Total Maximum Daily Loads (TMDLs) They Have Arrived Scott Taylor, - - PowerPoint PPT Presentation

Total Maximum Daily Loads (TMDLs)
 They Have Arrived

Scott Taylor, P.E., D.WRE Michael Baker International
 May 13, 2015

Overview

▪ What is an impairment of a receiving water? ▪ What is a TMDL? ▪ Common pollutants in listed waterbodies ▪ Information for Utah ▪ How are TMDLs developed, implemented and enforced ▪ Numeric and narrative limits ▪ Some Examples and other options to comply ▪ Final Thoughts from the GAO

What is an Impaired Water?

▪ These are waters that are too polluted or

• therwise degraded to meet the water quality

standards set by states

Impaired Waters: 303(d) Listings

TMDL
 (Total Maximum Daily Load)

▪ The maximum amount (load) of a pollutant that can be discharged to a waterbody and still allow attainment of water quality standards. ▪ Pollutant load should be distributed to sources in the implementation plan ▪ The TMDL is a plan for the waterway to meet WQ standards ▪ Waste Load Allocation (WLA) and Load Allocation (LA) and MOS. ▪ Needed when permits don’t bring a waterway into compliance with WQ standards ▪ TMDL is developed for each pollutant/waterbody combination

The TMDL Big Picture

▪ Listing ▪ Planning ▪ Implementing ▪ Improving ▪ Recovery

Pollutants and Sources

▪ Bacteria

• Natural Sources (e.g. Soil litter, Bird, Wildlife)
• Homeless, septic systems

▪ Nutrients (Nitrogen and Phosphorus)

• Atmospheric deposition
• Fertilizer
• Sediments

▪ Metals

• Copper – autos, metal plating, fungicides, insecticides
• Lead – Leaded gasoline, tire wear, bearing wear, cigarettes
• Cadmium – tire wear, insecticides
• Zinc – Tire wear, motor oil, grease

▪ Sediment

• Slopes, Construction activities, logging practices, etc.

▪ Trash

• Intentional and unintentional litter

▪ Pesticides

• Pyrethroids, fpronil, indoxacarb, cyantraniliprole

Point vs. Nonpoint Sources

▪ POTW ▪ Combined Sewer Overflow ▪ MS4s ▪ Agriculture ▪ Construction ▪ Industrial ▪ Aerial Deposition ▪ Silvaculture

EPA TMDL Website

Utah TMDL Status

▪ 156 303d listed waterbodies on EPA site, 49 approved TMDLs ▪ Utah:

• Good waters 7,000 miles
• Previously impaired, now attaining: 12.7 miles
• Impaired waters 3,618.5 miles, (2,463 miles TMDL needed)
• Reservoirs: 316,554 Ac good, (126,048 Ac TMDL needed)

▪ Main impairments: Recreation and aquatic life ▪ Pollutants: Unknown, phosphorus, temperature, TDS, hydromod, sediment, selenium, boron, DO, arsenic, E. Coli, pH ▪ Utah approved TMDLs: http://www.deq.utah.gov/ProgramsServices/ programs/water/watersheds/approvedtmdls.htm ▪ Or:http://www.deq.utah.gov/ProgramsServices/programs/water/ wqmanagement/assessment/docs/2011/04Apr/IR2008/Part3/ Final_Utah_2008_IR_303d_list.2.10.2012.pdf

Utah Impaired Waters

TMDL and Waste Load Allocations

▪ TMDL= numeric target x critical flow ▪ TMDL = LADirect Air+LAOpen+WLAPOTW+WLA Storm Water

+Margin of Safety

▪ WLA Storm Water = MS4 + General Permits

TMDL Key Elements

Source Assessment

• Sewage Plants (POTWs)
• Stormwater
• Point and Non-point sources

Numeric Targets

• Water quality objective
• Sediment objective
• Human health

Linkage Analysis

• Between sources & targets

Allocation

• Both point & nonpoint

Implementation

• How, timeline & tracking

Typical TMDL Approval Process

TMDL Staff (Public Input) State Regulator Approves* EPA Approves TMDL Effective

Implementation

▪ WLA are implemented through NPDES Permits. Permit limits are set, usually with a schedule for compliance. ▪ LA – This is a potential weakness in the system. LA are implemented through State non-point source programs, which may be voluntary. There is no federal enforcement ‘hook’ for the LA portion of a TMDL. ▪ Implementation Plans – another potential weak point. ▪ Schedule: “Central among the requirements is that the effluent limitation(s)

must be met “as soon as possible.”

▪ Monitoring: “NPDES permits must specify monitoring requirements

necessary to determine compliance with effluent limitations.”

How to Get There

▪ Use integrated solutions that balance multiple

• bjectives
• Source Control
• Watershed Approach
• Existing infrastructure
• BMP Retrofit
• Collaboration
• Public Education

Structural

Watershed/Regional Source Control/Non-structural/ Public Education

TMDLs are Enforceable

▪ Delegated States Issue NPDES Permits ▪ TMDLs are enforceable through NPDES Permits ▪ Include a schedule ▪ Usually expensive ▪ No teeth in rural areas ▪ You must track progress and make sure you have input to the process!

BMP Retrofit Opportunities

Detention basins or Infiltration basins Media Filter Media Filter - Earthen

Treatment BMPs (Stormwater Devices)


Bioretention Biofilter Strip/Infiltration Trench

Copper TMDLs and BMP Performance

▪ Total Copper compared to LA Region TMDLs

Numeric and Narrative Limits

▪ TMDLs can have either numeric limits (WQS) or narrative (BMP based) limits. WQBEL can be either ▪ See EPA memo dated Nov 26, 2014 on this issue

• Include Clear, Specific, and Measurable Permit Requirements and, Where Feasible, Numeric

Effluent Limitations in NPDES Permits for Stormwater Discharges

• The CWA provides that stormwater permits for MS4 discharges “shall require controls to

reduce the discharge of pollutants to the maximum extent practicable … and such other provisions as the Administrator or the State determines appropriate for the control of such pollutants.”

• “Where the TMDL includes WLAs for stormwater sources that provide numeric pollutant

loads, the WLA should, where feasible, be translated into effective, measurable WQBELs that will achieve this objective.”

Integrated Watershed Assessment Tool for Restoration iWATR.com

Implementation Example - Caltrans

▪ Named in 84 TMDLs ▪ Variety of pollutants, waterbodies and schedules for compliance ▪ State has implemented a ‘compliance unit’ approach, and required attainment with 33,000 compliance units within 20 years. ▪ Estimated cost: $145M to $220M per year ▪ Compliance is BMP based

Other Options

▪ WERs: Accounts for the effect of site water characteristics on metal toxicity and bioavailability. ▪ QMRA: Look at the potential, using data and mathematical models to determine if bacteria exposures have human or other risk. ▪ Regulatory offramps: Pollutant not controllable by MS4, not generated by MS4, an administrative exceedence, naturally occurring.

Final Thoughts

▪ GAO Report Findings on TMDL Program:

• Pollutants reduced, but few impaired waters have

attained WQSs

• TMDLs as written ‘seldom’ can attain standards
• No adaptive process
• Nonpoint sources are a problem: 83 percent of

TMDLs achieve targets for point sources, 20 percent for NPS

• Funding is a problem

GAO Recommended Actions

▪ Issue New TMDL Regulations

• ID impairment
• Better monitoring

▪ Better Review of State TMDLs

• Better guidance
• Information on pollutant sources and abatement

actions

▪ Increase Funding for NPS programs ▪ Gather Better TMDL Program Data

Questions?

Michael Baker International Scott Taylor, P.E., D.WRE