The Water Quality Assurance Revolving Fund (WQARF) was created by the Environmental Quality Act of 1986 to support hazardous substance cleanup efforts in the state.  A complete description of the program can be found at the Arizona Department of Environmental Quality (ADEQ) website.

The Ground Water Cleanup Task Force was created by the Governor in early 1996, and made recommendations on groundwater cleanup issues at WQARF sites.  The Well Design & Use Subcommittee was formed specifically to address the goal of providing ADEQ and ADWR with the authority to address wells that facilitate vertical cross-contamination of aquifers.

The Ground Water Cleanup Task Force Final Report’s position paper on well design and use expresses the concern as follows, “Fifteen years of experience with Superfund groundwater cleanups has taught us that, not only can remediation of contaminated aquifers be an expensive proposition, but it is all too often an impractical if not impossible task.  We have learned that otherwise innocuous wells can act as vertical conduits for spreading contamination from one aquifer to another or from one portion of an aquifer to another (i.e., vertical cross-contamination).”   The North Indian Bend Wash Superfund site in Scottsdale, Arizona is an example of a groundwater contamination site that has been severely impacted by vertical cross-contamination through conduit well flow.

Recommendations from the subcommittee included the following:

  Existing ADEQ programs should be modified to address vertical cross-contamination and a statutory definition of vertical cross-contamination adopted

  The ADWR drilling approval process should be modified to prevent vertical cross-contamination in new wells by reviewing well designs in relation to known contamination

  A well inspection program should be developed which identifies existing wells that are contributing to vertical cross-contamination and rank the wells based on their potential to act as pathways for vertical transport of contamination. According to the recommendations, only those high-ranking wells should be inspected. In addition, assured funding for the well inspections and remediation was also recommended.

The subcommittee identified that “accurate, accessible data on groundwater quality and existing water wells are necessary to a successful WQARF program”.  Critical inadequacies and poor interagency coordination were observed between ADWR and ADEQ databases.

The Ground Water Cleanup Task Force recommendations were formulated in the “Ground Water Cleanup Task Force Final Report” (1996).  As a result of the Task Force’s recommendations, a statutory definition of vertical cross-contamination was established (A.R.S. §§ 45-605[A]) and 49-281[15]).  A.R.S. § 45-605 (Well inspections; cross-contamination; remedial measures), became effective April 29, 1997.

In response to the legislation, ADWR has developed a program for well inspection in consultation with ADEQ, and developed review procedures for Notices of Intent (NOI) to Drill and Abandon wells within known areas of contamination.