§ 33.250  SAMPLE COLLECTION
   Samples collected to satisfy reporting requirements must be based on data obtained through appropriate sampling and analysis performed during the period covered by the report, based on data that is representative of conditions occurring during the reporting period.
   (A)   Except as indicated in subsections (B) and (C) below, the user must collect wastewater samples using twenty-four- (24-) hour flow-proportional composite or twenty-four- (24-) hour time proportional composite sampling techniques, The samples must be representative of the discharge. Using protocols (including appropriate preservation) specified in 40 CFR Part 136 and appropriate EPA guidance, multiple grab samples collected during a twenty-four- (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. See 40 CFR 403.12(g)(3).
   (B)   Samples for oil and grease, temperature, pH, cyanide, total phenols, sulfides, and  volatile organic compounds must be obtained using grab collection techniques.
   (C)   For sampling required in support of baseline monitoring and ninety-day (90-) day compliance reports required in § 33.240 and 33.242 (40 CFR 403.12(b) and (d)), a minimum of four (4) 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 Superintendent may authorize a lower minimum. For the reports required by § 33.243 (40 CFR 403.12(e) and 403.12(h)), 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. (See 40 CFR 403.12(g)(4).)
(Ord. 2015-12, passed 8-7-15)