Toxic Effects Of Urban Runoff
As humans develop an area, they add an increasing amount of surfaces that water cannot permeate—roads, parking lots, sidewalks, anything built with materials like asphalt, cement and concrete. So when it rains, the water cannot immediately sink into the soil, instead flowing downhill over the surface of the ground. As it does so, it picks up everything on the ground—not just all the trash that ends up in the gutters, but also heavy metals and gasoline from leaky cars, pet waste road salt used for deicing, pesticides and fertilizer from lawns, tar from rooftops, lead from old paint, anything toxic that we leave exposed to the rain.
What happens with all this toxic water? Surprisingly little. Eventually, most of the water makes its way to a storm drain. From here, the vast majority of municipal sewers release this water, untreated, back into the rivers and bays surrounding it. Here it wrecks absolute havoc on the environment, from critters being trapped into six-pack-rings swept away from the local football field to heavy metal toxicity building up in the very fish you catch and eat. Many parks are also placed alongside waterscapes, where many will swim, surf, or just enjoy the water, all while getting their daily dose of environmental poisons—including many deadly bacteria which flourish in such waters. In fact, urban runoff is widely considered to be one of the most insidious forms of water pollution.