Description: Nitrogen and phosphorus (also called nutrients) are natural elements in the environment that are essential for plant and animal growth in normal amounts but are harmful in excess – too much of a good thing. These are among the top three water pollutants nationally, degrading over 100,000 river and stream miles and over 3.5 million acres of lakes, reservoirs and ponds. About 6,000 nutrient-impaired waterbodies have been reported throughout the US. Most nutrient pollution comes from insufficiently controlled rain runoff or discharges from fertilizing lawns and croplands, municipal waste treatment systems, and animal wastes from livestock farming. Excess nitrogen or phosphorus can cause too much aquatic plant growth and algae blooms, sometimes choking off waterways and causing toxic or oxygen-poor conditions in which fish and other aquatic life often cannot survive. Nitrogen and phosphorus pollution can be harmful to human health if the affected waterway is used for swimming or if its contaminated water is consumed, and nitrates in drinking water have been linked to the fatal “blue baby syndrome.” These pollutants can also harm local economies through increased drinking water treatment costs, poor fish and shellfish harvests, less income from reduced recreational tourism, and reduced property values on polluted waterways.
Description: Pathogens are disease-causing microbes (bacteria, viruses and protozoa) that usually come from human or animal waste. They are the most commonly reported cause of water pollution nationwide, with over 10,300 waters identified. These microbes enter US waterways from both human-caused and natural sources, and can affect human and animal health as well as several beneficial uses. Pathogens reach the water directly in urban and suburban areas from wastewater treatment plants, sewer overflows, failing sewer lines, slaughterhouses and meat processing facilities; tanning, textile, and pulp and paper factories; fish and shellfish processing facilities; sewage dumped overboard from recreational boats; and pet waste, litter and garbage. Rural sources include livestock manure from barnyards, pastures, rangelands, feedlots, unfenced farm animals in streams, improper manure or sewage land application, poorly maintained manure storage, and wildlife sources such as geese, beaver and deer. The amount of microbes present, and thus the health risks they represent, can change rapidly due to factors such as rainfall and runoff from the sources mentioned above. Serious but rarely life-threatening illnesses are caused mainly by swallowing pathogen-contaminated water during swimming or other recreation, but can also come from skin contact with the water or eating contaminated fish or shellfish. Livestock, pet and wildlife illnesses can also occur. Besides causing illnesses, pathogens in waterways can cause significant economic losses due to beach closures, swimming and boating bans, and closures of shellfish harvest beds. When present in raw drinking water sources, they can be treated but require more advanced and expensive methods to disinfect and filter the water supply. People can help reduce pathogen contamination by never dumping animal or boat waste in a waterway, fixing leaky septic tanks, picking up pet waste, and avoiding manure application close to shorelines or drainage ditches.
Name: Oxygen Enrichment and Oxygen Depletion (305(b))
Display Field: RAD305B_ALL_Water_Name
Type: Feature Layer
Geometry Type: esriGeometryPolyline
Description: Dissolved oxygen in the water is essential for healthy waterways. Prolonged periods of low dissolved oxygen are harmful to most aquatic life and can cause fish kills and large dead zones (areas that can’t support aquatic life). Oxygen levels in the water change naturally, but severe depletion of oxygen is usually due to human activities that increase the amount of plant parts and animal and human waste in the water. This increase is known as organic enrichment. Algae and aquatic plants consume oxygen at night even in healthy waters, and naturally occurring decay also lowers oxygen. When excess organic matter enters the water and decays, it depletes the oxygen below levels that fish and other aquatic life forms need to survive. Some types of chemical pollutants also decrease oxygen in water and have similar effects. Oxygen depletion can be caused by runoff of chemical and manure-based fertilizer applied to lawns and croplands, septic or untreated sewage overflow, animal wastes from livestock farming and pets, and industrial waste, such as discharges from pulp and paper mills. Reservoirs and activities that involve straightening streams can also cause oxygen-poor waters because they mix the water less and decrease aeration. Prolonged high temperatures can also decrease oxygen since warm water cannot hold as much oxygen as cold water. Low dissolved oxygen and decay can cause foul smells and encouraging the growth of nuisance species, making waterfront properties and recreation unattractive. Around 6,000 waters have been reported in the organic enrichment/oxygen depletion category nationwide, making this the third most common impairment category, and several thousand more waters with nitrogen and phosphorus pollution or high temperature impairments also affect dissolved oxygen in waters. People can help avoid low dissolved oxygen problems in their local waters by never dumping plant or animal waste in a waterway, applying the correct amount of fertilizer on lawns and never before storms, disposing of pet waste in the trash, pumping out septic tanks regularly, and pumping boat waste to an onshore facility.
