Newton Creek & Hog Island Inlet Contaminated Sediment Remediation Project

Transcription

1 Newton Creek & Hog Island Inlet Contaminated Sediment Remediation Project

2 The St. Louis River is the largest U.S. tributary to Lake Superior The Area of Concern is shared by Minnesota and Wisconsin AOC includes the 39 miles of the St. Louis River, its estuary & bays, including Superior & Allouez Bays, & the Nemadji River. Newton Creek flows 1.5 miles into Hog Island Inlet a 17 acre embayment of Superior Bay.

3 Site Location

4 Murphy Oil s Impoundment

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6 Newton Creek Creek is approximately 3 wide and 6 deep at normal flow levels Floodplain is heavily vegetated with wetland plants and trees Creek typically flows at 1 cfs into Hog Island Inlet. Segment L - affected by seiche currents

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10 Hog Island Inlet Approximately 17 acres. Connected to Lake Superior Bay via a narrow channel. Water depth ranges from 1 to 7 feet. Sediment in both NC and HI Inlet are fine grained materials (silt and clay). Affected by seiche currents

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13 Project History Early 1990 s studies found elevated levels of PAHs, diesel range organics, oil, grease, and heavy metals 1995 Murphy Oil constructs new Wastewater Treatment Plant Memorandum of Understanding Murphy Oil removes contaminated sediment from their impoundment and Segment A of Newton Creek Department removes 7,400 tons of contaminated sediment and soil from Segments B-K, of Newton Creek Murphy Oil constructs wetland treatment system 2004 Application for Great Lakes Legacy Act Funding

14 Hog Island Inlet Newton Creek Studies since 1992 Identification of Pollutants of Concern, Further Needed Site Assessments, and Estimated Remediation Costs for Contaminated Sediments in Newton Creek, Hog Island Inlet, and Potentially, Superior Harbor, WDNR, April 6, 1992; Newton Creek/Hog Island Inlet Investigative Survey, Eder Associates Consulting Engineers (for Murphy), November 1993; Evaluation of Sediment Contamination at Newton Creek and Hog Island Inlet, ENSR Consulting Engineers (for Murphy), December 1993; Human Health Risk Assessment for Newton Creek and Hog Island Inlet, ENSR (for Murphy), August 1994; Assessment of Wetland Habitats Associated with the Newton Creek System, Don Reed (for WDNR), November 23, 1994; Characterization of Sediment Contamination in the Newton Creek System, WDNR, December 15, 1994; DRAFT RCRA 3008(h) Consent Order to Murphy Oil USA, Inc., Superior, Wisconsin Facility. USEPA ID No. WID USEPA, March 01, 1995 Summary of Investigation Activities - WDNR Newton Creek Feasibility Study Supplementary Site Characterization, Burns & McDonnell (for Murphy) 1995; Remedial Alternatives Array Document for Newton Creek System, RMT (for WDNR), April 1995; Feasibility Study Report for Newton Creek System, RMT (for WDNR), October 1995; Newton Creek System Sediment Contamination Site Characterization Report, WDNR, December 1, 1995; Results of Aerobic Biodegradation Screening Treatability Study for the Newton Creek System, RMT (for WDNR), January 1996; Superior Refinery Pond Closure Project Final Workplan for Newton Creek Segment A Remediation, Roy F. Weston (for Murphy), August 1997; Site Investigation Report - Newton Creek Segments B and C, SEH (for WDNR), September 2000; Preliminary Engineering Report Newton Creek Remediation, SEH (for WDNR), November 2001; Site Investigation Work Plan Newton Creek and Hog Island Inlet, SEH (for WDNR), August 2002; Remedial Investigation Report Newton Creek Segments B-K SEH (for WDNR), February 2003; Remedial Action Options Report Newton Creek, SEH (for WDNR), April 2003; Remedial Design Report and Plans Newton Creek, SEH (for WDNR), April 2003; Site Investigation Report Hog Island Inlet, SEH (for WDNR) September 2003; and Remedial Action Options Report Hog Island Inlet SEH (for WDNR) November 2003

15 Key Studies WDNR Newton Creek System Site Characterization Report indicated: Elevated levels of contaminants exist in Newton Creek and Hog Island Inlet Toxicity to exposed laboratory organisms Ecological impacts severe in several segments of Newton Creek and Hog Island Inlet SEH confirmed findings

16 Toxicity Studies Found To aquatic organisms To tree swallows Human Health Human exposures to chemical contaminants found in soils, sediments and surface water Exposure scenarios include swimming, recreational wading and fish ingestion Risks exceed regulatory guidelines due to exposure to surface water with suspended sediment concentrations

17 Newton Creek/Hog Island Inlet Sediment and Soil Contamination Polynuclear aromatic hydrocarbons (PAHs) TPAHs List of 18 nd to 11,280 ug/kg Expanded list 11,354 to 100,000 ug/kg Diesel range organics (DRO) 6.8 to 600 mg/kg Lead 7.8 to 86 mg/kg

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19 Project Goals To use community based partnerships to: Remediate the Newton Creek and Hog Island Inlet system Protect human health and the environment, Provide for healthy and safe recreational area(s), Provide quality productive aquatic habitat in Hog Island Inlet.

