Local residents expressed their concerns regarding the tailings from the Iron King Mine and Humboldt Smelter at Dewey-Humboldt, AZ. The purpose of this health consultation is to evaluate the available water and soil sampling results to determine if the detected metal levels pose adverse health effects when residents come into contact with the water or soil. In 2008, EPA initiated the field investigation portion of the Remedial Investigation and Feasibility Study for the Site. The primary objectives of the RI/FS are to determine the nature and extent of contamination and to gather sufficient information so that EPA can select a long-term remedy that eliminates, reduces, or controls risks to human health. The investigation included the collection of airborne particulates, groundwater, surface water, surface soil, subsurface soil, and sediment data across the entire Site. Data from the RI/FS was not available at the time the health consultation was prepared and thus it was not incorporated into this health consultation.

In August 2001, a resident of New River contacted the Arizona Department of Health Services, Office of Environmental Health to request information on the health risks of arsenic in drinking water. The resident collected two well water samples and submitted them to a private laboratory for arsenic analysis. The analyses detected arsenic at 560 and 600 μg/L. To confirm these very high arsenic results, ADHS staff sampled the well for arsenic and submitted the samples for analysis by the ADHS State Laboratory. Arsenic was detected at 340 μg/L. After that, a large number of people requested health advice on arsenic in their well water. This public health consultation primarily evaluates arsenic levels found in private wells and documents health advice provided to well owners. When other metals were found at levels of concern, health advice was provided to well owners regarding exposure to those metals too.