Acidic Deposition and Cistern Drinking Water Supplies

摘要

The water quality characteristics, including the trace elements Cd, Cu, Pb, and Zn, in rainwater cistern supplies representing an area receiving acidic deposition were compared to cistern water chemistry in a control area that does not receive a significant input of acidic deposition. Mean volume-weighted pH for bulk deposition was two pH units higher and SO4 was 50% lower in the control region. Rainwater was neutralized upon contact with cistern masonry in both regions, as indicated by a 1.5-unit increase in pH and an increase in calcium and alkalinity. While there seemed to be a clear difference in water quality for the two study regions, any difference in trace metals was marginal. Metal concentrations were below current drinking water limits in all but a few samples. Cistern water that remained in the home plumbing system overnight exceeded the proposed drinking water standard of 5 micrograms/L for lead in 18 homes in the region receiving acidic deposition and 10 homes in the control region. No relation between metal concentrations and roofing material, plumbing materials, or water stability indices could be found. (Copyright (c) 1989 by the American Chemical Society.)