Unless the context specifically indicates otherwise, the meaning of terms used in this chapter shall be as follows:
(a) "Operation and Maintenance Costs" means all costs associated with the operation and maintenance of the wastewater collection and treatment facilities, including salaries and wages, electric power, propane gas and fuel oil, chemicals, miscellaneous supplies and equipment, maintenance of equipment and facilities, employee fringe benefits, other necessary expenses and all costs associated with equipment replacement.
(b) "Equipment Replacement Costs" means expenditures made for obtaining and installing equipment, accessories or appurtenances which are necessary during the service life of the treatment works to maintain the capacity and performance for which such works were designed and constructed (Reference 40 CFR 35.905-17).
(c) "Normal Strength Wastewater" as defined for the purpose of determining surcharges means wastewater having an average daily suspended solids concentration of not more than 250 mg/1, an average daily BOD5 of not more than 200 mg/1, an average daily total phosphorous concentration of not more than 10 mg/1, and containing not more than 100 mg/1 of Freon soluble matter (grease and oil).