Tetra Tech (2004). San Jacinto Nutrient Management Plan Identify existing and planned nutrient controls and recommend additional projects Lake Elsinore aeration Canyon Lake aeration/destratification in deep water Canyon Lake dredging in East Bay Structural BMPs Sewer and septic improvements Interception and treatment of nuisance urban runoff Riparian habitat restoration and development of agricultural buffers Determination of crop-specific agronomic rates for guidance in fertilizer and manure application management Assessment of nutrient loads to San Jacinto River watershed from flooding of agricultural areas Regional organic waste digester This planning report supplemented the models developed to understand sources and allowable loads for the development of the 2004-adopted TMDL. No quantitative water quality benefit estimates were developed for the listed existing and potential projects. LECL Task Force (2007). Nutrient Reduction Plans Develop implementation plan to meet the 2004 TMDL numeric targets in Lake Elsinore Phase 1: Lake level stabilization with levee and reclaimed water additions Destratification with axial flow pumps Large scale in-lake aeration system Fishery management including carp netting and stocking of fish to control shad population Phase 2: Supplemental projects – if needed Enhanced aeration system - more frequent operation or additional pipelines/aerators Enhanced treatment of reclaimed water to < 0.5 mg/L Direct application of alum or other chemical P treatment Targeted suction dredging Constructed wetlands in back basin Active aquatic plant management Enhanced fishery management Enhanced lake stabilization (groundwater or reclaimed water) Expected results from 1 projects estimated to achieve ~78% reduction in phosphorus load based on studies by Anderson (2006) not accounting for indirect benefits from higher lake level or larger zooplankton population. Continued monitoring recommended to determine whether a supplemental Phase 2 project would be needed. Additional special studies recommended including (1) in-lake measurements of sediment organisms as a living sink for nitrogen; (2) estimation of sediment denitrification as an atmospheric sink for nitrogen; and (3) in-lake samples of nitrogen fixing potential of lake as source for nitrogen.
Indirect Potable Reuse Hydrologic flushing Internal Canyon Lake (Main/East Bay) $$$$ EVMWD may consider using Canyon Lake as an environmental buffer to allow for potable reuse of advanced treated reclaimed water. Advanced Wastewater Treatment (AWT) water would be discharged at the upstream end of the lake to maximize residence time prior to reaching the drinking water treatment plant intake. AWT water would serve to dilute ambient water in the lake as well as create additional flushing of water when overflows are not occurring. Reduction of TP and TN in water column; flushing of nutrients and phytoplankton out of Canyon Lake Water quality in the lake may limit the amount of reclaimed water that can be diverted for potable supply. Operation of the system during the wet season may be less reliable given water quality and capacity limitations. Vegetation Management Algae control Internal Lake Elsinore, Canyon Lake (Main/East Bay) $$ Establishment of submerged aquatic vegetation that will take up nutrients and release oxygen to the water column. Macrophytes can compete for limited nutrients and light with algae thereby providing another control on algae growth. Reduction of TP and TN in water column, control of algae growth Macrophytes may not get established. Water level fluctuations can kill vegetation by either desiccation or drowning. Ultrasonic Algae Control Algae control Internal Canyon Lake (East Bay) $ Devices can be deployed that will kill algae within a radius by sonication Control of algae growth Sonication is effective over a area and may require too many devices to impact larger zones. Impact to other aquatic species could become an important consideration Algaecide Algae control Internal Canyon Lake (Main/East Bay) $ Algaecides may be effective in controlling algae blooms as they begin to occur Control of algae growth Repeated use of some algaecides can cause elevated levels of toxins in the lake bottom Nutrients are not addressed and therefore new blooms may arise shortly after an algaecide treatment Physical Harvesting Algae control Internal Lake Elsinore, Canyon Lake (Main/East Bay) $$ Skimmers and tools can be used to physically remove algae from the surface of the lake Control of algae growth intensive Nutrients are not addressed and therefore new blooms may arise shortly after physical removal
