Cal. Code Regs. tit. 23 § 3945.2

Current through Register 2024 Notice Reg. No. 50, December 13, 2024

Section 3945.2 - Program for Control of Methylmercury and Total Mercury in the Sacramento-San Joaquin Delta Estuary

The amendment establishes water quality objectives for average methylmercury concentrations in large (150-500 mm total length), trophic level 3 and 4 fish, in waterways within the legal boundary of the Sacramento-San Joaquin Delta Estuary (Delta) and the Yolo Bypass within and upstream of the legal Delta boundary. It also establishes a water quality objective for the average methylmercury concentration in whole fish less than 50 mm in length.

The amendment adds the commercial and sport fishing (COMM) beneficial use to waterways within the legal Delta boundary and Yolo Bypass.

The amendment establishes a control program for methylmercury and total mercury discharges in the Delta and Yolo Bypass, including assimilative capacity and load and wasteload allocations for nonpoint and point sources, respectively. The amendment also includes a program of implementation and compliance schedule and a surveillance and monitoring program.

The amendment establishes the following implementation provisions:

1. Establishes load allocations for methylmercury from tributary inputs and nonpoint sources (including wetlands, open water, and irrigated agriculture) within the Delta and Yolo Bypass, and wasteload allocations for methylmercury from point sources (including wastewater treatment plants and urban runoff) within the Delta and Yolo Bypass.

2. Requires methylmercury load and waste load allocations to be met as soon as possible, but no later than 2030, unless the Central Valley Water Board modifies the implementation schedule and final compliance date.

3. Implements the control program through a phased approach. Phase 1 spans 9 years with activities including:

a. Requiring point and nonpoint sources to conduct studies to develop and evaluate methylmercury management practices, including potential costs and environmental effects, and submit results for Central Valley Water Board review at end of Phase 1;

b. Requiring point sources to implement pollution minimization programs and meet interim mass limits for inorganic (total) mercury;

c. Reducing total mercury loading to San Francisco Bay, as required by the Water Quality Control Plan for the San Francisco Bay Basin;

d. Developing upstream mercury control programs for major tributaries;

e. Developing and implementing a mercury exposure reduction program to protect humans; and

f. Developing a mercury offset program.

4. Requires proponents of new wetland restoration projects to participate in Phase 1 methylmercury control studies and implement methylmercury controls identified in the Phase 1 studies.

5. Requires Delta NPDES-permitted municipal separate storm sewer system dischargers to implement best management practices (BMPs) to control erosion and sediment discharges.

6. Requires that dredging and dredge material reuse activities minimize methylmercury and mercury discharges to Delta waterways.

7. Requires agencies responsible for the Cache Creek Settling Basin to develop a plan to reduce loads of total mercury exported from the basin.

8. Requires Central Valley Water Board staff to report to the Board the progress of upstream mercury program development.

9. Requires the Central Valley Water Board to review the Delta mercury control program at the end of Phase 1.

10. Establishes a start date for Phase 2, by which the implementation of methylmercury management practices must commence. Compliance monitoring and implementation of upstream control programs will also occur in Phase 2.

Cal. Code Regs. Tit. 23, § 3945.2

1. New section summarizing amendment to basin plan filed 9-15-2011; amendment approved by State Water Resources Control Board Resolution No. 2011-0028 on 6-21-2011; approved by OAL 9-15-2011 pursuant to Government Code section 11353 (Register 2011, No. 37).