The City shall from time to time establish quantitative or other limitations where necessary to protect against pass through and interference and to provide for protection of the POTW, worker safety, public health, or environment.
A. Prohibited Discharge: No user shall discharge, directly or indirectly, any wastewater having a pH less than five (5.0) standard units or equal to or greater than twelve and one- half (12.5) standard units as measured at the point of discharge into the wastewater collection system or at a point otherwise designated by permit or agreement.
B. Concentrations Specified: In addition to categorical pretreatment standards referenced in section 10-5-5 of this chapter, no user shall discharge wastewater containing concentrations (and/or mass limitations) of substances in excess of the following:
Ammonia | 194 mg/L |
Arsenic | [R] mg/L |
BOD5 | [R] mg/L |
Cadmium | [R] mg/L |
Chromium | [R] mg/L |
Copper | [R] mg/L |
Cyanide | [R] mg/L |
Lead | [R] mg/L |
Mercury | 0.0007 mg/L |
Molybdenum | [R] mg/L |
Nickel | [R] mg/L |
Selenium | [R] mg/L |
Silver | [R] mg/L |
Zinc | [R] mg/L |
Total oil and/or grease | [R] mg/L |
Total phenols | [R] mg/L |
Total phosphorus | 35,9 mg/L |
Total suspended solids | [R] mg/L |
[R] - Reserved for effluent limitation at a later date.
C. Mass Loading Basis: Certain pollutants shall be allocated to users on a case-by-case mass-loading basis to keep the total industrial discharges of such pollutants within the maximum allowable industrial loading (MAIL), as calculated by the most recent local limits analysis. Due to the interconnectedness of the City's wastewater collection system, wastewater from most locations throughout the system might be treated at either Lander Street or West Boise WRF. In order to be protective of both facilities, the following MAILs shall apply at each facility:
Ammonia: 2,868 lbs/day ammonia (as N)
Phosphorus: 531 lbs/day phosphorus (total)
D. Industry Specific BMPs: Where possible and appropriate, the City may establish and implement industry specific BMPs (Best Management Practices) in conjunction with or in lieu of numerical local limits. Such BMPs shall be considered pretreatment standards and are fully enforceable under this chapter.
E. More Stringent Limit Or Standard: Based upon assessment of need and on a user specific basis, the City may incorporate pollutant specific BMPs or concentration or mass limits into indirect discharge permits. Whenever a user is subject to both a categorical pretreatment standard and a local limit for a given pollutant, the more stringent limit or pretreatment standard shall apply. (Ord. 8-19, 7-9-2019; amd. Ord. 22-22, 5-10-2022; Ord. 42-23, 12-12-2023)