Table 7-11. Phased Implementation Framework for Lake Elsinore and Canyon Lake TMDLs Phase Time Period Completed or Anticipated Key Activities Existing or Anticipated Outcomes Phase 1 Effective date of original TMDLs to effective date of revised TMDLs (2005 - ~2019) LECL Task Force Management Alum applications implementation Fishery management Watershed BMPs (CNRP, AgNMP) Supplemental water additions Special studies to support TMDL revisions Monitoring and reporting activities Implementation of and in-lake BMPs to reduce nutrient loads to the lakes and mitigate nutrient impacts Development of new data to support revision of nutrient TMDLs Phase 2 15-20 year period after effective date of revised TMDLs Revised permits and management Continued/enhanced implementation of existing water quality control programs Supplemental project implementation, as needed Additional research/studies, as needed Annual monitoring and reporting Periodic assessment to evaluate progress towards compliance with TMDLs and attainment of water quality objectives Compliance with TMDL numeric targets and attainment of water quality objectives Evaluation of the need for 3 implementation if compliance with TMDL targets or water quality objectives not yet attained Phase 3 (as needed) After completion of Phase 2 to no later than 40 years after revised TMDLs effective date Consider additional projects Consider revision of beneficial uses and/or water quality objectives to better define highest attainable use(s) Revise based on latest data/information Compliance with TMDL numeric targets and attainment of water quality objectives 7.4.1.3 Phase 3 The TMDLs will be re-evaluated after about 20 years (end of Phase 2, or approximately 2040). This next phase will be required only if after implementation of Phase 2 activities it is determined that compliance with TMDL nutrient targets and attainment of water quality objectives may not be achieved under completed and ongoing water quality control activities. If Phase 3 is deemed necessary, not only would additional water quality projects be evaluated for implementation, but modification to applicable beneficial uses and water quality objectives also would be considered, as discussed below.
7-12. Summary of Implementation Activities Implementation Element Activity Responsible Entity (ies) Complete by Stakeholder Coordination LECL Task Force collaborate at least quarterly on TMDL implementation activities All entities with a WLA or LA and Santa Ana Water Board Throughout Phase 2 Revision to Existing Permits and Other Regulatory Actions Riverside County MS4 Permit Santa Ana Water Board Initiate revisions necessary within 90 days of TMDL effective date Air Reserve Base MS4 Permit Conditional Waiver for Agricultural Operations WDR Dairy General Order Caltrans MS4 Permit Water Board USFS Nutrient Management Plans Santa Ana Water Board, State Water Board, and EPA Revised Management Plans within 3 years of TMDL effective date Implementation and/or Revision of Existing Water Quality Controls Canyon Lake Alum Project Entities with a WLA or LA applicable to Canyon Lake As needed application LEAMS Entities with a WLA or LA applicable to Lake Elsinore Continued implementation as per operational agreements Fishery Management Entities with a WLA or LA applicable to Lake Elsinore As needed Comprehensive Nutrient Reduction Plan MS4 Permittees Revised CNRP within 2 years of reauthorization of MS4 permit Agricultural Nutrient Management Plan Agricultural Operators Revised AgNMP within 2 years of TMDL effective date Supplemental Reclaimed Water EVMWD Maintain minimum discharge of supplemental Evaluation of Technical Basis of TMDL Assumptions Nutrient Loads from Reference Watershed All entities with a WLA or LA Complete study within 3 years of TMDL effective date Special Studies All entities with a WLA or LA As needed, milestones determined by specific study
Revised Monitoring Program Revised Monitoring and Reporting Program All entities with a WLA or LA Submitted within 90 days of TMDL effective date; implemented within 90 days of Santa Ana Water Board approval Annual Water Quality Reports All entities with a WLA or LA By August 15 each year Evaluate Status of TMDL Compliance All entities with a WLA or LA By August 15 of every fifth year after TMDL effective date Supplemental Projects Determine need for and select Supplemental Projects; establish workplan and schedule for implementation All entities with a WLA or LA Within 4 years of effective date of TMDLs Adaptive Management Analysis Evaluation of need for Phase 3 All entities with a WLA or LA No later than 20 years after TMDL effective date Demonstrate Attainment with Quality Objectives Adaptive Management All entities with a WLA or LA Focus of TMDL implementation in second 20 years; milestones determined based on Phase 3 evaluation above TMDL re-opener (if deemed necessary following completion of special studies) All entities with a WLA or LA Determine need for revised beneficial uses and/or site-specific objectives for Lake Elsinore; establish workplan and schedule for implementation All entities with a WLA or LA