A. Users must use properly cleaned sample containers appropriate for the sample analysis and sample collection and preservation protocols specified in 40 CFR Part 136 and appropriate EPA guidance.

B. Users must obtain samples for oil and grease, temperature, pH, cyanide, total phenols, sulfides, and volatile organic compounds using grab collection techniques.

C. For certain pollutants, Users may composite multiple grab samples taken over a 24 hour period. Users may composite grab samples for cyanide, total phenols, and sulfides either in the laboratory or in the field, and may composite grab samples for volatile organics and oil & grease in the laboratory prior to analysis.

D. For all other pollutants, Users must employ 24-hour flow-proportional composite samplers unless the Director authorizes or requires an alternative sample collection method.

E. The Director may authorize composite samples for parameters unaffected by the compositing procedures, as appropriate.

F. The Director may require grab samples either in lieu of or in addition to composite sampling to show compliance with instantaneous discharge limits.

G. In all cases, Users must take care to ensure the samples are representative of their wastewater discharges.

H. Users sampling to complete baseline monitoring and ninety (90) day compliance reports required by Section 14.10.300 and Section 14.10.320, must satisfy some specific requirements. These reports require at least four (4) grab samples for pH, cyanide, total phenols, oil and grease, sulfide and volatile organic compounds. Users may composite samples prior to analysis if allowed in Section 14.10.400(C). Where historical sampling data exists; the Director may also authorize fewer samples.

I. For periodic compliance reports, (Section 14.10.330), the Director may specify the number of grab samples necessary to assess and assure compliance with applicable Pretreatment Standards and requirements. (Ord. M-3970 §2, 2010)