A watershed is an area of land from which all water drains into a common waterbody. Watersheds come in many shapes and sizes: hilly, flat, rocky, forested, and marshland. Watersheds can be quite small, such as a few hundred acres draining into a small creek, or very large, like the 64,000 square mile drainage basin of the Chesapeake Bay.

A watershed can include a river or the tributaries that empty into it along its course. Several small watersheds make up large watersheds, creating a series of watersheds within a larger area called a drainage basin.

Water enters a watershed through both direct and indirect means. Precipitation in the form of rain or snow enters directly as surface runoff or indirectly as water seeping through the soil via the groundwater system.

Pollution in a Watershed

Events occurring in the smaller watersheds, whether good or bad, ultimately affect the quality of water that flows into the larger watershed and into the downstream rivers and lakes.

Water is not the only substance to end up in stream systems. Chemical pollutants, fertilizers, pesticides, trash, and debris all enter streams with the water draining from the watershed. These foreign substances come from many sources and can be detrimental to the health of stream systems by continually degrading surrounding habitats and the life they support.

Even if a home is not next to a stream, it is in a watershed, and common household practices can contribute to overall pollution entering stream systems. Actions taken anywhere in a watershed can affect both the quality and quantity of stream water...and ultimately the water supply.

Land Use in a Watershed

Land use changes are inevitable. However, the rate at which land use is changing causes problems for the environment, specifically stream water quality.

Urban development increases impervious surface (rooftops, roads, driveways, sidewalks, and parking lots), which leads to more stormwater runoff. More runoff entering streams changes the natural ecosystem. Unless stormwater management, erosion control strategies, and riparian zone management are carefully considered in the watershed plan, degradation can be expected.

Careful planning that takes into consideration the location and design of man-made structures is essential. Planning for a new building or road must include plans for stormwater runoff control, maintenance of riparian buffer zones, and location of wetlands and upland forests.

Development should not necessarily be stopped, but its potential harm to local streams should be minimized. Local governments should encourage developers to practice proper stewardship of land and streams when development occurs within a watershed. The entire watershed must be viewed as a whole ecosystem; unbalance in one part adversely affects other parts.

Managing the Watershed

Land uses preventing soil erosion, heavy runoff of stormwater, and pollutants characterize a well-managed watershed. On the other hand, overgrazing, overuse, improper management of agricultural land, uncontrolled urban runoff, and mismanaged urban development sites characterize abused watersheds.

Watersheds are an integral component of a healthy ecosystem—one that sustains water quality suitable for fish, waterfowl, and other aquatic life, and of course for swimming, fishing, and human consumption. Taking care of streams and rivers is an important part of cleaning up the environment and preserving the land and water for future generations.

Make a Difference

• Factor in the cost of lost habitat when establishing the cost/benefit analysis for development.
• Maintain buffer zones on both sides of streams sufficient in area to accommodate the volume of water delivered during storms.
• Restore and maintain wetlands. Wetlands act as filtration and flood control mechanisms.
• Use permeable paving materials that allow rain to penetrate the surface rather than running off directly into a stream.
• Maintain natural vegetation as much as possible. A sapling cannot replace benefits of a mature tree.
• Control soil erosion on development sites.
• Promote an environmentally friendly setting by restoring damaged areas, maintaining the quality of streams, and encouraging wildlife.

Water supplies in the Northern Virginia area are more than adequate to meet current needs, but it may not be that way in the future. This valuable resource must be conserved and protected.

Conservation Saves Money

Widespread reduction in water use can also mean a reduced need for new or expanded sewer treatment facilities. Tax dollars saved by not expanding existing facilities could be used to improve water treatment techniques.

Facts About Earth's Water

• Approximately 80% of the Earth's surface is covered with water.
• Earth has the same amount of water as when the planet was formed.
• Only one percent of the Earth's water is usable fresh water. The remainder is salt water (97%) and water frozen in glaciers (2%).
• Nature recycles water in an endless cycle.
• The water consumed today may have been a drink for a dinosaur.
• The average person uses 100 gallons of water a day.
• In 1995 (most recent year for which figures are available) the United States used more than 36 trillion gallons of fresh water.
• More than 50% of wetlands that recharge and purify groundwater have been destroyed in the United States.
• Earth will not get any more water.

