(A) (1) Users of the city sewerage facilities works shall be identified as belonging to one of the following user classes:
(a) Residential;
(b) Commercial;
(c) Industrial; or
(d) Institutional and governmental.
(2) The allocation of users to these categories for the purpose of assessing user charges and debt service charges shall be the responsibility of the city staff. Allocation of users to user classes shall be based on the substantive intent of the definitions of these classes contained herein.
(B) The user shall pay operation, maintenance and replacement costs in proportion to the user's proportionate contribution of wastewater flows and loadings to the treatment plant, with the minimum rate for loadings of BOD and of TSS being the rate established for concentrations no greater than 300 mg/l BOD and 300 mg/l TSS (i.e. normal domestic strength wastewater).
(C) (1) Unit costs for treatment of flow, BOD and TSS shall be determined and fixed annually in the sewer service charge system according to the following procedure:
(a) Determine the annual O, M & R budget;
(b) Allocate total annual O, M & R costs to flow, BOD and TSS proportionately, according to the costs of collection, and of the specific treatment processes required to affect or reduce flow, BOD and TSS; and
(c) Divide the O, M & R costs attributable to flow, BOD and TSS respectively, by the total annual volume and loadings of flow, BOD and TSS, to arrive at unit costs.
(2) For purposes of determining user charges, the following definitions of unit costs shall apply:
(a) OF equals the unit cost for treatment of domestic flow in $/ccf.
(b) UBOD equals the unit cost for treatment of BOD in $/lb.
(c) UTSS equals the unit cost for treatment of TSS in $/lb.
(D) User charges for normal domestic strength users.
(1) The billable amount of flow will be calculated from the volume of metered water usage, or at the discretion of the city, from the measurement of effluent flow at user's point of discharge. Measurements shall be according to a regular program prescribed by the city. The billable amounts of BOD and TSS are included in the domestic flow unit charge.
(2) Calculating user charges.
UC(NDS) = (OF x F)
(a) UC(NDS) equals user charge for treatment of normal domestic strength wastewater.
(b) OF equals the unit cost for treatment of domestic flow in $/ccf.
(c) F equals the billable flow in ccf.
(E) User charges for users contributing wastes greater than normal domestic strength.
(1) The billable amount of flow will be calculated from the volume of metered water usage, or at the discretion of the city, from the measurement of effluent flow at user's point of discharge. Measurements shall be according to a regular program prescribed by the city. The billable amounts of BOD and TSS will be calculated by the measurement of these wastes according to a program prescribed by the city in keeping with the latest edition of Standard Methods for the Examination of Water and Wastewater and in accordance with Ordinance No. 555, “An Ordinance Establishing Sewer Use Regulations.”
(2) Calculating user charges.
UC(GNDS) = (OF x F) + (UBOD x QBOD) + (UTSS x QTSS)
(a) UC(GNDS) equals the user charge for treatment of wastewater that is greater than normal domestic strength.
(b) OF equals the unit costs for treatment of domestic flow in $/cff.
(c) F equals the billable flow in ccf.
(d) UBOD equals the unit cost for treatment of BOD in $/lb.
(e) QBOD equals the quantity of BOD greater than domestic strength in lbs.
(f) QTSS equals the unit cost for treatment of BOD in $/lb.
(g) QTSS equals the quantity of TSS greater than domestic strength in lbs.
(F) The city may, at its discretion, require nonresidential users to install wastewater flow meters or additional water meters as may be necessary to determine wastewater volume. The city may require residential connections to install water meters for the purpose of determining wastewater volume. When so required, the meters shall be of a type approved by the city equipped with remote registering recorders, and located at an accessible site on the owner's property.
(G) A portion of new construction costs for the sanitary sewerage facility will be recovered from users in proportion to their contributions of wastewater flow and loadings into the treatment facility as follows:
(1) Unit costs for debt service of capital expenditures attributable to flow, BOD and TSS shall be calculated according to the sewer service charge system. For purposes of determining debt service charges, the following definitions shall apply:
(a) DF equals the unit cost for debt service of capital expenditures attributable to domestic flow.
(b) DBOD equals the unit costs for debt service of capital expenditures attributable to SOD.
(c) DTSS equals the unit cost for debt service of capital expenditures attributable to TSS.
(d) The calculation of flows and loadings for the debt service charge shall be the same as described in divisions (D) and (E) above.
(2) For normal domestic strength users:
DC(NDS) = (DF x F)
(3) For users contributing wastes greater than normal domestic strength:
DC(GNDS) = (DF x F) + (DBOD x QBOD) + (DTSS x QTSS)
(a) DC(NDS) equals the debt service charge to normal domestic strength users.
(b) DC(GNDS) equals the debt service charge to users contributing wastewater that is greater than normal domestic strength.
(c) DF equals the unit cost for debt service of capital expenditures attributable to flow in $/ccf.
(d) F equals the billable flow in ccf.
(e) DBOD equals the unit cost for debt service of capital expenditures attributable to BOD in $/lb.
(f) KBOD equals the constant used to calculate the quantity of BOD in lbs./ccf of NDSW (300 mg/l BOD) as follows.
(g) KBOD equals .00834 x 300 mg/l (BOD concentration of NDS waste).
(h) DTSS equals the unit cost for debt service of capital expenditures attributable to TSS in $/lb.
(i) KTSS equals constant used to calculate the quantity of TSS in lbs./ccf of NDSW (300 mg/l TSS) as follows.
(j) KTS equals .00834 x 300 mg/l (TSS concentration of NDS waste).
(k) QBOD equals the quantity of BOD in lbs.
(l) QTSS means the quantity of TSS in lbs.
(m) SSC equals Uc + Dc.
1. SSC equals the annual sewer service charge.
2. Uc equals the annual user charge.
3. Dc equals the annual debt service charge.
(H) A portion of new construction costs for the sanitary sewer facility will be recovered through a per connection charge based on the total annual debt service and the total number of connections as follows:
Dc = TDS
TC
(a) Dc equals the annual debt service charge attributable to connections.
(b) TDS equals the total annual debt service.
(c) TC equals the total number of connections.
SSC = Uc + Dc
(a) SSC equals the annual sewer service charge.
(b) Uc equals the annual user charge.
(c) Dc equals the annual debt service charge.
(`86 Code, § 3.59)