The results of two U.S. Geological Survey water-quality studies in the Lower Susquehanna and Potomac River Basins provide a message that hits close to home for rural residents that drink water from private wells: Owners of rural wells in these two basins, part of the Chesapeake Bay watershed, need to ensure their water supplies are safe to drink.
The USGS studies found high levels of nitrate and high counts of bacteria in ground water from wells used for household supply in several rural areas. The study results underscore the need for awareness that untreated ground water may not always be safe to drink.
There was good news, however, about these same rural wells. Concentrations of pesticides and other organic contaminants in the water from the wells did not exceed levels established by Federal and State agencies as drinking-water standards.
Of the well-water samples in which a pesticide was present, nearly 70 percent contained more than one detectable pesticide. This is a significant new finding from the USGS studies.
"Human activities on the land surface, such as application of fertilizers and manure on croplands, have a significant effect on the concentration of nitrogen that ends up in the ground water or streams," said Scott Ator, USGS Hydrologist and principal author of the Potomac River Basin report. Ator's colleague, Bruce Lindsey, USGS Hydrologist and principal author of the Lower Susquehanna report, added, "Animal manure, used as an agricultural fertilizer, and commercial fertilizers are major sources of nitrogen and phosphorus in the Chesapeake Bay watershed. We now have good baseline data to measure changes as the new Pennsylvania law for nutrient management goes into affect this year."
"The old adage `Too much of a good thing' applies in certain areas,"
Lindsey said. Nitrogen in manure and fertilizers added to agricultural
land is essential for plant growth; however, a concentrated animal
Contact: Bruce Lindsey
United States Geological Survey