§ 50.27. Adjustment of charges based on strength and character of sewage

(A) In order that rates and charges for the use of the sewage works may be justly and equitably adjusted to the service rendered, the sanitary district shall have the right to base its charges not only on volume but also on the strength and character of the sewage and wastes which it is required to treat and dispose of. The sanitary district shall have the right to measure and determine the strength and content of all sewage and wastes discharged, either directly or indirectly, into the sanitary district's sewerage system, in such manner and by such method as it may deem practicable in order to determine the proper charge.

(B) Each person discharging wastes into the sanitary district sewers shall be subject to a surcharge in addition to the regular sewerage service charge based on the B.O.D. or C.O.D. and the suspended solids (SS) content of the wastes, if the wastes have a concentration higher than that set forth in § 50.09, except C.O.D. which is set at 600 ppm.

(1) B.O.D.—300 ppm.

(2) Suspended solids—300 ppm.

(C) Sampling and testing.

(1) The discharge sewage will be sampled during each sewage billing period for a minimum of a one-day period (24 continuous hours) by means of a composite sample. An extended sampling period of up to one week (seven continuous days) may be requested to enable the gathering of a sample representative of a business's sewage. The extension of the sampling period beyond the initial one day sampling period may be requested by either the sewer user involved or the Muncie Sanitary District. If an extended sampling period is requested, the parameter values used to calculate the surcharge will be the arithmetical average of the individual values. In the event a business or industry has multiple discharges of sewage, each discharge shall be sampled according to quality. The volume of each discharge shall be determined by actual measurement or by means of process usage. If significant process changes are made to affect quality of any discharge, resampling may be requested by either the sewer user involved or the Muncie Sanitary District.

(2) The sewage sample shall be measured for the following parameters: B.O.D. or C.O.D. and suspended matter or solids (SS). These tests shall be made in accordance with the latest editions of Standard Methods for the Examination of Water and Wastewater by APHA, AWWA, WPCF or Methods for Chemical Analysis of Water and Wastes by the United States Environmental Protection Agency.

(D) Computation of surcharge. The excess pounds of B.O.D. or C.O.D. and of suspended solids will each be computed by multiplying the sewage billing volume measured in units of 100 cubic feet for the current sewage billing period by the factor 0.006238 and then multiplying the difference between the concentration measured in milligrams per liter of the B.O.D. or C.O.D. and of the suspended solids, respectively, in the customer's sewage and the allowed concentrations set out above and in § 50.09 (A), resulting in the pounds of each constituent. The surcharge of each constituent will then be determined by multiplying the excess pounds of ech constituent by the appropriate rate of surcharge set out in subsection (E).

(E) Rates of surcharge. The rates of surcharge for each of the aforementioned constituents shall be as follows:

(1) For B.O.D. in excess of 300 ppm. $.018 per pound.

(2) For suspended solids (SS) in excess of 300 ppm. $.016 per pound.

(3) For C.O.D. in excess of 600 ppm. $.018 per pound.

(F) Revision of rates of surcharge. Prior to April of each year, the superintendent and the director of the division of water quality shall submit to the board of sanitary commissioners a detailed report showing cost for removing B.O.D. and/or C.O.D. and suspended solids from wastewater treatment plant influent during the previous calendar year with the unit charges currently in effect, in order that the board may determine whether the current rates are adequate or should be changed.

(Code 1968, § 50.28)