Large water and sewer users in the city still aren’t sure what to think about proposed rate increases that Lawrence city commissioners are scheduled to discuss Dec. 14.

About a dozen representatives from large users attended a informational meeting on Tuesday with the Lawrence Chamber of Commerce. Several said they were still trying to determine just how much proposed rate increases would affect their businesses.

“What we know at this point is that it could be a significant increase for us,” said Jim Long, director of facility planning and management for Kansas University.

Long said one estimate had the university paying a total of $750,000 more for sewer services during the next five years.

Several business representatives said the proposed sewer rate increases were creating more concern than the proposed water rate increases. Commissioners are considering two options for water rates. Both would increase the monthly bills of typical industrial and commercial water users by less than 5 percent.

The lone proposal city commissioners are considering for sewer rates, though, would increase monthly bills for most industrial and commercial users by more than 25 percent.

Residential sewer rates also would rise significantly, anywhere from 10 percent to 20 percent for typical users. A large portion of the new revenue would be used to pay for a long-talked-about sewage treatment plant on the Wakarusa River.

That plant has left some business managers with conflicted thoughts.

“I have some concerns about that plant,” said Steve Brown, engineering manager at Berry Plastics. “It is a big, bold step for a relatively small city. But I guess the city is just doing what it has to do. The city is growing.”

Chamber officials said they weren’t taking an official position on any of the water or sewer rate proposals, but rather were urging city commissioners to think long and hard about the effects the increases would have on both residents and businesses.

“If we didn’t have some concerns about possible impacts, we wouldn’t have spent several months discussing and researching this issue,” said Lavern Squier, president and chief executive of the chamber.

City commissioners are scheduled to discuss the rate increases at 6:35 p.m. at their meeting on Dec. 14.