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TMDL Implementation in the Calleguas Creek Watershed Ashli Desai Larry Walker Associates.

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Presentation on theme: "TMDL Implementation in the Calleguas Creek Watershed Ashli Desai Larry Walker Associates."— Presentation transcript:

1 TMDL Implementation in the Calleguas Creek Watershed Ashli Desai Larry Walker Associates

2 Presentation Outline What is a TMDL? Calleguas TMDLs TMDL Sources Required reductions from agricultural sources TMDL Implementation and Costs

3 303(d) List and TMDLs Foundation for Protecting Water Quality -Water Quality Objectives Waterbodies Exceeding Water Quality Objectives (Impaired) -Clean Water Act Section 303(d) List Mechanism for Removing Impairment -Development of Total Maximum Daily Load (TMDL) Calleguas Creek Watershed 8 TMDLs for 28 constituents by 2012

4 What is a TMDL? Calculation of maximum amount of pollutant discharge from each source that allows waterbody to meet water quality objective Considers all sources to waterbody Ag+Urban+Wastewater+Background=TMDL Background covers groundwater, soils, atmospheric deposition, etc.

5 TMDLs in Calleguas Effective Nitrogen and Algae Historic Pesticides (DDT, Chlordane) Metals (Copper, Nickel, Zinc, Mercury) Toxicity Sediment Trash Awaiting EPA Approval Salts (Chloride, TDS, Boron, Sulfate) Bacteria to be developed in next year

6 TMDL Development Calleguas Creek Watershed Management Plan developed TMDLs Public review process for about a year each Implementation coordinated with existing programs to extent possible Agricultural Stakeholders RWQCB/EPA TMDL Development Urban Stakeholders

7 Agricultural Source Analysis TMDL analysis determines amount from each source Agricultural contribution varies depending on constituent Can also vary between wet and dry conditions Source analysis part of analysis of how much can be discharged

8 Nitrogen Sources

9 Sources of Chlorpyrifos and Diazinon

10 Metals and Selenium Sources

11 Sources of DDE (DDT)

12 Estimated DDT Usage Map

13 Summary Agriculture is a source for all of the constituents in TMDLs Magnitude of the source varies by constituent Historic practices may need to be addressed Some of the constituents discharged are not due to agricultural use, but could be impacted by agricultural practices

14 Required Reductions ConstituentCalleguas Nitrogen and algae70% Historic Pesticides50-99% Toxicity (Diazinon & Chlorpyrifos) 68-99% Metals38-83% Sediment~25% Salts10-73%

15 Load Allocations Load allocations are interim and final limits to be met by agriculture Interim limits Go into effect when TMDL effective Set at 95 th /99 th percentile of existing discharge data Designed to ensure discharges don’t increase Final limits Go into effect at end of implementation period Set based on water quality objective Designed to achieve water quality objectives Used to allocate costs for TMDL implementation

16 TMDL Implementation vs. Ag Waiver TMDLConditional Waiver Similar Requirements Grower Education Implement BMPs Similar Requirements with Additional TMDL Actions Develop AWQMPs for all TMDL waterbodies Develop AWQMPs for waterbodies exceeding benchmarks Conduct receiving water and land use monitoring Conduct land use monitoring No Similar Conditional Waiver Requirements Special Studies

17 Implementation Schedule ConstituentCalleguas Nitrogen and algae2010 Historic Pesticides2026 Toxicity (Diazinon & Chlorpyrifos) 2016 Metals2022 Sediment2015 Salts2023 Trash2011

18 TMDL Implementation Receiving Water- water, sediment, fish tissue Agricultural land use sites. Coordinated with conditional waiver sites where possible Required studies to answer outstanding questions Optional studies allow for site- specific objective development Identify and install BMPs Education TMDL Monitoring Special Studies Implementation Actions

19 Completed Implementation Actions TMDL Monitoring Program Submitted plan in September 2006 Monitoring begins August 2008 Special Study Workplans Sediment Transport and Habitat Impacts Study High Concentration Areas for DDT and Metals and Flood Control Practices Urban Source Identification for DDT and Metals Agricultural Source Identification for DDT and Metals Selenium in Groundwater

20 Completed Implementation Actions Special Studies Completed Algae, Greenhouses, and Groundwater Studies Alternatives to Diazinon and Chlorpyrifos Study Completed work so far has been funded by POTWs only Work conducted from 2007 to date to be reimbursed

21 Upcoming Implementation Items- Covered by Conditional Waiver Develop Agricultural Water Quality Management Plans Identify and install BMPs Implement Agricultural Educational Program on BMPs Evaluate effectiveness of BMPs

22 Upcoming Implementation Items Not Covered by Conditional Waiver Conduct work for submitted special study workplans Develop workplans and conduct work for optional studies Copper WER for Revolon SSO for Mercury and Selenium Implement historic pesticide collection program

23 Cost of Implementing TMDLs Implementation ActionApproximate Cost TMDL Monitoring$1,200,000/year TMDL Administration$150,000/year Required Special Study Workplans$75,000 Optional Special Study Workplans$160,000 Special Study Implementation>$850,000 Implementation ActionsTo Be Determined

24 Approach for Cost Sharing Based on amount each source allowed to discharge to stream More allowable discharge, more cost Different percentage of costs for each TMDL Memorandum of Agreement developed for funding Budget developed every year for approval Agriculture Discharge Urban Runoff Wastewater Storm Flows

25 Cost Allocations by TMDL Responsible Party NutrientDDT and Sediment ToxicityMetalsOverall POTWs68%1%29%15%28% Urban0%27%37%33%24% Agriculture32%72%34%52%48%

26 Agricultural Share of Costs 2007- 2009 Implementation ActionApproximate Cost TMDL Monitoring $696,000 ($527,000 future years) TMDL Administration $72,000 (annual cost) Required Special Study Workplans$21,000 Optional Special Study Workplans$15,000 Special Study Implementation$126,000

27 Summary Agricultural costs based on amount allowed to discharge in TMDL Costs of studies will be spread over several years Costs shown are just first year budget Monitoring will be ongoing every year Amount billed is for first year, but will be ongoing costs throughout TMDL implementation Most of costs for special studies during first five years

28 Regulatory Issues and Enforcement VCAILG being used as a mechanism for implementing TMDLs as a group RWQCB will require individuals not participating in group to conduct actions on own Recent Writ of Mandate Specific to urban discharges Doesn’t protect against lawsuits from others Calleguas group continuing TMDL implementation

29 Future Calleguas is first for TMDLs, but won’t be last Salts and Bacteria implementation will be added later Trash will be addressed separately Santa Clara River has effective nutrient TMDL and is listed for: Salts Bacteria Toxicity (Diazinon and Chlorpyrifos) Historic Pesticides Ventura River has effective trash TMDL and is listed for: Nutrients Bacteria Historic Pesticides


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