Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: WEDNESDAY, January 5, 1995 TAG: 9501050028
SECTION: CURRENT PAGE: NRV-3 EDITION: NEW RIVER VALLEY
SOURCE: JOE HUNNINGS
DATELINE: LENGTH: Long
Nonpoint source pollution is pollution that adversely affects our surface and groundwater resources. It does not come from a single source or point, such as a sewage treatment plant or industrial discharge pipe. It is more diffuse. It originates from suburban lawns, farm land, city streets and construction sites. It is the result of man's activity on the land.
Types of nonpoint source pollution:
There are four major types of NPS pollution: Sediments, nutrients, toxic substances and pathogens.
Sediments are soil particles carried by rainwater into streams, lakes, rivers and bays. In sheer volume, sediment is the greatest pollutant of all. It's caused mainly by erosion resulting from bare land, construction and development, and poor farming practices.
Nutrients are substances which - at least to a point - help plants and animals grow. NPS officials are most concerned with the nutrients nitrogen and phosphorus. Fertilizers and animal waste are the main sources of these substances.
Toxic substances are chemicals which cause human and wildlife health problems. These include organic chemicals and metals, pesticides, formaldehyde, household chemicals, gasoline, (motor oil, battery acid, road salt) and so on.
Pathogens are disease-causing micro-organisms present in human and animal waste. Most pathogens are bacteria.
Effects of nonpoint source pollution:
Pathogens and toxic substances have a very direct effect: They impair or destroy aquatic life. Sediment and nutrients have less obvious effects.
Life in Virginia's rivers, streams, lakes and bays could not exist without nutrients, but too much of a good thing often causes more harm than good. Nutrients overly enrich our waterways, causing massive and more-frequent 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. The plants also die.
Sediment clouds water too,. but it also obstructs waterways, clogs sewers, interferes with boating, and smothers fish and shellfish spawning grounds. Natural erosion and sedimentation occur at a much lower rate than that resulting from man's land-altering activities.
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, even in a complex geopolitical situation. For example, submerged aquatic vegetation and striped bass populations in the Chesapeake bay both are making modest comebacks.
NPS pollution not only is important to the Chesapeake Bay, it is important to the New River Valley. The New River and Roanoke River watersheds experience the same problems as the Chesapeake Bay does. How can you make a difference?
Since all of us are NPS polluters, it will take all of us to control the pollution. Here's what you can do around your home to help:
Use appropriate cultural practices to minimize the need for fertilizers and pesticides, which can leach into surface groundwater.
Test soil to determine the need for enrichment and, if any, the appropriate amount and type. Use compost, as appropriate, to improve the quality and nutrient-holding capacity of your soil.
Use mulch, as appropriate, to cut down on water consumption and reduce the need for herbicides and weeding.
Investigate the use of alternative pest control measures, such as floating row covers, insect lures and traps, and low-toxicity pesticides, such as Bt and soap sprays.
When chemicals are needed, choose the least-toxic chemical that will get the job done, and choose small containers to limit disposal problems. Also, apply pesticides according to instructions on the label.
Collect litter and animal waste before they wash into storm drains.
If you change your own motor oil, take the used oil to a recycling station. Check with your local service station for the location most convenient for you. Never dump oil into a storm drain.
Make sure household septic tanks are located, constructed and installed according to regulations. Maintenance and prompt correction of problems are important.
Direct roof runoff onto a grassy area. Do not connect roof drains to a sanitary or storm sewer system.
Watch for soil erosion around your home. Seed, install sod or plant ground cover to protect the site.
Use porous surfaces such a flagstone, gravel, stone, and interlocking pavers rather than concrete and asphalt.
If you're concerned about the effects of runoff leaving a nearby construction site, consider contacting the local governing body responsible for erosion and sediment control in your area. Almost all land disturbance is regulated under the Virginia Erosion and Sediment Control Law.
Be active! Join a civic or environmental group, and let others know how you feel. Give talks, man booths, volunteer, spread the word.
Joe Hunnings is the Virginia Cooperative Extension agent for agriculture in the Montgomery County Extension Office in Christiansburg. If you have questions, call him at 382-5790.
by CNB