Description: Toxic organic chemicals are harmful, man-made chemicals containing carbon. These often remain in the environment for long periods and can accumulate in animal and fish tissues and sediments. They also can get into drinking water supplies, posing potential long-term health risks to humans. Toxic organic chemicals are the reported cause of waterbody impairment in over 280 waters nationwide. These pollutants include a large number of chemicals such as solvents, pesticides, dioxins, PCBs, furans, and other nitrogen compounds. Common sources include wood preservatives, antifreeze, dry cleaning chemicals, cleansers, and a variety of other chemical products. Two important sources of toxic organic chemicals in water are improper disposal of industrial and household wastes and runoff of pesticides. Excessive application of insecticides, herbicides, fungicides, and rodenticides, or application of any of these shortly before a storm, can result in toxic pesticide chemicals being carried from agricultural lands, construction sites, parks, golf courses, and residential lawns to receiving waters. Other organic pollutants come from auto exhaust and from burning municipal and chemical wastes. Organic pollutants can build up in aquatic animals and increase in concentration through the food chain. These substances can be toxic to all forms of life, and are known to cause cancer in animals. For humans, some of them are suspected to cause cancer and are also known to have negative impacts on our immune, reproductive, nervous, and endocrine systems.
Description: Degraded habitats are areas in which the conditions needed for fish and other aquatic life to feed, reproduce, find shelter, and survive have been reduced or lost. About 3,000 waters distributed throughout the US are currently identified in this impairment category. Because impairments to habitat by flow changes or specific pollutants (such as sediment) are reported separately, this habitat degradation category mainly refers to structural changes, such as loss of pools or deep channels where fish can congregate, removal of plants, logs and rocks that provide cover, or changes that make areas for spawning unsuitable. Stream straightening, channelization, lining streambeds with concrete, and replacing natural shorelines with artificial walls are other common forms of manmade habitat degradation. These types of changes can have high impacts on aquatic life but do not directly pose risks to human health. However, degraded habitats often make fishing and other forms of water-based recreation undesirable, and can impact the appearance and value of waterfront property. Waterfront property owners or users can reduce habitat degradation and maintain their recreational uses and appearance (while avoiding unnecessary maintenance costs) by not removing streamside vegetation or channelizing streams, not filling wetlands or other waters, keeping natural shorelines intact, and leaving some rocks, logs or native aquatic plants as cover for fish.
Description: Major changes in stream or river flow are a form of pollution because they can reduce or eliminate fish survival, degrade a variety of beneficial human uses and indirectly make other pollutants more harmful. Although withdrawing water for use is essential and widespread throughout the US, reporting of flow alteration as a direct cause of impairment is limited to approximately 100 waters mostly in the eastern and central states. Common causes of altered flow include water withdrawal for irrigation, municipal water supplies and industry. These uses of water are important, but in extreme cases they can reduce or eliminate other uses such as navigation, fishing or recreation; some flow-impaired waterways dry up entirely. Reduced water flow also indirectly affects many pollutants by providing less water to dilute contaminants. Lower water volumes can contribute to stagnant, warmed water, buildup of mucky sediments, low oxygen in the water and loss of fish and other aquatic life.
Description: Sediment is fine material eroded from rocks or soil and then transported and deposited in water. Sediment in the proper quantity is a natural part of the banks and bottom of lakes, streams and other waterways, but it becomes a problem when too much of it enters the water or when it is contaminated by other pollutants. Excess fine sediment is one of the most common forms of impairment reported in over 6,000 water bodies from all parts of the US. These waters most often suffer from excessive suspended sediment in the water or too much deposited fine sediment on the bottom. Too little sediment below dams sometimes impairs streams and causes them to scour their channels and destroy fish habitat. Sediment problems happen when rain washes silt and other soil particles off of plowed fields, construction sites, logging sites, urban areas, and strip-mined lands into waterbodies. The sediment may clog and damage fish gills or suffocate eggs and aquatic insects on the bottom. Suspended silt may interfere with recreational activities like boating, fishing or swimming and degrade the beauty of waterbodies by reducing water clarity. Although sediment itself is generally harmless to human health or safety, indirect environmental or health risks can happen when nitrogen and phosphorus pollution and a variety of toxic chemicals attach to sediment particles on land and ride the particles into surface waters, where the pollutants may settle to the bottom or dissolve. People can help make sediment impairment less common or less serious by limiting soil erosion in any way possible, not contaminating soil near waterways, and routing rainwater runoff to areas where it can soak in rather than directly dump into a lake, stream or sewer system.