§ 7.20.630 Sewage sampling, analysis and flow measurement.
   (A)   Except in the case of non-significant categorical users, the reports required in § 7.20.520(A), (B), (C), and § 7.20.530 of this chapter shall contain the results of sampling and analysis of the discharge, including the flow and the nature and concentration, or production and mass where requested by the General Manager, of pollutants contained therein which are limited by the applicable pretreatment standards. This sampling and analysis may be performed by the General Manager in lieu of the industrial user. Where the POTW performs the required sampling and analysis in lieu of the industrial user, the user will not be required to submit the compliance certification required in this section. In addition, where the POTW itself collects all the information required for the report, including flow data, the industrial user will not be required to submit the report.
   (B)   The reports required in § 7.20.520(A), (B), (C), and § 7.20.530 of this chapter must be based upon data obtained through appropriate sampling and analysis performed during the period covered by the report, which data are representative of conditions occurring during the reporting period. The General Manager shall require that frequency of monitoring necessary to assess and assure compliance by industrial users with applicable pretreatment standards and requirements. Grab samples must be used for pH, cyanide, total phenols, oil and grease, sulfide, and volatile organic compounds. For all other pollutants, 24-hour composite samples must be obtained through flow-proportional composite sampling techniques, unless time-proportional composite sampling or grab sampling is authorized by the General Manager. Where time-proportional composite sampling or grab sampling is authorized by the General Manager, the samples must be representative of the discharge and the decision to allow the alternative sampling must be documented in the industrial user file for the facility or facilities. 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 General Manager, as appropriate.
   (C)   For sampling required in support of baseline monitoring and 90-day compliance reports required in § 7.20.520, 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 General Manager may authorize a lower minimum. For the periodic reports on continued compliance and the reports required in § 7.20.520, the General Manager shall require the number of grab samples necessary to assess and assure compliance by industrial users with applicable pretreatment standards and requirements.
   (D)   If an industrial user subject to the reporting requirements in periodic reports on continued compliance, monitors any regulated pollutant at the appropriate sampling location more frequently than required by the General Manager, using the procedures prescribed in division (A)(5)(e) of this section, the results of this monitoring shall be included in the report.
   (E)   The General Manager may use a grab sample(s) to determine noncompliance with pretreatment standards.
   (F)   All samples for laboratory analyses of the characteristics of water and wastes determined in accordance with 40 C.F.R. part 136, as described in §§ 7.20.520 and 7.20.530, shall be collected at the control manhole. In the event that no special manhole has been required, the control manhole shall be considered to be the nearest downstream manhole in the public sewer to the point at which the building sewer is connected.
   (G)   The General Manager shall have reasonable access onto the industrial user’s property to collect samples and perform tests, as defined in § 7.20.040.
   (H)   Periodic measurements of flow rates, flow volumes, BOD and suspended solids for use in determining the monthly industrial wastewater treatment service charge and such measurements of other constituents believed necessary by the General Manager shall be made by all industrial users, unless specifically relieved of the obligation by the General Manager.
   (I)   All such sampling, analyses and flow measurements of industrial wastewaters shall be performed by a state-certified independent laboratory, by a laboratory operated by an industrial user and approved by the General Manager or by personnel of the city. Prior to submittal to the General Manager of data developed in the laboratory of an industrial user, the results shall be verified by a responsible administrative official of the industrial user under the penalty of perjury.
   (J)   All users making periodic measurements shall furnish and install at the control manholes or other appropriate location a calibrated flume, weir, flow meter or similar device approved by the General Manager and suitable to measure the industrial wastewater flow rate and total volume. A flow indicating, recording and totalizing register may be required by the General Manager. In lieu of wastewater flow measurement, the General Manager may accept records of water usage and adjust the flow volumes by suitable factors to determine peak and average flow rates for the specific industrial wastewater discharge.
   (K)   The minimum requirement for self- monitoring shall be at least two times per year for significant industrial users, whether or not they are subject to national categorical standards.
   (L)   Industrial users with large fluctuations in quantity or quality of wastewater may be required to provide continuous sampling and analyses for every day of operation. When required by the General Manager, users shall install and maintain automatic flow proportional sampling equipment and/or automatic analysis and recording equipment, approved by the General Manager.
(1995 Code, § 7.20.540) (Ord. 17-03, passed 3-21-2017; Ord. 15-02, passed 5-5-2015)