The Miller Road Treatment Facility was built by the North Indian Bend Wash Participating Companies to treat groundwater in order to reduce the levels of volatile organic compounds that have contaminated the aquifers. The facility was brought on-line in March 1997, and ownership was transferred to AAWC in December 1997. The facility processes the groundwater to remove the VOCs. Between January 15–17, 2008 trichloroethylene (TCE) was detected in the Paradise Valley Water System. Arizona American Water Company, who own and operate the Paradise Valley system, contacted the Arizona Department of Health Services and requested assistance in determining possible health risks from exposures related to this incidence. In response, the Arizona Department of Health Services reviewed existing data and performed a health consultation to evaluate the possibility of adverse health effects associated with this event.

In May 2003, a Scottsdale, Arizona, resident asked the Agency for Toxic Substances and Disease Registry in Atlanta to investigate possible sewer gas exposures in a Scottsdale residential neighborhood. In June 2003, the Agency asked the Arizona Department of Health Services, to conduct an investigation to determine if sewer gas exposures were occurring. Because ambient and indoor air hydrogen sulfide data for the neighborhood were not available, the Arizona Department of Health Services and the resident collaborated in conducting an air monitoring investigation in the neighborhood from June 26, 2003, through July 15, 2003.