Maryland's counties and cities say they will need to spend billions of dollars to take the extra steps needed to restore the Chesapeake Bay to health by 2020, the deadline the state gave them for action.

In cash-strapped Baltimore, for example, officials estimate added cleanup measures will cost more than $250 million over the next six years. They say they'll seek City Council approval next month to levy a fee on all property owners to help pay for controlling polluted runoff from streets, alleys and parking lots.

Baltimore County officials project needing up to $200 million for similar projects, while Anne Arundel County foresees needing more than $1.6 billion to upgrade septic systems and to curb storm-water runoff.

Other counties, meanwhile, failed to deliver draft cleanup plans to the state by the November deadline, and still others questioned the state's targets and data.

Faced with such price tags and the need to significantly increase their pollution-control efforts, local officials have joined farm groups in appealing to the state to give them more time, relaxing the cleanup timetable to match that being used by all other bay states.

In response, Maryland Environment Secretary Robert M. Summers said in an interview that top O'Malley administration officials have agreed to stretch the state's bay cleanup action deadline by five more years, from 2020 to 2025.

Gov. Martin O'Malley had pledged that Maryland would show its leadership in the regional restoration effort by completing its plan five years earlier than other states. Under a "pollution diet" adopted last year by the U.S. Environmental Protection Agency, all six bay states must act by 2025 to achieve a 15 percent to 25 percent reduction in the nitrogen, phosphorus and sediment fouling the bay's waters.

Summers said O'Malley's "Bay Cabinet" of agency heads recently decided to back off the early deadline the state had set, though he insisted it's no relaxation of the overall cleanup effort.

"We're just recognizing the reality that this is a huge hill we're climbing here," he said. "And looking at the plans and the types of funding and so forth, it just seems clear it's just physically going to take that time frame to complete."

Summers said counties and municipalities were asked to outline what they plan to do at least over the next two years to help reduce bay pollution. Maryland is using the local plans to prepare its own bay cleanup road map for the EPA, which is due Thursday.

Calvert, Talbot and Worcester counties did not submit plans by the deadline. Talbot Planning Officer Sandy Coyman emailed that the county's strategy had to be redone because the state changed the county's pollution targets less than three weeks before the due date. The County Council approved the plan last week, he said.

Calvert's commissioners are scheduled to review their plan Tuesday, according to a county planner. And Worcester's commissioners, after expressing some discomfort with getting too specific in their plan, ordered changes to it and informed the state they'd submit it after their next meeting Dec. 20.

Carroll County submitted a report to the state of the steps it was already taking to help restore the bay but didn't propose any additional measures because of doubts about the state's pollution targets for the county. Brenda J.M. Dinne, special projects planner with the county, said officials believed the state's figures were "wildly off base" and so were wary of proposing anything based on them.

Summers said state officials would fill in the blanks for the counties that didn't propose any new cleanup efforts or didn't submit a plan at all. But the cleanup plan won't be final until July, the MDE secretary noted, so there's still time for local officials to join in and "help control their own destiny."

"The numbers are evolving," Summers said of the pollution reductions assigned to each locality. Adjustments have been and will be made as better information comes in, he said.

But the ambiguity shouldn't be an excuse for inaction, he said. "There's no danger that anybody is going to overshoot their targets using this model."

The size of the pollution reductions required to meet the EPA's baywide "pollution diet" is requiring states — and localities — to vastly increase the scope and pace of cleanup efforts.

Jenn Aiosa, senior scientist with the Chesapeake Bay Foundation, said that some local officials seem reluctant to commit to anything because of the cost estimates and questions about the computer model the state was using to assign cleanup targets. She predicted that costs would abate as experts figure out more efficient ways to reduce pollution.

"We know that especially in some counties it is going to expensive," she said. "But I think that is indicative of how much damage we have done to our watersheds over the last several decades."

According to Baltimore's draft plan, a public works staff that has managed up to six stream restoration and storm-drain retrofit projects a year would have to handle 40 projects annually, with costs topping $250 million over the next six years.

Under the city's plan, a bill would be introduced in January asking the City Council to set a storm-water fee. Officials would not say how large a fee they would propose but said it would be based on the amount of pavement and buildings a property owner has, and that credits would be given for steps taken by owners to reduce runoff from their land.

Kimberly L. Burgess, chief of surface water management in the Public Works Department, said officials are mindful of the burden additional fees place on residents and businesses, but without more funds the city cannot make the mandated pollution reductions.

In Baltimore County, officials have yet to mull storm-water fees, focusing for now on whittling down what's required of them by questioning some of the state's data and seeking credits for pollution controls already installed. But even if those appeals are granted, county officials project needing $140 million, according to Vincent Gardina, director of the Department of Environmental Protection and Sustainability.

"Eventually, unless something changes, it's going to have to come from somewhere," Gardina said of the money. The county would need essentially to double the pace of its current spending on stream restoration and other environmental projects, based on the data he provided.

Anne Arundel's public works director, Ronald E. Bowen, said officials have not figured out how they'll come up with the funds needed, including $760 million for upgrading septic systems or hooking them up to sewer, and $867 million for retrofitting storm drains. The County Council is weighing a storm-water fee, but County Executive John Leopold opposes it.

A state task force has recommended tripling the statewide "flush fee" levied on all property owners to pay for upgrading sewage plants and helping localities pay for the costly storm-water projects. The increase would require legislative action, and O'Malley has not said yet if he'll push for it.

Jeff Corbin, senior adviser to EPA Administrator Lisa P. Jackson on the Chesapeake Bay cleanup, said the steep cleanup cost estimates coming from local governments aren't surprising.

"I know some of these costs are going to appear alarming to some of those governments, but it is what Phase 2 [of the bay pollution diet planning] is about," Corbin said. "We've never gotten down to that level before."

Corbin said he suspected that at least some cost estimates are high, and that federal, state and local officials still have time to figure out how to reduce them and spread them over the 14 years remaining for the cleanup deadline.

Restoring the bay remains a priority of the Obama administration, Corbin said, though he acknowledged it's unclear if Congress is on board. The president asked for $67 million toward the cleanup this year, up from $54 million last year, and House and Senate leaders are split over whether to cut or increase last year's bay funding.

"We encourage the states and local governments to look for different ways to do this over time," Corbin said, adding: "This is not a bean-counting exercise. This is about making sure we get the pollution out."