Rapid City Regional Airport explains why it dumps sewage without permission

The wastewater lagoon at Rapid City Regional Airport. (KOTA TV)

RAPID CITY, S.D. (KOTA TV) - Rapid City Regional Airport responds to what the South Dakota Department of Environment and Natural Resources describes as illegal dumping of thousands of gallons of sewage water in a site on airport property.

In mid-July, Rapid City Regional Airport hired a septic contractor to pump 30,000 gallons of water from their overfilled wastewater lagoon to an off-airport site.

Then in early August, out of urgency, another 74,100 gallons were pumped out to that same area.

Concerned citizens started calling the South Dakota Department of Environment and Natural Resources.

"We were getting calls that the airport was land applying the water, which was one of their options, but they had not gone through the necessary steps to get DENR's approval," said Brian Walsh, environmental scientist manager with South Dakota DENR.

Rapid City Regional Airport's Executive Director Patrick Dame said this year's heavy rain and more use of car washes for rental cars, resulted in an extra 100,000 gallons of water flowing into the lagoon.

Dame said he was under the impression that they could move forward with moving the water sewage to a flat-based area.

In hindsight, he said he would have done things differently.

"I maybe would have asked a few more questions of the DENR. We called them on the phone directly, you know that was our direct contact," said Dame.

Walsh said they immediately told the airport to stop and discussed the permit process for land application approval.

The sewage dumping is concerning for DENR.

"One of the biggest concerns is what is the water quality and will there be any runoff. If a land application is approved we want to be sure that the product that the land applying is staying where it's meant to stay and not running off the airport's property, or getting into a stream or a creek," said Walsh.

DENR sent a staff member to evaluate the area and Dame said the worker deemed their sewage problem as urgent.

Dame said in 2017, a study was done on the 55-year-old lagoon suggesting it will need to be replaced.

A contractor conducted a water test of the sewage water dumped at the off-airport location, and the results are expected to come in on Thursday.