An Oklahoma-based company pleaded guilty to a violation of the Clean Water Act and has agreed to pay a $3.1 million fine for discharging water with oil and other pollutants into the Breton Sound over a two-year period.

XPLOR Energy SPV-1, an Oklahoma corporation that has offices in Southlake, Texas, operated an offshore oil and gas platform from November 1997 until it was sold in November 2011.

Part of the production involved disposing of produced water, or brine, that comes up with the oil and gas and contains pollutants. The platform was supposed to dispose of the pollution by putting the produced water into an injection well near the platform.

However, when ownership of the well was transferred to a new company in 2011, the new company found the produced water was just being discharged directly into the water of Breton Sound, according to a news release from the U.S. Department of Justice.

The new company reported the problem, and an investigation found that not only were faulty injection lines and pipes leading from the platform to the disposal wells leaking, but the disposal wells themselves were spilling out produced water because they were too small.

“Despite knowing of this consistent discharge from the injection lines and the insufficient capacity of their disposal wells, XPLOR failed to adequately repair these faulty injection lines and disposal wells,” according to the release. The spill appeared to continue from October 2009 until November 2011.

Failing to repair these problems saved the company an estimated $1.5 million, according to the release.

As part of a guilty plea announced by U.S. Attorney Kenneth Polite on Wednesday, XPLOR will pay $3.1 million and serve a three-year probation, all subject to the approval of U.S. District Judge Sarah Vance at the formal sentencing set for March 4. The terms of the three-year probation also will be set at that time.

If the terms are accepted by the court, $2.5 million of that will go to the U.S. Treasury, with $600,000 to be paid to the Louisiana Department of Environmental Quality Trust Fund.

The case was investigated by the Criminal Investigation Division of the U.S. Environmental Protection Agency and the Criminal Investigation Division of the Louisiana DEQ.

Follow Amy Wold on Twitter, @awold10.