§ 6-13.806. Sampling and analysis procedures.

Samples and flow measurement must represent the normal wastewater flow to the public sewer over a twenty-four (24) hour period. Composite samples shall be collected according to flow or time, with at least one sample collected hourly. Samples may be collected either manually or by automatic integrated sampling equipment approved by the Director. Chain-of-custody logs must be maintained by the user for all samples required by this chapter.

(a)

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)

The sampling, handling, storage, and analysis of all samples taken for the determination of the characteristics of wastewater discharges must be performed in accordance with procedures established in 40 CFR 136, unless otherwise specified in an applicable categorical pretreatment standard, by laboratories certified by the State of California, by a laboratory of the user approved by the Director. If 40 CFR 136 does not contain sampling or analytical techniques for the pollutant in question, or where the EPA determines that Part 136 sampling and analytical techniques are inappropriate for the pollutant in question, sampling and analyses must be performed by using validated analytical methods or any other applicable sampling and analytical procedures approved by EPA. If performed by City personnel, an appropriate charge shall be paid by the user requesting the tests. Prior to submittal to the Director of data developed in the laboratory of a user, the results must be verified by an authorized representative of the user, certified to by a qualified professional, and signed by an authorized representative of the user. Any independent laboratory or user performing tests must immediately furnish any required test data or information on the test methods or equipment used upon request by the Director.

(c)

Except as indicated in subsections (d) and (e) 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 the Director. Where time-proportional composite sampling or grab sampling is authorized by the director, the samples must be representative of the discharge. Using protocols specified in 40 CFR Part 136 and approved EPA procedures, 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 Director. In addition, grab samples may be required to show compliance with Instantaneous Limits.

(d)

Samples for oil and grease, temperature, pH, cyanide, total phenols, sulfides, and volatile organic compounds must be obtained using grab sample techniques.

(e)

For sampling required in support of baseline monitoring and 90-day compliance reports a minimum of four (4) grab samples must be used for pH, cyanide, total phenols, oil and grease, sulfides, and volatile organic compounds for facilities for which historical sampling data do not exist. For facilities with historical sampling data available, the Director may authorize a lower minimum. For the reports required by Section 6-13.812(d) the user is required to collect the number of grab samples necessary to assess and assure compliance with applicable pretreatment standards and pretreatment requirements.

(§ 1, Ord. 1170, eff. April 21, 2011)