Prior to March 31 each year, the Superintendent, based on the previous year's records of operation, flows, loads, costs and water consumption shall compute or cause to be computed the following:
(a) Annual Treatment Volume (F). The total yearly volume of sewage collected, conveyed and treated. Such total yearly volume of sewage shall consist of the volumes as measured at the Wastewater Treatment Plant.
(c) Annual Unaccountable Volume (Vu). The sum of all volumes originating at unknown sources. This annual volume shall represent the difference between annual treated volume (F) and the annual accountable volume (VA).
(d) Percent Accountable (PA). That portion of the total annual treated flow which is accountable. The value shall be determined by dividing the annual accountable flow (VA) by the annual treated volume (F).
(e) Percent Unaccountable (Pu). That portion of the total annual treated flow which is unaccounted tor. The value shall be determined by dividing the annual unaccountable volume (Vu) by the annual treated volume ( F ) .
(f) Total Annual BOD (B). The estimated BOD of all treated wastewater for a period of one year as determined from treatment records.
(g) Percent High Level BOD (BH). That portion of the annual BOD which is derived from accountable wastewater with a high level BOD. The value shall be determined by multiplying the annual accountable volume (VA) by the normal level BOD limitation of 200 milligrams per liter, and then dividing the product by the total annual BOD (B) and subtracting from unity.
(h) Total Annual SS (S). The estimated SS of all treated wastewater for a period of one year as determined from treatment plant records.
(i) Percent High Level SS (SH). That portion of the annual SS which is derived from accountable wastewater with high level SS. The value shall be determined by multiplying the annual accountable volume (VA) by the normal level SS limitation of 200 milligrams per liter, dividing the product by the total annual SS and subtracting from unity.
(j) Annual Volume of Other Pollutants (P). Volumes shall be determined of any other pollutants for which facilities and/or treatment is provided or which generate expense because of its existence.
(k) Percent High Level - Other Pollutants (PN). That portion of the annual volume of a particular pollutant derived from accountable wastewater with high levels of the pollutant in question. The value shall be determined by multiplying the accountable volume (VA) times the maximum concentration of the substance considered normal in wastewater, dividing the result by the annual volume of the pollutant in question and subtracting from unity.
(l) Total Users (U). The total number of known users connected to or otherwise discharging wastewater into the City Treatment Works.
(m) Total Annual Bills (T). The total number of user charge bills for sewer service issued during the previous year.
(n) Annual Administrative Costs (CA). The total yearly administrative costs, which shall include the items listed below. In addition, all expenses below shall be limited to items and services necessary for and directly attributable to carrying out the administration of the wastewater treatment system.
(1) That portion of all salaries, wages and other accountable compensations paid to employees for performing administrative services.
(2) Consulting fees for administrative professional services (i.e., legal, financial, engineering) .
(3) Overhead costs such as rent, telephone and utilities.
(4) Meter reading costs for estimating monthly usage by customers.
(5) Postage expense for all billing and administrative correspondence.
(6) Billing materials and office supplies.
(7) Interest costs, in cases where normal operating funds are insufficient to meet current demands and money is borrowed for such purposes.
(8) Miscellaneous costs for items not covered in the above categories but which are valid administrative expenses.
(o) Annual Sewer Operation and Maintenance Costs (Cs). The total yearly sewer operation and maintenance cost which shall include the items listed below. In addition, all items listed below shall only be for items and services necessary for and directly attributable to operating and maintaining the sewer collection system.
(1) That portion of all salaries, wages and other accountable compensation paid to employees for performing sewer operations and maintenance services. This item shall include estimated overtime costs for emergency work.
(2) Consulting fees for professional services relating to the sewer system.
(3) Overhead costs for items such as telephone, rent, vehicles and utilities.
(4) Expenses for materials, equipment repairs and rentals, supplies and inspection and surveillance devices.
(5) Interest costs, in cases where normal operating funds are insufficient to meet current demands and money is borrowed for such purposes.
(6) Miscellaneous costs for items not covered in the above categories but which are valid sewer operation and maintenance expenses.
