State and federal Bay officials are weighing whether to change their deadline for cleaning up the Chesapeake.

No decision has been reached, but in recent meetings, many have acknowledged there is little likelihood that the 2010 deadline set for removing the Bay from the EPA’s list of impaired waters can be met because of the need to achieve steep nutrient and sediment reductions.

Some people have worried that sticking with a 2010 deadline would lead to a weakening of proposed new water quality standards for the Bay and its tidal tributaries before they are adopted by states. Time frames suggested for a new deadline range from 2015 to 2020.

Right now, it appears that attaining the water quality standards being developed by the Bay Program will require slashing nitrogen loads to the Bay, now about 285 million pounds a year, to about 175 million pounds annually. A similar proportion of cuts would be needed for phosphorus loads.

By comparison, it has taken the Bay region about 15 years to achieve roughly a 50 million pound nitrogen reduction.

“We need to get good, solid, science-based standards on the books,“ said Rich Batiuk, associate director for science with the EPA’s Bay Program Office. Extending the deadline “gives people the comfort to move toward the 175 million pound allocation.”

The Chesapeake 2000 agreement set a 2010 deadline for cleaning up the Bay to avert a cleanup plan known as a Total Maximum Daily Load, which could force more regulatory actions to control nutrients within the watershed.

Under a court-approved consent decree that resolved a suit by environmental groups, a TMDL would must be developed for the Bay if it does not meet water quality standards by 2011.

But, Batiuk said, it’s possible that parts of the Bay will be cleaned up enough by 2010 so they could be removed from the EPA’s impaired waters list.