(A) General. Although the proposed sewage treatment works will be capable of treating certain abnormal industrial wastes defined in § 152.001, the actual treatment of such wastes may increase the cost of operating and maintaining the city’s publicly owned treatment works (“POTW”). Therefor, there is hereby levied and assessed against each person, industry or corporation discharging more than 10,000 gallons per month of such abnormal industrial waste into the POTW, a surcharge, or surcharges, which are intended to cover such additional cost to the City of Kingwood Sanitary Board (“KSB”). Said surcharges shall be in addition to the regular sewerage service charge set forth in this subchapter and shall be payable as hereinafter provided in the amount thereinafter provided. ABNORMAL INDUSTRIAL WASTES is defined as any industrial waste having a suspended solids concentration, a five-day biochemical oxygen demand (“BOD”) or a chlorine requirement appreciably in excess of that normally found in municipal sewage, which for this subchapter shall mean any industrial waste containing more than 250 ppm of suspended solids or five-day BOD or having a chlorine requirement in excess of 25 ppm, regardless of whether or not it contains other substances in concentrations differing appreciably from those normally in municipal sewage.
(B) Sampling. The strength of any industrial waste, the discharge of which is to be subject to surcharge, shall be determined monthly, or more frequently, from samples taken at a manhole or at any other sampling point mutually agreed to by the KSB and the producer of said waste. The frequency and duration of the sampling period shall be such as, in the opinion of the KSB, will permit a reasonably reliable determination of the average water runoff. Representative samples of the wastewater discharge shall be collected, by a representative of the KSB, in proportion to the flow of waste, exclusive of stormwater runoff, and composited for analysis in accordance with the current edition of Standard Methods for the Examination of Water and Wastewater, as published by the American Public Health Association. Upon request by the industrial user, the KSB may split samples with the industrial user for its own analysis, but the KSB’s results will be used for determining any applicable surcharges. Except as hereinafter provided, the strength of the waste so found by analysis shall be used for establishing the surcharge, or surcharges hereinafter provided for. However, the KSB may, if it so elects, accept the results of routine sampling and analysis by the producer of said wastes in lieu of making its own samplings and analyses.
(C) Chlorine requirement.
(1) In the event any industrial waste, the average volume of which exceeds 10,000 gallons per month, is found by the KSB to have a chlorine requirement in excess of 25 parts per million (25 ppm),
the producer of said waste shall be surcharged an amount equal to the product of the actual volume of wastes in thousand gallons per billing period, exclusive of stormwater runoff, discharged to the POTW and the chlorine requirement surcharge rate.
(2) The chlorine requirement surcharge rate shall be determined by the following formula:
Rc = 0.00834 Pc (C - 25) |
Where: |
R = the chlorine requirement surcharge rate in cents per thousand gallons of waste discharged |
Pc = the average cost of chlorine to the city in cents per pound |
C = the average chlorine requirement of the industrial waste expressed in parts per million (ppm) as determined in accordance with divisions (B) or (D) of this section |
The figure 25 appearing in the above formula corresponds to the maximum chlorine requirement permissible without surcharge |
The figure 0.00834 is the factor to convert parts per million to pounds per thousand gallons |
(3) No discount will be permitted for sewage or industrial wastes having a chlorine requirement of less than 25 parts per million.
(D) Difficulty in determining.
(1) It is recognized that the chlorine requirement of certain undiluted chemical wastes may be difficult to determine because of excessive concentrations of interfering substances. In such instances the waste may first be diluted waste and the sewage used in making the dilution shall then be allowed to stand at room temperature, approximately 68°F, for a period of not less than two hours, or more than eight hours.
(2) The chlorine requirement of each shall then be determined and the chlorine requirement of the undiluted waste computed by the following formula:
C = M(V1+V2) - SV2 |
Where: |
C = the chlorine requirement of the waste to be used in the formula of division (C) above |
M = the chlorine requirement of the mixed sewage and waste in parts per million |
S = the chlorine requirement of the sewage used for dilution in parts per million |
V1 = the volume of waste used in the mixture |
V2 = the volume of sewage used in the mixture |
(3) In the application of this procedure the volumes of waste and diluting sewage used shall be
such that the ratio of V1 to (V1 + V2) is approximately equal to the ratio of the average daily flow of wastes in question to the average daily flow of sewage entering the treatment works. This procedure shall be used only in those instances where the KSB believes its use to be necessary or desirable in order to determine the equitable chlorine requirement surcharge rate.
