Sep. 21--As the Columbia City Council votes tonight on a 2010 budget with a proposed increase in basic service rates for each city sewer user, there is a source of money that some in the Public Works Department believe is being ignored.

According to one estimate, the underbilling of sewer users could be costing the city hundreds of thousands of dollars annually -- and, going back decades, has cost millions.

The man making the most noise about sewer billing is Bill Weitkemper, 61, the city sewer maintenance superintendent and a 34-year employee of the department. Although Weitkemper declined a request for an on-the-record interview, e-mails and internal memos the Tribune obtained through a Freedom of Information Act request show that he has forcefully and relentlessly pushed to add thousands of sewer users to city billing registers for the past three years.

In July 2008, Weitkemper received an award of $3,000 for his work identifying a citywide billing mistake. But since then, he has had repeated clashes with department heads.

According to multiple e-mails by Weitkemper, he believes the city is enforcing the sanitary sewer billing ordinance haphazardly and is giving certain users preferential treatment. He believes there might be thousands of commercial users going unbilled.

The debate centers on the monthly sewer service charge of $5.30 -- proposed to increase to $6.09 -- paid by users of the city's wastewater system. In 2006, Weitkemper discovered that a large number of these users were not being billed. The city's policy was to bill users based on the number of water meters contained on a property, but on many properties -- including apartment complexes, mobile home parks and strip malls -- a single water meter serves multiple dwellings.

The result, Weitkemper said, was a massive underbilling of thousands of users. "The monthly basic sewage service charge is a relatively small charge but when it is multiplied by several thousand users it becomes a significant portion of the sewer budget," Weitkemper wrote in a 2007 memo. He added that the discovery of unbilled customers could make it unnecessary to ask users for a service rate increase in coming years.

An internal audit in 2007 proved Weitkemper was correct. It identified more than 5,800 residential users who were hooked into the city's wastewater system but were not paying the monthly fee.

Additionally, an internal review of the University of Missouri's billing found its properties contained about 8,100 sewer hookups for which MU was paying nothing -- an underbilling of more than $500,000 per year.