(a) Domestic wastewater discharges from wastewater treatment systems, other than oxidation pond systems, must meet a daily effluent limit for total phosphorus of 1.0 milligram per liter, based on a 30-day average, if the wastewater treatment system:
  (1) has a permitted annual or daily average flow greater than or equal to 0.10 million gallons per day and a discharge point located in the Benbrook Lake water quality area; or
  (2) has a permitted annual or daily average flow greater than or equal to 0.25 million gallons per day and a discharge point located in the Benbrook Lake watershed, but outside the Benbrook Lake water quality area.
(b) For discharge permits with more than one flow phase, the effluent limit requirements in subsection (a) of this section apply only to those flow phases that meet the flow requirements in subsection (a) of this section.
(c) For wastewater treatment systems with more than one outfall, the permitted flow limits for all outfalls will be combined to determine if the system meets one of the flow requirements in subsection (a) of this section.
(d) This section only applies to wastewater treatment systems that apply for a new discharge permit or a discharge permit amendment to increase permitted flow after January 1, 2015.

Source Note: The provisions of this §311.67 adopted to be effective January 8, 2015, 40 TexReg 74