Make a Difference

• Use low flow faucets and showerheads, reduced flow toilet flushing equipment, and water saving dish and clothes washers.
• Check for water leaks. If the water meter dial moves while no water is being used, there is a leak.
• Take short showers instead of full tub baths. Avoid letting faucets run unnecessarily.
• Only use fully loaded dish and clothes washers.
• Wash cars only when necessary. Use a bucket and a spray nozzle to save water.
• Go to a commercial car wash that uses water efficiently and disposes of runoff properly.
• Water lawns at the coolest part of the day to avoid evaporation. Use slow watering techniques such as trickle irrigation or a soaker hose.
• Use mulch to hold in soil moisture.
• Do not over-water lawns or gardens.

The water in stream systems is used several times before it reaches the ocean. People drink it, cook with it, bathe in it, and swim in it. Farmers use water in food production, and businesses use it in commerce. Water supports fish, wildlife, and recreation, and creates an aesthetically pleasing environment.

With all of its uses, the need for good water quality is imperative. Good quality water contains sufficiently high physical, chemical, and biological properties to sustain all of its uses.

Water quality is a reflection of a body of water's composition as natural processes and human activities affect it. Water quality has many different definitions. For an ecological scientist it means a balanced and properly functioning aquatic ecosystem; for a public health official it means clean, clear, drinkable water; and for a local fisherman, it means the quality and quantity of fish.

Pollution is an undesirable change in the physical, chemical, or biological characteristics of air, land, or water that adversely affects the living conditions for either humans or other living organisms. Water pollution is the adverse and unreasonable impairment of the beneficial uses of water.

Water quality can be disrupted by direct and indirect sources. Direct sources are fairly obvious and include such practices as dumping waste and hazardous pollutants into streams. Indirect sources are called nonpoint source (NPS) pollution. Stormwater runoff, which may contain fertilizers and pesticides, soil lost from development sites, and oil residue washed off streets, is NPS pollution. This type of pollution is much more difficult to pinpoint and control.

Make a Difference

• Practice water conservation. Use less!
• Stop nonpoint source pollution in backyards by using appropriate lawn care techniques.
• Limit use of pesticides and fertilizer. Use them at appropriate times of the year in recommended amounts.
• Prevent property erosion. Cover bare soil with vegetation and mulch.
• Encourage local government to make water quality improvements a high priority.
• Encourage environmentally friendly development in the community.
• Participate in a stream cleanup program.
• Learn to recognize water quality problems in local streams.
• Bring water quality problems to the attention of the proper government officials.

Water pollution is an overabundance of one or more natural or man-made substances in a body of water. Sources of natural pollutants include sulfur from soils, iron deposits, residue from volcanic springs, calcium, and tannic acid and methane gas from marshlands. The two major types of man-made pollutants are point source pollution and nonpoint source pollution (NPS).

Point Source Pollution

Nonpoint Source Pollution

Controlling Pollution

Point source pollution has been controlled during the last 50 years through wastewater treatment, air scrubbers, and filtration devices. The cleanup of municipal and industrial sources has resulted in the remarkable improvement of water quality in streams.

One example is the Potomac River, which until recently was considered a polluted river. The control of point source pollutants has contributed to the revival of the Potomac and many other major river systems throughout the country.

There is still a long way to go. Significant sources of pollution continue to enter streams, and NPS pollution is the major culprit, accounting for more than 50% of nutrients reaching the Chesapeake Bay.

Make a Difference

Start at home and in the yard.

• Fertilize according to soil test results.
• Apply pesticides according to instructions on the label.
• Maintain septic systems.
• Recycle grass clippings and leaves by mulching or composting.
• Recycle used motor oil.
• Collect litter and animal waste.
• Drain pools on a large expanse of grass to dissipate chlorine and allow water to filter through soil.
• Conserve water.
• Control soil erosion by seeding grass, installing sod, or planting ground cover to protect bare areas.
• Direct roof water onto grassy areas.
• Use porous surfaces such as flagstone or gravel, rather than asphalt or concrete.
• Dispose of household hazardous waste properly. Never pour paint, antifreeze, motor oil, cleaners, or solvents down drains inside or outside the home.

How NPS Pollution Occurs

With rain, no matter the amount, comes serious pollution washing from the land into lakes, bays, rivers, streams, and aquifers. Where stormwater cannot soak into the soil, it runs off, eroding exposed land and filling street gutters.

The onrush of rain water or snowmelt runoff sweeps accumulated dust, dirt, debris, organic matter, and toxic pollutants from roads, construction sites, and lawns into city storm sewer lines and sometimes directly into surface waters. Farm runoff may channel water muddy with sediment, fertilizer and pesticide residues, salt, and animal wastes into streams and larger bodies of water. The adverse impacts of NPS pollution relate to how close sources are to waterbodies, land use, type of soil, and slope of the land, although pollutants from distant sources may reach the same waterbodies after several storms.

