Transcript The Development of Total Maximum Daily Loads (TMDLs) in

TMDL Implementation in the
Calleguas Creek Watershed
Ashli Desai
Larry Walker Associates
Presentation Outline
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What is a TMDL?
Calleguas TMDLs
TMDL Sources
Required reductions from agricultural sources
TMDL Implementation and Costs
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
What is a TMDL?
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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.
TMDLs in Calleguas
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Effective
 Nitrogen and Algae
 Historic Pesticides (DDT,
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Chlordane)
Metals (Copper, Nickel, Zinc,
Mercury)
Toxicity
Sediment
Trash
Awaiting EPA Approval
 Salts (Chloride, TDS, Boron,
Sulfate)
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Bacteria to be developed in
next year
TMDL Development
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Calleguas Creek Watershed Management Plan
developed TMDLs
Urban Stakeholders
Agricultural Stakeholders
TMDL
Development
RWQCB/EPA
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Public review process for about a year each
Implementation coordinated with existing
programs to extent possible
Agricultural Source Analysis
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TMDL analysis determines amount from each
source
Agricultural contribution varies depending on
constituent
 Can also vary between wet and dry conditions
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Source analysis part of analysis of how much
can be discharged
Nitrogen Sources
Sources of Chlorpyrifos and Diazinon
Diazinon Dry Weather
Current Conditions
Other
<1%
Diazinon Wet Weather
POTW Other Current Conditions
Agriculture
19%
1%
<1%
Urban
37%
POTW
51%
Agriculture
62%
Urban
30%
Chlorpyrifos Dry Weather
Current Conditions
Other
POTW
27%
Chlorpyrifos Wet Weather
POTW Other Current Conditions
Urban <1%
21%
<1%
<1%
Agriculture
55%
Urban
18%
Agriculture
79%
Metals and Selenium Sources
Sources of DDE (DDT)
Estimated DDE Loading to Water in the CCW
100%
93%
80%
60%
40%
7%
20%
5%
0.2%
0%
GW
Native
0%
Agric
Urban
POTWs
Estimated DDT Usage Map
Summary
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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
Salts
~25%
10-73%
Load Allocations
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Load allocations are interim and final limits to be
met by agriculture
Interim limits
 Go into effect when TMDL effective
 Set at 95th/99th percentile of existing discharge data
 Designed to ensure discharges don’t increase
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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
TMDL Implementation vs. Ag Waiver
TMDL
Similar Requirements
Grower Education
Implement BMPs
Conditional Waiver
Grower Education
Implement BMPs
Similar Requirements with Additional TMDL Actions
Develop AWQMPs for all TMDL Develop AWQMPs for waterbodies
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
Salts
2015
2023
Trash
2011
TMDL Implementation
TMDL
Monitoring
Receiving Waterwater, sediment,
fish tissue
Agricultural land
use sites.
Coordinated with
conditional waiver
sites where
possible
Special Studies
Required studies
to answer
outstanding
questions
Optional studies
allow for sitespecific objective
development
Implementation
Actions
Identify and
install BMPs
Education
Completed Implementation
Actions
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TMDL Monitoring Program
 Submitted plan in September 2006
 Monitoring begins August 2008
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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
Completed Implementation
Actions
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Special Studies Completed
 Algae, Greenhouses, and Groundwater Studies
 Alternatives to Diazinon and Chlorpyrifos Study
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Completed work so far has been funded by
POTWs only
 Work conducted from 2007 to date to be reimbursed
Upcoming Implementation ItemsCovered by Conditional Waiver
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Develop Agricultural Water Quality Management
Plans
Identify and install BMPs
Implement Agricultural Educational Program on
BMPs
Evaluate effectiveness of BMPs
Upcoming Implementation Items
Not Covered by Conditional Waiver
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Conduct work for submitted special study
workplans
Develop workplans and conduct work for
optional studies
 Copper WER for Revolon
 SSO for Mercury and Selenium
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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
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Based on amount each
source allowed to
discharge to stream
Agriculture Discharge
Urban Runoff
 More allowable discharge,
more cost
 Different percentage of
costs for each TMDL
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Memorandum of
Agreement developed for
funding
Budget developed every
year for approval
Wastewater
Storm Flows
Cost Allocations by TMDL
Responsible Nutrient
Party
DDT and Toxicity
Sediment
Metals
Overall
POTWs
68%
1%
29%
15%
28%
Urban
0%
27%
37%
33%
24%
Agriculture
32%
72%
34%
52%
48%
Agricultural Share of Costs 20072009
Implementation Action
TMDL Monitoring
TMDL Administration
Approximate Cost
$696,000
($527,000 future
years)
$72,000
(annual cost)
Required Special Study Workplans
$21,000
Optional Special Study Workplans
$15,000
Special Study Implementation
$126,000
Summary
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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
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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
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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
Future
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Calleguas is first for TMDLs, but won’t be last
 Salts and Bacteria implementation will be added later
 Trash will be addressed separately
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Santa Clara River has effective nutrient TMDL and is
listed for:
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Salts
Bacteria
Toxicity (Diazinon and Chlorpyrifos)
Historic Pesticides
Ventura River has effective trash TMDL and is listed for:
 Nutrients
 Bacteria
 Historic Pesticides