To be sure, there is a lack of balance and perspective in our efforts to protect the water. While the EPA tightens existing regulations on the poultry farms of Maryland's Eastern Shore, the region's urban sewage plants continue to dump nutrients into the water. Washington, for example, has a combined storm water and sewage system, as do many cities. Thus, every time there is a rain, there is potential for untreated human sewage to flow into the Potomac River and make its way to the Chesapeake. Not all nutrient runoff is bad.
Marine life depends on nutrients to grow.
Likewise, not all heavy metals are bad. Recent experiments at the Moss Landing Marine Station in California showed that dumping controlled amounts of iron filings in the ocean created a 40-fold increase in zooplankton, the first link in the aquatic food chain. Our laws should not presuppose science, but instead be based on the latest science. Second, pinpoint the sources of pollution. Nutrient runoff does indeed come from agricultural sources, but more comes from urban sewage.