§ 51.119 SAMPLE COLLECTION AND ANALYSIS.
   (A)   (1)   All pollutant analyses, including sampling techniques, to be submitted as part of a wastewater discharge permit application or report shall be performed in accordance with the techniques prescribed in 40 C.F.R. Part 136 and amendments thereto, unless otherwise specified in an applicable categorical pretreatment standard.
      (2)   If 40 C.F.R. Part 136 does not contain sampling or analytical techniques for the pollutant in question, or where the USEPA determines that the Part 136 sampling and analytical techniques are inappropriate for the pollutant in question, sampling and analyses shall be performed by using validated analytical methods or any other applicable sampling and analytical procedures, including procedures suggested by the District or other parties approved by USEPA. IUs shall collect representative samples using 24-hour, flow proportional composite sampling techniques, time-proportional sampling, or grab sampling in accordance with 40 C.F.R. § 403.12(g)(3) and (4).
      (3)   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.
   (B)   (1)   Except as indicated in divisions (C) and (D) below, the IU must collect wastewater samples using 24-hour flow-proportional composite sampling techniques, unless time-proportional composite sampling or grab sampling is authorized by the District.
      (2)   Where time-proportional composite sampling or grab sampling is authorized by the District, the samples must be representative of the discharge.
      (3)   Using protocols (including appropriate preservation) specified in 40 C.F.R. Part 136 and appropriate USEPA 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.
      (4)   Composite samples for other parameters unaffected by the compositing procedures as documented in approved USEPA methodologies may be authorized by the District as appropriate. In addition, grab samples maybe required to show compliance with instantaneous limits.
   (C)   Samples for oil and grease, temperature, pH, cyanide, total phenols, sulfides, and volatile organic compounds must be obtained using grab collection techniques.
   (D)   (1)   For sampling required in support of baseline monitoring and 90-day compliance reports required in §§ 51.105 and 51.107 (40 C.F.R. § 403.12(b) and (d)), 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 District may authorize a lower minimum.
      (2)   For the reports required by § 51.106 (40 C.F.R. §§ 403.12(e) and 403.12(h)), the IU is required to collect the number of grab samples necessary to assess and assure compliance by with applicable pretreatment standards and requirements.
(Ord. 18-0017, passed 11-13-2018)