He also defended the stream setback requirements, saying that even though livestock dropping manure in streams is not a huge source of the nutrient pollution fouling the bay, "It's just not a wise thing to do."
"[Speaking] as a scientist, they all make sense," Brinsfield said of the draft rules. "Now whether you've got the political will … that's a whole different debate."
Farmers wouldn't be the only ones affected by the draft rules. The draft regulation would force an end by 2016 to spreading sewage sludge on farm fields in winter and impose other limits on its application to land other times of year.
Operators of sewage treatment plants said the limits would effectively bar them from putting sewage sludge on farm fields most of the year, forcing them to build costly storage facilities, dispose of it in landfill space or truck it out of state. Many of the state's counties and municipalities contract to have the treated sludge from their sewage plants trucked away and spread as fertilizer on croplands.
Anne Arundel County, for instance, estimates it would have to spend $30 million to build a facility large enough to hold all the sludge its sewage plants generate in winter, according to a letter from the Maryland Association of Municipal Wastewater Authorities. While some might be disposed of in landfills, those facilities can't accommodate all that's generated, the group says.
Association President Julie Pippel argued that the restriction is unwarranted, because state-financed upgrades of the largest sewage plants are reducing the nutrient content of the sludge.
Hance acknowledged that there were "flaws in the language" of the draft rules that are leading some farmers to conclude, wrongly, that they wouldn't be allowed to put horses, cows and other livestock out to pasture in the winter. He said state agriculture officials will correct and clarify such issues and weigh feedback before deciding what regulations to go forward with.
The rules also would have to be scrutinized by a joint legislative committee before being formally proposed.
Hance said many of the restrictions under consideration would not take effect for up to five years, giving farmers time to plan for them and adjust. As he often does, the agriculture secretary said farmers have already taken many steps voluntarily to reduce pollution from their fields and pasture. "But in this new age of [pollution diets], goals and deadlines," he added, "we're just trying to put in place a plan that helps the community reach its goals."