The U.S. government yesterday sought a court order to close down a new Prince George's County landfill that the government charged is environmentally harmful to the adjacent Patuxent Wildlife Research Center northwest of Bowie.

County officials asserted that the landfill, opened three weeks ago, is crucial to the country's ability to dispose of refuse and closing it could eventually raise trash collection costs for county residents.

The Bevard landfill is one of four in the county, but two of these already have been ordered closed by Maryland officials and the third will have reached its capacity by 1981, a county official said.

The suit seeking to close down the landfill charged that the wildlife center already has felt adverse effects because of surface water run-offs from the landfill, which is adjacent to the 4,200-acre wildlife center. The suit charged that the landfill lacks the proper controls to prevent the runoff.

The center is the principal U.S. Fish and Wildlife Service facility for wildlife research in the eastern United States and some of its programs are "very sensitive to external disturbance," according to the lawsuit.

Further, the suit charged that the landfill will attract seagulls and other birds that feed on refuse, that these birds then will visit the ponds in the wildlife center and that this would "greatly increase the probability that disease would be spread to the endangered species" that inhabit the wildlife center.

The wildlife center, supported by an annual budget of $8 million, is the home for eight endangered birds and mammals including bald eagles and whooping cranes, according to the lawsuit.

However, a lawyer for the Maryland-National Capital Park and Planning Commission, which acquired the property for the landfill and is named as a defendant in the suit, denied the allegations.

"What they're talking about is water runoff, and that's not happening," said Thurman Rhodes, associate general counsel for the commission.

"There are streams that run from our property to their property, but there is no garbage being dumped where there could conceivably be a runoff problem," Rhodes said.

Rhodes also asserted that sediment control systems are being put in.

Yesterday, at a hearing in U.S. District Court in Baltimore, the wildlife center's assistant director testified that last Wednesday after it rained laboratory tests of a wildlife center pond showed an exceedingly high amount of sediment particles that had not been present the day before.

The lawsuit is the first action taken by a new environmental unit in the U.S. attorney's office in Baltimore. The suit was filed in conjunction with the U.S. Department of the Interior and the U.S. Fish and wildlife Service.

Ken Duncan, administrator for the Prince George's County Council, said that closing the Bevard facility could eventually raise the cost of waste disposal for county residents because the county would be forced to seek other, and likely more expensive, methods to dispose of refuse. This would probably involve prosessing the waste rather than dumping it.

The Belair landfill, one of the county's major dumping grounds for refuse, was scheduled to cease operations yesterday, county officials said. The Laurel landfill will be open in the future only for the dumping of refuse from the city of Laurel itself. That leaves one other landfill, the Brown Station Road facility for general county use, Duncan said.