NPS pollution is not restricted to a single area. Ninety-nine percent of sediment, 88% of nitrates, and 84% of phosphates entering the United States' lakes and streams are considered NPS pollution.

Effects of NPS Pollution

• Poison fish, aquatic animals, and wildlife.
• Cover fish spawning beds, killing fish eggs.
• Act as a grinding mechanism on stream beds, destroying aquatic life residing on the stream bottom—from macroinvertebrates to fish and reptiles.
• Increase decomposition of organic debris, depleting the oxygen in water that is necessary to support aquatic animal life.
• Fill in streams and reservoirs.
• Add nitrates and phosphorous to water causing extensive algae blooms and the potential death of lakes and estuaries.

Sediment

Sediment is eroded soil particles. Erosion occurs when rain or moving water dislodges and carries soil particles, organic matter, and plant nutrients as it flows. The process of erosion creates excess sediment. This sediment is considered an NPS pollutant because it comes from a variety of sources: cropland, pasture, urban/suburban settings, construction sites, and sanitary landfills.

The texture of the soil, its potential for absorbing water, the amount of time it is exposed to water, the steepness and length of the slope, and the amount of protective cover on the soil are all factors influencing the extent of erosion. Disturbed land erodes more easily than land in a natural condition.

Erosion is a natural process. Some erosion is inevitable and cannot be stopped. However, urban development that disturbs soil and vegetative cover results in an unnatural acceleration of the process and can cause water quality problems, local area flooding, and increased maintenance costs.

Erosion degrades water quality when pollutants, such as phosphorus, bind to the soil and are carried into waterways along with runoff. Local area flooding can result from the eroded soil clogging storm drains and from sediment altering the depths of local creeks and streams. Erosion-induced flooding can cause property damage and added maintenance costs to both the property owner and the agency responsible for surface water management.

Soil particles resulting from the erosion of land are carried by rainwater to streams, lakes, rivers, and bays. Phosphorous, a nutrient, attaches to sediment and is carried to streams by runoff. Sediments accumulate in waterbodies and destroy feeding grounds for aquatic life, clog fish gills, block light, and increase water temperature.

Erosion Hurts Streams

When large quantities of soil enter waterways, pollution occurs. In terms of sheer volume, sediment is one of the most devastating pollutants affecting waterways.

Sediment pollution of streams and reservoirs reduces their volume capacity and increases the expense municipalities and industries pay to treat water. Millions of dollars are spent each year dredging channels, harbors, and drainage ditches to remove excess sediment.

Sediment suspended in water destroys fish and wildlife habitat. Sediment from eroding stream banks and land surfaces and agricultural and industrial chemicals carried by that sediment could smother aquatic life, clog fish gills, and cut off light to underwater plants. In addition, eroded areas may be unable to support vegetation. Sediment pollution can be just as deadly to aquatic life as cyanide or DDT.

Signs of Erosion

• Bare spots on lawns or property
• Exposed roots of trees and vegetation
• Small stones or rocks becoming evident
• Soil splashed on windows and exterior walls
• Small rills or gullies beginning to show
• Buildup of silt in certain areas
• Widening and deepening of stream channels
• Undercut and fallen trees in stream channels

Make a Difference

• Consult a trained professional about structural or vegetative solutions for controlling erosion.
• Remove obstructions from stream channels and revegetate stream banks.
• Establish adequate vegetative cover with appropriate plants and grasses, especially on all bare spots.
• Landscape yards to minimize rainwater runoff.
• Preserve neighborhood trees that help minimize the damage caused by surface runoff.
• Control rainfall runoff by diverting water away from streams.
• Place retaining walls or diversions on steeply sloping ground to reduce the rate of water flow and erosion.

Trash and Organic Debris

Leaves, grass clippings, garbage, and animal waste become part of the runoff entering storm drains and local waterways and clogging the system. Decaying organic matter depletes oxygen needed by aquatic life, leaving fish and shellfish to suffocate.

Trash and organic debris is one of the easiest types of NPS pollution to control.

Dispose litter in garbage cans or in recycling bins. Recycle glass, aluminum, plastic, paper, motor oil, and newspapers. Compost yard and garden waste. Pick up pet waste and bag it with regular household trash or flush it in the toilet. And, never intentionally dump anything into a storm drain.

Nutrients

Nutrients are essential to water life, but too much can harm more than help. Phosphorous, nitrogen, and potassium are nutrients that help plants and animals grow. Found in fertilizer, sewage, detergents, and animal wastes, these elements are not harmful to the environment in low doses. However, excess nutrients in an already healthy environment can be dangerous. Nutrients carried by stormwater runoff from the land into the water become nonpoint source pollutants.

