(A) All wastewater samples must be representative of the user’s discharge. Wastewater monitoring and flow measurement facilities shall be properly operated, kept clean, and maintained in good working order at all times. The failure of a user to keep his or her monitoring facility in good working order shall not be grounds for the user to claim that sample results are unrepresentative of his or her discharge.
(B) Grab samples must be used for pH, cyanide, total phenols, oil and grease, sulfide, volatile organic compounds, and any other pollutants, as required by 40 C.F.R. part 136. The POTW Director shall determine the number of grabs necessary to be representative of the user’s discharge (see 40 C.F.R. § 403.12(g)(5) for additional grab sample number requirements for BMR and 90 day compliance reports). Additionally, the POTW Director may allow collection of multiple grabs during a 24-hour period which are composited prior to analysis as allowed under 40 C.F.R. part 136.
(C) All wastewater composite samples shall be collected with a minimum of hourly aliquots or grabs for each hour that there is a discharge. All wastewater composite samples shall be collected using flow proportional composite collection techniques, unless time-proportional composite sampling or grab sampling is authorized by the POTW Director. When authorizing time-proportional composites or grabs, the samples must be representative, and the decision to allow the alternative sampling must be documented.
(Ord. 33-2002, passed 10-21-2002; Ord. 29-2008, passed 10- -2008)