Section 3-1 - Utility Service and Facilities; Quality and Adequacy (a) Each utility shall furnish its customers with safe, adequate and reliable service in accordance with accepted good utility practice. It shall maintain its entire plant and system in a condition enabling it to furnish required service and inspect its system and facilities in a manner and at such frequency as necessary to obtain sufficient knowledge of its current condition and adequacy.
(b) Electric utilities shall: - (i) Design and operate the electric system to maintain its voltages within the limits of ANSI 84.1;
- (ii) Use portable indicating voltmeters or electronic monitors capable of recording the continuous voltage in time for testing voltage regulation and portable graphic voltmeters or electronic monitors capable of recording the continuous voltage in time for testing power quality and reliable operation. These instruments shall be of a type and capacity suited to the voltage supplied and adequate to comply with section 18 of this Chapter;
- (iii) Conduct a sufficient number of voltage surveys to adequately indicate the character of service furnished to its customers and to demonstrate compliance with voltage requirements. Voltage surveys shall include measurements at the point of delivery or nearest downstream device; and
- (iv) Establish per tariff standard nominal voltages as required by the unique distribution system for the service area or for each district of a divided system.
(c) Gas utilities shall: - (i) Have access to or require use of a properly maintained calorimeter or chromatograph of a standard type with all necessary accessories for the determination of the Btu value of gas delivered;
- (ii) Maintain in its tariff a standard to determine gas Btu value that equates a cubic foot of gas with the amount of gas that occupies one cubic foot, dry, at 60° F at 14.73 pounds per square inch absolute;
- (iii) Maintain in its tariff a standard to measure gas provided to a customer that equates a cubic foot of gas with the amount of gas that occupies one cubic foot under the conditions at the customer's meter. The real gas law shall be used to calculate any volume adjustment for the gas delivered;
- (iv) Deliver gas that:
- (A) Contains no more than 0.25 grains of hydrogen sulfide per 100 standard cubic feet;
- (B) Contains no more than 2.5 mole percent of oxygen;
- (C) Contains no more than seven pounds of water vapor per million standard cubic feet;
- (D) Has a heating value of at least 950 Btu per standard cubic foot; and
- (E) Has a hydrocarbon dew point compatible with normal system operating conditions.
- (v) Monitor changes to tariff-established Wobbe Indices.
- (A) The tariff sheets shall describe, and include a map illustrating, the distinguishable distribution area(s) in which each Wobbe Index applies, the effective dates of each Wobbe Index and each change in service with the date of its related customer notification.
- (B) Unless otherwise authorized by the Commission, a Wobbe Index for a distinguishable distribution area that deviates more than 4% from the established Wobbe Index is considered a change in service. A cumulative change of 4% in the Wobbe Index or other service condition over a period of more than three consecutive calendar years may also be considered a change in service.
- (C) A utility shall apply to the Commission when seeking to establish or change a Wobbe Index. The application shall include the proposed Wobbe Index for each distinguishable distribution area and shall use a calculation of the weighted mean Wobbe Index for the gas delivered to the distribution area during a representative historic 12-month period.
(d) Water utilities shall: - (i) Comply with the requirements of DEQ and/or EPA when furnishing any water for human consumption or domestic use;
- (ii) Flush their system periodically, no less than semi-annually, to eliminate or minimize discoloration or other abnormal conditions. Records of the date, place and duration of all flushings shall be retained and used as a guide in determining the necessary frequency of subsequent flushings; and
- (iii) Maintain a pressure gauge at a central point in the distribution system where continuous records shall be made of the pressure observed.