Summerlee AMD Treatment

Overview

One of the main tributaries of Wolf Creek begins at the base of a large coal refuse pile. Coal refuse was hauled and dumped at Summerlee until the late 1970’s. Summerlee contained a “gob pile” approximately one hundred feet deep, spread over a substantial portion of the site (approximately 72 acres). Water percolating through the gob pile accumulated contaminants known as acid mine drainage (AMD). In 1978 the State of West Virginia (the State) required Mountain Laurel to install a treatment plant to treat and mitigate the AMD. The water treatment system was subject to a National Pollution Discharge Elimination System (NPDES) permit obtained by New River.

In 1980 MMI purchased a portion of the surface rights of Summerlee from Mountain Laurel. The sale included a preparation plant, a series of ponds, the gob pile, and the water treatment system. Despite repeated notice, neither MMI nor Law applied for an NPDES permit authorizing AMD discharges. MMI and Law failed to operate the water treatment system effectively, allowing AMD discharges on at least sixteen occasions between March 1987 and November 1991. Over time the water quality of Wolf Creek degraded due to acidic runoff from the gob pile, and Wolf Creek was listed in 2002 as impaired by the West Virginia Department of Environmental Protection, according to section 303(d) of the Clean Water Act.

Between 1984 and 1993, the State and the Town of Fayetteville (the Town) filed a series of civil actions in state court against Mountain Laurel, the CSX entities, MMI and Law. The Wolf Creek Environmental Trust was created from complex litigation, spanning almost two decades concerning the environmental cleanup of the 241 acre site. (Learn more about the history of the Summerlee site here .)

In an effort to remove Wolf Creek from the  303(d) list, PAN has strived to fund Passive Treatment projects that treat the  AMD using a bioremediation approach.  Passive treatment systems do not require continuous chemical inputs and take advantage of naturally occurring chemical and biological processes to clean contaminated waters. Bioremediation is any process that uses microorganisms, fungi, green plants or their enzymes to return an environment altered by contaminants to its natural condition. The goal of this project is to exploit the natural processes that occur at Summerlee, thereby reducing acidity and iron discharging from the site. The natural processes occurring at Summerlee that can enhance this potential include the photosynthetic production of dissolved oxygen by eukaryotic microorganisms (green algae, euglenophytes, and diatoms) and the iron-oxidizing metabolism of acidophilic prokaryotes (bacteria). These naturally occurring phenomena are critical to the performance of the passive treatment system.

Phase 1.1 Project Gallery

Cell B Excavation & Retrofit

Engineered Iron Terrace

Baffle Retention System

Floating Wetlands

Phase 1.2 Project Gallery

Cell A Maintenance

Engineered Iron Terrace

More information on iron removal

Goals for Phase 1.1 & 1.2

The objective of Phase 1.1 & 1.2 is to reduce iron discharging from the Summerlee Site, by constructing engineered “iron terraces” that will help promote low-pH ferrous Fe(II) oxidation. By exploiting natural processes that occur on a low-pH iron terrace, emergent, anoxic, acidic water (i.e. low-pH and high Fe(II) concentration as measured at the site) can be rapidly oxidized by passing the water over natural/manipulated “iron terraces.” Iron oxidized to the ferric form (Fe(III)) can precipitate out of solution to low concentrations even at low pH values. The reduced load of iron continuing into an adjacent wetland for further treatment should significantly increase the treatment efficiency and operational lifetime of the future treatment systems. As a result of Phase 1.1, load reductions of 36% – 23% Iron (17,270 lbs/yr) and 33% – 12% Acidity (37,295 lbs/yr) have been documented. The goal of Phase 1.2 is to get iron reductions closer to 80% before moving forward with additional treatment options, and load reductions for iron are estimated at 46,491 lbs/yr. Both projects will remove thousands of pounds of iron, making Wolf Creek one-step closer to Total Maximum Daily Load allocation reductions. The implementation of Phases 1.1 & 1.2 are not a final solution to all of the problems at the site, but will enhance the operation and reduce the cost of subsequent phases.

Iron Removal Elements

1. Terraced Iron Formations (TIFs) – centimeter scale water falls (micro terraces) that promote water oxygenation and enhance the oxidation of Fe(II). Uniform sheet flow and increased surface area also aid in atmospheric oxygenation.
2. Microbes – The photosynthetic production of dissolved oxygen by eukaryotic microorganisms (green algae, euglenophytes, and diatoms) and the Fe-oxidizing metabolism of acidophilic prokaryotes are critical factors for the formation of TIFs, whereas abiotic parameters, such as water composition, flow rate and velocity, or stream channel geometry, also appear to be essential variables.
3. Water chemistry – a pH around 2.6-2.8, which permits the hydrolysis/precipitation of aqueous Fe(III), and a pH range (2.6 – 4.1) that favors a diverse microbiological community (algae, euglenophytes, diatoms, and bacteria) that enhances the oxidation of Fe(II).
4. Residence Time – The hydraulic residence time of acid mine drainage across an iron terrace is extremely important with respect to the extent of Fe(II) oxidation and Fe removal. By distributing water around the site residence times can be increased, and as a result enhance Fe(II) oxidation.

Pollutant Load Reductions

Summerlee Pollutant Load Reductions

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