Too many nutrients can cause an overgrowth of vegetation or bloom of algae—tiny plants that give water a green to blue-green color. Eventually the excess plants die and decay. The decaying process depletes oxygen in the water, leaving less for aquatic plants and animals. The balance of life in the stream ecosystem is interrupted and disturbed.

An overgrowth of algae also minimizes the amount of light that can reach aquatic plants. An increase in dead organic material from the dying plants exacerbates the problems associated with low oxygen levels.

The loss of sea grasses in the Chesapeake Bay and its tributaries is an example of the harmful effects of nutrient enrichment. Once destroyed, sea grasses do not grow back easily.

Make a Difference

• Use fertilizers and pesticides only when necessary and then at recommended rates. Follow the manufacturer's instructions for application.
• Ensure that animal waste from operations such as dairies, chicken, hog, and horse operations, feed lots, and catfish ponds is managed properly.
• Make sure septic tanks work properly.
• Use low-or no-phosphate detergent.
• When operating a boat, be sure to handle trash and wastewater properly.

Toxins

Toxins are chemicals that can cause human and wildlife health problems. They include organic chemicals and metals, pesticides, herbicides, formaldehyde, household chemicals, paint, paint cleaners, gasoline, motor oil, battery acid, and roadway salt. Toxins accumulate in fish and shellfish either killing them or making them more susceptible to disease. Infected fish and shellfish can have a direct impact on humans in the food chain.

Pesticides—insecticides, herbicides, rodenticides, and fungicides—are chemicals widely used by farmers, foresters, exterminators, and homeowners to kill harmful insects and weeds, to increase crop and timber harvests, and to prevent the spread of plant, animal, and human parasites and diseases.

When improperly applied, pesticides can pollute waters and poison fish, plants, and animals living in and around water. Pesticides are considered NPS pollutants because their source of origin is often difficult to locate. They can migrate considerable distances via air or water and be released by rainfall, complicating the process of pinpointing the source.

Although targeted at pests, certain pesticides inadvertently can harm nontarget organisms—stream insects, fish, wildlife, domestic animals, and humans.

Alternatives to Toxic Pesticides

Use less toxic pest control products. When used according to label instructions, insecticidal soap, BT (Bacillus Thuringiensis), milky spore, and dormant oil sprays are less toxic to the environment than other commercial products.

Integrated Pest Management (IPM) emphasizes frequent monitoring to assess pest population buildup and the evaluation of factors, including environmental effects, prior to pesticide application.

IPM Tactics

• Use natural predators. Introduce animals and insects that eat pests.
• Time plantings. Regulate planting and harvesting to avoid times when insects are most abundant and damaging.
• Do a little hand work. Remove eggs, larvae, cocoons, and adults from plants by hand.
• Use resistant plants. Cultivate plants that are relatively free of major pests and diseases.
• Know the appropriate growing conditions. Make sure the amount of shade and sunlight, moisture, and pH levels are appropriate for plants.
• Mix plant varieties. A mixed stand of vegetation is less susceptible to insect damage than single species crops.
• Introduce natural pathogens and parasites. Use bacteria, viruses, and insect parasites to kill pests without harming other non-pests.
• Control insect hormones. Prevent an insect from growing into a sexually mature adult.
• Use chemicals only as needed. Smaller amounts and careful application ensure a healthier environment and better pest control.
• Mulch. Use where appropriate to control weeds.
• Rotate plants/crops. Yearly rotation of garden plants decreases the need for pesticides.

Minimize Pesticide Hazards

• Read and follow the label carefully.
• Buy only the quantity needed.
• Wear any protective clothing specified on the product label.
• Wash hands immediately after application.
• Apply only the amount specified on the product label and only on the plants and areas listed in the instructions
• Make sure people and pets are out of the area during application and until the spray has dried.
• Never apply near wells, streams, ponds, or marshes unless the instructions specifically allow such use.
• Never apply to bare soil.
• Don't apply if rain is forecast, unless specified on the label (some pesticides do need to be watered after application).
• Dispose of containers according to label directions.
• Choose the least toxic pesticide. Those with the signal word Caution on the label are considered the least toxic, whereas the signal word Warning indicates moderate toxicity.

Pathogens

The presence of bacteria in water, which are normally found in the intestinal tracts of humans and animals, signal that disease-causing pathogens may be present. Giardia and cryptosporidium are pathogens that have been found occasionally in public-water supplies and have caused illness in a large number of people in a few locations. Pathogens can enter our water from leaking septic tanks, wastewater-treatment discharge, sewer overflows, and animal waste. Like toxins, pathogens build up in fish and shellfish killing them or making them susceptible to disease.

