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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 Slide 2 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 Slide 3 Background Information Definitions, overview of location, description of instruments and tests Slide 4 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 Slide 5 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 Slide 6 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 Slide 7 Location Overview New Hanover County Solid Waste Disposal Site, 5210 US Hwy 421 N, Wilmington, NC Slide 8 Location, continued Two leachate treatment systems in use at the landfill: Constructed wetlands system Traditional water treatment plant Slide 9 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 Slide 10 Location: Constructed Wetlands Untreated leachate enters the wetlands system here from six inlets Slide 11 Location: Constructed Wetlands Leachate flows via gravity through this vegetative mass Slide 12 Location: Constructed Wetlands Cleaned water is stored in a holding pond after flowing through wetlands Slide 13 Location: Constructed Wetlands Leachate treated with the wetland system should be clean enough to use for irrigation of old landfill cells Slide 14 Location: Water Treatment Plant Leachate piped into package plant Mechanical and biological processes used to remove pollutants Slide 15 Location: Water Treatment Plant Leachate is treated in a more traditional package plant Slide 16 Location: Water Treatment Plant Leachate is aerated to add oxygen, and microbes are added to decrease the nutrient load Slide 17 Location: Water Treatment Plant Cleaned water leaving this system should meet standards for discharge into the Cape Fear River Slide 18 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 Slide 19 Permits NPDES permits and allowable discharge levels Slide 20 NPDES Permit Received from Sergei Chernikov, NC NPDES permitting office Slide 21 NPDES permit: DO levels Slide 22 Sampling and Testing Sampling process, documentation, and results Slide 23 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 Slide 24 Constructed Wetlands Sampling Slide 25 Influent turbidity testing Slide 26 Constructed Wetlands Sampling Influent turbidity testing, continued Slide 27 Constructed Wetlands Sampling Influent DO testing Slide 28 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 Slide 29 Constructed Wetlands Sampling Effluent turbidity testing Slide 30 Constructed Wetlands Sampling Effluent turbidity testing, continued Slide 31 Constructed Wetlands Sampling Effluent DO testing Slide 32 Constructed Wetlands Sampling Effluent BOD sampling Slide 33 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 Slide 34 Treatment Plant Sampling Slide 35 Effluent turbidity testing Slide 36 Treatment Plant Sampling Effluent turbidity testing, continued Slide 37 Treatment Plant Sampling Effluent DO testing Slide 38 Treatment Plant Sampling Effluent BOD sampling Slide 39 Treatment Plant Sampling Effluent BOD sampling, continued Slide 40 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 Slide 41 Results vs. limits Comparison of sampling results with NPDES permit limits: constructed wetlands and treatment facility Slide 42 Comparison of Discharge Levels with Permit Limits:Wetlands Permit LimitsOur Results Dissolved Oxygen N/A7.55 mg/L TSS45.0 mg/L max. daily.080225 mg/L BOD545.0 mg/L max. daily 2.85 mg/L Slide 43 Comparison of Discharge Levels with Permit Limits:Treatment Plant Permit LimitsOur Results Dissolved Oxygen N/A6.22 mg/L TSS45.0 mg/L max. daily 12.9175 mg/L BOD545.0 mg/L max. daily 15.9 mg/L Slide 44 Results Discharge from artificial wetlands was in compliance with landfills NPDES permit Discharge from treatment plant was in compliance with landfills NPDES permit Quality of effluent from constructed wetlands is higher than effluent from package plant Slide 45 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.. Miller, G. Tyler Jr. Living In the Environment. 12 th 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..