Surveying Boron and Naturally Soft Groundwater with a Computer Database.* Groundwater in Ingham County, Michigan Ingham County is a county in the U.S. state of Michigan. The 2000 census recorded its population at 279,320; a 2006 estimate placed the population at 276,898. The county seat is Mason6. Lansing, the state capital of Michigan, is also within the county. , is generally characterized as "hard," with the exception of naturally "soft" groundwater (less than 200 ppm of calcium carbonate calcium carbonate, CaCO3, white chemical compound that is the most common nonsiliceous mineral. It occurs in two crystal forms: calcite, which is hexagonal, and aragonite, which is rhombohedral. ) in one area of bedrock. * The naturally soft groundwater has above-normal levels of boron--in excess of 1.0 parts per million parts per million mg/kg or ml/l; see ppm. . * A computer mapping program and a water quality database were used to delineate the area of naturally soft groundwater. * A review of well construction records indicated that wells in the soft-water area had more shale bedrock than hard-water wells. * A statistical analysis confirmed the correlation between high levels of boron boron (bōr`ŏn) [New Gr. from borax], chemical element; symbol B; at. no. 5; at. wt. 10.81; m.p. about 2,300°C;; sublimation point about 2,550°C;; sp. gr. 2.3 at 25°C;; valence +3. in groundwater and a higher percentage of shale bedrock. * A correlation also was found between water hardness and sodium-to-boron ratios in groundwater. * Medical research has shown that boron can have positive effects in reducing osteoporosis: In one study, a boron supplement of 3 ppm reduced urinary excretion of calcium and magnesium. * At the same time, several reports have indicated a health concern over the negative effects boron may have on the male reproductive system reproductive system, in animals, the anatomical organs concerned with production of offspring. In humans and other mammals the female reproductive system produces the female reproductive cells (the eggs, or ova) and contains an organ in which development of the fetus . * Boron also is important in agriculture. It is essential for plant growth, but the difference between a level sufficient for proper plant growth and a toxic level can be very small, depending on the plant species. * A U.S. EPA EPA eicosapentaenoic acid. EPA abbr. eicosapentaenoic acid EPA, n.pr See acid, eicosapentaenoic. EPA, n. health advisory recommends a limit of 0.9 ppm for long-term (usually seven years') exposure to boron in drinking water drinking water supply of water available to animals for drinking supplied via nipples, in troughs, dams, ponds and larger natural water sources; an insufficient supply leads to dehydration; it can be the source of infection, e.g. leptospirosis, salmonellosis, or of poisoning, e.g. for a 10 kg child. * In Ingham County, routine tests of water wells currently include tests for water hardness and sodium. Boron is not usually sampled for. * If, however, a routine test indicates low hardness and high sodium, the boron value may be above U.S. EPA's recommended drinking-water limit. * Thus, for wells that have naturally soft water, it is recommended that a boron test also be conducted. * A computerized mapping system and the health department's computerized groundwater database both were instrumental in studying this public health issue. |
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