Many jurisdictions routinely monitor urban streams to measure the amounts of bacteria that, although harmless themselves, have similar sources (animal and human waste) as do the waterborne pathogens. The harmless bacteria therefore act as indicators of the possible presence of other bacteria that are not harmless.

Everything that goes into a storm drain, flows out into neighborhood streams, local lakes and rivers, and eventually into larger bodies of water such as bays and oceans. Each time trash, motor oil, litter, pet waste, fertilizer, yard and garden debris, household chemicals, and road sand and salt are dumped into or washed into storm drains, aquatic life is endangered.

However, these nonpoint source pollutants are some of the easiest to control.

Make a Difference

• Never dump anything into a storm drain.
• Dispose of trash and litter in the proper garbage or recycling receptacles.
• Recycle motor oil at a local gas station.
• Pick up and bag pet waste separately, then dispose of it with the regular trash or flush it down the toilet.
• Use fertilizer sparingly and according to soil test results.
• Compost yard and garden debris.
• Dispose of household chemicals according to label directions.
• Road sand and salt should be vacuumed up by the proper transportation authority. If this is not being done, call the Department of Transportation. Homeowners can help by sweeping up and disposing of road sand and debris.
• Mount a Don't Dump campaign. Organize neighbors, homeowner or civic associations, or youth groups to educate the community about the dangers of dumping into a storm drain. Then stencil Dumping Pollutes—Drains to Stream on the storm drains as a reminder.

Remember, storm drains on public streets are owned by the Department of Transportation or the local homeowner association and may not be painted without specific permission. Contact the Northern Virginia Soil and Water Conservation District for advice on conducting a stenciling project.

There are many things that can be done right now to prevent NPS pollution. Here are some important best management practices:

Homeowners

• Have septic systems pumped out and inspected by a licensed septic tank contractor every three to five years.
• Keep cars in good working condition and try to reduce amounts of driving. Studies show toxic materials and nitrogen compounds spewed into the air by cars fall back onto the land where they can be washed into the water.
• Compost yard wastes.
• Apply fertilizers and pesticides sparingly and use alternatives when possible.
• Fertilize according to soil test results.
• Pick up trash, litter, and pet wastes.
• Dispose of motor oil, chemicals, and other hazardous waste properly.

Farmers

• Get a conservation plan or follow an existing one.
• Manage manure for maximum crop nutrient value and minimum runoff.
• Keep livestock out of streams and riparian zones.
• Reduce erosion from crop fields by using conservation practices such as strip cropping, reduced tillage, and crop rotation.
• Minimize barnyard runoff.
• Use rotational grazing systems for pasture.
• Leave vegetative buffers along stream banks.
• Integrate chemical and biological controls to manage crop pests.
• Compost organic yard wastes.

Developers and Contractors

• Use porous pavements on low-traffic areas, leave vegetative buffer strips around streams and lakes, and preserve forested areas and wetlands.
• Leave as much vegetation as possible when clearing construction sites.
• Install silt fences, stormwater detention and retention ponds, and sediment basins to retain sediment on site.
• Manage stormwater to minimize the adverse effects of new development.

Local Officials

• Develop and implement a stormwater management program for the community.
• Require contractors and developers to consider solutions to the long-term impact of runoff from the development.
• Consider the impact on streams, rivers, and lakes when making planning and zoning decisions.
• Protect wetlands. Wetlands are proven to filter pollutants before they enter other bodies of water.
• Identify potential sources of NPS pollution, such as eroding roadbanks. Take corrective action where needed.
• Install good stormwater management practices in areas that are already developed.

Businesses and Factories

• Monitor wastewater for hazardous chemicals from the operation.
• Prevent leaks and spills of hazardous substances.
• Follow government regulations pertaining to storage tanks.
• Develop best management practices (BMPs) designed specifically for that type of business.

Swimmers, Boaters, Anglers

• Limit speed and obey boat speed limits. Boat wakes erode riverbanks and lake shores, thereby releasing sediment.
• Dispose of trash and toilet wastes properly, both on shore and in the boat.

A riparian zone is the area of land immediately adjacent to a stream. Typically the area is 35 or more feet wide on either side of a stream and may experience frequent flooding.

Importance of Vegetation

Vegetation growing within a riparian zone is essential to the maintenance of a healthy stream system. For example, trees in the riparian zone shade the water resulting in lower water temperatures in the hot summer. Cooler water has greater oxygen carrying capability. Leaves from trees and bushes provide raw organic material for the food chain. The dense, deep root systems of the riparian plants help hold the stream banks together during flooding. Riparian vegetation is essential during floods for slowing the flow of water and protecting adjacent land from the scouring effects of flood waters.

