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ADOPT A RESOLUTION TO APPROVE FINDINGS AND AUTHORIZE CONTRACT AMENDMENT NO. 1 WITH AQUA-SCIENCE LLC FOR AQUATIC TOXICITY TESTING
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RECOMMENDATION
It is recommended that the City Council adopt a resolution to:
1. Approve findings pursuant to Stockton Municipal Code Section 3.68.3070, which support and justify an exception to the competitive bidding process.
2. Authorize the City Manager to execute a two (2) year contract extension with Aqua-Science LLC of Davis, California.
It is also recommended that the City Manager be authorized to take appropriate and necessary actions to carry out the purpose and intent of this resolution.
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Summary
The Municipal Utilities Department (MUD) operates the Regional Wastewater Control Facility (RWCF). Quarterly wastewater testing is required as part of the City’s National Pollution Discharge Elimination System (NPDES) discharge permit. The RWCF permit requires the testing of treated wastewater referred to as chronic toxicity testing. These tests are used to demonstrate if treated effluent is potentially harmful to fish species when discharged into the San Joaquin River.
Chronic toxicity tests are very sensitive, and results can vary depending on small changes in a laboratory’s control water. It is important to continue toxicity testing at the same lab to ensure consistent and comparable results. MUD has contracted with Aqua-Science LLC (Aqua-Science) as an independent lab for testing since 2016. State requirements for a Toxicity Reduction Evaluation (TRE) will continue until the RWCF Modifications Project is completed and for at least one year following the activation of the new outfall. Because of the sensitive nature of the chronic toxicity tests, it is recommended to continue using Aqua-Science for TRE testing for dependable data comparisons and trend analysis.
If approved by the City Council, this action will approve findings pursuant to Stockton Municipal Code Section 3.68.070 to support and justify an exception to the competitive bidding process and authorize a two-year contract extension (Exhibit 1 to the Resolution) with Aqua-Science LLC of Davis, California.
DISCUSSION
Background
The RWCF wastewater discharge NPDES permit requires quarterly testing of treated wastewater referred to as chronic toxicity testing. These tests are used to demonstrate if the effluent is potentially harmful to fish species in the receiving waters. The chronic toxicity test has a subjective element that allows each lab to develop their own control water. The degree of sensitivity in control water varies and can have a detrimental effect on the test results. Because of the sensitivity variance in the control water, results on the same sample can vary from one lab to another and cannot be reproduced.
In 2016, the MUD experienced a series of failed chronic toxicity tests that resulted in the City entering a Toxicity Reduction Evaluation (TRE) program. Under the TRE, the MUD was obligated to explore all treatment processes and conditions to determine the cause of the failed tests. The MUD contracted with Aqua-Science in 2016 based on their reputation, performance record with other agencies, cost, and proximity to Stockton. After more than two years of extensive testing and analysis, staff was able to determine the cause of the failed chronic toxicity tests was linked to the application of mosquito control chemicals applied at the ponds on the direction of San Joaquin County Vector Control.
In November 2018, a TRE Action Plan was submitted to the Central Valley Regional Water Quality Control Board (CVRWQCB) that detailed staff efforts to identify the cause of toxicity. The chemicals are applied to control mosquito populations in the treatment ponds at the RWCF. This issue has since been corrected with the application of vector-control materials that are not toxic to fish. To confirm this, MUD agreed to continue the permit-required quarterly chronic toxicity tests until the completion of the RWCF Modifications Project. In 2019, a five-year contract was awarded to Aqua-Science LLC for the ongoing toxicity testing services for a not-to-exceed amount of $331,820. Once the RWCF Modifications Project is complete, the ponds will no longer be part of the treatment process. The CVRWQCB accepted the data and analysis provided by the MUD and the proposed TRE exit plan.
Present Situation
Construction of the RWCF Modifications Project is nearing completion, and a new outfall has been constructed. However, once the new outfall is accepted and in service and the ponds are no longer part of the treatment process, an additional four-quarters of toxicity testing is required before the MUD may exit the TRE.
Due to the species sensitivity to variations in control water, and the inability to reproduce test results between labs, it is recommended that the City continue the quarterly toxicity testing at the same lab to ensure consistent and comparable results. Using the same lab for the next two years of testing provides the necessary consistency for data trends, as well as cost savings to MUD. Aqua-Science LLC has requested cost adjustments to be implemented during the extended contract term with no additional funding added to the contract (Exhibit 1 to the Resolution).
Findings
Pursuant to Stockton Municipal Code Section 3.68.070, the City Council may approve findings which support and justify an exception to the competitive bidding process. The following findings support and justify an exception:
1. Chronic Toxicity tests are extremely sensitive to ambient test conditions, including control water, and test results on the same sample cannot be reproduced in different labs. Aqua-Science is the current lab performing chronic toxicity testing for MUD.
2. Nearly eight years of data has been collected from Aqua-Science on the source of failed chronic toxicity tests.
3. The CVRWQCB accepted the City’s proposed plan to exit the TRE, which includes continued chronic toxicity testing through completion of the RWCF Modifications Project and for four additional quarters once the new outfall is accepted and in service.
4. It is cost effective for the City to continue to use Aqua-Science to provide ongoing chronic toxicity testing until the TRE ends in 2026.
Staff recommend the City Council approve these findings as an exception to the competitive bidding process and authorize a two-year contract amendment with Aqua-Science LLC of Davis, California, for Chronic Toxicity Testing with no change to the not-to-exceed contract amount.
FINANCIAL SUMMARY
This change order is for time extension only. There are sufficient funds remaining on contract 419000255 to cover the extension. If additional funding is needed in future years, we will request for budget through the annual budgeting development process.
This action has no impact on the General Fund or any other unrestricted funds.