After being unable to agree on setting a new target date for the long-running Chesapeake Bay restoration effort, state and federal officials have decided to take six months to come up with a set of short-term goals.  At the same time, they said they hope in the spring to pick a new, more realistic deadline for cleaning up the bay's water quality, to replace the 2010 deadline they've acknowledged won't be met.

When they do gather again next year, though, they're likely to find that the elusive goal of a cleaner bay has grown even more difficult to reach.

Preliminary runs of a new, more sophisticated computer "model" of the bay suggest that a lot more pollution is washing or dropping into its rivers and streams than previously thought. 

That's according to people privy to the initial runs of the new computer simulation of the 64,000-square-mile watershed -- version 5.1, compared with the old 4.3.  The Environmental Protection Agency's Chesapeake Bay program held a two-day workshop for its water-quality steering committee recently in Shepherdstown, W.Va., to review the new model's preliminary results.

The lastest simulation, say those briefed on it, seems to confirm earlier calculations of the cleanup goal - the level of nutrient pollution at which the bay's oxygen-starved "dead zone" will shrink and underwater grasses flourish.  

While the goal may not have moved, the field seems to have gotten a lot longer, the model indicates.  Based on earlier computer modeling, for instance, officials had believed they still needed to reduce the amount of nitrogen getting into the bay by 110 million pounds to reach the level at which the water clears up.  

The new model, though, is indicating nitrogen pollution may need to be reduced even more - by 40 to 50 million pounds, maybe even more.  

"It’s looking like to save the bay, we’re going to have to have greater pollution reductions than we’re currently shooting for," says Beth McGee, senior scientist with the Chesapeake Bay Foundation, who attended the West Virginia workshop.

Rich Batiuk, associate director of EPA's bay program office in Annapolis, cautioned against reading too much into the results so far.   He said the new model, which attempts for the first time to incorporate the water-quality impacts of air pollution and of restoring oysters in the bay, is still in development and needs more work before its calculations generate much confidence.

Batiuk said scientists hope to have the bugs worked out by spring, in time to give some useful guidance to leaders of the bay restoration effort when they get back together to figure out a new cleanup timetable. 

In the private meeting in Washington on Thursday, Maryland Gov. Martin O'Malley and Virginia Gov. Tim Kaine had wanted to set 2020 as the new deadline for cleaning up the bay, say aides who were present.  But Pennsylvania's environment secretary, John Hanger, balked and said he wanted to wait for the new computer model before deciding anything.  Pennsylvania state officials have been dealing with a revolt among municipalities over the high costs of upgrading sewage treatment plants to reduce nutrient pollution in the Susquehanna River, the bay's largest tributary.

Asked if the leaders were aware before Thursday's meeting of which way the model was pointing, Batiuk said:  "Certainly we haven’t sent them any message that it’s going to be any easier."