Arizona General Permit For Minor WWTP Discharges

The Arizona Department of Environmental Quality (ADEQ) has released a draft permit for minor wastewater treatment plants (WWTPs) (MWGP2011-001) for public comment. The comment period ends December 26, 2011. This permit is applicable only to secondary treated effluent discharges from domestic wastewater treatment facilities with a design flow of less than 1 million gallons per day (1 mgd). It is estimated that approximately 30 – 50 facilities in Arizona will fall into this category. The new permit will be issued for a 5 year term.

This general permit is applicable for discharges from facilities that meet the following conditions:
1) Domestic wastewater treatment plants with a design capacity of less than 1 million gallons per day ; and
2) Discharge treated wastewater to WUSs that have the designated uses of Partial-body contact (PBC) and Aquatic and wildlife effluent-dependent water (A&Wedw); or PBC and Aquatic and wildlife ephemeral (A&We) as per A.A.C. R18-11-104.D, Appendix B; the designated uses of Agricultural irrigation (AgI) and/or Agricultural livestock watering (AgL) may be included; and
3) The facility does not accept wastewater from significant industrial wastewater; and
4) The permit is applicable within the State of Arizona, except for Indian Country.

The permit includes technology-based limitations, requirements to comply with Numeric Water Quality Standards, Effluent Characterization (EC) Testing, and Whole Effluent Toxicity (WET) testing.

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