Biological Systems Engineering
Date of this Version
1975
Citation
TRANSACTIONS of the ASAE (Vol. 18, No. 1, pp. 106, 107, 108, 109, 110, 1975)
Abstract
In many areas of the Midwestern United States, a safe and plentiful supply of groundwater is a primary concern. Groundwater is sporadic, unreliable, shallow, and often polluted, even though these same areas often have an annual rainfall in excess of 1 m.
The pollution problems associated with these groundwater supplies are both chemical and bacterial. Older wells are often the most dangerous. Linings made of open brick near the surface, cracked casings and covers, and nearby privy, septic tank, and barnyard sites accentuate the problems in shallow groundwater aquifers. High levels of nitrates frequently present in the shallow domestic well water of Illinois were recognized as a health problem by Weart (1948).
A preliminary study by Smith et al. (1970) in Washington County, Illinois, of 213 dug wells (2.1-9.2 m deep), 31 drilled wells, and 72 farm ponds showed that water from 73.4 percent of the dug wells exceeded the U.S. Public Health Standard of 10 mg/1 nitrate nitrogen. Only 19.3 percent of the drilled wells exceeded the standard for safe drinking water. All the ponds sampled were found to be well below the U.S. Public Health Standard for nitrate content.
Pryor (1956) has reported that because of the geology of the area groundwater supplies in most of Washington County, Illinois, are inadequate. The geologic situation makes successful drilled wells almost nonexistent. Existing low-quality and low-yielding wells are being supplemented by cisterns, transported water, and some ponds.
An economic analysis of farm water supplies in Washington County by Moore (1972) revealed that present well water systems are the least costly available, but the quality and quantity make most of these sources unreliable. Alternatives considered by Moore included farm ponds, municipal water supplies, transported water, and various combinations of these potential sources. Moore concluded that farm ponds with a treatment system could be one of the more satisfactory sources of water provided storage is available to meet demands during a prolonged drought.
The data reported by Smith et al. ( 19 7 0) concerning nitrate levels in Washington County ponds were from samples collected during late spring. Hill et al. (1962) reported an average maximum level of 3.1 mg/1 of nitrate nitrogen occurred in 14 Ohio ponds with a mean value of 0.17 mg/1. Hill also reported that maximum values for some chemical parameters occurred during early spring months. The authors felt that ponds in Washington County could potentially exceed the public health limit for nitrate because contamination could occur from the same sources causing widespread groundwater contamination. Also, it was felt that differences in watershed types could influence the quality of pond water.
Pryor (1956), Smith (1970), and Moore (1972) have shown that Washington County needs an alternate water supply to existing low-quality wells. A project was initiated in December 1970 to determine seasonal and monthly fluctuations of several water quality parameters in farm ponds having different watershed types. Additionally, the premise that Washington County farm ponds could provide water of acceptable quality to repace existing low-quality wells was considered.
Comments
Copyright 1975 American Society of Agricultural Engineers