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 3939.23 - Total Maximum Daily Load for Metals and Selenium in Calleguas Creek, Its Tributaries, and Mugu Lagoon

Current through Register 2024 Notice Reg. No. 28, July 12, 2024
Los Angeles Regional Water Quality Control Board (Los
					 Angeles Water Board) Resolution No. R4-2006-012, adopted on June 8, 2006 by the
					 Los Angeles Water 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 metals and selenium in Calleguas Creek, its tributaries, and Mugu Lagoon.
					 The State Water Resources Control Board approved the amendment on October 25,
					 2006 under Resolution No. 2006-0078.
Three of 14 reaches in the Calleguas Creek Watershed,
					 including Revolon Slough, Lower Calleguas Creek -- Reach 2, and Mugu Lagoon
					 have been listed under the federal Clean Water Act section
					 303(d) as not
					 meeting standards due to elevated concentrations of metals and selenium in
					 water. Technical studies indicate Mugu Lagoon is a sink for metals, which
					 endanger aquatic organisms and impair the existing habitat. Aquatic organisms
					 also accumulate metals, which cause human health concerns. The beneficial uses
					 most affected by metals and selenium loadings into Calleguas Creek, its
					 tributaries, and Mugu Lagoon include habitats which support wildlife and rare,
					 threatened, or endangered species, as well as habitats which support estuarine
					 and wetland ecosystems. The amendment establishes four types of numeric targets
					 with which load allocations and waste load allocations were calculated. The
					 types of numeric targets are water quality targets for copper, nickel, zinc,
					 mercury, and selenium; fish tissue targets for mercury; bird egg targets for
					 mercury and selenium; and sediment quality guidelines for copper, nickel, and
					 zinc for 303(d)-listed reaches. In addition, the Basin Plan amendment specifies
					 final waste load allocations for point source discharges and load allocations
					 for nonpoint source discharges of metals and selenium. The TMDL establishes a
					 ten year implementation schedule for publicly owned treatment works and other
					 National Pollutant Discharge Elimination System Permittees, and a 15 year
					 implementation schedule for agricultural and permitted storm water dischargers
					 to reduce the loading of metals and selenium to Calleguas Creek. The TMDL also
					 authorizes the use of best management practices, to the extent authorized by
					 law, for various dischargers including agricultural and storm water
					 dischargers. The implementation plan includes a combination of water quality
					 monitoring, hot-spot waste removal, waste collection, and sediment control. The
					 TMDL also consists of a monitoring program to assess compliance with waste load
					 allocations. The monitoring program also stipulates the collection of
					 additional data to evaluate the uncertainties and assumptions made in
					 development of the TMDL and to consider potential management scenarios.
The Basin Plan amendment includes a brief description of
					 the Calleguas Creek Watershed and the existing conditions contributing to water
					 quality problems. Calleguas Creek metals and selenium TMDL numeric targets,
					 source analysis, linkage analysis, waste load allocation, load allocation,
					 margin of safety, future growth, critical conditions, implementation plan, and
					 compliance schedule are also discussed in the Basin Plan amendment.
(b) On October 13, 2016, the Los Angeles
				  Regional Water Quality Control Board adopted Resolution R16-007, amending the
				  Basin Plan to revise the Total Maximum Daily Load for Metals and Selenium in
				  Calleguas Creek, its Tributaries, and Mugu Lagoon.
The Basin Plan amendment, adopted by Resolution No.
					 R16-007, revises the TMDL adopted by Resolution No. R4-2006-012 to incorporate
					 the Water Effect Ratios (WERs) adopted and approved under the Basin Plan
					 amendment, Resolution No. 2006-022, into the Calleguas Creek Metals and
					 Selenium TMDL, and revises the wasteload allocations (WLAs) for the Hill Canyon
					 and Camarillo wastewater treatment plants based on recent data showing improved
					 water quality.
1. New
					 section summarizing amendments to basin plan filed 2-6-2007; amendment approved
					 by State Water Resources Control Board Resolution No. 2006-0078 on 10-25-2006;
					 amendments approved by OAL pursuant to Government Code section
					 11353 on
					 2-6-2007 (Register 2007, No. 6).
2. New subsection (b) summarizing
					 amendments to basin plan filed 5-18-2017; amendments approved by State Water
					 Resources Control Board Resolution No. 2017-0007 on 2-2-2017; amendments
					 approved by OAL pursuant to Government Code section
					 11353 on
					 5-18-2017 (Register 2017, No. 20).