915.11 SURCHARGE COMPUTATION.
   (a)   Surcharges for excessive pollutant loadings shall be chargeable each billing period during the calendar year and shall be based upon the following values for that calendar year:
      (1)   Estimated total operation, maintenance and replacement expenses attributed to the sewer treatment plant pursuant to Section 915.04(a);
      (2)   Estimated total pounds per day of BOD received at the plant determined by the average daily plant flow (million gallons per day) times the average daily concentration of BOD (milligrams per liter) times 8.34;
      (3)   Estimated total pounds per day of TSS received at the plant determined by the average daily plant flow (million gallons per day) times the average daily concentration of TSS (milligrams per liter) times 8.34.
   Data not available shall be estimated in the most practical manner possible.
   (b)   The excessive pounds of BOD subject to surcharge per billing period equals: [Average concentration of BOD, calculated pursuant to Section 911.11 (in milligrams per liter) minus the maximum allowable BOD concentration per Section 911.14(a)] times the volume of flow pursuant to Sections 915.09 or 915.10 times .00624.
 
   (c)   The excessive pounds of TSS per billing subject to surcharge equals: [Average concentration of TSS, calculated pursuant to Section 911.14, in ppm minus the maximum allowable TSS concentration in Section 911.14(b)] times the volume of flow pursuant to Sections 915.09 or 915.10 times .00624.
   (d)   The unit rate of charge, in dollars per pound, for BOD equals: the value of subsection (a) (1) hereof times 0.35 divided by the value of subsection (a) (2) hereof times 365.
   (e)   The unit rate of charge, in dollars per pound, for TSS equals: the value of subsection (a) (1) hereof times 0.55 divided by the value of subsection (a) (3) hereof times 365.
   (f)   The surcharge per billing period for excessive pounds of BOD discharged into the Sewage Disposal System equals: the value pursuant to subsection (b) hereof times the value pursuant to subsection (d) hereof.
   (g)   The surcharge per billing period for excessive pounds of TSS discharged into the Sewage Disposal System equals: the value pursuant to subsection (c) hereof times the value pursuant to subsection (e) hereof.
(Ord. 84-91. Passed 10-16-84.)