Section 246-271-170. Appendix—Engineering report—Sewage treatment works.

The engineering report for the sewage treatment works shall include the following items together with any other relevant data -

(1) The purpose and need for the proposed project.

(2) The nature and extent of the area included in the present system and the area and extent to which plans provide sewage works for future development. If the area to be served by existing and proposed sewers does not include the entire municipality, sewer district, or natural drainage area, give a brief description of that portion not included, together with information as to the probability of future development, and the method by which this area can be served by treatment works.

(3) The population trend as indicated by available records, and give the estimated future population for the design period. Describe briefly the method used to determine future population trends.

(4) Any existing sewage treatment works as they are related to the proposed project.

(5) Discuss the location of water supply and distribution structures as they relate to the various portions of the proposed sewage works.

(6) The considerations given to possibility of garbage disposal in sewage works.

(7) List of all establishments producing appreciable quantities of industrial wastes and the quantity, production periods, and character of industrial wastes in so far as they may affect the sewerage system or sewage treatment works. Consideration shall be given to future industrial expansion.

(8) The degree of treatment proposed based upon the size, usage and character of the receiving body of water and upon the amount and strength of sewage or waste to be treated and other influencing factors.

(9) The type or types of treatment process proposed based upon the character of sewage or waste to be handled and the degree of treatment required.

(10) Data on the volume and strength of sewage and the design data regarding flow and strength.

(11) The ratio of interception in connection with existing combined sewers, and the quantity expected to be bypassed during storms.

(12) The basic design data of each unit of the treatment works.

(13) Provision for future needs.

(14) Discussion of the various sites available and the advantages of the one recommended. The proximity of residences or developed areas to any treatment works. The relationship of maximum high water to the plant site and various plant units.

(15) Expected efficiencies of each unit and the entire plant, and the character of effluent expected.

(16) A flow diagram showing general layout of various units.

[Statutory Authority: RCW 43.20.050. WSR 91-02-051 (Order 124B), recodified as § 246-271-170, filed 12/27/90, effective 1/31/91; Public Sewage Appendix, effective 3/11/60.]

RCW 43.20.050. WSR 91-02-051 (Order 124B), recodified as § 246-271-170, filed 12/27/90, effective 1/31/91; Public Sewage Appendix, effective 3/11/60.