Passive Treatment System Constructed"
April 2, 2004
(Aultman, PA) - Through a public-private partnership effort, the first passive treatment system in the Aultmans Run Watershed has been constructed and is successfully treating an alkaline, iron-bearing mine discharge known as the SR 286 Discharge. For the first time in over 75 years, this abandoned mine discharge will no longer flow untreated into Aultmans Run.
To tackle this discharge, the Aultman Watershed Association for Restoring the Environment partnered with Stream Restoration Incorporated, a non-profit organization experienced in the implementation of mine reclamation projects. Together with a mining company and environmental firms, the team received a Growing Greener grant to design, permit, and install a passive treatment system.
The SR 286 Discharge emanates from a large underground mine outside the town of Aultman, PA. Early PENNDOT design plans from the 1930's indicate that the discharge was moved to its current location with the construction of State Route 286. According to this plan, an 18" vitreous clay pipe conveys the water beneath State Route 286 from the mine into a trench that empties into Aultmans Run. Due to the impact of the discharge to Aultmans Run and the high visibility along heavily-traveled State Route 286, this discharge was chosen to be the first major restoration project.
Monitoring supplied by the Stream Team, AWARE, and BioMost, Inc., indicates that the discharge is net alkaline (67mg/L) with a moderate iron concentration (17 mg/L) and a maximum flow of 200 gpm. During low-flow conditions, the discharge is the major source of water to the stream. Due to this pollution, aquatic organisms within Aultmans Run have been impacted. Aultmans Run is classified as a trout-stocked fishery. One of the main goals of AWARE is to improve the health of Aultmans Run to become a viable fishery throughout its entire length.
Macroinvertebrates are important indicators of the health of streams. In a study conducted by the PA Department of Environmental Protection, Bureau of Mining and Reclamation in the summer of 2001, macroinvertebrates with low tolerance to pollution were found upstream of the discharge, while none were found downstream. Every year, over 11,000 pounds of iron enter Aultmans Run suffocating macroinvertebrates and destroying their habitat. As a result of the iron deposition, this primary food source for trout is no longer available.
Based on the available monitoring data and the accepted principles in passive treatment technology, a system consisting of a 730 SF forebay and a 25,000 SF aerobic wetland was designed to treat the discharge for an estimated 25 years. Construction began by Amerikohl Mining, Inc. on December 17, 2003 and was completed within one month.
The forebay collects the discharge and equally distributes the flow to the wetland. The wetland has a large surface area to maximize the oxidation, precipitation, and accumulation of iron. In order to provide a high wetland plant diversity to increase habitat value, the wetland has small elevation variations, known as microtopographical relief. The innovative design also incorporates a 4,000-SF existing, degraded wetland to provide additional treatment area.
Samples taken on April 2, 2004 indicate that the system is successfully removing about 10 mg/L of iron with a flow of over 175 gpm, nearly the maximum flow ever seen at the site! Below is a table of field analysis of the results:
Note: Lab pH measure in S.U.; alkalinity, acidity, D. Fe, D. Mn, and D. Al measured in mg/L; D- Dissolved
Not only is this wetland expected to remove 5.5 tons of iron from Aultmans Run every year, it also provides beneficial wildlife habitat. Later this spring, the wetland will be planted with a variety of native species with the help of Indiana University of Pennsylvania students and the local community. These plants will encourage oxidation and help filter the iron particulates from the water.
This SR286 Passive Treatment System has been a valuable project for the community and will be the model for future restoration efforts. If you would like to be involved in this project or become a member of AWARE, please contact Brian Okey at (724) 357-3766.
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