(E) Application. Since the above stipulated surcharge is only intended to compensate the KSB for the additional cost of chlorinating abnormal industrial wastes, it will only be applied during those periods when the KSB is actually using chlorine. In the event the KSB used chlorine for only a portion of some given billing period then the surcharge for that particular period, as computed in accordance with division (C) or (D) above, shall be reduced by the percentage of said period during which no chlorine is used.
(F) Suspended solids concentration.
(1) In the event any industrial waste, the average volume of which exceeds 10,000 gallons per month, is found by the KSB to have an average suspended solid concentration in excess of 250 parts per million, the producer of said waste shall be surcharged an amount equal to the product of the actual volume of wastes in thousand gallons per billing period, exclusive of storm runoff, discharged to the public sanitary sewerage system and the suspended solids surcharge rate.
(2) The suspended solids surcharge rate shall be determined by the following formula:
Rs = 0.00834 x 0.80 x Ps (S - 250) |
Where |
Rs = the suspended solids surcharge in dollars per thousand gallons of waste discharged. |
Ps = the average annual cost of operating and maintaining the sludge dewatering and disposal facilities at the treatment works, in dollars per pound of sewage solids handled by those units (prior to completion of the first year of operation the value of Ps shall be assumed to be $0.009) |
S = the average suspended solids concentration of the abnormal industrial waste, expressed in parts per million as determined in accordance with division (G) below |
The figure 250 appearing in the above formula corresponds to the maximum suspended solids concentration permissible without surcharge |
The figure 0.80 appears in the formula because it is anticipated that the average removal of suspended solids as a result of the proposed treatment process will be about 80% |
As before, the figure 0.00834 is the factor to convert parts per million to pounds per thousand gallons |
(3) No surcharge for excessive suspended solids will be applied until the treatment works goes into actual operation. No discount will be permitted for sewage or industrial wastes having a suspended solids concentration less than 250 parts per million.
(G) BOD concentration.
(1) In the event any industrial waste, the average volume of which exceeds 10,000 gallons per month, is found by the KSB to have an average BOD concentration in excess of 250 parts per million, the producer of said waste shall be surcharged an amount equal to the product of the actual volume of the wastes in thousand gallons per billing period, exclusive of storm runoff, discharge to public sanitary sewerage system and the BOD surcharge rate.
(2) The BOD surcharge rate shall be determined by the following formula:
RB = 0.00834 x 0.80 x PB(B - 250) |
Where: |
RB = the BOD surcharge rate in dollars per thousand gallons of waste discharge |
PB = the average annual cost of operating and maintaining the preparation tanks, RBC tanks, process air blowers and chlorination facilities at the treatment plant in dollars per pound of BOD handled by those units (prior to completion of the first year of operation the value of PB shall be assumed to be 0.01) |
B = the average BOD concentration of the abnormal industrial waste, expressed in parts per million as determined in accordance with division (B) above |
The figure 250 appearing in the above formula corresponds to the maximum BOD concentration permissible without surcharge |
The figure 0.80 appears in the formula because it is anticipated that the average removal of BOD as a result of the proposed treatment process will be about 80% |
As before, the figure 0.00834 is the factor to convert parts per million to pounds per thousand gallons |
(3) In the event that an industrial user is subject to both BOD and chlorine requirements surcharges, the cost of the chlorination facilities will be deleted from the formula above to prevent double charging for chlorine. No surcharge for excessive BOD will be applied until the secondary treatment works goes into actual operation. No discount will be permitted for sewage or industrial wastes having a BOD concentration less than 250 parts per million.
(H) Surcharges. The surcharges provided for in this section will be added to the normal sewerage service charge set forth in this subchapter. They will be billed either monthly or quarterly and shall be subject to the delayed payment penalty in this subchapter. However, no surcharges will be levied until the secondary treatment works are placed in operation.
(Ord. 25, passed 3-13-2018)