The Arizona Department of Environmental Quality (ADEQ) issued the first version of the De Minimus General Permit (DMGP) on March 17, 2004 under the Arizona Pollutant Discharge Elimination System (AZPDES) program. The permit allows for the discharge of certain waters that have been determined to be de minimus and that have potential to enter a water of the United States, including, but not limited to: lakes; rivers; streams (including intermittent streams); ephemeral washes; and certain canals.

De minimus discharges are defined as those containing relatively low levels of pollutants, are of limited flow and/or frequency, and generally do not last more than 30 days).

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The ADEQ requires a permit for de minimus discharges to all waters of the United States in Arizona except for those conducted within Indian Country. Coverage is available for individual discharges or on an area wide permit basis. Area wide coverage generally applies to municipal entities and utility companies.

Discharges eligible for coverage under the AZPDES DMGP [Part I(B)] include:

1. Potable water systems. Discharges related to installation and maintenance of potable water supply systems (pipelines, tanks, reservoirs, fire hydrants, etc.).
2. Subterranean dewatering (groundwater from foundation, footer drain, basement, underground structure or construction dewatering, and water from subterranean seepage).
3. Well development and maintenance and/or aquifer testing (water associated with drilling, rehabilitation and maintenance of potable or non-potable water wells and peizometers, or water supply or quality evaluations).
4. Hydrostatic testing (groundwater, surface water, or potable water associated with testing of new pipes, tanks or vessels; potable water system, reclaimed water system, or sewer collection system components; pipes, tanks or vessels that have been used to transport oil and gas; the installation and maintenance of reclaimed water transport systems; and, class B + or A+ reclaimed water used to perform the specified hydrostatic testing.
5. Reclaimed water systems (post repair flushings and pressure releases).
6. Other Discharges (residential non-contact cooling water, charitable noncommercial car washes, building and/or street wash water, or, de-chlorinated drainage from swimming pools.
7. Specific approvals as approved in writing by ADEQ.

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To find out what your community requires for these types of discharges or permits, visit the Members & Sponsors page and select the community of interest.

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ADEQ AZPDES Permits:
www.azdeq.gov/environ/water/permits/gen.html

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