Katherine Antos, seen in Annapolis, has been nominated for an award for her work to curb pollution in the Chesapeake Bay. (Marvin Joseph/WASHINGTON POST)

A court-imposed deadline looming, the Environmental Protection Agency needed someone to get six states, the District and the federal government to craft 15-year plans to dramatically reduce Chesapeake Bay pollution. The person would have 20 months.

Officials had been trying — and failing — to get a handle on the bay’s problems for decades. Governments have spent millions of dollars, but nobody has been able to bring bay pollution down to levels the government says would allow for a sustainable marine ecosystem.

Enter District resident Katherine Antos. Antos, 31, joined the EPA’s Chesapeake Bay Program office on May 11, 2009, a day before President Obama signed an executive order pushing for bay restoration. It turned out that Antos, a Massachusetts native whose interest in water quality began as a rower at Brown University, was the right person for the job.

On Dec. 29, 2010, two days before the deadline, the federal government established a road map based on the pollution-reduction plans Antos helped assemble. Scientists hope the map will guide strategies that will bring the amounts of phosphorus, nitrogen and sediment in the bay to government-approved levels by about 2040.

In recognition of her efforts — and the 14-hour days and tens of thousands of calls and e-mails that went with them — the nonprofit Partnership for Public Service named Antos a finalist for this year’s Service to America medals, considered the Academy Awards of federal work.

A winter scene in Annapolis near the Chesapeake Bay. Katherine Antos helped coordinate a plan to rid the bay of pollutants. (Michael S. Williamson/THE WASHINGTON POST)

The real trick, her colleagues say, was in coordinating the work of seven governments to do so. It was a “hard game,” said EPA spokeswoman Joanne Oxley, who called Antos a “mastermind at getting everyone to play.”

Antos likened her work to setting weight-loss goals — and then creating the diet plans to get there.

Under her guidance, the six watershed states and the District set target limits for bay pollution caused by daily and routine activities such as lawn fertilization and pollution caused by water flowing into the bay from roads, parking lots and other paved areas.

To achieve those targets, they crafted strategies that include changing the amount of phosphorus in lawn fertilizers, installing cleaner technology in water treatment plants and encouraging residents, businesses and governments to plant rain gardens, Antos said.

As the December 2010 deadline approached, Antos often worked from 7:30 a.m. to 10 p.m., according to her mother, Lucy Wallace, who often spoke with her at the end of long weekdays. She also worked weekends. Last summer, Antos held biweekly conference calls amid a steady flow of e-mails and phone calls from government staff members.

And, she lost her father, Jim Wallace, to esophageal cancer on Aug. 2. For about two weeks in July, she took weekend trips to Massachusetts to be with him, checking in with the EPA via conference call. Few of her colleagues knew of her father’s failing health, and she was at the office when he died.

“She just was like, ‘I can’t change the [federal] schedule. I can’t change both events, so somehow I must make it work,’ ” Lucy Wallace said. “And somehow she did.”

To help her stay focused, Antos hung two photographs on her office wall. One was a family portrait her father kept as a reminder to stay on his cancer treatment pills; the other was a picture of a tributary near her home town of Harvard, Mass., that her mother gave her to encourage her to finish her thesis at MIT.

The December 2010 deadline marked the end of a first stage for the bay project. Early next year, the watershed states and the District are scheduled to complete the second, refining their “pollution diets” and explaining how they will spread awareness about them.

Antos’s team is working on the second stage, providing more guidance and support to the participating bay watershed governments.

The governments will fully implement their diets by 2025, Antos said, although pollution isn’t projected to reach the targeted levels for about 10 to 15 years. (There have also been legal challenges to the diets: In January, the American Farm Bureau Federation, a farmers’ lobbying group,sued the EPA in federal court, saying the diets cannot be legally enforced. A trade federation filed a similar suit in June.)

Some policies, meanwhile, have already begun to change: Maryland, for example, passed a law in May limiting the amount of phosphorus in residential lawn fertilizer.

And if a state or the District falls through on its commitments, Antos said, the EPA can penalize them in a number of ways — including diverting federal funds elsewhere. Part of her team’s work amounts to regular checkups on state and partner federal agencies to make sure they stay on track, offering help when needed.

“Even all the states and EPA working together can’t clean up the Chesapeake Bay by themselves,” she said.