11.803 Wastewater Rate Determination.
Extra strength industrial waste discharge shall be defined as industrial, commercial, or hospital industrial wastes discharged into the sewer system containing a total of more than 60 pounds of biochemical oxygen demand, or suspended solids in any one day and having an average strength in excess of 300 ppm of biochemical oxygen demand, or suspended solids.
(1) Composite Charge Rate. For each extra strength industrial waste discharger, the composite charge rate shall normally be employed. The composite charge rate shall be based on the average of composited samples obtained in accordance with the provisions of the wastewater strength determination section of this chapter and the wastewater volume as determined in accordance with the provisions of the wastewater volume determination section of this chapter.
The rate shall be established per 300 ppm of biochemical oxygen demand, or suspended solids, or fraction thereof in excess of the first 300 ppm of biochemical oxygen demand, or suspended solids per 1,000 gallons of water. The rate shall be for the higher concentration of either BOD or suspended solids, but not assessed for both.
(2) Other Charge Rates. If unusual effluent conditions make the calculations by the composite method impossible or unrealistic, another method of sampling and computation may be implemented by the WRD Manager.
(3) Allowances.
(a) Appropriate allowances may be made, at the discretion of the WRD Manager, for the volume of domestic sewage at permissible limits of strength. The domestic sewage allowance shall be based on a ratio of 1,000 gallons per month for each 27 employees using the sanitary sewer system.
(b) Favorable consideration will be given to users that can discharge compatible wastes during low flow periods of the night and on weekends. Case-by-case consideration will be given to those users at the discretion of the WRD Manager, to make rate adjustments commensurate with decreased impact on the sanitary sewer system.
(c) In the event wastewater volume determination is computed using metered water flow and deduct meters are not utilized, special allowances may be made at the discretion of the WRD Manager, for water consumption or loss based on verifiable industry standards (e.g., evaporation, use in product, etc.).
(4) Adjustments. The WRD Manager may check sewage strength as outlined in this section and give notice that extra strength charges be adjusted where applicable at any time in accordance with the most recent analysis.
(5) Resampling Request – Fees. Any user may request the WRD Manager to resample wastewater at no charge if 18 months or more have elapsed since the last such sampling. If less than 18 months have elapsed since the last sampling, then requests for the WRD Manager to resample wastes shall be submitted in writing and may require payment for a resampling fee. The resampling fee for each day of sampling shall be established by the WRD Manager.
(6) Implementation of Charges. Changes in extra strength charges shall be effective for the month next following the month in which notice of adjustment was given.