Pennsylvania’s TMDL Program

Restoring water quality

(June 2003)

What is a TMDL?A Total Maximum Daily Load (TMDL) is the amount of pollutant loading that a waterbody can assimilate and meet our water quality standards.

The TMDL process is a planning tool to develop pollution reduction goals that will improve impaired waters to meet water quality standards.

TMDL Minimum ElementsIdentify Watershed

Identify and locate pollutant sourcesEstimate existing pollutant loading

Determine assimilative capacity

Point Source NPDES Permits

Control Nonpoint Sources

List Impaired Waters

Monitor/Assess WQS Attainment

Water Quality Standards

Integrated Watershed

Plan

Clean Water Act Framework

Legal BackgroundSection 303(d) of the Federal Clean Water Act

States must identify, list and prioritize all waters were technology-based treatment requirements will not attain and /or maintain applicable water quality standards.

Total Maximum Daily Loads (TMDLs) must be established for these waters to ensure attainment of water quality standards.

EPA LAWSUIT

•EPA Region III was sued by environmental groups for not requiring PA to completeTMDLs•Settlement agreement between EPA and litigants reached in April 1997•EPA and DEP entered into MOU to complete TMDLs on a schedule

DEP Plan of ActionAssess all unassessed streams within 10 yearsAssess 100 significant lakes within 10 yearsEstablish TMDLs for all 1996 303(d) listed waters (575 segments) - in 10 years for Non-AMD; 12 years for AMD Also, prepare TMDLs for newly listed waters (403 in 1998)

Pennsylvania’sWatershed Management Cycle

A stream/watershed assessment

Streams that are impaired are put on the 303(d) list.

The TMDL is completed to address the impairments

Implementation plan developed.

Remediation activities

The watershed will be re-surveyed

The TMDL Process has 3 Steps…

1. Identify impaired or threatened waters (303(d) List)

2 Develop the total allowable load necessary to attain and maintain the applicable water quality standards (the TMDL)

3 Identify the measures necessary to achieve the allocations (implementation plan)

OR…303d List—›TMDL—›Implementation Plan

Step 1

• Identify impaired waters and put them on the Section 303(d) List of impaired waters

The Assessment Process

One of Pennsylvania’s objectives is to assess every stream in the Commonwealth.

“Unassessed Waters” biological surveys.macro-invertebrateshabitat and the watershed landscapechemical analysis

2002 305(b) Report

“Unassessed Waters” Action Summarythrough Year 2002

Miles of Streams: 83,161 miles

Assessed:52,889 miles

(63.6%)

Supporting uses: 44,504 miles

Impaired: 8,385 miles(16% of assessed)

Leading Sources of Impairment

Agriculture – 37.3%

AMD – 37.2%

Urban Runoff – 16.1%

* Based on 2002 305(b) Report

Leading Causes of ImpairmentSiltation – 47%

Metals – 34%

Nutrients – 26%

pH – 21%

Organic Enrichment/Low Dissolved Oxygen – 11.8%

Flow Alterations –10.2%

Habitat Alterations – 9%

* Based 2002 305(b) Report

Step 2

• Develop the total allowable loads necessary to attain and maintain the applicable water quality standards (TMDL)

TMDL Development• Evaluate watershed land use and all potential

sources of the pollutant causing the impairment• Develop applicable WQS goals• Use water quality and land use models to

calculate total allowable load (WLAs and LAs)• Consider impacts of background pollution,

critical, and seasonal environmental conditions• Include a Margin of Safety (MOS)• Demonstrate that the proposed TMDL can

reasonably be met• Provide for public participation

Current Categories For TMDL Development in PA

Point Source Only Impairments

Fish Consumption Advisories

Acid Mine Drainage

Lakes

Nonpoint Source Impairment

Point Source Only Impairments

Completed using existing steady state mass balance models that are used for NPDES Permit evaluationsNot many stream impairments on the 303(d) List due solely to point source discharges Point sources also addressed in other TMDL types

Fish Consumption Advisories

PCBs and Chlordane

The Fish Tissue Sample data is converted to a water column concentration to show a current loading rate

Allocations are made appropriately to point and nonpoint sources

Acid Mine Drainage

Simple mass balance using Monte Carlo SimulationMost of the problems associated with AMD are from historic mining activityFor the purposes of TMDL development, we are treating Abandoned mine discharges as nonpoint sourcesPoint sources for active mines with NPDES permits receive WLAs

Lakes (Nutrients/Sediment)Estimate current loading to the lake based on loading coefficients or watershed modeling plus point source loadingVerify this number from loading determination based on in-lake Phosphorus levelsTwo ways to determine sediment endpoint

Use the original design sediment storage capacity of the lake (used for Lake Luxembourg), orAll forest or natural quality scenario to establish the uncontrollable loading to the lake

Make appropriate allocations to aggregated land uses and point sources

Nonpoint Source (Nutrient and Sediment)

Use the loading rate from a stream that has been surveyed using PADEP bioassessment protocol and is attaining its designated uses as a basis to establish loading reductions in an impaired watershed

The reference watershed is selected based on matching size, land use, geology of the impaired watershed

Allocations are made appropriately to aggregated land use categories and point sources (NPDES permits)

Reference Watershed Approach

TMDL Submittal Committments by Year

Year Non-

AMD Cumulative

CommittmentAnnual

CommittmentSubmitted

& Approved

AMD Cumulative

CommittmentAnnual

CommittmentSubmitted

& Approved

1 1998 5% 8 8 8 0% 0 0 0 2 1999 10% 16 8 8 (7) 7 7 10 4 2001 40% 61 45 46 10% 43 33 38 6 2003 60% 91 30 20% 85 42 8 2005 80% 121 30 40% 170 85 10 2007 100% 151 30 60% 255 85 12 2009 -- 100% 424 169

Total to date - nonAMD 62 Total to date - AMD 48

12 Year Plan for TMDLs

(1996 303(d) List)

1996 List TMDLs Approved by EPA

1998 – 6 Point Sources2 Delistings8 total

1999 - 1 Lake5 PCB2 Delistings10 AMD18 total

2001 – 4 Lake10 PCB23 NPS9 Delistings31 AMD7 Delistings

84 total

(Also, 40 TMDLs from 1998 List)

Notice of Draft TMDL published in the PA Bulletin,

local newspaper and posted on DEP web site.

Minimum 30 day comment period (60 days when possible)

Public meeting to discuss each TMDL

DEP will work with Watershed Groups in

implementation of TMDLs.

Public Participation

http://www.dep.state.pa.usDirect Link: “TMDL”

Web site contains the followingCompleted TMDLs by year and Category

List of proposed TMDLs by year and Category

Five Year Plan for TMDL Development

TMDL Fact Sheets

Maps

Web Site Information