LEWISTON — The Town Board, with little fanfare or discussion, unanimously passed a sewer use law Monday that prohibits discharge of any industrial waste from the operation of a hazardous waste-treatment facility into the town’s public sewer system.

Chemical Waste Management, the only company affected by the measure, currently does not use the town sewer system and stores all its waste on site, but company landfill-expansion proposals have raised concerns that this could change.

Town Attorney Joseph L. Leone Jr. said that under the newly adopted law, it is illegal for someone who discharges hazardous waste to do so into the town sewer system.

Leone said that the Town Board last month agreed to amend the sewer code to delete solid-waste disposal facilities from the new local law, which would therefore not affect Modern Disposal.

During the public hearing Monday, there was no comment from CWM, but the company’s general counsel said in a letter to the board that the law singles out one industry and called the law an abuse of the town’s municipal power.

“The town is entitled to regulate what may be released into its sewer system; however, it must do so in a nondiscriminatory manner,” wrote John S. Skoutelas, who also is a CWM vice president.

Citing the 14th Amendment to the Constitution, he called the distinction of “hazardous waste” improper, contending that it creates an irrational and unreasonable classification that denies CWM equal protection under the law.

Skoutelas also called the current town administration “openly hostile” and said the purpose of the law was to target and harm one business. He said the company intends to pursue all legal remedies.

CWM spokeswoman Lori Caso attended the meeting but declined to comment, saying, “You have the letter.”

Town resident Amy H. Witryol spoke for quite some time in favor of the local law.

“The best thing we can do for the Niagara River is to reduce the amount of leachate that’s going to go into that river,” Witryol said. “And even though CWM says they don’t need that facility [for their expansion], I believe they will have a great deal of difficulty expanding without it.”

Witryol pulled out a long list of fines that regularly had been imposed on CWM as part of its regular operations in the last several years and stressed the need to regulate the industry.

“I would disagree with CWM [that this is discriminatory],” she said. “This is like any industry operating in the Town of Lewiston. This law applies to any facility. How do we make the discharge safer?”

Supervisor Fred M. Newlin II called the law “a good idea” after its passage.

“As we are faced with more and more contaminated water issues in the future,” Newlin said, “not just in Lewiston but in all of America, as fresh water becomes a more precious resource, I think we are smart to protect this any way we can.”