These types of pollutants either flow directly into the small streams that run through urbanized areas or enter storm drains and dump directly into larger waterways. Water pollutants harm fish and wildlife, can kill native vegetation, foul drinking water supplies and make recreational areas unsafe. The two coastal zones in the state, one in the east and other in the northwest, pose unique concerns. Water which enters bays, such as the Presque Isle Bay or Delaware Bay, stays there longer than water entering rivers and streams. Thus, it is more difficult and takes longer for bays to process, or wash away, pollutants.
Concentrated pollutants create a variety of problems.
Heavy sediments, for instance, can settle and suffocate aquatic plants and animals. In the Presque Isle Bay, pollutants from urban and industrial activities are suspected of causing tumors and other deformities in fish. Delaware County, in southeastern Pennsylvania bordering Philadelphia County, is considered one of the state s most highly urbanized counties. It contains many streams that flow through rural, suburban and urban sections of the county, eventually making their way to the Delaware Bay. Along the way, the streams pick up fertilizers, pesticides, and other nonpoint source pollutants.