COLUMBIA — Catherine Heigel starts a job this week with one of the state’s chronic water polluters just six months after stepping down as the director of the Department of Health and Environmental Control.

South Carolina law prohibits state officials from taking a job with a company their former agency regulates for at least a year.

But Carolina Water Service, one of the state’s largest for-profit water and wastewater utilities, says that law doesn’t apply here. Its legal argument comes down to a few words stowed away in the state’s ethics law.

The former DHEC director, according to the company, wasn’t “directly and substantially” involved in any of the regulatory decisions involving Carolina Water Service during her tenure. That argument is based on a legal opinion obtained from the Columbia law firm Nelson Mullins Riley & Scarborough.

State lawmakers and government watchdogs don’t buy it. The law is meant to slow the revolving door between government and the state’s regulated industries. If the ethics rules don’t apply to a former state agency leader, they ask, who does it cover?

“I think that whether you are directly involved or tangentially involved really makes no difference,” said Rep. Gary Clary, a Republican from Pickens County who has pushed for changes to the state’s ethics laws.