A healthy stream depends on well-managed riparian zones. Sparse vegetative cover causes flooding and water quality problems. Maintaining and restoring natural riparian vegetation can prevent many water quality problems.

Stable Banks

Healthy Streams

Unhealthy Streams

Making a Difference

• Maintain at least a 30-foot vegetative buffer between a lawn and stream.
• Plant native trees and bushes to help revegetate the riparian zone.
• Practice good lawn care techniques to prevent excess runoff into streams.
• Talk to and educate neighbors about taking care of streams and riparian zones.

Wetlands Protect Water Quality

Wetlands are among the most diverse and productive natural resources on Earth. There are two basic types of wetlands, tidal and nontidal. Nontidal wetlands are not subjected to the ebb and flow of tides. These include bogs, marshes, swamps, and ponds. More than 75% of Virginia's one million acres of wetlands are nontidal.

In order to qualify as a wetland, an area of land must:

1. Have water on or near the surface for all or part of the year.
2. Have soil identified as wet (hydric) soil.
3. Have living plants that occur in wet soil (hydrophytic plants).

Benefits of Wetlands

Wetlands are critical to fish and wildlife populations. They provide an important habitat for about one-third of the plant and animal species federally listed as threatened or endangered.

Human activities have changed and destroyed many wetlands. Wetlands have been filled in to make way for development projects; drained and cleared to create croplands; and dredged and channeled for navigation. It is critical that these destroyed wetlands be restored or replaced in order to maintain a healthy ecosystem.

Making a Difference

Governments

• Regulate activities that destroy wetlands.
• Provide tax incentives for preservation.
• Manage publicly owned wetlands properly.

Landowners

• Identify sensitive wetlands areas on the property.
• Ensure that activities compatible with wetlands preservation are carried out on the property.
• Donate or sell sensitive lands or easements to government agencies or private groups dedicated to wetlands protection.

Citizens

• Make public officials aware of the need to protect wetlands.
• Support conservation initiatives by public and private groups concerned with wetlands protection.
• Monitor wetlands and become involved in the regulatory process.
• Learn more about wetlands and their values.
• Inform friends, neighbors, and coworkers about the importance of protecting wetlands.

Data is needed to identify troubled streams and/or to spot trends that will cause future problems. This will lead to the initiation of corrective action. There are three approaches to assess the health of a stream: a stream walk, biological monitoring, and chemical monitoring.

Before deciding which type of monitoring to pursue, find out what monitoring may already be in progress. Check with other groups in the watershed (citizen groups, homeowner associations, youth groups), the local Department of Health, the local Department of Public Works, and state and federal environmental agencies. Investigating a little time in the beginning may prevent duplication of efforts later.

Conduct a Stream Walk

Biological Monitoring

The general health of a stream can be measured by comparing the differences in insect populations and diversity of insect species between impaired and unimpaired streams. Healthy streams have diverse families of aquatic insects. Biological monitoring procedures describe how to collect macroinvertebrates (aquatic insects) in a systematic manner and how to count the numbers of each different kind or family. This examination will yield a measure of the degree of pollution but not the type of pollution. The Northern Virginia Soil and Water Conservation District provides ongoing volunteer training, equipment and reporting forms.

Chemical Monitoring

Safety Considerations

• Do not go to stream alone.
• Wear proper clothing.
• Avoid flood stage and storm conditions.
• Be able to identify poisonous plants and animals and avoid them.
• Know the location of the nearest medical center.
• Wash carefully before eating, rubbing eyes, or touching mouth, after being in a stream. There may be poisonous substances or biota in the water.

Septic systems are individual household wastewater treatment systems that use soil to treat small wastewater flows. Septic systems are generally found in rural and large-lots settings where centralized wastewater treatment is impractical.

Ground and surface water are integral components of a watershed and either potentially can interact with the normal functioning of a septic system. A properly functioning septic system does not pollute the groundwater. On the other hand, an improperly functioning system can cause a serious health threat to family and neighbors, degrade nearby waterbodies and groundwater, reduce property value, be costly to repair, and put water supply users at risk.

Causes of Malfunctions

Improperly cleaned systems, clogged drainfield lines, frequent use of chlorine bleaches, tree roots in the system, a water table higher than the system, poor soil percolation, and saturated soils all cause septic system failure and possible water contamination.

