A proposed natural gas export facility in Southern Maryland cleared another hurdle Thursday, when a federal review found the controversial project poses no significant risks to nearby residents' safety and no major environmental impacts.

The Federal Energy Regulatory Commission staff concluded that "with appropriate mitigating measures" the $3.8 billion project could go forward to build a gas liquefaction plant, a gas-fired power plant and to convert an existing import terminal at Cove Point, on the Chesapeake Bay in Calvert County.

Dominion, an energy company based in Richmond, Va., welcomed the conclusions of the 230-page environmental assessment. The company wants to export up to 5.75 million metric tons of liquefied natural gas annually from Cove Point, which has seen only sporadic import activity in the nearly 40 years since it was built.

Dominion Energy president Diane Leopold called the federal assessment "thorough and independent," saying it represents "another step forward in a project that has very significant economic benefits," including a projected $40 million annual tax revenues for the county. National manufacturing and building trades union groups also praised the review, which found the project could employ more than 1,000 construction workers and add 93 full-time jobs.

But environmental groups and some local citizens criticized the assessment, saying it glossed over or ignored their concerns, including the risk of fire or explosion and the potential to increase emissions of climate-warming greenhouse gases.

"FERC has failed the public once again with the release of this flimsy and deeply flawed environmental review," said Jorge Aguilar, southern regional director for Food & Water Watch. He charged that the commission is "fast-tracking" the Cove Point project.

Critics renewed their call for the commission to prepare an "environmental impact statement," which they said requires a higher standard of scrutiny and gives the public more chances to have its say. Environmental groups have intervened in Dominion's case, and have said they plan to sue if the environmental review falls short.

Dale Allison, a retired engineer who lives with his wife and two daughters less than a half-mile from LNG tanks at Cove Point, said nearby residents deserve a consideration of "worst-case scenarios," in light of recent explosions and evacuations at gas facilities in Washington and Wyoming.

Mike Tidwell, director of the Chesapeake Climate Action Network, said the review fails to fully address Cove Point's role in triggering increased greenhouse gas emissions. The availability of lucrative export markets is likely to spur more drilling for natural gas using hydraulic fracturing, activists say, resulting in leaks of climate-warming methane.

The review notes that Dominion plans to build a 3,500-foot sound barrier on the side of the facility nearest residences, and it concludes that a 60-foot-high wall will also contain any flammable gas cloud that might leak out. The plant's operations would increase the state's total greenhouse gas emissions by 2.6 percent, the reviewers found, but concluded that they could not calculate the project's overall cumulative impact on climate change.

Commission staffers did propose requiring the company to perform 82 additional measures to mitigate the project's impact. Company spokesman Jim Norvelle said Dominion was still studying those, but saw no major problems so far. He dismissed critics' complaints about the review and their threat to sue.

"Many of these arguments have been dismissed in previous cases by the courts," he said. "There is nothing new here."

Cove Point is the fourth LNG export project to get an environmental review by the federal commission. Dominion also needs approval from the Maryland Public Service Commission, which is reviewing the company's application.

Before making its final decision, the commission will take public comments on its staff's environmental assessment until June 16. In addition to submitting written comments, the public may also speak at a meeting planned Saturday, May 31, from 1 p.m. to 6 p.m. at Patuxent High School in Lusby.

tim.wheeler@baltsun.com