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Landfill Water Quality Project. Paul Brooks, Lea Bullard, Leslie Harper, Amanda Strickland, Sarah van Schagen. April 30, 2004 University of North Carolina at Wilmington Department of Biological Sciences BIO 488-Forensic Environmental Science. Project Purpose.
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Landfill Water Quality Project Paul Brooks, Lea Bullard, Leslie Harper, Amanda Strickland, Sarah van Schagen April 30, 2004 University of North Carolina at Wilmington Department of Biological Sciences BIO 488-Forensic Environmental Science
Project Purpose • Determine if wastewater discharge from New Hanover County Secure Landfill is within limits set in NPDES permit • Step One: determine allowable levels • Step Two: measure/test parameters in question • Step Three: compare results with permit limits
Background Information Definitions, overview of location, description of instruments and tests
Definitions • Leachate-liquids that have percolated through land- disposed wastes • Wetland-land that is covered all or part of the time with salt- or fresh water, excluding streams, lakes, and open ocean
Definitions, continued • Biological Oxygen Demand (BOD)-amount of dissolved oxygen needed by aerobic decomposers to break down the organic materials in a given volume of water at a certain temperature over a specified time period • Measured in mg/L • Dissolved Oxygen (DO)- amount of oxygen gas dissolved in a given volume of water at a particular temperature and pressure • Measured in mg/L
Definitions, continued • Turbidity-expression of the optical property that causes light to be scattered and absorbed rather than transmitted in straight lines through a sample • Measured in nephelometric turbidity units • Total Suspended Solids-measure of solids in the water column that are not in true solution and can be removed by filtration • Measured in mg/L • Turbidity to TSS conversion formula • TSS (mg/l) = [1.075 (turbidity in NTUs)] - 1.681
Location Overview • New Hanover County Solid Waste Disposal Site, 5210 US Hwy 421 N, Wilmington, NC
Location, continued • Two leachate treatment systems in use at the landfill: • Constructed wetlands system • Traditional water treatment plant
Location: Constructed Wetlands • Artificial wetlands planted with vegetation • Untreated leachate flows via gravity through the wetlands • Natural physical and biological processes can remove pollutants like nitrogen, phosphorous, and metals
Location: Constructed Wetlands Untreated leachate enters the wetlands system here from six inlets
Location: Constructed Wetlands Leachate flows via gravity through this vegetative mass
Location: Constructed Wetlands Cleaned water is stored in a holding pond after flowing through wetlands
Location: Constructed Wetlands Leachate treated with the wetland system should be clean enough to use for irrigation of old landfill cells
Location: Water Treatment Plant • Leachate piped into package plant • Mechanical and biological processes used to remove pollutants
Location: Water Treatment Plant Leachate is treated in a more traditional package plant
Location: Water Treatment Plant Leachate is aerated to add oxygen, and microbes are added to decrease the nutrient load
Location: Water Treatment Plant Cleaned water leaving this system should meet standards for discharge into the Cape Fear River
Instrumentation and Tests • Instruments used • YSI 85 Instrument • Measures DO, salinity, and temperature • Manufacturer's spec sheet • HF Scientific DRT-15CE Meter • Measures turbidity • Manufacturer's spec sheet • Lab tests performed • BOD test • Method summary
Permits NPDES permits and allowable discharge levels
NPDES Permit Received from Sergei Chernikov, NC NPDES permitting office
Sampling and Testing Sampling process, documentation, and results
Constructed Wetlands and Treatment Plant Sampling • Took measurements of both influent waters and effluent waters of the system • Recorded results and photographed instruments during testing • Created a chain-of-custody for all samples taken
Constructed Wetlands Sampling Influent turbidity testing
Constructed Wetlands Sampling Influent turbidity testing, continued
Constructed Wetlands Sampling Influent DO testing
Constructed Wetlands Sampling • Results from testing waters coming into wetlands system: • Turbidity: 25 nephelometric turbidity units • Equivalent to 25.194 mg/L TSS • DO: 7.63 mg/L
Constructed Wetlands Sampling Effluent turbidity testing
Constructed Wetlands Sampling Effluent turbidity testing, continued
Constructed Wetlands Sampling Effluent DO testing
Constructed Wetlands Sampling Effluent BOD sampling
Constructed Wetlands Sampling • Results from testing waters leaving wetlands system: • Turbidity: 2.31 nephelometric turbidity units • Equivalent to 0.80225 mg/L TSS • DO: 7.55 mg/L • BOD5: 2.85 mg/L
Treatment Plant Sampling Effluent turbidity testing
Treatment Plant Sampling Effluent turbidity testing, continued
Treatment Plant Sampling Effluent DO testing
Treatment Plant Sampling Effluent BOD sampling
Treatment Plant Sampling Effluent BOD sampling, continued
Treatment Plant Sampling • Results from testing waters leaving treatment plant: • Turbidity: 13.58 nephelometric turbidity units (corrected by 1.42 NTU for calibration factor) • Equivalent to 12.9175 mg/L TSS • DO: 6.22 mg/L • BOD5: 15.9 mg/L
Results vs. limits Comparison of sampling results with NPDES permit limits: constructed wetlands and treatment facility
Comparison of Discharge Levels with Permit Limits:Treatment Plant
Results • Discharge from artificial wetlands was in compliance with landfill’s NPDES permit • Discharge from treatment plant was in compliance with landfill’s NPDES permit • Quality of effluent from constructed wetlands is higher than effluent from package plant
Sources Chernikov, Sergei. “Re: Requested Information.” E-mail to Lea Bullard. 24 April 2004. “Method Summary Information, BOD 5-Day Test”. National Environmental Methods Index. 24 April 2004. <http://t210dwimdn.er.usgs.gov:7777/reports/rwservlet?report=nemi_method_details.rdf+userid=nemi_pub/nemi_pub@wiport+desformat=html+destype=cache+paramform=no+p_method_id=5715>. Miller, G. Tyler Jr. Living In the Environment. 12th ed. Stamford: Brooks/Cole, 2002. “Total Maximum Daily Load (TMDL) for Sediment and Turbidity in the Waters of Granite Creek in Sitka, Alaska.” Website of the Department of Environmental Conservation of the State of Alaska. 24 April 2004. <http://www.state.ak.us/dec/dawq/tmdl/tmdl/granitecreek.htm>.