Completed and Future Projects on the Cheat River and Use of Tmdl Trading
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COMPLETED AND FUTURE PROJECTS ON THE CHEAT RIVER AND USE OF TMDL TRADING Paul F. Ziemkiewicz and Jennifer S. Simmons ABSTRACT The NMLRC works with federal and state agencies and watershed groups, to implement passive treatment methods to remediate watersheds damaged by AMD. In the Cheat Watershed the NMLRC works with the River of Promise, a volunteer group dedicated to restoring the ecological health of the Cheat River. To date, NMLRC has been involved in the construction of 4 passive treatment systems in the Cheat River watershed and, in cooperation with the Friends of the Cheat (FOC), has proposed the installation of 7 additional systems in the watershed before September 2004. These systems, along with large scale AMD treatment systems proposed by WV DEP Office of Abandoned Mine Lands and US Corps of Engineers for Pringle Run and Lick Run, will remove hundreds on tons of acid from the Cheat River every year. CHEAT RIVER WATERSHED In 1995 the National Mine Land Reclamation Center joined together with Friends of the Cheat, West Virginia Division of Environmental Protection, US Office of Surface Mining, West Virginia Division of Natural Resources and several other public and private organizations to form the River of Promise. The River of Promise is a collaborated effort by academia, industries, government agencies and citizens groups to address acid mine drainage problems in the Cheat River Watershed. Some state agencies estimate that approximately 200 miles of streams in the Cheat River Watershed have been impacted by acid mine drainage. Most of those miles are within the Preston County portion of the watershed. The largest contributors of acid load to the Cheat River are the streams within the Big Sandy Creek, Greens Run, Pringle Run, Lick Run, Heather Run, Muddy Creek watersheds. Several passive treatment systems have been installed in the Big Sandy, Sovern Run and Greens Run watersheds since the formation of the River of Promise in 1995. Passive systems at Big Bear Lake and McCarty Highwall in the Beaver Creek, a sub watershed of Big Sandy Creek, have significantly influenced water quality in the mainstem of Beaver Creek to the point that many native fish species are thriving. In addition, large-scale AMD treatment systems are being proposed by WV DEP Office of Abandoned Mine Lands and US Corps of Engineers for Pringle Run and Lick Run. COMPLETED PROJECTS Big Bear Lake Big Bear Lake is a 35-acre recreational lake located near Hazelton in Northeastern Preston County, West Virginia. Although the area was never mined, the lake receives acid water from natural bogs and local, acid forming rock. This increases acidity and reduces pH of nearby streams, which serve as the headwaters for Big Bear Lake and, subsequently, Beaver Creek. Prior to construction, the pH of the lake was about 4, however it was only moderately acidic (20 mg/L) and contained little to no metals. In spring of 1999 a 100-ft open limestone channel (OLC) was constructed between the two ponds above the main lake. In addition, a limestone leach bed (LS Bed) was constructed downstream of the swimming pond. The leach bed was constructed using 1500 tons of limestone and receives water from the swimming pond through a pipe. During high flow periods water also exits the swimming pond through two large culverts, which run underneath the dam road. In September 2000 a second OLC was constructed parallel to the LS Bed to treat this overflow water. A second, smaller limestone leach bed was also constructed in September 2000 above the Top Pond to boast the alkalinity of water entering subsequent systems. Although, there have been some seasonal variations in the data due to high flows associated with winter and spring snow melt, on average the site has continued to discharge net alkaline water into the headwaters of Beaver Creek. Currently the pH of water discharging the lake is 4.6 and contains 2.2 mg/L of alkalinity. By the time this discharge reaches Mt Dale Church Rd, approximately 1 mile downstream, the pH has increased to 5.6 and remains net alkaline. McCarty Highwall The McCarty Highwall is an abandoned surface mine site located about 10 miles Southeast of Bruceton Mills in Preston County, West Virginia. Prior to construction at McCarty, water seeping out along an old spoil pile was flowing into a channel and mixing with a second spoil seep approximately 500 ft downstream. These two seeps form a small stream that flows south into Beaver Creek and eventually into the Cheat River. Along the way the stream picks up several other small