Section R18-11-407. Aquifer Water Quality Standards in Reclassified Aquifers

A.       All aquifers in the state are classified for drinking water protected use except for aquifers which are reclassified to a non-drinking water protected use pursuant to A.R.S. § 49-224 and A.A.C. R18-11-503.

B.       Aquifer water quality standards for drinking water protected use  apply  to  reclassified  aquifers  except  where  expressly

2,4,5-Trichlorophenoxypropionic Acid

(2,4,5-TP or Silvex)

0.05

superseded   by   aquifer    water   quality   standards   adopted pursuant to subsection (C) of this Section.

E.       The  following  are   the  aquifer  water  quality  standards   for radionuclides:

1.        The maximum concentration for gross alpha particle activity, including Radium-226 but excluding radon and uranium, shall not exceed 15 pCi/l.

2.        The maximum concentration for combined Radium-226 and Radium-228 shall not exceed 5 pCi/l.

3.        The average annual concentration of beta particle and photon radioactivity from man-made radionuclides shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 millirem/year.

4.        Except for the radionuclides listed in this subsection, the concentration of man-made radionuclides causing 4 millirem total body or organ dose equivalents shall be calculated on the basis of a 2-liter-per-day drinking water intake using the 168-hour data listed in “Maximum Permissible Body Burdens and Maximum Permissible Concentration of Radionuclides in Air or Water for Occupational Exposure,” National Bureau of Standards Handbook 69, National Bureau of Commerce, as amended August 1963 (and no future editions), incorporated herein by reference and on file with the Office of the Secretary of State and with the Department. If two or more radionuclides are present, the sum of their annual dose equivalent to the total body or to any organ shall not exceed 4 millirem/year. The following average annual concentrations are assumed  to produce a total body or organ dose of 4 millirem/year:

Radionuclide            Critical Organ   pCi/l Tritium            Total body               20,000 Strontium-90 Bone Marrow          8

F.        The   aquifer   water   quality    standard   for   microbiological

contaminants is based upon the presence or absence of total

C. The Director shall adopt, by rule, aquifer water quality standards for reclassified aquifers within one year of the date of the order reclassifying the aquifer to a nondrinking water protected use. The Director shall adopt aquifer water quality standards for reclassified aquifers only for pollutants that are specifically identified in a petition for reclassification as prescribed by A.R.S. § 49-223(D) and A.A.C. R18-11-503(B). Aquifer water quality standards for reclassified aquifers shall be sufficient to protect the use of the reclassified aquifer.

Historical Note

Adopted effective January 4, 1990 (Supp. 90-1).

Amended effective August 14, 1992 (Supp. 92-3).