The Perkins family in Osborne uses about 18,000 gallons of water every three months.

Dave Perkins sends the payments -- about $170 -- to the Sewickley Water Authority.

Perkins, 71, a retired district sales manager for Eastman Kodak, usually doesn't give the combined water and sewage bill a second thought. But the March bill for $784.10 got his attention. It said he had used 75,000 gallons of water from early December through early March.

"We don't use that much water in a year, let alone a quarter," Perkins said.

Since the first quarter of 1997, the most water the family has used in a quarter was 29,000 gallons in the fall of 2003. The least amount -- 9,000 gallons -- was consumed last summer.

After checking the flapper valves and overflow tubes in his three toilets and the humidifier control valve on his forced-air furnace and finding no leaks, Perkins called the water authority. He told it there must be some mistake and asked the authority to review its records.

A few weeks later, the authority replaced his 37-year-old Worthington water meter. Water authority Superintendent Ray Wolfgang said it was part of the agency's program to replace old meters and save steps for meter readers. The new meter can be read electronically from the street.

Wolfgang said high bills usually involve an exterior or interior leak. The culprit frequently is a malfunctioning commode, especially one that is out of the way and isn't often used. What appears to be an inconsequential drip from an outside or inside faucet or a tiny leak can be expensive too.

But 75,000 gallons in three months? That would constitute a lot of drips.

Perkins said he didn't have any plumbing problems during the quarter in question and hadn't had any for several years.

When I asked if he had an indoor pool or a backyard ice skating rink, he said, "I wish I did."

Perkins exchanged phone calls and letters with Wolfgang. He also appeared before the water authority board. He said the problem had to be a malfunctioning water meter, especially because of its age and the authority's decision to replace it.

Wolfgang sent Perkins' old meter to be tested. A company based in Ocala, Fla., said it was working within the standards established by the American Water Works Association.

Based on the test results, the authority said Perkins owes $784.10. But, if he pays it by Aug. 19, it will reduce the bill by $195.16 as a "one-time waiver."

"That still leaves me with a bill for $588.94," Perkins said. "That is almost $500 higher than any water bill I have paid in the last 26 years."

He is reluctant to accept the waiver because in doing so he must acknowledge there was a leak in his plumbing. I told him I didn't think he had any choice.

"But there haven't been any leaks anywhere," he said. "Somehow this huge problem solved itself without me doing a thing. The new meter showed we used 12,000 gallons from early March through early June. That 75,000 gallons remains a mystery."

Rebate roundup

The state Bureau of Consumer Protection wants to hear from consumers who are trying to obtain a $100 rebate for items they purchased at Swimming Pool Discounters stores in Ross, New Castle and Zelienople. The store purchased the rebate forms in bulk from Cashback America of Orlando, Fla.

I wrote about Mary Anne Klein's problem with the rebate offer Friday.

Among other things, consumers would have to wait almost a year to receive the rebate and only if they complied with a complicated list of terms and conditions. United States Administrative Services in Mount Dora, Fla., is handling the rebate program.

To reach the bureau, go to www.attorneygeneral.gov or call toll-free 1-800-441-2555.