Ariz. Admin. Code § R18-4-217 - Use of Blending to Achieve Compliance with Maximum Contaminant Levels

A. A public water system may use blending to achieve compliance with a MCL if all of the following requirements are met:

1. The public water system has obtained the Department's written approval for a blending plan that includes the following elements:

a. Detailed drawings and schematics that show flow, concentrations, and controls;

b. Proposed automatic or electronic devices that will be incorporated to ensure that the blend remains in the desired range or shuts off the offending source or triggers an alarm when the blend falls out of the desired range;

c. Individual test results from all sources proposed to be blended;

d. Projected contaminant levels that will result from blending that show both best-case and worst-case scenarios;

e. Identified techniques, and any other information requested by the Department, that show how the blending plan will produce water that will comply with MCLs; and

2. The public water system has obtained the Department's written approval for a monitoring program designed to verify continued compliance with MCLs at all subsequent downstream service connections. This program shall include monitoring on at least a quarterly basis of both of the following:

a. All sources contributing to the blend; and

b. Blended water to ensure that the provisions of this Section are met.

B. A public water system shall submit an amended blending plan to the Department to confirm that the new blend achieves compliance with MCLs whenever sources are added to or removed from service or the relative flow rates from blended sources are changed in a way that changes the blend.

Notes

Ariz. Admin. Code § R18-4-217

Adopted effective April 28, 1995 (Supp. 95-2). Amended effective June 3, 1998 (Supp. 98-3). Amended by final rulemaking at 7 A.A.R. 5067, effective October 16, 2001 (Supp. 01-4). Section R18-4-217 repealed; new Section renumbered from R18-4-221 and amended by final rulemaking at 14 A.A.R. 2978, effective August 30, 2008 (Supp. 08-3).