Some wells are “orphaned” Bruseth said, meaning that there isn’t a viable operator to hold responsible for closing the well. Sometimes this is just the result of operators giving well sites to the government without plugging them properly. Other times the previous owners are no longer viable due to bankruptcy. The National Park Service must find and plug these sites themselves to avoid the related methane problems.
Other wells are already sealed. In some cases parks have active “grandfathered” wells still in operation.
Recently, the NPS got help from the Bipartisan Infrastructure Law signed by President Joseph Biden on Nov. 15, 2021. Bruseth said the NPS received about $9.8 million in 2022 to find and inspect oil and natural gas sites on their land and plug and reclaim the orphaned ones. The NPS plans to plug six of these orphaned wells in Big South Fork with just over a million dollars from that law.
Inspections in the Big South Fork, he said, were still ongoing. They worked with the park, the state of Tennessee and private databases to find them.
“The older the well, the worse the information is,” he said.
In the field, inspectors look for wells using metal detectors, GPS, personal gas monitors, gas concentration monitors, anemometers to measure wind speed and “sniffers” — tools that help pinpoint the source of methane.
Then they use an equation to calculate the rate the methane is flowing out from the well.
Once the park service identifies a well as orphaned, it removes any surface equipment. Workers cut the casing below grade. A crew installs a plug and pumps cement on top of it. They then plant local vegetation to cover the site. In order to do these steps, the NPS often has to clean up old roads and bring in cement trucks and sometimes other trucks as well.