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Phosphate-Based Treatment of Contaminated Land in Jasper County, Missouri Missouri Department of Natural Resources David E. Mosby, RG dave.mosby@dnr.mo.gov 573/751-3356 Slide 2 Two Separate EPA Grants Bioavailability of Lead Contaminated Residential Soil treated using In Situ Phosphate Abandoned or Former Lead/Zinc Mine Reclamation Demonstration Slide 3 1994 lead exposure study done by the Missouri Department of Health and Senior Services 14% of the children had elevated blood lead 25% of the children near the smelter had elevated blood lead EPA began Lead Strategy - started sampling thousands of homes all over Joplin Residential Soil Background Slide 4 Lead Contamination in surface soils over 800 ppm in Joplin, MO Slide 5 EPA ROD on Residential Soils Excavate soil above 800 ppm Pb Replace garden soils above 500 ppm Pb Provide loaner HEPA Vacs Soil Repository covering mill waste Long-term Health Education and blood-Pb screening Phosphate treatment above 500 ppm Pb, if proven effective. Slide 6 Slide 7 5 Pb 2+ + 3 H 2 PO 4 - + Cl - ----> Pb 5 (PO 4 ) 3 Cl + 6H + log K = -25.05 PHOSPHATE TREATMENT Working Hypothesis Addition of phosphoric acid to Pb contaminated Joplin soil will result in formation of chloropyromorphite and reduce the Pb bioavailability and solubility. Slide 8 Bioavailability Testing Using Immature Swine Pigs fed soil + feed by hand after fasting 15 pigs dosed per soil at 3 different dose ranges Pigs dosed for 15 days 12 Blood Pb at various times + femur, kidney, liver samples analyzed per pig Bioavailability value combination of tissues, but heavily weighted toward blood-Pb Slide 9 Study Design I. A. Soil Characterization and Bench Treatment of Smelter Soils I. B. Dosing of Treated and Untreated Bench Soils to Immature Swine to Determine Bioavailability II. A. Field Treat Soils and Characterize Pb and Distribution II. B. Dosing of Treated and Untreated Field Treated Soils Slide 10 Study Design cont. III. A. Incubation of Bench Soils III. B. Dosing of Incubated Soils IV. Dosing of Field Soils Over Time to Pigs V. Analyze Plant Tissue in Field Plots Over Time Slide 11 Metal Analysis of Test Materials Slide 12 Slide 13 Slide 14 Slide 15 Slide 16 Slide 17 Slide 18 Plans for Implementation Intend to implement at ~500 residential properties in Jasper County Will apply to properties with soil between 400 - 800 ppm Pb Should take 3-4 days per property Costs estimated between 1/2-1/3 soil removal= $4000-$5000/yard MDNR hopes to implement as part of state match Slide 19 Former and Abandoned Pb/Zn Mine Demonstration Project Slide 20 Project Description Jasper County Site Revegetation Using Biosolids Enhanced Wetland Close mine shafts Slide 21 Slide 22 Barren Chat & Tailings Slide 23 Organic Amendments Selected organic amendments from local sources were utilized. Mushroom compost Mizzou Doo Composted chicken litter Uncomposted turkey litter City of Springfield composted sewage sludge Topsoil Soil repository Slide 24 Phosphate Treatment Phosphate in organic matter mushroom compost 0.36% composted chicken litter 1.73% turkey house litter 1-2% composted sewage sludge 1.9% Inorganic phosphate - added 2500-5000 ppm P as TSP to highly contaminated areas Slide 25 Organic Matter Application Slide 26 Upland Site 1 Year Post Reclamation Slide 27 Center Creek Site 6 Months Post Reclamation Slide 28 Pre & Post Treatment Sampling Storm water plant tissue soils/sediment groundwater Slide 29 Slide 30 Slide 31 EPA study on impacts of Biosolids application in Jasper County Metals in worms in biosolids lower than those found in control Biosolids application does not pose ecological risk Slide 32 Slide 33 A happier duck!!!