An industrial user shall cause sampling and analysis and reports thereof to be made to the city, of flow and waste characteristics to determine strength and quantity of BOD and TSS under average conditions. Further testing requirements will be as they appear in the discharge permit issued under § 51.122(D).
(A) Sampling procedures. Samples and measurements shall be representative of the volume and nature of the monitored discharge. Samples shall be taken during normal working hours at the specified monitoring manholes.
(1) Except as indicated in division (A)(2) below, the user shall collect wastewater samples using flow proportional collection techniques, or time proportional collection techniques, if authorized by the Wastewater Superintendent. Time proportional samples are composed of constant volume aliquots collected at constant time intervals. This method provides representative samples when the wastewater flow does not vary more than 10% of the average flow rate over time. The time proportional sample can be obtained using an automatic sampler, or by the compositing of a minimum of four individual grab samples of the same volume of wastewater, taken during the course of a normal work day.
(2) Samples for oil and grease, temperature, pH, cyanide, phenols, sulfides, and volatile organic compounds must be obtained using grab collection techniques. A grab sample can be composed of discrete samples, but all samples must be obtained and combined within a 15-minute time period from start of sampling to finish. When taking a grab sample, the entire mouth of the sample jar must be submerged below the surface of the wastestream. The pH sample should be analyzed immediately and must not be held longer than two hours in any case.
(B) Grab sample. The Wastewater Superintendent may use a grab sample to determine noncompliance with any pretreatment standards.
(Ord. 2009-02, passed 5-12-2009)