Get the facts . . . Volume 1
What is in Water?
Water (H2O) is not just pure hydrogen and oxygen. Many substances may be dissolved in water, such as microorganisms or minerals from rocks, air, and soils it contacts. Human activities also contribute substances to water. Some, such as bacteria, come from waste products of people and animals. Others, such as petrolem products and solvents, are synthetic chemicals made and used for special purposes. Still other materials, such as nitrate and phosphorus, are nutrients required for plant growth that occur naturally. However, these substances are applied to crop fields and later washed from the surface of the land into lakes and streams, where they cause water quality problems.
Where does my tapwater come from?
As long as water continues to flow from our tap, we don't often think about where it comes from. Drinking water sources may be surface waters or ground water. Surface water, as its name implies, lies on the earthâ€™s surface, such as a dam, lake, stream or river. Groundwater comes from below the earthâ€™s surface where it lies in aquifers. These aquifers can be shallow, lying less than 100 feet below the surface (for example, the Big Sioux Aquifer) or deep, lying thousands of feet down (such as the Sundance, Dakota, and Madison formations common in western South Dakota).
What is water quality?
It is the chemical, biological and physical characteristics of water. Chemical pollution includes any chemicals in the water that are not natural in origin. Biological water quality pertains to the organisms living in the water, such as fish, macroinvertebrates (bugs), plankton, shellfish or any other form of life that lives in water. Many fish and macroinvertebrates are sensitive to pollution, and may be used as indicators of water quality. The physical characteristics of water, such as temperature, viscosity, and general appearance are also important. Temperature is important because many organisms prefer water within a specific temperature range and may die off if water gets too hot or too cold. The appearance of water is also an indicator of pollution. Scum on the water's surface, nuisance algal blooms, and discolored water may signal that water quality issues exist.
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How does water quality and quantity affect me?
Water is vital for humans, animals and plants to survive. Nothing can live long without it. Therefore, a reliable, safe source of water is important to everyone and everything. Point and nonpoint source pollution must be carefully monitored and controlled.
What is point and nonpoint source pollution?
Point source pollution is commonly defined as water pollution that can be traced to a specific source of discharge such as a pipe. Nonpoint source (NPS) pollution is more difficult to define. A simplified definition would be water pollution that does not discharge from a pipe. Examples include, but are not limited to, runoff from construction sites and agriculture, silviculture, mining and urban areas. Nonpoint sources of pollution can come from any area, and most do not discharge at a specific, single location. In general, nonpoint pollutants are carried over and through the ground by rainfall, runoff and snowmelt. Legal distinctions complicate the definition, however. When runoff is collected and discharged through a pipe (such as combined storm and sanitary sewers, or in cases of runoff from active mines), it is usually considered to be a point source. The Clean Water Act defines irrigation return flows as nonpoint source, however, despite the fact the water is collected and returned to the stream through a channel or pipe. Remember, though, water movement alone is not pollution unless the water is carrying contaminants.
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What are contaminants?
Contaminants are minerals or microorganisms occurring in water that may pose a risk through the use of the water.
They are regulated by the US Environmental Protection Agency (EPA) when they occur in drinking water supplies and can threaten public health. Such contaminants must be detectable in drinking water using current laboratory methods. Some contaminants of concern to EPA are:
Bacteria - Health officials agree the most direct health threat associated with drinking water is from bacterial contamination. Bacteria from human or livestock wastes can cause serious health problems, such as dysentery, hepatitis, and typhoid fever.
Nitrates - Nitrate levels in ground water have been rising in many areas. Common sources of nitrates include septic systems, livestock wastes, and use of nitrogen fertilizer on farm fields and lawns.
Minerals - Some of the minerals found in ground water, iron and sulfur for example, can give water an unpleasant odor or color without making it unsafe. Occasionally, metals such as chromium or lead leach into water from surrounding rock in sufficient concentrations to present a health risk.
Synthetic Chemicals - Public health officials understand the health effects of bacteria, nitrate, and some minerals. But the health effects of certain synthetic chemicals are not so clear. Determining the health effects of such contaminants is difficult, since researchers are still learning how these chemicals react in the body.
Is my water safe?
The Environmental Protection Agency has set standards for determining safe drinking water. To learn how your community water supply ranks on these standards, you may contact the SD Office of Drinking Water in Pierre, 773-3754. If you have a private water supply. you must take the initiative to have your water tested periodically. For more information on correctly testing your water supply, contact the SD Office of Drinking Water in Pierre, 773-3754.
How can I protect my water?
Water protection begins with YOU. Similar fact sheets will provide basic, usable information on protecting the waters of South Dakota. Please read this information and put it to work.
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