Chemical Quality of Ground Water
Water is often referred to as the universal solvent. Various gases and minerals are taken into solution by water as it falls through the air and as it percolates through materials in the earth. The kind and amount of impurities in ground water can be determined by chemical analysis. The corrosiveness, encrusting tendency, potability, and other properties can he predicted from the results of a quantitative analysis.
The analyses of 25 samples of water from wells and springs in Miami County are given in Table 2. Factors for converting parts per million of mineral constituents to equivalents per million are given in Table 3.
Table 3--Factors for converting parts per million of mineral constituents to equivalents per million.
|Mg++||0.0823||SO4 - -||0.0208|
Quality in Relation to Use
Ground water from properly constructed wells will have good sanitary quality. The chemical content of the water also is important. Water to be used for drinking should not contain excessive amounts of iron, magnesium, chloride, sulfate, nitrate, or other undesirable constituents.
Water to be used for cooking and washing should not have an excessive hardness and should not have a high bicarbonate content. The quality of water in relation to use, with principal constituents and characteristics, acceptable concentrations, and range in concentrations in water in Miami County, is found in Table 4.
Table 4--Quality of water in relation to use, Miami County, Kansas.
|Dissolved Solids||Water high in dissolved solids may have a disagreeable taste or have a laxative effect. When water is evaporated the residue consists mainly of the minerals listed in Table 2.||500 ppm||174-1,227|
|Hardness||Hardness is caused by calcium and magnesium. Forms scale in vessels used in heating or evaporative processes. Hardness is commonly noticed by its effect when soap is used with the water. Carbonate hardness can be removed by boiling, noncarbonate hardness||120 ppm (easily detected) 200 ppm (sometimes softened for household use)||109-886|
|Iron (Fe)||Stains cooking utensils, plumbing fixtures, and laundry. Water may have a disagreeable taste.||0.3 ppm||0.06-126|
|Fluoride (F)||Fluoride concentrations of about 1 ppm in drinking water used by children during the period of calcification of teeth prevents or lessens the incidence of tooth decay. 1.5 ppm may cause mottling of the tooth enamel (Dean, 1936). Bone changes may occur wit||1.5 ppm||0-0.6|
|Nitrate (NO3)||Nitrate concentration of 90 ppm may cause cyanosis in infants (Metzler and Stoltenberg, 1950). Comly (1945) states that 45 ppm concentrations may be harmful to infants. Adverse effects from drinking high nitrate water are also possible in older children a||45 ppm||0.4-239 (2 samples >90 ppm; 3 samples > 45 ppm)|
|Sulfate (SO4)||Derived from solution of gypsum and oxidation of iron sulfides (pyrite, etc.). Concentrations of magnesium sulfate (Epsom salt) and sodium sulfate (Glaubers salt) may have a laxative effect on some persons.||250 ppm||16-379|
|Chloride (Cl)||Chloride in ground water may be derived from connate marine water in sediments, surface contamination, or solution of minerals containing chlorides.||250 ppm||4-415|
* Concentrations as recommended by the Public Health Service, Drinking Water Standards, 1962.
The analyses of water (Table 2) show only the amount of dissolved solids and do not indicate the sanitary quality of the water. Well water may contain dissolved mineral matter that gives the water an objectionable taste even though it may be free of harmful bacteria and consequently safe for drinking. On the other hand, well water, good tasting and seemingly pure, may contain harmful bacteria. Excessive amounts of certain ions, such as chlorides or nitrates, may indicate pollution.
Recommendations for the location and construction of wells and suggestions for pump installations for the different types of wells can be obtained from the Kansas State Department of Health.
Kansas Geological Survey, Miami County Geohydrology
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Web version June 2002. Original publication date June 1966.