Physical Properties of Minesoils in West Virginia and Their Influence on Wastewater Treatment

Abstract

AbstractWastewater treatment in southern West Virginia is limited by steep terrain and shallow soil. Surface mine reclamation replaces soil materials that may be suitable for wastewater treatment. Two minesoil series, Kaymine (a loamy‐skeletal, mixed, nonacid, mesic Typic Udorthent) and Sewell (a loamy‐skeletal, mixed, acid, mesic Typic Udorthent), were selected and soil samples were collected on six reclaimed surface mines to determine texture, bulk density, water retention, and saturated hydraulic conductivity (Ksat). Kaymine had more clay and silt and higher moisture retention than Sewell. In A horizons, Kaymine Ksat was about two orders of magnitude faster than Sewell, but Ksat values were highly variable within and among sites. On two reclaimed mine sites (one Sewell and one Kaymine), tapwater or wastewater was surface applied to 9 m2 field plots over 32 wk. Leachate was collected in 50 and 100 cm wells and analyzed for chemical and microbiological properties. On the Sewell minesoil, little water was collected in wells after application, therefore water failed to move adequately in this minesoil. On Kaymine, Fe, Mn, sulfate, and suspended solids were present in all wells, indicating flushing of these materials from minesoils into wells. Nitrate (NO3)‐N was about two times greater in wastewater than tapwater and this same ratio was found in corresponding wells. Biological oxygen demand was decreased by 87% from wastewater to water in wells. Fecal coliform bacteria were not removed by wastewater passing through Kaymine soils. In general, these minesoils are not suitable for wastewater renovation based on the application methods and rates employed in this study.