Cal. Code Regs. tit. 23 § 3939.52
On September 8, 2016, the Los Angeles Regional Water Quality Control Board (Los Angeles Water Board) adopted Resolution No. R16-006, amending the Water Quality Control Plan for the Los Angeles Region (Basin Plan) to incorporate a total maximum daily load (TMDL) for nutrients in the Santa Clara River Lakes (Elizabeth Lake, Munz Lake, and Lake Hughes). The State Water Resources Control Board (State Water Board) approved the amendment under Resolution No. 2017-0011 on March 7, 2017.
The TMDL sets numeric targets for dissolved oxygen and pH based on numeric water quality objectives provided in the Basin Plan. The TMDL also includes numeric targets for chlorophyll a and nutrients (total nitrogen and total phosphorus) as numeric interpretations of the water quality condition that will demonstrate attainment of the narrative water quality objective for biostimulatory substances in the Basin Plan. Internal loading from lake bed sediments comprises over 99% of the current nutrient loading to Elizabeth Lake and Lake Hughes. Other sources of nutrients to these lakes include sheet flow from the surrounding land, atmospheric deposition, onsite wastewater treatment systems (OWTS), and the Lake Hughes Community Wastewater Treatment Facility (WWTF).
Waste load allocations (WLAs) will be implemented through the Los Angeles County MS4 Permit; or for additional responsible entities in the future, MS4 permits under Phase II of the US EPA Stormwater Permitting Program. Load allocations (LAs) for internal loading will be implemented through a Memorandum of Agreement (MOA), a Clean Up and Abatement Order, or other regulatory order. The LAs for nonpoint source runoff will be implemented through WDRs, waivers of WDRs, or other regulatory mechanisms in accordance with the Nonpoint Source Implementation and Enforcement Policy. The LAs for OWTS will be implemented through WDRs or waivers of WDRs. The LAs for the Lake Hughes Community WWTF will be implemented through the facility's WDRs. Waste load allocations must be achieved within 15 years of the effective date of the TMDL. The LAs for OWTS and the Lake Hughes Community WWTF must be achieved as soon as possible, but no later than 12 years after the effective date of the TMDL. The LAs for internal loading and nonpoint source runoff must be achieved within 15 years of the effective date of the TMDL.
Cal. Code Regs. Tit. 23, § 3939.52