A. Sampling Requirements For Users:
1. A minimum of four (4) grab samples must be used for pH, cyanide, total phenols, oil and grease, sulfide and volatile organics. The Superintendent will determine on a case-by-case basis whether the user will be able to composite the individual grab samples. For all other pollutants, twenty four (24) hour composite samples must be obtained through flow-proportional composite sampling techniques where feasible. The City may waive flow-proportional composite sampling for any user that demonstrates that flow-proportional composite sampling is infeasible. In such cases, samples may be obtained through time- proportional composite sampling techniques or through a minimum of four (4) grab samples where the user demonstrates that this will provide a representative sample of the effluent being discharged.
2. Samples shall be taken immediately downstream from pretreatment facilities, if such exist, immediately downstream from the regulated or manufacturing process, if no pretreatment exists, or at a location determined by the City and specified in the user's wastewater discharge permit. For categorical users, if other wastewaters are mixed with the regulated wastewater prior to pretreatment, the user shall measure the flows and concentrations necessary to allow use of the combined waste stream formula of 40 CFR section 403.6(e) in order to evaluate compliance with the applicable categorical pretreatment standards. For other SIUs, for which the City has adjusted its local limits to factor out dilution flows, the user shall measure the flows and concentrations necessary to evaluate compliance with the adjusted pretreatment standards.
3. All sample results shall indicate the time, date and place of sampling, and methods of analysis, and shall certify that the waste stream sampled is representative of normal work cycles and expected pollutant discharges from the user. If a user sampled and analyzed more frequently than what was required in its wastewater discharge permit, using methodologies in 40 CFR part 136, it must submit all results of sampling and analysis of the discharge as part of its self-monitoring report.
B. Analytical Requirements: All pollutant analyses, including sampling techniques, shall be performed in accordance with the techniques prescribed in 40 CFR part 136, unless otherwise specified in an applicable categorical pretreatment standard. If 40 CFR part 136 does not contain sampling or analytical techniques for the pollutant in question, sampling and analyses must be performed in accordance with procedures approved by the EPA.
C. City Monitoring Of User's Wastewater: The City will follow the same procedures as outlined in subsections A and B of this section. (Ord. 276, 11-10-1998; amd. Ord. 596, 5-24-2019)