TMDL Implementation in theCalleguas Creek Watershed

Ashli DesaiLarry Walker Associates

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

303(d) List and TMDLsFoundation 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 Watershed8 TMDLs for 28 constituents by 2012

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 waterbodyAg+Urban+Wastewater+Background=TMDLBackground covers groundwater, soils, atmospheric

deposition, etc.

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

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

TMDLDevelopment

Urban Stakeholders

Agricultural Source Analysis TMDL analysis determines amount from each

source Agricultural contribution varies depending on

constituentCan also vary between wet and dry conditions

Source analysis part of analysis of how much can be discharged

Nitrogen Sources

Sources of Chlorpyrifos and Diazinon

Agriculture55%

Urban18%

POTW27%

Other<1%

Chlorpyrifos Dry Weather Current Conditions

Agriculture79%

Urban21%

POTW<1%

Other<1%

Chlorpyrifos Wet Weather Current Conditions

Agriculture19%

Urban30%

POTW51%

Other<1%

Diazinon Dry Weather Current Conditions

Agriculture62%

Urban37%

Other<1%

POTW1%

Diazinon Wet Weather Current Conditions

Metals and Selenium Sources

Sources of DDE (DDT)

Estimated DDE Loading to Water in the CCW

5% 0.2% 0%

7%

93%

0%

20%

40%

60%

80%

100%

Agric Urban POTWs GW Native

Estimated DDT Usage Map

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

Required Reductions

Constituent Calleguas

Nitrogen and algae 70%

Historic Pesticides 50-99%

Toxicity (Diazinon & Chlorpyrifos)

68-99%

Metals 38-83%

Sediment ~25%

Salts 10-73%

Load Allocations Load allocations are interim and final limits to be met

by agriculture Interim limits

Go into effect when TMDL effectiveSet at 95th/99th percentile of existing discharge dataDesigned to ensure discharges don’t increase

Final limitsGo into effect at end of implementation periodSet based on water quality objectiveDesigned to achieve water quality objectivesUsed to allocate costs for TMDL implementation

TMDL Implementation vs. Ag Waiver

TMDL Conditional Waiver

Similar Requirements

Grower Education Grower Education

Implement BMPs Implement BMPs

Similar Requirements with Additional TMDL ActionsDevelop 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

Implementation Schedule

Constituent Calleguas

Nitrogen and algae 2010

Historic Pesticides 2026

Toxicity (Diazinon & Chlorpyrifos)

2016

Metals 2022

Sediment 2015

Salts 2023

Trash 2011

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

Completed Implementation Actions TMDL Monitoring Program

Submitted plan in September 2006Monitoring begins August 2008

Special Study WorkplansSediment Transport and Habitat Impacts StudyHigh Concentration Areas for DDT and Metals and

Flood Control PracticesUrban Source Identification for DDT and MetalsAgricultural Source Identification for DDT and MetalsSelenium in Groundwater

Completed Implementation Actions Special Studies Completed

Algae, Greenhouses, and Groundwater StudiesAlternatives to Diazinon and Chlorpyrifos Study

Completed work so far has been funded by POTWs onlyWork conducted from 2007 to date to be reimbursed

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

Upcoming Implementation ItemsNot Covered by Conditional Waiver Conduct work for submitted special study

workplans Develop workplans and conduct work for

optional studiesCopper WER for RevolonSSO for Mercury and Selenium

Implement historic pesticide collection program

Cost of Implementing TMDLs

Implementation Action Approximate 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 Actions To Be Determined

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

Cost Allocations by TMDLResponsible

PartyNutrient DDT and

SedimentToxicity Metals Overall

POTWs 68% 1% 29% 15% 28%

Urban 0% 27% 37% 33% 24%

Agriculture 32% 72% 34% 52% 48%

Agricultural Share of Costs 2007-2009

Implementation Action Approximate 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

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

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 dischargesDoesn’t protect against lawsuits from othersCalleguas group continuing TMDL implementation

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