(A) All significant industrial users shall sample/monitor their discharge a minimum of once each month for the determination of amounts of pollutants being discharged to the town’s treatment works. Such sample/monitoring results shall be reported as required in § 50.161.
(B) Wastewater flows shall be continuously monitored and totalized on a daily basis.
(C) All sampling/monitoring activities shall take place at the control structure approved by the town unless otherwise required by national categorical pretreatment standards.
(D) Sampling of pollutants, except for those pollutants requiring grab samples, shall be performed by a 24-hour composite of the flow proportional type, unless time-proportional composite sampling or grab sampling is authorized by the Chief Operator. Where time-proportional composite sampling or grab sampling is authorized by the town, the samples must be representative of the discharge. Using protocols (including appropriate preservation) specified in 40 CFR Part 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 town, as appropriate. In addition, grab samples may be required to show compliance with instantaneous limits.
(E) Sampling of pollutants through time proportional composite activities shall only be allowed if the user demonstrates that flow proportional sampling is unfeasible. Avoidance of costs to the User will not be considered adequate justification for allowance of time proportional composite sampling.
(F) For those pollutants requiring grab samples, a minimum of four grab samples must be used where the user can demonstrate that such sample frequency will provide a representative sample of the pollutants/effluent being discharged. Such pollutants/parameters requiring grab samples are pH, cyanide, total phenols, oil and grease, sulfides, and volatile organics.
(G) For sampling required in support of baseline monitoring and 90-day compliance reports required in 40 CFR 403.12(b) and (d) and/or R61-9 403.12 (b) and (d), a minimum of four 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 Chief Operator may authorize a lower minimum. For the reports required by 40 CFR 403.12(e) and (h) and/or R61-9 403.12(e) and (h), 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.
(H) Sampling and analysis shall be performed in accordance with the techniques prescribed in 40 CFR Part 136 and amendments thereto. Where 40 CFR Part 136 does not contain sampling or analytical techniques for the pollutant in question, or where the Administrator determines that the Part 136 sampling and analytical techniques are inappropriate for the pollutant in question, sampling and analysis shall be performed by using validated analytical methods or any other applicable sampling and analytical procedures, including procedures suggested by the POTW or other parties, approved by the Administrator.
(I) Should accidental discharges, slug loads, and/or by-pass occur at the users facility, the user shall immediately, after notification to the town, initiate sampling activities of his or her permit parameters and any hazardous or toxic substance which might have been discharged or is being discharged. Reporting of such results shall be in accordance with § 50.161 of this chapter. Results of such sampling may be used by the town in the determining of surcharges, penalties, etc.
(J) The town shall, at least once each year, sample and monitor the user's discharge to ensure compliance with this chapter and national categorical pretreatment standards. The results of such sampling and monitoring activity shall be made available to the user. Compliance monitoring and sampling by the town does not relieve the user of his or her requirement to sample and monitor his or her wastewater discharge.
(Ord. 11-01, passed 1-3-11; Am. Ord. 19-04, passed 5-6-19; Am. Ord. 22-07, passed 5-2-22; Am. Ord. 23-06, passed 4-4-23)