Research conducted for a legislatively mandated study in West Virginia has “found little concern” for the leachate associated with cuttings from unconventional oil and natural gas drilling that were properly disposed in permitted landfills.
The report was completed on behalf of the West Virginia Department of Environmental Protection (WVDEP), which was required under a law passed last year to study the public health impacts of drill cutting disposal (see Shale Daily, March 18).
Six of the state’s 22 landfills currently accept the cuttings, which are small pieces of rock that break away during drilling and return to the surface during flowback. The issue has been a contentious one, compounded after a WVDEP memo leaked in 2013 acknowledged that solid waste disposal was on the rise as a result of the state’s Natural Gas Horizontal Well Control Act of 2011, which required drill cuttings to be disposed of in regulated landfills (see Shale Daily, Jan. 13, 2014).
The Marshall University Center for Environmental, Geotechnical and Applied Sciences led the study.
“The researchers found little concern with regards to the leachate from drill cuttings that were placed in approved and permitted landfills, once that leachate was processed through a correctly operated treatment facility,” wrote WVDEP Secretary Randy Huffman in a letter submitted to legislators with the report earlier this month.
The study evaluated the four landfills with the highest monthly tonnages of drill cuttings and compared them to additional landfills that have not received the materials. Chief among the findings were that substances of concern found in leachate from drill cuttings, such as chloride, arsenic, barium, strontium and benzene were also found in the leachate at landfills that don’t accept cuttings, with the exception of barium.
Industry opponents and environmental groups in the state had also cited concerns about the naturally occurring radioactive properties in drilling cuttings and their effects on public health. But the study found that the rate of radioactive increases in the leachate over a short monitoring period was nominal.
“While these minimal increases may be associated with drill cutting materials, other landfilled materials may also be contributing to this trend,” the study said.
The legislature also asked the WVDEP to explore viable alternatives to disposing drill cuttings. The study, however, said that while drill cuttings generated during the shallower vertical drilling stage could be considered for alternative uses, those generated during the mud-drilling phase at deeper depths typically beyond 3,000 feet are not suitable to be reused for road building or reclaiming brownfield sites.
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