The planned expansion of the Cove Point liquefied natural gas terminal in Calvert County will not be derailed by allegations that imported gas from the site caused thousands of leaks in Prince George's County, a plant spokesman said.

Karl Neddenien of Richmond-based Dominion Resources Inc., which owns the plant, dismissed statements by Washington Gas officials last week that imported natural gas from Cove Point was "the key contributing factor" in the leaks in southern Prince George's.

He said the allegations were unfounded and would have no effect on the expansion project, which is scheduled to begin next year and would nearly double the plant's storage capacity and pump tens of millions of dollars into the Southern Maryland economy.

"The problem is not with Cove Point gas; it is with the condition and maintenance of Washington Gas's pipe couplings," Neddenien said. He said the seals in the couplings of underground pipes where the leaks occurred are 30 to 50 years old.

The dispute over the cause of the leaks centers on divergent interpretations of a Washington Gas-sponsored report released Thursday. The report identified three factors contributing to the leaks: the age of the couplings, the chemical composition of the gas and seasonal temperature fluctuations.

Timothy J. Sargeant, a spokesman for Washington Gas, said the leaks occurred in a 100-square-mile area of Prince George's that receives imported gas from Cove Point. Areas where domestic or blended gas passes through similar couplings did not have a similar increase in leaks.

"Age and temperatures are constant factors throughout our system," he said. "The one factor that is different there than in other areas is the gas composition."

Dominion said in a statement that Washington Gas was mischaracterizing its own report and called on the utility to "immediately cease and desist" from referring to imported gas as the key cause of the leaks. Neddenien said the 41-page report, prepared by Groton, Mass.-based Environ International Corp., points out that imported liquefied natural gas, known as LNG, will not cause leaks by itself.

"There is no fundamental incompatibility between re-vaporized LNG and the compounds" used in the seals, the report said. "In fact, we would hypothesize that properly installed seals exposed only to re-vaporized LNG would function well for decades also."

Sargeant said Washington Gas stood by its previous statements but emphasized the utility's commitment to working with Dominion and its continued support for the Cove Point expansion.

"This should not be considered as an indictment of Cove Point gas," he said. "We do see the important value of liquefied natural gas as an important addition to our portfolio."

The increased public focus on gas leaks renewed concerns among some Calvert County residents who oppose Dominion's plan to build a 47-mile natural gas pipeline through Southern Maryland. A local group, Concerns About Pipeline Expansion, said Dominion's suggested path will harm the environment and undermine land preservation efforts.

Brian Ferguson, a member of the group and a St. Leonard resident whose property lies in the proposed path of the pipeline, said the Washington Gas report has highlighted a major problem with Dominion's imported gas.

"That's always been one of my concerns: the safety, or lack thereof, and how it could affect us," he said.

Neddenien said Dominion's gas supply and pipelines are safe and in compliance with federal standards.

Damon A. Hill, a spokesman for the Office of Pipeline Safety, a federal agency that oversees the nation's 2.3 million miles of natural gas and hazardous liquid pipelines, said the department is looking into issues raised by the Washington Gas report.

But Hill said the leaks in Prince George's are not likely to affect federal approval of a new Dominion pipeline from the Cove Point terminal.

"They are not related," he said. "The concern is not about the transmission lines coming from Cove Point; it's about the Washington Gas distribution line.