Indiana Administrative Code
Title 327 - WATER POLLUTION CONTROL DIVISION
Article 5 - INDUSTRIAL WASTEWATER PRETREATMENT PROGRAMS AND NPDES
Rule 10 - Additional Treatment Requirements
Section 10-2 - Phosphorus removal
Current through September 18, 2024
Authority: IC 13-14-8; IC 13-15-1-2; IC 13-15-2-1; IC 13-18-3
Affected: IC 13-18-4; IC 13-18-19
Sec. 2.
(a) Phosphorus removal or control facilities shall be required for a point source discharge where:
(b) Where phosphorus removal is required under subsection (a) for a POTW, the treatment facility shall achieve a degree of reduction in total phosphorus in the discharge (calculated as elemental phosphorus) as prescribed in Table I below, or produce an effluent containing no more than 1.0 mg/l of elemental phosphorus as a monthly average, whichever is more stringent.
Table I
Phosphorus (P) Level in Raw Sewage (In mg/l) | Required % Removed (%) |
greater than or equal to 4 | 80% |
less than 4, greater than or equal to 3 | 75% |
less than 3, greater than or equal to 2 | 70% |
less than 2, greater than or equal to 1 | 65% |
less than 1 | 60% |
(c) Where phosphorus removal is required under subsection (a) for a point source other than a POTW, the amount of total phosphorus (calculated as elemental phosphorus) in the discharge from said source shall be reduced by at least ninety (90) percent, unless the person owning or operating the point source can affirmatively demonstrate that such degree of phosphorus reduction is technologically infeasible and that an alternate reduction rate is warranted because of factors unique to his facility.
(d) Notwithstanding subsection (b) or (c), a point source shall achieve the degree of phosphorus reduction necessary to comply with an applicable water quality standard for phosphorus.