MOUNT JUDEA, Ark. — Drilling is set to begin this week at a hog farm near Mount Judea to test the soil beneath manure ponds, according to the Arkansas Department of Environmental Quality.

The drilling will start Wednesday at C&H Hog Farms and is expected to last three or four days, according to ADEQ Director Becky Keogh.

“This investigation is a necessary and helpful part of our regulatory review process,” Keogh said. “We appreciate the owner’s cooperation in providing access to the property.”

A hole will be drilled about 120 feet deep, with soil samples collected every five feet, and any groundwater found will also be collected for testing for possible contamination.

The farm, which is allowed to have up to more than 2,500 sows and 4,000 piglets, sits on Big Creek, about 7 miles from where it flows into the Buffalo National River. Nearby residents and environmental groups have criticized the farm over fears of pollution from hog waste.

A lawsuit filed in 2013 by the Arkansas Canoe Club, the Buffalo River Watershed Alliance, the National Parks Conservation Association and the Ozark Society alleged the U.S. Small Business Administration and the U.S. Department of Agriculture Farm Services Agency failed to adequately consider the farm’s environmental impact in their first assessment of the project.

A report released last December by the two agencies after additional assessments said no significant environmental impact on the land near the river was found and concluded that construction and ongoing operation of the hog farms is unlikely to cause permanent damage to the environment.

The latest testing was requested earlier this year by opponents of the farm after they learned of research in 2015 showing what they say was an unexpectedly high amount of moisture beneath one of the ponds.

The samples that are collected this week will be transferred to Arkansas Analytical, an independent Arkansas certified environmental laboratory and results and analysis will require about six weeks to complete.

The findings are expected to be provided to the ADEQ by January 2017.

All work will be conducted under the observation of ADEQ and independent geologist Tai Hubbard.