(p) Annual Wastewater Treatment Operation and Maintenance Costs (CT). The total yearly wastewater treatment operation and maintenance cost which shall include the items listed herein. In addition, all items listed herein shall only be for items and services necessary for and directly attributable to operating and maintaining the sewage treatment facility.
(1) That portion of all salaries, wages and other accountable compensation paid to employees for performing wastewater treatment services or otherwise contributing to the maintenance of the facility. This item shall include estimated overtime costs for emergency work.
(2) Treatment costs for items such as electricity, gas, water, chemicals, equipment repair and rental, devices and general supplies .
(3) Consulting fees for professional services relating to the treatment process.
(4) Miscellaneous costs for items not covered in the above categories, but which are valid wastewater treatment operation and maintenance expenses .
(5) Interest costs, in cases where normal operating funds are insufficient to meet current demands and money is borrowed for such purposes.
(6) Individual pollutant treatment costs. A portion of the sum of each of the previously mentioned items shall be determined to be the representative cost for treating each of the pollutants listed herein. This portion shall be expressed as a dollar amount.
A. BOD treatment costs (X
B
)
B. SS treatment costs (X
S
)
C. Other pollutants treatment cost (X
P
)
(q) Annual Payment to Sewer System Replacement Fund (FS). The total yearly estimated payment to the sewerage system replacement fund.
(r) Annual Payment to Treatment Plant Replacement Fund (FT). The total yearly estimated payment to the Wastewater Treatment Plant's replacement fund.
(s) Annual Total Expenditure (C). The total yearly City expenditure for collection and treatment of all types of wastewater. This amount shall be determined by adding the following:
(1) Annual sewer system operation and maintenance cost (C
S
)
(2) Annual treatment operation and maintenance cost (C
T
)
(3) Annual payment SS replacement fund (F
S
)
(4) Annual payment TP replacement fund (F
T
)
(t) Treatment Cost of High Level Pollutants (CH). That portion of the total treatment costs which are attributable to wastewater with high levels of BOD, SS and other pollutants. To determine the cost for each type pollutant multiply the total cost for treatment of that pollutant times its percent of high level. By summing the product derived for each type pollutant, the desired cost shall be obtained.
High level BOD cost (Z
B
) = (X
B
) x (B
H
)
High level SS cost (Z
S
) = (X
S
) x (S
H
)
High level other cost (ZO) = (XO) x (OH)
Total high level cost = (C
H
)
(u) Annual Expenditure - Normal Level Pollutant Treatment (CN). The total yearly expenditure for collection and treatment of all wastewater with a normal level of BOD, SS and other pollutants, This value shall be determined by deducting the cost of treating high level pollutant (CH) from the total annual expenditure for collection and treatment (C).
(v) Treatment Cost of High Level BOD (YB). The cost of treatment per unit of high level BOD. This cost shall be determined by first multiplying the total annual BOD(B) by the percent high level BOD (BH). This result shall then be divided into the total cost of treating high level BOD (ZB)
(w) Treatment Cost of High Level SS (YS). The cost of treatment per unit of high level SS. This shall be determined by first multiplying the total annual SS (S) by the percent high level SS (S
H
). This result shall then be divided into the total cost of treating high level SS (Z
S
)
(x) Treatment Cost of High Level Other Pollutants. The cost of treatment per unit of the pollutant in question. This cost shall be determined by first multiplying the total annual amount of the pollutant (O) by the percent high level (O
H
). The result shall then be divided into the total cost of treating the high level pollutant (Z
O
).
(y) Summary Sheet for Computational Elements. The following list will provide a summary of computational elements to be used in subsequent sections for rate determination.
Annual administrative cost C
A
A =
Total annual bills T =
Normal level pollutant treatment cost C
N
=
Percent unaccountable flow P
U
=
Total users U =
Percent accountable flow P
A
=
Annual accountable volume V
A
=
High level pollutant treatment cost
BOD Z
B
=
SS Z
S
=
Other Z
O
=
(Ord. 31-81. Passed 12-1-81.)