California Code of Regulations › Title 23 - Waters › Division 4 - Regional Water Quality Control Boards › Chapter 1 - Water Quality Control Plans, Policies, and Guidelines › Article 4 - Los Angeles Region › Section 3939.6 - A Total Maximum Daily Load for Nitrogen Compounds in the Santa Clara River

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
Los Angeles Regional Water Quality Control Board (Regional
					 Board) Resolution No. 2003-011, adopted on August 7, 2003 by the Regional
					 Board, modified the regulatory provisions of the Water Quality Control Plan for
					 the Los Angeles Region (Basin Plan) by (1) revising the Table of Contents, (2)
					 adding introductory text for Chapter 7 (Total Maximum Daily Loads), and (3)
					 establishing a Total Maximum Daily Load (TMDL) for nitrogen compounds in the
					 Santa Clara River. The TMDL specifies concentration-based targets for ammonia,
					 nitrate, nitrite, and combined nitrate and nitrite. The TMDL includes a margin
					 of safety with both implicit and explicit components.
Numeric targets will primarily be achieved by limiting the
					 amount of nitrogen compounds discharged from four major permitted wastewater
					 treatment plants (Saugus Water Reclamation Plant (WRP), Valencia WRP, Fillmore
					 Publicly Owned Treatment Work (POTW), and Santa Paula POTW. These major point
					 sources are assigned wasteload allocations for ammonia, nitrite, nitrate, and
					 combined nitrite and nitrate. At the Regional Board's discretion, the Saugus
					 and Valencia WRPs may be allowed higher interim loads for nitrate, nitrite, and
					 combined nitrate and nitrite for a period as short as possible, but not to
					 exceed eight years from the effective date of the TMDL. The Fillmore and Santa
					 Paula POTWs may be allowed higher interim loads for combined ammonia, nitrate
					 and nitrite for a period also not to exceed eight years after the effective
					 date of the TMDL. Receiving water monitoring is required weekly of these major
					 point sources.
Minor point sources (including stormwater sources) in
					 Reaches 3 and 7 are also assigned concentration-based wasteload allocations for
					 ammonia and combined nitrite and nitrate. Wasteload allocations for minor point
					 sources will be implemented through effluent limits or Best Management
					 Practices (BMPs) for stormwater. Load allocations for nonpoint sources for
					 combined ammonia, nitrite, and nitrate are implemented through State Water
					 Resources Control Board Management Practices.
The County Sanitation District of Los Angeles County
					 (CSDLAC) must submit the results from a water effects ratio study for ammonia
					 when the TMDL takes effect. Within one year after the effective date of the
					 TMDL, the following workplans must be submitted to the Regional Board for
					 approval:
(1) a workplan for
				  estimating nitrogen loading from stormwater sources which includes triggers for
				  conducting source identification and implementing BMPs must be submitted by
				  affected MS4 (municipal separate storm sewer systems) permittees;
(2) a workplan for monitoring
				  nitrogen-related effects and evaluate progress in meeting targets must be
				  submitted by affected major National Pollutant Discharge Elimination System
				  permittees; and
(3) a special
				  studies workplan to evaluate site-specific objectives for nitrate must be
				  submitted by CSDLAC. If monitoring and study results indicate it is
				  appropriate, the Regional Board will consider adopting site-specific objectives
				  for ammonia within one year after the effective date of the TMDL, and
				  site-specific objectives for nitrate, and combined nitrite and nitrate within
				  four years after the effective date of the TMDL. If site-specific objectives
				  are adopted, the TMDL will be revised through a Basin Plan amendment. Five
				  years after the effective date of the TMDL, the Regional Board will consider
				  whether the numeric targets and wasteload allocations specified in the TMDL are
				  sufficient to protect the Santa Clara River from nutrient effects of discharged
				  nitrogen compounds or whether the TMDL must be revised through a Basin Plan
				  amendment.
1. New
					 section summarizing amendments to Basin Plan filed 2-27-2004; approved by OAL
					 2-27-2004 pursuant to Government Code section
					 11353
					 (Register 2004, No. 9).