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 - Program for Control of Diazinon and Chlorpyrifos Runoff into the Lower San Joaquin River

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
On October 21, 2005, the Central Valley Water Board adopted
					 Resolution No. 2005-0138. The Amendment incorporates the following provisions
					 into the Central Valley Regional Water Quality Control Board's (Regional
					 Board's) Water Quality Control Plan for the Sacramento River and San Joaquin
					 River Basins (Basin Plan):
Water Quality Objectives
A maximum chlorpyrifos concentration of 0.025 micrograms
					 per liter (µg/L) (1-hour average) and 0.015 µg/L (4-day average)
					 and a maximum diazinon concentration of 0.16 micrograms per liter (µg/L)
					 (1-hour average) and 0.10 µg/L (4-day average) in the San Joaquin River
					 from Mendota Dam to Vernalis not to be exceeded more than once in a three year
					 period.
Implementation Provisions for Discharge into the San
					 Joaquin River.
1. After December 1,
				  2010, the discharge of diazinon or chlorpyrifos is prohibited during dormant
				  and irrigation seasons if there was any exceedence of diazinon and/or
				  chlorpyrifos water quality objectives in the previous season. The prohibitions
				  do not apply if the discharge is subject to a waiver of waste discharge or
				  waste discharge requirement.
2.
				  Requires dischargers to consider whether an alternative to diazinon or
				  chlorpyrifos would degrade ground or surface water.
3. Requires compliance by December 1,
				  2010.
4. Requires Regional Water
				  Board review of the allocations and implementation provisions by December 31,
				  2009 and every five years thereafter.
5. Establishes the wasteload allocations for
				  National Pollutant Discharge Elimination System-permitted sources, load
				  allocations for nonpoint source discharges, and the Loading Capacity of the San
				  Joaquin River from the Mendota Dam to Vernalis as defined below:
TU =
CD
+
CC
[LESS THAN EQUAL TO]1.0
WQOD
WQOC
where
CD = diazinon concentration in
					 µg/L of point source discharge for the WLA; nonpoint source discharge for
					 the LA; or San Joaquin River for the LC.
CC = chlorpyrifos concentration in
					 µg/L of point source discharge for the WLA; nonpoint source discharge for
					 the LA; or San Joaquin River for the LC.
WQOD = acute or chronic diazinon
					 water quality objective in µg/L.
WQOC = acute or chronic chlorpyrifos
					 water quality objective in µg/L.
6. States that the Regional Water Board will
				  require any additional reductions in diazinon and chlorpyrifos necessary to
				  account for additive or synergistic effects or protect tributary
				  waters.
7. Requires dischargers to
				  submit management plans to the Regional Water Board.
8. Requires any waiver of 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
Requires a monitoring and reporting program to
					 determine:
1. Compliance with diazinon
				  and chlorpyrifos water quality objectives and loading capacity.
2. Compliance with load
				  allocations.
3. Degree of
				  implementation and effectiveness of management practices and strategies to
				  reduce off-site migration of diazinon and chlorpyrifos.
5. Degradation of surface water quality from
				  alternatives to diazinon and chlorpyrifos.
6. Additive or synergistic effects of
				  multiple pollutants
7. Management
				  practices are achieving the lowest pesticide levels technically and
				  economically achievable.
1. New
					 section summarizing amendment of basin plan filed 6-30-2006; amendment approved
					 by State Water Resources Control Board Resolution No. 2006-0025 on 5-2-2006;
					 amendment approved by OAL pursuant to Government Code section
					 11353 on
					 6-30-2006 (Register 2006, No. 26).