O'Malley administration officials urged lawmakers yesterday to leave them the flexibility to determine how best to spend a new $50 million Chesapeake Bay cleanup fund.

But they pledged to rely on scientists' advice and on the administration's new computerized BayStat system to underwrite projects most likely to curtail polluted runoff from farms, suburbs and cities.

"We realize resources in government and nongovernment are very tight," Natural Resources Secretary John R. Griffin told members of the Senate Education, Health and Environmental Affairs Committee.

If officials aren't free to focus the money on runoff control in areas that need it most, he said, "we're not going to change the bay."

The Chesapeake Bay 2010 Trust Fund, set up last fall by the General Assembly during its special session, draws revenue from new car rental and gasoline taxes approved at that time. The fund is designed to address runoff, but legislators could not agree last year on whether to earmark portions to deal specifically with various types of runoff pollution.

Griffin urged lawmakers to resist proposals floated last fall, and repeated yesterday, to earmark fixed percentages of the fund for farm runoff prevention or storm-water runoff controls.

He said BayStat could direct the funds to where they are most needed while enabling officials to monitor projects and shift money elsewhere when not getting the desired results.

Spokesmen for farmers, foresters, counties and municipalities all appealed to legislators to tighten the administration's spending plan to ensure that they get a share of the cleanup funds.

W. Michael Phipps, president of the Maryland Farm Bureau, asked that farmers be eligible for financial help whether they are curbing runoff voluntarily or complying with environmental regulations.

Meanwhile, a lobbyist for the Maryland Municipal League said development of parks ought to be eligible, too, because such open land can soak up polluted runoff.

William Baker, president of the Chesapeake Bay Foundation, said environmentalists also want more accountability for how the funds are spent.

"Let's not have flexibility be a euphemism for opening this fund up" to projects that are not critical to restoring the bay, he said.

Sen. Paul G. Pinsky, who previously had demanded that the administration make provisions to verify that money given to farmers, local officials and others gets spent on actual pollution reductions, said he is largely satisfied with the administration's current bill.

"I think it's close to where it needs to be," said the Prince George's County Democrat. "I just don't want to throw good money after bad."

tim.wheeler@baltsun.com