In biological tissue, pesticides were detected at 5 of 26 stream sites. Chlordane was detected downstream from Springfield, Mo. DDT, DDE, or dieldrin was detected at four sites in agricultural basins. Concentrations of sulfate and some trace elements in water from streams in areas of active or historical lead-zinc mining tend to be higher than in areas where mining has not occurred. These trace element concentrations decrease with increasing distance downstream from the mining activity. Concentrations usually did not exceed Federal standards or criteria for the protection of drinking water, human health, or aquatic life.
Concentrations are high enough to suggest potential adverse biological effects.
The State of Missouri has issued a fish consumption advisory for some streams. However, the levels of radium seldom exceeded the U.S. Environmental Protection Agency drinking-water standard. Radon can enter homes through their water systems. Homes served by private domestic wells and small public waterworks using ground water can be particularly vulnerable. Radon levels are greater in the Springfield Plateau aquifer and the unconfined part of the Ozark aquifer than in the confined part of the Ozark aquifer.