§ 52.20  GENERAL PROHIBITION EXEMPTIONS.
   (A)   It is an affirmative defense to any enforcement action for a violation of § 52.03 of this chapter that the discharge was composed entirely of one or more of the following categories of discharges:
      (1)   A discharge authorized by, and in full compliance with, an NPDES and/or TPDES permit (other than the NPDES and/or TPDES permit for discharges from the MS4);
      (2)   A discharge or flow resulting from firefighting by the Fire Department:
      (3)   A discharge or flow of fire protection water that does not contain oil or hazardous substances or materials that the Fire Code requires to be contained and treated prior to discharge, in which case treatment adequate to remove harmful quantities of pollutants must have occurred prior to discharge;
      (4)   A discharge from a fire hydrant flushing;
      (5)   Incidental discharges from water line pressure release valves;
      (6)   Uncontaminated runoff or return flow from landscape irrigation, lawn irrigation, and other irrigation utilizing potable water, groundwater, or surface water sources;
      (7)   Uncontaminated water used for dust control purposes;
      (8)   A discharge or flow from a diverted stream flow or natural spring;
      (9)   A discharge or flow from uncontaminated pumped groundwater or rising groundwater;
      (10)   Uncontaminated groundwater infiltration (as defined as 40 C.P.A. 35.2005(20)) to the MS4;
      (11)   Uncontaminated discharge or flow from a foundation drain, crawl space footing drain, or sump;
      (12)   A discharge or flow from a potable water source not containing any harmful substance or material from the cleaning or draining of a storage tank or other container;
      (13)   A discharge or flow from air conditioning condensation that is unmixed with water from a cooling tower, emissions scrubber, emissions filter, or any other source of pollutant;
      (14)   A discharge or flow from a riparian habitat or wetland;
      (15)   A discharge or flow from water used in street washing that is not contaminated with any soap, detergent, degreaser, solvent, surfactant, emulsifier, dispersant, or any other harmful cleaning substance;
      (16)   Stormwater runoff from a roof that is not contaminated by any runoff or discharge from an emissions scrubber, filter, or any other source of pollutant;
      (17)   Swimming pool water that contains no harmful quantity of free chlorine (less than 0.5ppm), muriatic acid or other chemical (less than 20ppm cyanuric acid) used in the treatment or disinfection of the swimming pool water or in pool cleaning;
      (18)   A discharge of flow from a temporary car wash sponsored by a civic group, school, religious, and/or nonprofit organization;
      (19)   A discharge of flow from individual residential car washing activities;
      (20)   Other allowable non-stormwater discharges listed in 40 CFR § 122.26(d)(2)(iv)(B)(1);
      (21)   Non-stormwater discharges that are specifically listed in the TPDES multi-sector general permit (MSGP) or the TPDES construction general permit; and
      (22)   Other similar occasional incidental non-stormwater discharges, unless the TCEQ develops permits or regulation addressing these discharges.
   (B)   No affirmative defense is available under this section if the discharge or flow in question has been determined by the Director to be a source of a pollutant or pollutants to the MS4, written notice of that determination has been provided to the discharger, and the discharge has occurred more than 15 days beyond the notice. The correctness of the Director's determination that a discharge is a source of a pollutant or pollutants may be reviewed in any administrative or judicial enforcement proceeding.
(Ord. 1680, passed 3-10-08)