Water: Traditional Approaches
Municipal water customers – residential, commercial, industrial, and agricultural – have water needs that are met by one or more of the following three public water systems:
DRINKING (POTABLE) WATER is intended for human consumption. As such it must meet federal safety requirements. The average American uses 100 gallons of drinking water per day, only a small fraction of which is used for drinking. The rest is used for toilet flushing, bathing, cooking, landscape watering, and the like.
WASTEWATER has been used for any residential, commercial or industrial purpose and contains liquid or solid waste products (sewage, factory discharges, etc). The average American produces 60 – 150 gallons of wastewater daily primarily from washing dishes and clothes.
STORMWATER is water from rain or snowmelt. Storm water that is not absorbed into the ground or waterways, flows into storm drain systems where it must be treated for pollutants before being released.
KEY WATER ELEMENTS
A city’s water infrastructure is composed of four primary elements:
- Watersheds and drainage basins are geographic areas where rain and snow melts flow downhill following the natural terrain to a water body. Understanding watersheds is critical for effective water management plans. For example, the fact that watersheds may cross multiple political boundaries means that cross-jurisdictional partnerships are often necessary for successful initiatives.
- Water sources are collections of water in sufficient quantity to supply the needs of a community. There are two common types of water sources:
- Ground water is located in underground aquifers and is reached though wells. Soil and rock act as natural filters to remove many pollutants. Consequently, this water is typically (but not always) cleaner and requires less treatment to make it safe for human use. Approximately 50% of all US residents and 97% of rural communities get their water from ground sources.
- Surface water comes from sources located above ground like rivers, lakes, and reservoirs. Surface water is more likely to contain pollutants from storm water runoff and other sources. Large cities generally rely on surface water sources.
Rainwater and desalinated seawater are two examples of other water sources that are becoming increasingly popular. However, they are not yet significant sources for cities.
3. Treatment - Water must be treated to render it safe for human consumption and use and for return to the natural environment. There are three basic treatment processes:
- Physical processes use mechanical methods (filter screens, gravity sedimentation, etc) to remove contaminants.
- Biological processes use bacteria and other microorganisms to eat sewage and other organic matter.
- Chemical processes use chemicals to neutralize impurities and noxious waste.
4. Distribution & Collection Infrastructure comprised of the array of underground pipes and water treatment facilities.
The used water from a home, community, farm, or industry that contains dissolved or suspended matter. Not fit for human consumption.An area of land which contributes overland flow of rainfall to a particular body of water. For example the Mississippi watershed stretches from the Rocky to the Appalachian Mountains.An underground water-bearing rock formation that supply groundwater, wells, or springs.Unwanted elements that may reduce the quality of natural systems (air, water, land).