20 Systematic Approach Investigate degree and extent of contamination Address upstream sources first Take appropriate interim actions Turn dirt

21 Partnerships EPA/GLNPO Funding Research St Louis River CAC Local Governments City of Superior Douglas County Property Owners Murphy Oil, BNSF, Enbridge Cross Program Permits, funding, fish rescue, research Citizens

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27 Indications of Success at Segments B-K Newton Creek Taxa Richness Pre-remediation 7.8 (October 2002) Post-remediation 14.8 (October 2003) Oligochaetes no longer dominant First caddis fly larvae collected Sunfish YOY observed Analysis of sediment traps are clean

28 2005 Activities Cleanup Segment L of Newton Creek approximately 900 feet Remove approximately 40,000 cubic yards of contaminated sediments from Hog Island Inlet Funding through the Great Lakes Legacy Act, GLNPO provided 65% funding and EPA provided contract oversight to project. Earth Tech began work in early July Last sediments removed from the Inlet on November 6th

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35 Cleanup Goal 2.6 mg/kg TPAH EPA set a goal of 4.5 mg/kg Protective for chronic toxicity to benthic invertebrates Evaluated impacts of UV in setting goal

36 Remedial Plan Sediment removal Divert Newton Creek Excavate sediments to design depth Stabilize slopes Confirmatory sampling

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38 HOG ISLAND INLET CONFINEMENT WILL EMPLOY BOTH SHEET PILING AND AQUA BARRIERS SHEET PILING WILL PROVIDE ROBUST PROTECTION FROM EMBAYMENT AQUA BARRIERS WILL PROVIDE READILY REMOVABLE COFFERDAM- LIKE FEATURES TEMPORARY BARRIER NEEDED AT MOUTH OF NEWTON CREEK TO SUPPORT EXCAVATION OF SEDIMENTS IN THE DRY SHEET PILING 6 DIAMETER AQUA BARRIER

39 NEWTON CREEK WILL BE DIVERTED OVER THE SOUTHERN AQUA BARRIER DIVERSION PIPE, STARTING ABOVE THE CULVERT, WILL BE LOCATED ALONG NEWTON CREEK, UNDER THE RAILROAD TRESTLE LIMITED WATER NEAR BASE OF NEWTON CREEK WILL BE PUMPED DIRECTLY INTO CONFINED HOG ISLAND INLET

40 HOG ISLAND INLET WATER WILL BE PUMPED TO POTW STORMWATER RETENTION BASIN MAXIMUM FLOW RATE OF 1,000 GPM PROBABLY 750 GPM AVAILABLE ROUTE GOES UNDER TRESTLE AND FOOTBRIDGE DEWATERING WILL REQUIRE ABOUT 15 DAYS CONCURRENT WITH NEWTON CREEK EFFORT

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49 Fish Rescue 1,800 fish rescued Black crappie, channel catfish, common shiner, log perch, muskellunge, northern pike, white and yellow perch, rock bass, redhorse, trout perch, walleye 138 freshwater clams 38 painted turtles

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65 Hog Island Results 60,175 tons of contaminated sediments removed Beneficial reuse of 50% of material incorporated into landfill cap rooting zone and/or grading layer Decision based on 50 mg/kg lead Cleanup goal of 2.6 mg/kg met

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67 Source Control Role of other Parties Murphy Oil Wastewater Facility Improvements Cleanup of Impoundment and Segment A Constructed Wetlands Funding Access Burlington Northern City of Superior Douglas County Enbridge Disposal and Treatment Future Use

68 Funding Sources Department of Natural Resources - Environmental Fund EPA GLNPO Department of Administration - Coastal Management Section EPA GLNPO - Wisconsin Share EPA GLNPO - Great Lakes Legacy Act Murphy Oil

69 Newton Creek/Hog Island Inlet The second Great Lakes Legacy Act Project completed first On time Under budget Great project team Focus on the future

70 What s Next Local Committee studying future use Biohabitats Hog Island and Newton Creek Ecological Restoration Master Plan Sediment Assessment Study Wisconsin Waters of the St. Louis River

71 What Should Hog Island Inlet Be Now That It Is Clean Sheltered Bay Habitat: forage fish habitat: emerald and spottail shiners feeding area for common terns and other waterbirds- near common tern nesting habitat

72 Waterfowl and other bird habitat Fringing wetlands Variety of aquatic vegetation Community resource