A. The City is authorized to establish local limits pursuant to 40 CFR 403.5(c).
B. The following pollutant limits are established to protect against pass through and interference. No person shall discharge wastewater containing in excess of the daily maximum limit.
Local Limits On Toxic Pollutants
Pollutant | Concentration (mg/L) |
Pollutant | Concentration (mg/L) |
Arsenic | 1.0 |
Cadmium | 0.05 |
Chromium | 6.9 |
Chromium (VI) | 0.05 |
Copper | 1.8 |
Lead | 2.5 |
Mercury | 0.0005 |
Nickel | 0.35 |
Silver | 3.0 |
Zinc | 4.0 |
C. Local limit guidelines are used as benchmarks for nonresidential users because the treatment of such pollutants is a loading issue rather than a toxicity issue. Guidelines are not legally enforceable and are not subject to escalated enforcement. Should a nonresidential user continually exceed the listed guideline values, it must either pay for increased capacity provided if the additional loading is not causing an impact to the City’s POTW, or it may be required to be classified within the City’s pretreatment program with the guideline concentrations or alternatives incorporated into a wastewater discharge permit as limits if an impact to the POTW has occurred. At the point of incorporation into a permit, the guideline discharge concentrations become enforceable as local limits.
Local Limit Guidelines On Nontoxic Pollutants
Pollutant | Concentration (mg/L) |
Ammonia-nitrogen | 25 |
Phosphorus | 10 |
BOD | 225 |
TSS | 260 |
FOG | 150 |
D. The Pretreatment Coordinator may develop best management practices, by ordinance or in individual wastewater discharge permits or general permits, to implement local limits and the requirements published in section 10-3F-2 of this title.
(Ord. 2408, 11-26-2013)