Geological Survey

In recent months many inquiries have been received by the U.S. Geological Survey regarding the occurrence of mercury in water resources. Although public interest has centered on learning more about the widespread natural and manmade sources of mercury, the implication in many inquiries has been: Are there other potentially dangerous chemical elements present in water resources? The nationwide reconnaissance sampling reported here was designed to provide a partial answer to that question. In view of the growing national concern, there is an acute need to place facts on record as soon as they accumulate. The Survey provides the enclosed data report to assist in establishing a continuing baseline of information about the quality of our water resources