(A) Sample collection.
(1) Except as indicated in division (A)(2), the industrial user must collect wastewater samples using 24-hour flow-proportional composite sampling techniques, unless time-proportional composite sampling or grab sampling is authorized by the City Manager. Where time-proportional composite sampling or grab sampling is authorized by the city, the samples must be representative of the discharge. Using protocols (including appropriate preservation) specified in 40 C.F.R. Part 136 and appropriate EPA guidance, multiple grab samples collected during a 24-hour period may be composited prior to the analysis as follows: for cyanide, total phenols, and sulfides the samples may be composited in the laboratory or in the field; for volatile organics and oil and grease, the samples may be composited in the laboratory. Composite samples for other parameters unaffected by the compositing procedures as documented in approved EPA methodologies may be authorized by the city, as appropriate. In addition, grab samples may be required to show compliance with instantaneous limits.
(2) Sample for oil and grease, temperature, pH, cyanide, phenols, toxicity, sulfides, and volatile organic chemicals must be obtained using grab collection techniques.
('63 Code, § 5-5.611)
(3) For sampling required in support of baseline monitoring and 90-day compliance reports required in §§ 50.070 and 50.071 a minimum of four grab samples must be used for pH, cyanide, total phenols, oil and grease, sulfide and volatile organic compounds for facilities for which historical sampling data do not exist; for facilities for which historical sampling data are available, the City Manager may authorize a lower minimum. For the reports required by § 50.073, the industrial user is required to collect the number of grab samples necessary to assess and assure compliance by with applicable pretreatment standards and requirements.
(B) Determination of noncompliance. The City Manager may use a grab samples to determine noncompliance with pretreatment standards. ('63 Code, § 5-5.612)
(Ord. 571-C.S., passed 6-2-94; Am. Ord. 737-C.S., passed 2-3-09; Am. Ord. 775-C.S., passed 12-20-11)