www.thinkprogress.org/climate/2014/04/16/3363281/states-block-chesapeake-cleanup/
"To understand why the 21 state AGs care about a cleanup plan that is, for the most part, outside of their boundaries, you first have to understand why outside groups are suing to strike down the cleanup plan in the first place. That comes down to the interests of one powerful entity: the U.S. agriculture industry.
When the EPA enacted its latest cleanup plan, the Chesapeake Bay Clean Water Blueprint, in December 2010, major agriculture groups were quick to sue, arguing the agency didn’t have the power to restrict the amount of pollutants that enter the bay. Their response came as no surprise, considering agriculture is the largest contributor of nutrient and sediment pollution to the Chesapeake Bay, accounting for 42 percent of the nitrogen, 58 percent of the phosphorous and 58 percent of the sediment that entered the bay in 2012. The EPA’s new cleanup plan established a Total Maximum Daily Load (TMDL) for how much nitrogen, phosphorus and sediment can enter the bay each year, potentially cutting pollution by 20-25 percent."