The soy-based ink could hardly have been dry on Christine Todd Whitman’s letter of resignation as the administrator of the U.S. Environmental Protection Agency before environmental groups blanketed the media with press releases about what they wanted in her replacement. They want someone who will be “an independent voice for public health and the environment,” someone who will advocate for a “more responsible environmental policy.”

They may have had someone with those qualities in Ms. Whitman but it was clear almost from her first day that she didn’t entirely fit with the Bush administration and its push for more business-friendly regulations. As governor of New Jersey, Ms. Whitman was considered a maverick for championing legislation to reduce greenhouse gas emissions in that state by more than 3 percent by 2005, a goal that has already been achieved. As EPA administrator, Ms. Whitman watched as the United States vowed to not sign on to an international global warming treaty that required reductions in greenhouse gas emissions and she watched as President Bush reversed a campaign pledge to reduce carbon dioxide emissions.

As governor, Ms. Whitman joined other Northeastern states in a court battle to compel power plants in the South and Midwest to reduce their emissions of mercury and other pollutants. As EPA administrator, she presided over the weakening of laws aimed at making these power plants clean up.

Some good things did happen under Ms. Whitman’s watch. Tougher rules for diesel-powered vehicles, both on- and off-road, were proposed. A proposed lowering of acceptable levels of arsenic in drinking water was reversed. General Electric still must remove the PCBs it dumped in the Hudson River in New York.

Maine, however, has a lot to lose if the next head of the EPA has more regard for industry than the environment. Continuing to allow upwind power plants to spew pollutants decades after it was assumed they would shut down or clean up means people in Maine with asthma and other respiratory ailments will continue to suffer. A weakening of wetlands protections means that developments can swallow up marshes and houses can supplant vernal pools. A disregard for global warming means continued beach erosion and forest fires.

Ms. Whitman says she is leaving Washington in June to spend more time with her family. A regular critic, independent Sen. James Jeffords of Vermont summed up her tenure best: “She brought grace and leadership to the EPA at a trying time and did the best job she could under very challenging circumstances.”

As her successor will find out, many challenges remain.