13.06.490 Sampling Requirements for Users.
The County may, in wastewater discharge permits or other notification, require users to collect and analyze representative samples of their discharge(s); require users to report results to the County; and require users to follow specific sampling protocols and procedures, which may involve factors such as frequency, techniques, location, flow monitoring and proportioning, sample volume, preservation, and handling. All sample results shall indicate the time, date, and place of sampling and methods of analysis, and shall certify that such sampling and analysis is representative of normal work cycles and expected pollutant discharges from the user. If a user sampled and analyzed more frequently than what is required by the County using methodologies in 40 CFR Part 136, it must submit all results of sampling and analysis of the discharge as part of its self-monitoring report.
Users must ensure all samples they collect to satisfy sampling requirements under this ordinance are representative of the range of conditions occurring during the reporting period. Users must ensure that, when specified, samples are collected during the specific period and also address the following:
A. Users must use properly cleaned sample containers appropriate for the sample analysis and sample collection and preservation protocols specified in 40 CFR Part 136 and appropriate EPA guidance;
B. Users must obtain samples for oil and grease, temperature, pH, cyanide, total phenols, sulfides, and volatile organic compounds using grab collection techniques;
C. For certain pollutants, Users may composite multiple grab samples taken over a 24 hour period. Users may composite grab samples for cyanide, total phenols, and sulfides either in the laboratory or in the field, and may composite grab samples for volatile organics and oil and grease in the laboratory prior to analysis;
D. For all other pollutants, users must employ 24-hour flow-proportional composite samplers unless the Manager authorizes or requires an alternative sample collection method;
E. The Manager may authorize composite samples for parameters unaffected by the compositing procedures, as appropriate;
F. The Manager may require grab samples either in lieu of or in addition to composite sampling to show compliance with instantaneous discharge limits;
G. In all cases, Users must take care to ensure the samples are representative of their wastewater discharges;
H. User sampling for the baseline monitoring and 90 day compliance reports required by PCC 13.06.370 and 13.06.380 must satisfy some specific requirements. These reports require at least four grab samples for pH, cyanide, total phenols, oil and grease, sulfide and volatile organic compounds. Users may composite samples prior to analysis if allowed in PCC 13.06.490. Where historical sampling data exists, the Manager may also authorize fewer samples; and
I. For periodic monitoring reports (PCC 13.06.390), the Manager may specify the number of grab samples necessary to assess and assure compliance with applicable pretreatment standards and requirements.