THE SPATIAL VARIABILITY OF RAINFALL pH IN THE WASHINGTON,D.C METROPOLITAN AREA *

This study evaluated the pH of rain water at 28 sample stations throughout the Washington, D.C. metropolitan area and determined the efficacy of utilizing a volunteer sampling network under a limited budget. Twelve rain events from September 1984 to August 1985 were analyzed. Despite the small number of events sampled, a strong relationship emerged between storm path, pH pattern, and average rainfall pH. A long, overland storm track yielded low rainfall pH and a simple spatial pattern of rain pH, while coastal storms produced relatively higher pH and a pattern with many areas of local variability.