Passive Treatment Planning & Construction for DOM-1 Seep
The context.
Beaver Creek is considered impaired on the 2014 303 (d) list for aluminum, iron, pH, fecal coliform, and biological impairment. AMD affects human health by degrading human drinking water supplies and is toxic to all forms of aquatic life. Based on the 2011 Cheat River TMDL, at the mouth of Beaver Creek load allocations need to be reduced by 52.5 and 53.7 percent for aluminum and iron respectively.
Mining in the Upper Freeport Coal Seam usually exposes pyrite to air, leading to pyrite oxidation, generation of sulfuric acid, and dissolution of metals from pyrite and other minerals. This Coal Seam crops out near Beaver Creek, a tributary to the Blackwater River in Tucker County, WV. Extensive strip mining has polluted Beaver Creek with acid mine drainage, including iron, dissolved aluminum, and acidity. The Beaver Creek watershed contains seven such discharges from abandoned mining areas, of various severity.
The project area.
DOM-1 Seep is the specific source of acid mine drainage that we are targeting in this project. Dom -1 Seep receives diffuse AMD from AML WV002122, is highly acidic, and contains low to moderate levels of iron and aluminum (and manganese).
Our work plan.
FOB has already determined the quality and quantity of the AMD discharging from the site.
FOB will use its own procurement procedures and to hire an engineer to produce plans and specifications for an AMD treatment project.
We anticipate that project will consist of a flushing limestone leachbed to collect all the drainage and limit its interaction with the spoil as it flows to a settling pond. The limestone bed will be sized so that it generates enough alkalinity to neutralize the load of acidity flowing from the site. It will discharge into a settling pond, in which aluminum and iron hydroxides will precipitate out of the water column. The settling pond will discharge into a second appropriately sized leachbed and then into an aerobic wetland before finally entering Beaver Creek.
Following construction, FOB will visit the site, assess the load reduction, and negotiate with the contractor for any minor adjustments needed. FOB will maintain the relevant field logs, calibration logs, chain of custody forms, and laboratory results as electronic and hardcopies accessible in the FOB offices. Data will be submitted into a database management system and maintained by the project manager in accordance with FOB’s QAPP. In addition, throughout this process FOB will author reports and comply with all reporting requirements issued by WVDEP and OSMRE.
