State lawmakers in Ohio are set to vote this week on a plan to curb the growth of algae blooms in Lake Erie.
It would be the first legislation addressing the toxic blooms since algae contaminated drinking water for hundreds of thousands of people in northern Ohio and southeast Michigan last summer.
The proposal would ban manure from being spread on frozen or rain-drenched farm fields, or when heavy rains are forecast.
Runoff from manure and other fertilizers is a major cause of algae blooms.
But the Ohio House and Senate differ on whether farmers should be penalized if they violate the ban or be given extra time to meet the requirements.
The plan also sets a five-year timetable for stopping the dumping of sediment dredged from waterways into the lake.
Experts say dredged material helps create the toxic blooms.