Ground-Water Quality in the Caguas-Juncos Valley, Puerto Rico, April to October 1990

Ground water from 48 wells and 1 spring in the Caguas-Juncos Valley was sampled and analyzed for major ions, nutrients, trace metals, and volatile synthetic organic chemicals from April to October 1990. This report presents the results of physical and chemical analyses made on these water samples.

Dissolved-solids concentrations exceeded 500 milligrams per liter in 28 percent of the samples. Concentrations of trace metals were below the maximum contaminant levels set by Federal and Commonwealth agencies. Volatile synthetic organic chemicals were detected in water from five wells, four of which were located in urban and industrial areas. Concentrations of benzene, ethylbenzene, toluene, and xylene detected in samples from one observation well exceeded the maximum contaminant levels set be Federal and Commonwealth agencies.