Potential health implications for acid precipitation, corrosion, and metals contamination of drinking water

Potential health effects of drinking water quality changes caused by acid precipitation are presented. Several different types of water supply are discussed and their roles in modifying acid rain impacts on drinking water are explained. Sources of metals contamination in surface water supplies are enumerated. The authors present some results from their research into acid rain impacts on roof-catchment cisterns, small surface water supplies, and lead mobilization in acid soils. A good correlation was obtained between cistern water corrosivity as measured by the Ryznar Index (RI) values and standing tapwater copper concentrations. However, lead concentrations in tapwater did not correlate well with cistern water RI. A modified linear regression model that accounted for Ryznar Index change during storage in vinyl-lined cisterns was used to predict the Ryznar Index value at a copper concentration of 1000 micrograms/L. The predicted RI was greater than the RI of precipitation with a pH of 5.3, indicating that anthropogenically acidified precipitation may result in cistern tapwater copper concentrations in excess of the 1000 micrograms/L suggested drinking water limit. Good correlations between tapwater Ryznar Index and tapwater copper and lead concentrations were not obtained for the small surface water supply. Aluminum concentrations in reservoir water were similar to those in stream source water. Limited data were also presented that indicated lead was present in acid forest soil leachate and streams draining such soils in relatively small concentrations. Where appropriate, recommendations for future research are included with the discussions of research results.