California Code of Regulations › Title 23 - Waters › Division 4 - Regional Water Quality Control Boards › Chapter 1 - Water Quality Control Plans, Policies, and Guidelines › Article 5 - Central Valley Region › Section 3949.4 - Amendment to the Water Quality Control Plan for the Sacramento River and San Joaquin River Basins for the Control of Diazinon and Chlorpyrifos Runoff into the Sacramento-San Joaquin Delta

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
On June 23, 2006, the Central Valley Regional Water Quality
					 Control Board (Central Valley Water Board) adopted Resolution No. R5-2006-0061,
					 and on May 22, 2007, it was approved by the State Water Resources Control
					 Board. This amendment incorporates the following provisions into the Water
					 Quality Control Plan for the Sacramento River and San Joaquin River
					 Basins.
Water Quality Objectives
This amendment establishes a maximum chlorpyrifos
					 concentration of 0.025 micrograms per liter (1-hour average) and 0.015
					 micrograms per liter (4-day average) and a maximum diazinon concentration of
					 0.16 micrograms per liter (1-hour average) and 0.10 micrograms per liter (4-day
					 average) that are not to be exceeded more than once in a three-year period.
					 These objectives apply to 146 named Delta waterways within the legal boundaries
					 of the Delta as described in section
					 12220 of the
					 California Water Code.
Implementation Provisions for Discharge into the Delta
					 Waterways
This amendment:
1.
				  Prohibits, beginning December 1, 2011, the discharge of diazinon or
				  chlorpyrifos into Delta waterways during the dormant or irrigation season if
				  there was any exceedance of the chlorpyrifos or diazinon water quality
				  objectives or loading capacity during the previous season. These prohibitions
				  do not apply if the discharge is subject to a waiver of waste discharge
				  requirements or waste discharge requirements. These prohibitions apply only to
				  dischargers causing or contributing to the exceedance of the water quality
				  objective or loading capacity.
2.
				  Requires dischargers to consider whether an alternative to diazinon or
				  chlorpyrifos would degrade ground or surface water.
3. Requires compliance by December 1,
				  2011.
4. Requires Central Valley
				  Water Board review of the allocation and implementation provisions by December
				  31, 2010 and every five years thereafter.
5. Establishes the waste load allocations for
				  all National Pollutant Discharge Elimination System-permitted point source
				  discharges, load allocations for nonpoint source discharges, and the loading
				  capacity of each of the Sacramento-San Joaquin Delta waterways as defined
				  below:
S = [C(d) / WQO(d)] + [C(c) / WQO(c)] <= 1.0
Where:
S = the sum.
C(d) = diazinon concentration in mcg/L of point source
					 discharge for the waste load allocations; nonpoint source discharge for the
					 load allocations; or a Delta waterway for the loading capacity (LC).
C(c) = chlorpyrifos concentration in mcg/L of point source
					 discharge for the waste load allocations; nonpoint source discharge for the
					 load allocations; or a Delta waterway for the LC.
WQO(d) = acute or chronic diazinon water quality objective
					 in micrograms per liter.
WQO(c) = acute or chronic chlorpyrifos water quality
					 objective in micrograms per liter.
6. States that the Central Valley Water Board
				  will require any additional reductions in diazinon and chlorpyrifos necessary
				  to account for additive or synergistic effects to protect tributary
				  waters.
7. Requires dischargers to
				  submit management plans.
8.
				  Requires any waiver of waste discharge requirements or waste discharge
				  requirements to be consistent with the provisions of the implementation
				  program.
9. Includes estimates of
				  the cost of the program for agriculture.
Monitoring
This amendment requires a monitoring and reporting program
					 for pesticide discharges to determine:
1. Compliance with diazinon and chlorpyrifos
				  water quality objectives, loading capacity and load allocations;
2. Degree of implementation and effectiveness
				  of management practices to reduce off-site movement of diazinon and
				  chlorpyrifos;
3. Surface water
				  quality impacts of alternatives to diazinon and chlorpyrifos;
4. If the pesticide discharges contribute to
				  additive or synergistic effects of multiple pollutants; and
5. If management practices are achieving the
				  lowest pesticide levels technically and economically achievable.
1. New
					 section summarizing amendments to basin plan filed 8-9-2007; amendments
					 approved by State Water Resources Control Board Resolution No. 2007-0028 on
					 5-22-2007; amendments approved by OAL pursuant to Government Code section
					 11353 on
					 8-9-2007 (Register 2007, No. 32).