Water Systems (Drinking J Water Quality)
STATEMENT OF PROBLEM AND SPECIAL INFORMATION
Historically, waterborne disease was one of the great problems of all societies, and had a profound effect on life and health within communities. The advances made in water treatment and disinfecting of water supplies helped our society, especially the young, since they were typically most affected. Globally, today 88% of diarrhea cases are linked to unsafe water or poor hygiene techniques. This results in 1.5 million deaths each year, mostly in young children. (See endnote 1, Chapter 3; 40.)
About 1% of the fresh water in the world is available for human use, and this has stayed constant over many centuries despite the fact that there is an enormous demand for water created by huge increasing populations, which will continue to grow in the foreseeable future. There is a vast difference in the distribution of fresh water in various parts of the world as well as in the United States. Climate change, increasingly more powerful storms, and droughts are making the situation worse in certain areas. This is compounded by substantial population pressure in coastal areas and the growth of large cities and communities. Certain water sources, such as fossil water which has been trapped for a very substantial amount of time, may be used but not replenished. While the demand for safe drinking quality water is expanding rapidly, the supplies are diminishing.
Disposal of sewage, solid and hazardous wastes, air pollutants, and use and misuse of the many chemicals that make the modern world more livable are also challenging existing water supplies. Modern agriculture consumes a considerable amount of the fresh water which is available. There is a substantial need for protecting watersheds, using existing water more efficiently, preventing environmental pollutants from contaminating fresh water supplies, and cleaning up the results of the carefree attitude of waste disposal in many areas which has occurred since the Industrial Revolution and certainly in much greater quantities since World War II. Water delivery services through pipes which are extremely old result in reduced water at the point of need and water which may become severely contaminated by the pipes or the surrounding ground. A perfect example of the contamination of water by pipes has occurred in Flint, Michigan, where thousands of children were put at severe risk of lead poisoning when the governor’s appointee to manage the city because of financial problems made a non-scientific highly questionable decision to stop water purchase from the City of Detroit and instead use the severely contaminated water from the Flint River. In addition, there have been multiple cases of Legionnaires’ disease from this drinking water source. (See endnote 47.) Water scarcity exists globally, including the United States and is expected to increase sharply through the coming years. (See endnote 2.)
Fresh water may be found in the form of ice, especially in glaciers, which is not readily accessible; precipitation in the form of rain, snow, sleet, fog, and hail which is readily accessible; in streams, lakes, and rivers which is readily accessible; and in underground aquifers where the water may have been deposited hundreds or thousands of years ago or very recently. The groundwater may be found in spaces between particles of rock and soil, in cracks in the rock, between rock formations (artesian well source), as soil moisture, or at times in underground rivers or underground lakes. The groundwater typically flows slowly through the aquifers. Where water fills an area, it is called the water table and is just below the unsaturated zone, which contains both air and water. The moving groundwater depending on the minerals that it crosses or goes through may become naturally contaminated with a series of substances.
Groundwater is a major component of the hydrologic cycle where precipitation falls and a portion of it evaporates back to the atmosphere, a portion of it is used by plants, trees, or other green materials and goes back to the clouds through transpiration, and a portion of it collects in reservoirs, lakes and ponds, especially in arid areas, and evaporates back to the clouds. The clouds then become the source of more precipitation and this water may be used for irrigation for agriculture where a portion of it re-evaporates back to the clouds, a portion of it runs off to surface bodies of water such as rivers, lakes, streams, and oceans, and a portion of it percolates down through the ground to become groundwater, which can be used at a later date. (See endnote 3.)
The US Environmental Protection Agency (EPA) has promulgated mandatory National Primary Drinking Water Regulations. These are legally enforceable standards which apply to public water systems. The standards provide a list of contaminants including microorganisms, disinfection byproducts, inorganic chemicals, organic chemicals, and radionuclides, their maximum contamination levels, and potential health effects from long-term exposure above the maximum contamination levels or from short-term contamination. The Maximum Contaminant Level (MCL) is the highest level of contaminant that is allowed in drinking water using the best available treatment technology at reasonable cost. (For specifics see endnote 4.)
This chapter will be dedicated to protecting the water supply for human, and agricultural and industrial use, as well as for ecosystems and environmental sustainability. Since water is used and reused constantly and water treatment and delivery systems are essential to the process, these will also be discussed.
Many of the topics which will be discussed in this chapter have already been developed in depth in Chapter 2, “Air Quality (Outdoor [Ambient] and Indoor)”; Chapter 3, “Built Environment— Healthy Homes and Healthy Communities”; Chapter 4, “Children’s Environmental Health Issues”; Chapter 5, “Environmental Health Emergencies, Disasters, and Terrorism”; Chapter 7, “Food Security and Protection”; Chapter 10, “Recreational Environment and Swimming Areas”; Chapter 11, “Sewage Disposal Systems”; Chapter 12, “Solid Waste, Hazardous Materials, and Hazardous Waste Management”; and Chapter 14, “Water Quality and Water Pollution.” As a result of this and the inter-relationship between air, land, and water environments, and the movement of pollutants from one medium to another, the reader will be referred to other chapters to avoid duplication of written materials and elongating this book. However, when there are additional problems and Best Practices, or the author wants to emphasize certain points which are very significant to the reader, additional information will be provided.