Virginia is a water rich state. But plenty of water doesn't necessarily mean having abundant usable water. As with all natural resources, we must use water wisely. We need clean water for drinking, food production, jobs, transportation, recreation, beauty and habitat for some of the most unique natural environs in the world. One of those is among the world's most productive estuaries, the Chesapeake Bay.
Preventing water pollution is difficult, however, because water is dynamic -- it flows freely from property to property, from locality to locality, even from the surface to underground. How water is used upstream can and does affect its quality downstream.
There's a type of pollution that degrades some of our state's waterways. Its called nonpoint source (NPS) pollution because it doesn't come from a single source, or point, such as a sewage treatment plant or an industrial discharge pipe.
NPS pollution occurs mainly through stormwater runoff. When it rains, runoff from farmland, city streets, construction sites, and suburban lawns, roofs and driveways enters our waterways. This runoff often contains harmful substances such as toxics, excess nutrients and sediments. NPS pollutions effects seldom show up overnight -- they often go unnoticed for years. This characteristic makes it all the more difficult to control.
There are four major forms of NPS pollution: sediments, nutrients, toxic substances and pathogens.
Just about everyone who owns or uses land contributes to nonpoint source pollution. In Virginia, most efforts concentrate on NPS pollution leaving farmland, urban areas, construction sites and forest land. Farms yield sediment, toxic substances and excess nutrients. Statewide, farmland loses several tons of soil per acre per year. While this soil is productive on land, in the water it cuts light needed by aquatic plants, obstructs waterways and covers aquatic habitat with sediment. Worse, soil from farmland sometimes takes with it pesticides and nutrients.
Most of the Virginia's NPS pollution prevention efforts focus on managing nutrients because they pose one of the greatest threats to the health of our waterways and, in particular, to the Chesapeake Bay. Experts estimate that 50 percent of the nitrogen and 29 percent of the phosphorus entering our states surface waters come from farmland. But farms aren't the only source of NPS pollution.
Urban and suburban areas also contribute significant levels of nutrients as well as toxic substances, pathogens and sediment. City streets and other impervious surfaces yield NPS pollutants such as motor oil, gasoline, antifreeze, and other toxic chemicals. Because these surfaces don't absorb rainwater, runoff from urban areas is nine times greater than is that from forest land.
Life in Virginias rivers, streams, lakes and bays could not exist without nutrients, but too much of a good thing often causes more harm than good. Nutrients over-enrich our waterways causing algal blooms which deplete oxygen. This makes the oxygen unavailable to fish and shellfish so they suffocate and die. The algae also cloud the water and coat underwater vegetation, cutting much needed sunlight.
Sediment clouds water too, and it obstructs waterways, clogs sewers, interferes with navigation, and smothers fish and shellfish spawning grounds. Natural erosion and sedimentation occur at a lower rate than that resulting from human land use activities.
Underwater plants and aquatic animals are particularly threatened by NPS pollution. Oysters, shad, herring, striped bass and submerged aquatic vegetation -- considered by many to be the foundation of a stable aquatic ecosystem -- are damaged by this pollution.
The problem is complicated and there are no easy answers, but recent efforts by Virginia and other bay region states show that NPS pollution can be controlled and that nature responds to restoration efforts. For example, trends indicate that striped bass populations in the bay are making a comeback. The best way to solve our NPS pollution problems is through effective local government and individual citizen intervention.
Fertilize your lawn and garden according to soil test results. Contact your local extension office agent for instructions. Try to apply fertilizer when heavy rain isn't likely to wash it away.
You couldn't live long without clean water. Nothing can. Above are just a few simple ways you can do your part to give something back to our waters.