AMD seeps. A 1997 reconnaissance study by the Corps of Engineers showed the first seep was moderately acidic with a pH of 4.1 and a net acidity of 27.5 mg/L. The second seep was similar with a pH of 3.9 and 24.5 mg/L acidity. In October 2000, a series of open limestone channels (OLCs) and steel slag leach beds were installed downstream of seeps 1 and 2. The leach beds consisted of a settling basin and steel slag check dam. Both check dams were formed from approximately 150 tons of steel slag and rip rapped along the downstream side with 6-8 ” limestone rocks. A 200 ft open limestone channel (OLC #1) was constructed from the upper spoil seep to the edge of the first settling basin. A secondary OLC (OLC #1b) was constructed to the left of OLC #1 to carry AMD from an intermittent spoil seep to the first basin. Water leaches from the basin through the center of a steel slag check dam and enters a 300 ft open limestone channel (OLC #2). OLC #2 exits into the second settlement basin, along with water from a 100 ft open limestone channel (OLC #3) constructed at the seep 2 site. Water enters into settling basin #2 from OLCs #2 and #3 and exits the system through a second steel slag check dam and forms the headwaters of an unnamed tributary of Beaver Creek. Initial water samples collected from the leach beds contained extremely high concentrations of alkalinity (1479-1513 mg/L) and high pH values (11.6). However, by the fourth month, alkalinity had fallen to about 30 mg/L (pH 9.0). Since that time both pH values and alkalinity concentrations have appeared to stabilize between 20-30 mg/L. However, samples taken during the month of December show that SLB #2 was discharging net acid water (11 mg/L acidity) at a pH of 6.2. It is difficult to predict if this trend is due to the exhaustion of alkalinity from the slag or to high flow situations caused by snowmelt. Middle Fork of Greens Run The Greens Run watershed, in Central Preston, County, West Virginia is severely impacted by acid mine drainage (AMD). One of the primary acid sources to Greens Run occurs in the headwaters of the Middle Fork of Greens Run. Mining in this area has significantly altered surface topography and downstream water quality. An acidic pit lake and down slope spoil seep transport an average of 164.1 tons of acid per year to the Middle Fork of Greens Run. High alkaline steel slag and limestone were used to increase pH and alkalinity and decrease iron, aluminum and manganese concentrations of AMD discharging into the Middle Fork of Greens Run. Treatment was accomplished through the construction of: • a steel slag check dam and a freshwater leach bed within the pit lake, • steel slag and limestone lined channels from the pit lake to the sump, • a slag infiltration bed above the spoil seep, • a kisch slag basin at the spoil seep, • a settling pond, which receives treated water from the open limestone channel and kisch basin, and a limestone check dam downstream of the settling pond. Construction of the Middle Fork site was completed on 10/7/02. The initial post- construction sampling event was conducted on November 14, 2002. At this time, water downstream of the pit lake slag check dam was pH 10.5 and contained 41.3 mg/L of alkalinity. However, the pit lake had not yet begun discharging into the top of the OLC. Additionally, the kisch basin did not appear to be sufficiently neutralizing the acidity of the spoil seep discharge. In December, when the lake was sufficiently filled and discharging, it was discovered that, during construction, the top of the OLC was set above the top of the slag check dam. Therefore, the seep water was flooding the dam and flowing across the top of the lake and not through the slag check dam as originally designed. During this sampling event, water discharging the lake had a pH of 4.1 and was only slightly alkaline (0.6 mg/L). Therefore, since the kisch basin is not sufficiently neutralizing the acid seep downstream, the site continues to discharge net acid water. However, once the top of the channel is lowered to below the top of the slag check dam, water exiting the lake should have a higher alkaline load and be able to neutralize much of the acid entering the system downstream. PROPOSED PROJECTS Sovern Run # 62 Upgrade During the winter of 1997/98 a passive AMD treatment system was installed at the #62 site to treat acidic water discharging from an abandoned Freeport underground mine. Water was discharging from the mine through a collapsed portal approximately 100 ft above Sovern Run. This discharge had a pH of 3.2 and added nearly 748 mg/L of acid, 76.8 mg/L Fe, 98.1 mg/L Al and 11.1 mg/L of Mn into the mainstem of Sovern Run.