§ 25-90. Sample collection and analytical requirements.

Samples collected to satisfy reporting requirements in this ordinance 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 subsections 25-90(b) and (c), 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 Superintendent. Flow-proportional composite sampling may be waived for any user that demonstrates that flow-proportional sampling is infeasible. In such cases, samples may be obtained through time-proportional composite sampling techniques or through a minimum of four grab samples where the user demonstrates that this will provide a representative sample of the effluent being discharged. Where time-proportional composite sampling or grab sampling is authorized by the city, the samples must be representative of the discharge.

(b)

Using protocols (including appropriate preservation) specified in 40 CFR 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.

(c)

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

(d)

For sampling required in support of baseline monitoring and 90-day compliance reports required in paragraph 25-91(c)(3), a minimum of four (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 superintendent may authorize a lower minimum. For the reports required by paragraph 25-91(c), 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.

(e)

Sampling and analysis shall be performed in accordance with procedures established by the EPA pursuant to section 304(g) of the Act and contained in 40 CFR 136, as amended. If 40 CFR 136 does not contain sampling or analytical techniques for the pollutant in question, or where the EPA determines that the Part 136 sampling and analytical techniques are inappropriate for the pollutant in question, sampling and analyses shall be performed by using validated analytical methods or any other applicable sampling and analytical procedures, including procedures suggested by the superintendent or other parties approved by EPA.

(Ord. No. 12-1700-936, § 1, 10-2-12)

(Ord. No. 12-1700-936, § 1, 10-2-12)