Nutrients and Permitting: FAQs

Frequently Asked Questions

I have a domestic wastewater facility under 2 million gallons a day. Will permits before 2027 include nutrient limits?

Unless you are a new facility, or in a specific area with a nutrient control regulation or TMDL, you do not need to control for phosphorus right now because the current nutrient regulation, Regulation #85, excludes existing domestic plants smaller than 2 mgd from nutrient limits before 2027. Even though your permit may not have Reg 85 nutrient limits, your permit may have nitrogen limits through Reg 31 and the Basin Regulations (in the form of total inorganic nitrogen, or T.I.N.) to protect drinking water supplies from nitrate contamination. You can tell the differences by the required statistical analysis, because a TIN limit for water supply is based on the  acute nitrate standard. 

The Water Quality Control Commission will be considering adopting water quality standards for total nitrogen, total phosphorus, and chlorophyll a in 2027. These standards may apply to domestic facilities under 2 mgd but the Commission has not made any decisions yet. 

I have a domestic wastewater facility at or larger than 2 million gallons a day. Will permits before 2027 include nutrient limits?

Maybe. Regulation #85 requires that most domestic wastewater treatment plants over 2 million gallons a day limit phosphorus and nitrogen in their effluent. However, Regulation #85 delays implementation of nutrient limits until 2027 in some areas of the state and calculates less stringent nutrient limits if  dilution is available. For facilities that do require nutrient limits, the Division is working to include these limits in permits when they are renewed. 

I have a domestic facility that is less than 2 MGD, but the facility is getting site approval to expand to over 2 MGD.  When do Reg 85 limits apply?

If the current permit is not administratively continued, the permittee can submit a permit modification after obtaining site approval for the expansion. Reg 85 limits will be added (unless delayed for another reason) during the modification.

If the current permit is administratively continued, the renewal permit will include the new capacity and Reg 85 limits. 

I am proposing a new domestic or food-related discharge (not an upgrade or change in treatment or existing impact) that is less than 2 MGD.  When would my permit include  nutrient limits?

Your first permit would include nutrient limits and they would apply immediately upon discharging.