AUGUSTA, Maine — In recent weeks, inspectors from the Department of Agriculture weights and measures unit have found several gas stations with pumps significantly shorting customers, but state officials can’t say if it is a trend because they are using a proprietary database system that greatly limits the ability to analyze the data collected by inspectors.

“We had one large station with 12 nozzles and six were so far out of tolerance that we ordered them immediately shut down until they could be fixed,” said Hal Prince, director of the Department of Agriculture division of quality assurance and regulations. At another station an inspector found all of the pumps were delivering less gasoline than customers were paying for.

“We usually find that one pump may be over-delivering a little while another is under-delivering a little,” he said. “It often roughly balances out.”

But not when a pump operates up to seven times outside the allowable error tolerance. Prince said in that case his inspector figured for every 1,000 gallons of fuel sold consumers were losing about $2,300.

“It can be significant,” he said. “We are talking about some consumers being significantly shorted.”

The state has just nine inspectors in the weights and measures unit, and another 29 local inspectors hired by about 100 cities and towns, with municipalities often sharing an inspector. And it is not just gas pumps they are inspecting, it is everything from weight scales in grocery stores to fuel delivery trucks.

“I would like to say we inspect every pump at least once a year,” Prince said. “But I can’t say that; we just don’t have the staff.”

He believes the unannounced inspections are deterrents to stations deliberately not repairing a nozzle that is malfunctioning or to tampering with the pumps. He said the unit also depends on consumer complaints and often does spot inspections of stations.

But in a memo dated Sept. 9, 2011, his staff reports other states have had cases of deliberate fraud.

“Several well-known retailers are knowingly overcharging the public and assuming that any fines that they pay are more than offset by the increased profit,” the memo stated.

That any stations have any pumps that are cheating consumers angers some lawmakers. Sen. Roger Sherman, R-Houlton, the co-chairman of the legislature’s Agriculture, Conservation and Forestry Committee, said with gasoline prices a dollar per gallon higher than a year ago, consumers deserve to know they are getting what they paid for.

“People put their thumb on the scales for a long time, this is certainly a new way to put a thumb on the scale,” he said. “I would think a station would know when a pump is not working right and would fix it.”

Sherman said he is very upset that the weights and measures unit cannot answer the simple question of how widespread the problem is. He said consumers need to be assured that they are getting what they pay for.

“To think that you have some station that half the pumps have to be shut down because they are not delivering the amount of gasoline or fuel that they are supposed to, that is atrocious,” he said.

Rep. Jeff McCabe, D-Skowhegan, is the lead Democrat on the committee. He shared Sherman’s outrage that some stations could have so many pumps so far off on delivery accuracy.

“Consumers should be given the correct amount of gas and need the appropriate protections if that is not occurring,” he said.

McCabe said he is very concerned that the department appears not to have the equipment they need to properly analyze what is happening in the state. He said the committee should hold hearings on the issue and Sherman agrees.

“This is something I think we really need to look at,” he said. “I am just astounded at what I am hearing.”

Sherman said if the agency’s computer system is outdated or not able to provide useful information, replacing the system with new and useful technology should be considered.

Prince acknowledges the shortcomings of the system in use. He said the issue is one often faced in state government: lack of resources. The problem with the existing database system is it must be searched by entering the names of individual gas stations. It can’t be searched using criteria such as parent companies or violations.

“It would be great to have a system that I could use to determine where to most efficiently use our inspectors,” he said. “Or to see if there are trends that we need to address. But we don’t have the resources to replace the system we have in place now.”

Sherman said lawmakers should take a look at the issue in the January session. He expects many lawmakers will be concerned about gas stations overcharging customers.