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 division B. and C. below, the user must collect wastewater samples using 24-hour flow-proportional composite sampling techniques, unless time-proportional composite sampling or grab sampling is authorized by Public Works Director. 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.
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 90-day compliance reports required in §§ 13.16.090 and 13.16.092 [40 C.F.R. 403.12(b) and (d)], a minimum of 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 Public Works Director may authorize a lower minimum. For the reports required by § 13.16.093 [40 C.F.R. 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.
D. Samples that are taken by city personnel for the purposes of determining compliance with the requirements of this chapter may be split with the discharger if requested (or a duplicate sample provided in the instance of fats, oils and greases) if requested before or at the time of sampling.
E. The Public Works Director or other designee may require a discharger to install and maintain at the discharger's expense a suitable manhole in the discharger's branch sewer or other suitable monitoring access to allow observation, sampling and measurement of all industrial wastes being discharged into the city sewer system. It shall be constructed in accordance with plans approved by the city and shall be designed so that flow measuring and sampling equipment may be conveniently installed. Access to the manhole or monitoring access shall be available to city representatives at all times.
(Ord. 1413 § 6.8, passed 4-1-2015)