§ 21-213. Sample collection and analytical methods.
(a)
Sample collection. Compliance determinations with respect to prohibitions and limitations in this article may be made on the basis of either grab or composite samples of wastewater as specified by the city. Such samples shall be taken at a point or points which the city determines to be suitable for obtaining a representative sample of the discharge. Composite samples may be taken over a twenty-four-hour period, or over a longer or shorter time span, as determined by the city to meet specific circumstances.
(b)
Sample type. 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, and based on data that is representative of conditions occurring during the reporting period.
(1)
Except as indicated in subparagraphs (2) and (3) below, the industrial user must collect representative wastewater samples using twenty-four-hour flow proportional composite sampling techniques, unless time-proportional composite sampling or grab sampling is required by the city. Where time-proportional composite sampling or grab sampling is authorized by the city, the samples must be representative of the permitted discharge.
(2)
Samples for oil and grease, temperature, pH, cyanide, total phenols, sulfides, and volatile organic compounds must be obtained using grab collection techniques. Using protocols (including appropriate preservation) specified in 40 CFR Part 136 and appropriate EPA guidance, multiple grab samples collected during a twenty-four-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. Composited 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 local limits, including pH.
(3)
For sampling required in support of baseline monitoring and ninety-day compliance reports required in subsections 21-215(b) and (c), 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 representative sampling data do not exist. Where historical data are available, the city may authorize a lower minimum. The industrial user is required to collect the number of grab samples necessary to assess and assure compliance with applicable pretreatment standards and requirements.
(c)
Analytical requirements. All pollutant analysis, including sampling techniques, to be submitted as part of an wastewater discharge permit application, report, permit or other analyses required under this article shall be performed in accordance with the techniques prescribed in 40 CFR Part 136 and amendments thereto, unless otherwise specified in an applicable categorical pretreatment standard. If 40 CFR Part 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 city or other parties approved by the EPA.
(d)
Records shall include for all samples:
(1)
The date, exact place, method, and time of sampling and the name of the person(s) taking the samples;
(2)
The date(s) and time analyses were performed;
(3)
The name of the person performing the analyses;
(4)
The analytical techniques/methods used, including method detection limits and QA/QC sample results;
(5)
All chain-of-custody records; and
(6)
The results of such analyses.
(Ord. No. 10-2014, 10-14-14)