A septic system treats wastewater by allowing solids to settle in the tank and excess water to seep into the subsurface soil which in turn filters the pollutants. Problems occur when the soil becomes plugged with solids carried from the septic tank to the drainfield. Once soil becomes plugged, it is not able to absorb the water from the septic system resulting in surface ponding of wastewater, which can be carried by rain to neighboring streams. A similar scenario occurs if tanks and drain lines are clogged allowing wastewater to enter soil untreated.

Warning Signs

• Sewage surfacing over the drainfield, especially after storms
• Sewage back-ups in the house
• Lush, green growth over the drainfield
• Slow draining toilets or drains
• Sewage odors

Make a Difference

• Have the tank pumped out and system inspected every 3-5 years by a licensed septic contractor (listed in the yellow pages).
• Keep a record of pumping, inspections, and other maintenance.
• Practice water conservation. Repair dripping faucets and leaking toilets, run washing machines and dishwashers only when full, avoid long showers, and use water-saving features on faucets, showerheads, and toilets.
• Learn the location of the septic system and drainfield. Keep a sketch of it handy for service visits. If the system has a flow diversion valve, learn its location and turn it once a year. Flow diverters can add years to the life of the system.
• Divert roof drains and surface water from driveways and hillsides away from the septic system. Keep sump pump outlets and house footing drains diverted as far away from the septic system as possible.
• Take leftover hazardous household chemicals to an approved hazardous waste collection center for disposal. Use bleach, disinfectants, and drain and toilet bowl cleaners sparingly and in accordance with product labels. Look for those that state septic system safe.
• Leave the area covering the drainfield undisturbed with only a mowed grass cover. Roots from nearby trees and shrubs may clog and damage the drain lines.
• Don't drive or park on top of any part of the system.
• Don't make repairs to septic system without obtaining the required health department permit. Use professional licensed septic contractors when repairs are needed.
• Don't plant trees and shrubs near the septic tank or field.
• Don't use commercial septic tank additives. These products usually do not help and may hurt a system in the long run.
• Don't use toilets or drains as trash cans by dumping in nondegradables.
• Don't poison septic system and ground water by pouring harmful chemicals down the drain. They can kill the beneficial bacteria that treat wastewater. Keep the following materials out of the system:
  • nondegradables—grease, disposable diapers, and plastics.
  • poisons—gasoline, oil, paint, paint thinner, pesticides, and antifreeze.

A Healthy Lawn Helps the Environment

Lawn care knowledge and responsible practices are keys to maintaining a good lawn and a healthy environment in the surrounding community.

Work with nature, not against it. Healthy grass provides a feeding ground for birds who find it rich with insects and worms. Thick grass prevents soil erosion, filters contaminants from rainwater, and absorbs many types of airborne pollutants such as dust and soot. Grass is also a highly efficient converter of carbon dioxide to oxygen, which helps clean the air.

Make a Difference

• Have soil composition tested. Virginia Cooperative Extension can recommend the nutrients that need to be added to support the intended use.
• Develop healthy soil. To grow well, lawns need soil with good texture, some key nutrients, and the right pH or acidity/alkalinity balance.
• Water deeply, but not too often. It's best to water only when the lawn really needs it.
• Choose a grass type that thrives in a specific climate. The right type of grass, one that suits specific needs and likes the local weather, will always yield better results.
• Mow high, often, and with sharp blades. Keeping the blades taller will produce stronger, healthier grass with a better root system and fewer pest problems.
• Correct thatch build up. When thatch gets deeper than 1/2 inch, it prevents water and nutrients from penetrating to the soil and grass roots. Reduce thatch by raking the lawn or using a machine to break it up.
• Aerate soil. Aeration helps water penetrate soil and allows air to circulate around the roots of grass. For information about buying or renting a soil aerator, call a local nursery or rental company.
• Recycle grass clippings. Leaving them on the lawn can reduce fertilizer application up to 70%. Cool season grass should be fertilized in the fall to promote a healthy root system.
• Set realistic goals. Putting green perfection does not have to be a goal.

Mulch is organic material such as wood chips, grass clippings, leaves, or compost that is spread over the surface of the soil. Mulch is an easy way to recycle yard wastes.

What Does Mulch Do?

Mulch conserves water, keeps down weeds, and regulates soil temperature. It also protects the ground from erosion and compaction caused by rain and foot traffic. Mulch provides ideal conditions for earthworms and other soil organisms necessary for healthy soil and plants. Mulch breaks down into humus, which feeds the soil. A good mulch should be readily available, easy to apply, and stay in place without much effort.

