Staff Report TDSnews@civitasmedia.com
March 23, 2014
POMEROY — Over the past two years, a mostly-dead creek located in the heart of Meigs County has received a new lease on life, with evident improvements in water quality and a return of fish not seen in years.
The creek in question — Thomas Fork — is located mostly in Salisbury Township and drains roughly 32 square miles from the Bradbury and Hysell Run communities behind Middleport, along Ohio 143 behind Pomeroy, up to Horner Hill, Ball Run, and the Laurel Cliff and Rock Springs communities.
The deadly culprit is acid-mine drainage, or AMD, a legacy of the neighborhood’s coal-mining past formed when pyrites and other rocks uncovered by mining are exposed to oxygen and water, forming sulfuric acid. As this acid passes over different layers of rock, it dissolves metals, including iron, aluminum and manganese and deposits them into the stream.
According to several studies conducted over the years by various agencies and universities, Thomas Fork is the most severely AMD-impacted tributary to Leading Creek. Coal mining occurred in approximately 23 percent of the watershed in the form of underground and surface mining from the late 1940s to the 1960s.
The worst contributor of AMD in Thomas Fork, out of 14 sources identified, is a small, unnamed tributary near the Ohio 143 end of Bailey Run Road. Despite its diminutive size, it has a huge effect on Thomas Fork. From the point where it enters Thomas Fork to its confluence with Leading Creek near Middleport (a distance of roughly 7.5 miles), Thomas Fork is largely devoid of quality aquatic life — or at least it was until the past couple of years.
The AMD in the “unnamed trib” discharges into the stream from underground mines and auger holes via drainage pipes installed by Ohio Department of Natural Resources in the 1980’s as part of reclamation projects to stabilize landslides and reduce soil erosion from abandoned strip mines.
Extensive pre-construction sampling at the unnamed tributary, conducted over a period of several years, indicated a typical pH of 3 – an acidity level which is toxic to almost all aquatic life, more akin to vinegar or lemon juice. Several years of year-round sampling and feasibility studies determined that the best course of action would be to “dose” the stream with lime, raising the pH to a tolerable level for aquatic creatures.
A project is born
The result was the Thomas Fork Doser Reclamation Project — a partnership between agencies at the local, state and federal level — designed and built to help neutralize acidic mine water pouring into Thomas Fork from the unnamed tributary.
The project is the result of a partnership between the U.S. Fish and Wildlife Service, the Ohio Department of Natural Resources’ Division of Mineral Resource Management and the Meigs Soil and Water Conservation District.
Dosing with limestone has been used successfully in other streams throughout the country and in southeastern Ohio to treat acidic run-off from abandoned mines.
The design was completed by ODNR-DMRM staff. Major components included the installation of 164 feet of concrete pipe, two concrete headwalls, a concrete-lined channel and foundation, construction of the doser and silo, installation of 240 feet of PVC pipe, manholes and approximately 515 tons of various sizes of stone, concrete, sidewalk, fencing and other work items.
The total construction cost was $377,416, including $171,000 for the doser machinery and structure. D.V. Weber Construction of Reedsville began construction on Sept. 12, 2011, and the doser was loaded with limestone and put into operation on Jan. 27, 2012.
The entire structure resembles a tall water tank, or perhaps an oil storage tank — a sight not uncommon in that part of Meigs County. A large silo contains the “lime,” actually calcium oxide pellets, which are dropped into the stream to neutralize the acidity.
The system, developed by Aquafix in Kingwood, W.Va., is entirely water-operated with an enclosed water wheel powering an auger beneath the silo. The calcium oxide pellets drop by gravity from the silo and are metered out by the auger into the water which is channeled back into the stream.
The doser uses about 500 pounds of lime per day or about roughly 91 tons per year. Acidic water goes in, alkaline water comes out.
“The past couple of years have been spent learning how to operate and maintain the doser,” said Jim Freeman with the Meigs SWCD, who handles most of the weekly maintenance of the doser. “Although numerous dosers are in use throughout the country, each one is different, custom-built to the stream, and it takes a series of small tweaks to get it working just right.”
Over the past two years, the Thomas Fork doser has weathered a number of floods, a drought, and most recently a couple of deep freezes, he said, adding that the doser handles floods just fine but during recent cold weather, some of the pipes froze and burst, taking it temporarily out of commission.
