public health, safety or welfare, including repairs that require a reasonable amount of planning to address an anticipated emergency, and actions necessary to prevent or mitigate an emergency are exempt from review under the California Environmental Quality Act (CEQA) pursuant to Sections 15269(b) and (c) of the CEQA Guidelines. Staff determined that the project was exempt from CEQA under the above sections before proceeding with the work.
DISCUSSION
East pond’s north levee section
On October 12th, 2023, during routine inspections, WPCP staff noticed water flowing from the Guadalupe slough into the east pond through the north levee of the pond. Staff discovered a large rodent burrow starting from within the slough entering under the levee road. Staff successfully plugged the opening on the slough side which slowed the leak. However, permanent repairs were needed to fill the several remaining boroughs under the levee roadway.
West pond west levee section
On November 17th, 2023, during routine inspections, WPCP staff noticed wastewater seeping from the west pond through its west levee into the adjacent former salt pond. A repair was attempted by plant staff but was unsuccessful. This section was previously repaired by plant staff in May 2023. As such, emergency repairs were required to permanently repair portions of the levees affected by seepage.
Staff was also concerned that the structural integrity of the levees would be compromised as the pond water levels increased. Typically, pond levels are high during the rainy season as the ponds also serve a storage function during storm events and the high water levels could put further stress on the levees.
Staff retained Hydroscience Engineers to provide geotechnical reports and design and Environmental Science Associates to support regulatory permitting and environmental compliance. Staff received two construction proposals, from Brannon Corporation for $489,315 and from Walsh Group for $730,000. Staff executed a contract with Brannon Corporation in March and the repair work was completed by the first week of April.
FISCAL IMPACT
The estimated overall cost for this emergency repair project is $677,315. A detailed breakdown of expenses is outlined in the table below. These repairs were funded out of Project 831730, WPCP Oxidation Pond Levee Rehabilitation which has available annual funding for the maintenance and repair of the levees. Staff will review the project during the FY 2025/26 project cycle to see if any additional funds are need to replace the resources used to fund this emergency repair.
|
Description |
Cost |
|
Design |
$50,000 |
|
Geotechnical |
$55,000 |
|
Permitting |
$47,000 |
|
Construction |
$489,315 |
|
Engineering Services During Construction |
$36,000 |
|
Total |
$677,315 |
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
Receive a Report of an Emergency Repair Project for the Water Pollution Control Plant Oxidation Pond Levees. The project was urgent, as it was required to ensure public health and safety and continued WPCP operations.
Prepared by: Leonard Espinoza, Maintenance Manager, WPCP
Reviewed by: Rohan Wikramanayake, Division Manager, WPCP
Reviewed by: Ramana Chinnakotla, Director, ESD
Reviewed by: Sarah Johnson-Rios, Assistant City Manager
Approved by: Kent Steffens, City Manager