Delaware River Basin Commission

Transcription

1 Delaware River Basin Commission Updating TMDLs for PCBs for the Delaware Estuary Thomas J. Fikslin, Ph.D. Namsoo S. Suk, Ph.D. Delaware Estuary Science & Environmental Summit January 24, 2017

2 Outline Background History of PCB TMDLs in the Delaware Estuary Need for Update of Stage 1 TMDLs Comparison of Loadings: Stage 1 vs Stage 2 Stage 2 Principles Proposed Schedule 2

3 The estuary consists of 5 water quality management units called Zones. EPA Regions II & III establish Stage 1 PCB TMDLs for Zones 2 5 in December Each Zone is assigned a TMDL. EPA Regions II & III establish Stage 1 PCB TMDL for Zone 6 (Delaware Bay) in December TMDL History

4 TMDL History (cont.) These TMDLs were complicated for several reasons: 1) Legal deadlines. 2) The current human health criteria of both the states and the DRBC at that time needed updating. 3) Point and non point sources were not well characterized. 4) A PCB water quality model was needed to develop the TMDLs. 5) An equitable wasteload allocation procedure was needed. 6) An implementation strategy was needed to address the concerns of stakeholders. 7) Consensus decision for a staged approach for TMDLs.

5 Stage 2 TMDLs Stage 2 TMDLs are needed to: Update the TMDLs to the revised WQ criterion, Refine loadings using consistent, high quality data, Utilize a new, more equitable wasteload allocation procedure agreed upon by stakeholders, Implement a new procedure for developing the TMDLs for each Zone, and Include a revised implementation strategy for point and non point sources as an Appendix to the Stage 2 TMDL report. Provide certainty to this long term process.

6 Stage 2 TMDLs The conceptual approach for developing the Stage 2 TMDLs involved: 1) The use of a uniform Total PCB criterion of 16 pg/l. 2) The use of a representative hydrological year (February 2002 January 31, 2003) for long term model simulations. 3) The use of an allocation procedure called Equal Effluent Concentration (EEC). 4) Use of an explicit Margin of Safety of 5% (same as in Stage 1 TMDLs). 5) Comparisons of Stage 1 PCB loadings from each source category to the current loadings from each category.

7 Stage 2 TMDLs By Zone Stage 2 TMDLs for each of the Zones 2 6 consist of wasteload allocations (WLAs) for point sources including CSOs and MS4s, and load allocations (LA) for non point sources including: Contaminated sites, Tributaries, Two upstream boundaries (Delaware River at Trenton and the Schuylkill River), and the remaining non point sources (direct runoffs and atmospheric deposition). Allocations were calculated by multiplying the daily average flows during the cycling year by a water quality target of 15.2 pg/l.

8 Point Sources 96 NPDES Permittees Penta PCB load (kg/year) Outfalls Comparison of Stage 1 and Stage 2 Annual Penta PCB loads Point Sources Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Stage 1 Load Stage 2 Load

9 Contaminated Sites Comparison of Stage 1 and Stage 2 Annual Penta PCB loads Contaminated Sites Sites: NJ 8 PA 20 DE 69 Penta PCB load (kg/year) Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Stage 1 Load Stage 2 Load"

10 Tributaries 37 Tributaries NJ 13 PA 6 DE Comparison of Stage 1 and Stage 2 Annual Penta PCB loads Tributaries penta PCB load (kg/year) Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Stage 1 Load Stage 2 Load

11 Major Upstream Boundaries Comparison of Stage 1 and Stage 2 Annual Penta PCB loads Delaware River at Trenton and Schbuylkill River 3.65 Penta PCB Load (kg/year) Delaware River at Trenton Upstream Boundary Schuylkill River Stage 1 Loads Stage 2 Loads

12 Comparison of Annual Penta PCB Loads from each Source Category 7.9 Stage 1 Penta PCB Load Stage 2 Penta PCB Load Annual penta PCB Load (kg/year) CONTAMINATED SITES SCHUYLKILL RIVER DELAWARE RIVER AT TRENTON OTHER TRIBUTARIES POINT SOURCES CSOS MS4S REMAINING NPS Source Category

13 Current Status Significant reductions (over 70%) in loading from point sources occurred following establishment of Stage 1 TMDLs through the implementation of Pollutant Minimization Plans through NPDES permits, and monitoring to track progress. The additional Stage 2 implementation requirement of Action Levels will serve to maintain loading reductions achieved. Focused effort is needed in Stage 2, however, to: 1. Further identify and reduce loadings from contaminated sites. 2. Develop and implement TMDLs in tributaries with a priority on those with the largest PCB loading. Are the loadings reductions reflected in the media???

14 PCBs in Fish Tissue Delaware River Estuary 2000 to Nanograms per gram (ppb) - wet weight Years White Perch Channel Catfish

15 Historical Trend in PCBs in Fish Tissue Crosswicks Creek - Delaware Estuary 2,000 1,800 1,600 Nanograms per gram (ppb) wet weight 1,400 1,200 1, CC 123 ppb WP 79 ppb Years Channel Catfish White Perch

16 Historical Trend in Total PCBs in Fish Tissue Tacony-Palmyra Bridge - Delaware Estuary 2,000 1,800 1,600 Nanograms per gram (ppb) - wet weight 1,400 1,200 1, Years Channel Catfish White Perch

17 Summary The adaptive management approach utilized for the PCB TMDLs for the Delaware River Estuary is working, but this approach requires periodic assessment of progress and adjustment. The Stage 2 TMDLs reflect this approach through the measurement of progress, the updating of the TMDLs, and the implementation strategy that will continue progress to achieving the TMDLs. While some progress is evident, the focus of load reductions in Stage 2 needs to shift to contaminated sites and tributaries while load reductions at point sources continue under the PMPs.

18 Acknowledgements The authors wish to acknowledge the following members of the Science & Water Quality Management Branch who contributed to the development of the Stage 2 PCB TMDLs: John Yagecic, P.E. Gregory Cavallo, P.G. Elaine Panuccio