“We took that as a learning experience, repaired the damage, and came up with a way of dismantling it to protect it from freezing water,” he added.
The area downstream of the doser is continually monitored for water quality and to allow “fine tuning” of the doser system, he said.
“We also learned that when the creek is at extreme low flow in late summer and fall there isn’t enough water flowing from upstream to push the lime on downstream. That is a condition where further work is needed.”
“The first year of operation I noticed fish in places I hadn’t seen them before, but I wasn’t sure if it was the beginning of a trend or just wishful thinking on my part,” Freeman said.
According to ODNR-DMRM environmental specialist Jeff Calhoun, an increase in the number of fish and fish species does indicate a trend toward improvement.
The health of a stream can be determined by the quality and quantity of fish and bugs that call it home. Some species are more tolerant of pollution than others, so a high percentage of pollution-intolerant species may indicate a high-quality ecosystem.
According to the 2006 Acid Mine Drainage Abatement and Treatment Plan for the Leading Creek Watershed, five sites in the watershed were completely devoid of fish in a 2004 biological study conducted by Midwest Biodiversity Institute and Ohio University’s Voinovich School, while the lower Thomas Fork site and the East Branch had poor fish communities.
In 2011, only four fish (three green sunfish and one creek chub) were found at monitoring points in Thomas Fork downstream of Ohio 124 and Ohio 7, according to the ODRN-MRM.
The following year, the first year of doser operation, sampling at the same locations yielded 10 different species and 167 fish. This past summer, 15 species and 314 fish were found.
“It is improved, and I think we can say there is at least a trend toward improvement that was not there before the doser was installed,” Calhoun said, but as far as meeting the goals of the state, “we’re still far away.”
Jen Bowman is the senior environmental project manager for the Voinovich School of Leadership and Public Affairs at Ohio University. For the past four years she has sampled the macroinvertebrates (i.e. aquatic bugs) in Thomas Fork along with Dr. Kelly Johnson from biological sciences at Ohio University.
“We are noticing incremental changes in the macroinvertibrates found along Thomas Fork from the doser to the mouth,” Bowman said. “The appearance of mayflies where they weren’t present four years ago is an indicator of positive change.”
Bowman explained that mayflies are one of the three types of macroinvertebrates that are an indicator species, found when the water quality and habitat conditions are higher.
“They are sensitive to pollution and poor habitat,” she said, “so when we find mayflies in the Thomas Fork, we assume positive changes are occurring. There has also been an increase in the abundance of riffle beetles and caddisflies, indicating either greater food sources or better habitat.”
“I spent about seven years water sampling in and around Thomas Fork, and in that time there were many locations where life just wasn’t seen in the stream,” said Raina Fulks, former Leading Creek watershed coordinator with the Meigs SWCD and now employed with the Gallia SWCD.
“Now to hear that the stream is slowly but steadily coming back to where it should be is just so exciting. We never saw fish and bugs in these locations in the past, so I’d jump for joy to see them now.
“The fact that life is coming back to the watershed is truly wonderful. There is still plenty of work to be done, but this is the start of a recovery that hasn’t been seen here before.”
“I’m not a biologists or chemist, but it seems I’m in Thomas Fork all the time recording water quality data, taking care of the doser or adjusting the amount of lime we’re putting into the stream, and I can see fish in places where I’ve never seen fish before,” Freeman said.
“People call the office or stop by when they see me working at the doser and they’ll ask about it. It is mostly people who have seen the undissolved lime in the creek and want to know what it is or if it is bad for the creek,” Freeman said, acknowledging that the lime looks “ugly and out of place.”
“This undissolved limestone isn’t actually a bad thing, even though it looks bad. It continues to add alkalinity and gives us a ‘buffer’ in the event that we have to shut down the doser or we run out of lime.
“The ‘slug’ of lime isn’t permanent; a decent-sized storm will wash it on downstream,” Freeman said. “The proof is in the pudding, less than half a mile downstream of the doser you can see fish in Thomas Fork, in places we have never seen fish before.”
Since the alkalinity produced by the doser may not sufficiently treat other significant downstream sources of AMD in Thomas Fork, future reclamation projects are being considered to further improve the water quality in Thomas Fork.
Information regarding AMD treatment in Ohio can be found at www.watersheddata.com under the “AMD projects” tab.