Pennsylvania s TMDL Program

Transcription

1 Pennsylvania s TMDL Program Restoring water quality (June 2003)

2 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.

3 Clean Water Act Framework Water Quality Standards Monitor/Assess WQS Attainment List Impaired Waters TMDL Minimum Elements Identify Watershed Identify and locate pollutant sources Estimate existing pollutant loading Determine assimilative capacity Integrated Watershed Plan Point Source NPDES Permits Control Nonpoint Sources

4 Legal Background Section 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.

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

6 DEP Plan of Action Assess all unassessed streams within 10 years Assess 100 significant lakes within 10 years Establish TMDLs for all (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)

7 Pennsylvania s Watershed 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

8 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

9 Step 1 Identify impaired waters and put them on the Section 303(d) List of impaired waters

10 The Assessment Process One of Pennsylvania s objectives is to assess every stream in the Commonwealth. Unassessed Waters biological surveys. macro-invertebrates habitat and the watershed landscape chemical analysis

11 Unassessed Waters Action Summary through 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) (b) Report

12 Leading Sources of Impairment Agriculture 37.3% AMD 37.2% Urban Runoff 16.1% * Based on (b) Report

13 Leading Causes of Impairment Siltation 47% Metals 34% Nutrients 26% ph 21% Organic Enrichment/Low Dissolved Oxygen 11.8% Flow Alterations 10.2% Habitat Alterations 9% * Based (b) Report

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

15 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

16 Current Categories For TMDL Development in PA Point Source Only Impairments Fish Consumption Advisories Acid Mine Drainage Lakes Nonpoint Source Impairment

17 Point Source Only Impairments Completed using existing steady state mass balance models that are used for NPDES Permit evaluations Not many stream impairments on the 303(d) List due solely to point source discharges Point sources also addressed in other TMDL types

18 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

19 Acid Mine Drainage Simple mass balance using Monte Carlo Simulation Most of the problems associated with AMD are from historic mining activity For the purposes of TMDL development, we are treating Abandoned mine discharges as nonpoint sources Point sources for active mines with NPDES permits receive WLAs

20 Lakes (Nutrients/Sediment) Estimate current loading to the lake based on loading coefficients or watershed modeling plus point source loading Verify this number from loading determination based on in-lake Phosphorus levels Two ways to determine sediment endpoint Use the original design sediment storage capacity of the lake (used for Lake Luxembourg), or All forest or natural quality scenario to establish the uncontrollable loading to the lake Make appropriate allocations to aggregated land uses and point sources

21 Nonpoint Source (Nutrient and Sediment) Reference Watershed Approach 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)

22 12 Year Plan for TMDLs ( (d) List) Year Non- AMD TMDL Submittal Committments by Year Cumulative Committment Annual Committment Submitted & Approved AMD Cumulative Committment Annual Committment Submitted & Approved % % % (7) % % % % % % % % % Total to date - nonamd 62 Total to date - AMD 48

23 1996 List TMDLs Approved by EPA Point Sources 2 Delistings 8 total Lake 5 PCB 2 Delistings 10 AMD 18 total Lake 10 PCB 23 NPS 9 Delistings 31 AMD 7 Delistings 84 total (Also, 40 TMDLs from 1998 List)

24 Public Participation 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.

25 Web Site Information Direct Link: TMDL Web site contains the following Completed TMDLs by year and Category List of proposed TMDLs by year and Category Five Year Plan for TMDL Development TMDL Fact Sheets Maps