The Success of the Marchand System
The Ponds
| The Discharge Channel |
The Pond Series |
| Clear Effluent |
The Treatment Wetland |
| The Replacement Wetland (spring) |
The Replacement Wetland (fall) |
| New Growth |
Flowering Plants |
SUCCESS!
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Treatment Performance of the System
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The system precipitates most of the iron contamination in ponds designed for sludge removal, while residual iron is removed in a constructed wetland. The design follows Robert Hedin’s patent, “Recovery of Iron Oxides from Polluted Coal Mine Drainage” (USPTO Patent No. 5,954,969). The ponds are arranged in series and water is transferred between them in troughs that are intended to lessen short circuiting.
The formation of iron oxide in the ponds is visually striking.
The system is functioning as designed. The ponds are retaining all by 10 mg/L of the iron. The wetland is intended to remove residual iron and assure a good quality final effluent. The wetland is not yet grown in, but it is already providing the intended polishing. The final discharge is clear with low iron concentrations.
The figure below shows system flow rates and influent and effluent iron concentrations.
This figure shows the effluent iron concentrations on an expanded scale.
Effective passive treatment of large flows of polluted mine water has been questioned because of concerns about handling large flows and cold weather performance. The performance of the Marchand system should allay these concerns.
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History of Mining at the Marchand Site
Our historical information for the site is obtained from the Virtual Museum of Coal Mining in Western PA. This remarkable collection of information on old mines is produced by Raymond A. Washlaski (Historian, Editor), Ryan P. Washlaski, (Technical Advisor) and Peter E. Starry, Jr. The sections on the Marchand Mine describe the coal mining and processing facility, the town of Lowber, and provides names of almost 150 men who worked in the mine, many of whom were injured or killed there.
Click here to view the Virtual Museum: http://patheoldminer.rootsweb.com/penngas3.html
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Marchand Mine Discharge Characteristics
The discharge is a result of a connection made between the abandoned Marchand and Ocean Mines in 1942. The connection into the Marchand Mine occurs through two 10 inch boreholes. The size and condition of these holes likely limits the flow that can pass into the Marchand Mine and, ultimately, out the discharge point.
The discharge is a distinct flow that is easily sampled and, with the use of a weir, is readily measured for flow rate. We have compiled information on the discharge flow and chemistry. While the discharge has polluted Sewickley Creek since the 1940s, the oldest data we have found is from the Pullman Swindell’s Operation Scarlift (OS) study between 1973 and 1975. The OS study included 26 monthly measurements of flow, pH, acidity, total iron, ferrous iron, and sulfate. Between 1998 and 2000, the discharge was sampled four times by University of Pittsburgh graduate students working under Dr. Rosemary Capo in the Program in Geological and Planetary Sciences. Since 2001, Hedin Environmental has measured the flow rate and collected water samples on a regular basis. The collected data are shown HERE. Flow rates during both studies are similar. Since 2001, the discharge flow rate has averaged 1,550 gpm. The discharge demonstrates low flow variability. The range of flow measurements is only 1,300 – 1,900 gpm. For the HE dataset, the 90% flow measurement is only 30% higher than the average flow. During this period there were two drought years (2002 and 2003) and a near record rainfall year (2004). The low variability is likely a consequence of the boreholes connecting the Ocean and Marchand Mines, which have limited capability for passing water.
The discharge chemistry has improved since the 1970s. In the 1970’s, the discharge was acidic and averaged 198 mg/L Fe tot. Since 1998, the discharge has been strongly net alkaline with an average 64 mg/L Fe tot. The iron loadings have decreased by 73%. Even with the improvement, the discharge produces about 1,200 lb/day of Fe, which is equivalent to 1900 lb/day of iron oxide solid (FeOOH).
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Iron Recovery at Lowber
LOWBER SYSTEM PERFORMANCE
POUNDS
OF IRON OXIDE
RECOVERED TO DATE
The Lowber site is the first site in Pennsylvania (and likely in the world) where a resource has been recovered from polluted mine drainage and sold as a product . The Marchand deep mine discharges 1500 gpm of water contaminated with 70 mg/L iron at the Lowber site. Over the last 50 years it has polluted Sewickley Creek and left deposits of iron sludge on this abandoned coal mining and processing facility. Iron recovery projects by Hedin Environmental and Iron Oxide Recovery, Inc. in 2001, 2002 and 2003 removed 1,500 tons of waste iron sludge from the site. The iron product was processed and sold to a pigment producer in Virginia, who refined the product and sells it as a finished earth-tone pigment to concrete, paint, and stain manufacturers.
Iron Oxide Recovery, Inc. holds a patent on the production of pigment-quality iron oxide from coal mine drainage. In 2002 the Sewickley Creek Watershed Association received a grant from the Pennsylvania Growing Greener Program to support the design and construction of a passive mine water system that is designed to optimize the production of recoverable, saleable iron oxide. The system, designed by IOR, is under construction. When completed, the system will passively precipitate and collect 750,000 lb per year of iron solids in a series of ponds and constructed wetlands. The iron will be recovered every 5-10 years. The proceeds from future iron sales will offset the long-term maintenance costs of the system. The Lowber system will be the world’s first self-sustaining mine drainage treatment system.
For more information on using mine drainage pollutants as a resource, visit our sister company, Iron Oxide Recovery, Inc. at www.environoxide.com.
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The Lowber project involved the design, permitting, and construction of a large system of ponds and wetlands that passively treats a large discharge from the Marchand Mine. The system is located in the outskirts of the small town of Lowber in Sewickley Township, Westmoreland County, PA. The site is a former slope entry, coal processing and railroad tipple facility that operated in the late 1800s and early 1900s. The mine was closed in the 1930s and in 1942 a large discharge of acid mine drainage began flowing from the mine portal. For the next 64 years, the discharge polluted Sewickley Creek with more than one ton per day of iron contamination. With completion of this project, this major source of pollution to Sewickley Creek has been eliminated. 