Applying Mulch

• Before applying mulch, weed area.
• Spread mulch around plants as far as the distance of its outermost branching (the drip line) or cover an entire garden bed.
• Spread mulch thickly if water is able to penetrate and if it does not smother the roots of the plant being mulched.
• Three inches of mulch is safe for any woody plant and up to eight inches is acceptable for large trees.
• Avoid using thick mulches on azaleas, rhododendrons, or other shallow-rooted plants.

Finding Materials

• Look in the yard. Every yard has grass or leaves that can be made into mulch.
• Wood chips. Contact a local tree service, landscaper or nursery.

Tools

Purchase shredders and chippers at lawn and garden equipment stores.

• Rotary mower: Run across dry leaves to make fine-textured mulch for annuals and smaller plants.
• Small electric chipper: Use on woody stalks and branches up to 1/4 inches thick to make fine-textured mulch.
• Gas-powered shredders: A five to eight horsepower unit is capable of processing materials up to three inches in diameter.
• Large gas-powered shredders: This type of unit can handle woody wastes up to six inches in diameter. The larger the machine, the faster the mulch-making.

General Rules

• Annuals and perennials: Use mulch that breaks down in a relatively short period of time, such as grass clippings and leaves.
• Trees and shrubs: An attractive thick layer of wood chips requires little maintenance.
• Grass clippings: Spread in thin layers over vegetable and flower beds or mix with leaves and spread in a thick layer. Keep clippings to less than one inch to prevent matting and to allow water to penetrate the soil.
• Leaves: Leaves from deciduous trees can be spread as mulch in the fall. Evergreen leaves can be used, but take longer to turn a dark color and decay.
• Sawdust and other finely ground woody materials: Use on the surface, but do not mix into the soil.

What is Compost?

Compost, also called humus, is recycled organic matter. It is a dark, crumbly, partially decomposed collection of plant products. Compost is created by a biological process in which numerous bacteria break down the plant material.

What is the Value of Compost?

Composting is a practical, convenient way to transform yard wastes into a resource. It is a valuable tool for anyone with a garden, lawn, trees, shrubs, or even planter boxes. By using compost, organic materials are returned to the soil. The process improves plant growth by breaking heavy clay soils into a better texture, adding water and nutrient-holding capacity to sandy soils, and adding essential nutrients to any soil. Improving the soil is the first step toward improving the health of plants, reducing fertilizer use, cleaning the air, and preventing soil loss through erosion.

What can be Composted?

Many types of organic materials can be used for compost. Sod, grass clippings, leaves, hay, straw, weeds, manure, chopped corncobs, corn stalks, sawdust, shredded newspaper, wood ashes, hedge clippings, and plant refuse from the garden are just a few possibilities for compost.

Use care when composting kitchen scraps. Compost only vegetable scraps. Do NOT compost meat scraps, bones, fatty foods (cheese, salad dressing, and cooking oil), or pet feces. These items may attract dogs, rats, and other animals and may develop an unpleasant odor during decomposition. Instead, place these items in the regular garbage.

Individuals can enhance their ability to promote water quality by forming small groups to reinforce efforts to identify actual or potential problems and to exert the necessary pressure to initiate corrective action. Affiliating with state or national organizations with experience in such programs will increase the effectiveness of such groups.

Starting Up

• Make a commitment. Recognize that it takes an investment of time and energy over a period of years. Don't get started unless there will be a follow through effort on the project.
• Limit objectives. Select a portion of a waterway or stream to place under continuing care.
• Form a group. Publicize the effort. Contact local homeowner organizations, conservation groups, civic associations, and youth groups to provide support and a membership base. Have a kickoff meeting.
• Develop an action plan. Perform an initial "stream walk" to inventory problems. Plan responses to obvious problems. Get advice from established organizations when making an action plan.
• Know the law. There are many laws and ordinances designed to protect the environment and regulate hazardous activities. Call state and local officials for more information.
• Establish an organizational structure. Define and assign responsibilities. Survey the community for talent and funds.
• Obtain backing of local political organizations and of the national/state volunteer organizations dedicated to improving water quality. Contact the Northern Virginia Soil and Water Conservation District as a first step to networking with the involved organizations.
• Do something concrete and rewarding. Plan and conduct a stream cleanup. Involve the entire membership of the cooperating organizations.
• Initiate water quality monitoring. Affiliate with an organization such as the Northern Virginia Soil and Water Conservation District or the Audubon Naturalist Society and obtain training, kits, and survey forms. Assign monitoring points to small groups of volunteers to keep people active and to see hard results.
• Publicize. Spread the news about findings and corrective actions to be taken to improve water quality. Conduct seminars for homeowners on lawn care, fertilizing, mulching, and composting.