Washington Administrative Code › Title 173 - Ecology, Department of (See also Titles 197, 317, 372, and 508) › Chapter 173-240 - Submission of plans and reports for construction of wastewater facilities › DOMESTIC WASTEWATER FACILITIES › Section 173-240-050 - General sewer plan

Current through Register Vol. 24-14, July 15, 2024
(1)
				All general sewer plans required of any governmental agency before providing
				sewer service are "plans" within the requirements of
				RCW
				   90.48.110. Three copies of the proposed
				general sewer plan and each amendment to it must be submitted to and approved
				by the department before implementing the plan.
(2) The general sewer plan must be
				sufficiently complete so that engineering reports can be developed from it
				without substantial alterations of concept and basic considerations.
(3) The general sewer plan shall include the
				following information together with any other relevant data as requested by the
				department. To satisfy the requirements of the local government jurisdiction,
				additional information may be necessary.
(a)
				The purpose and need for the proposed plan.
(b) A discussion of who will own, operate,
				and maintain the systems.
(c) The
				existing and proposed service boundaries.
(d) Layout map including the following:
(i) Boundaries. The boundary lines of the
				municipality or special district to be sewered, including a vicinity
				map;
(ii) Existing sewers. The
				location, size, slope, capacity, direction of flow of all existing trunk
				sewers, and the boundaries of the areas served by each;
(iii) Proposed sewers. The location, size,
				slope, capacity, direction of flow of all proposed trunk sewers, and the
				boundaries of the areas to be served by each;
(iv) Existing and proposed pump stations and
				force mains. The location of all existing and proposed pumping stations and
				force mains, designated to distinguish between those existing and
				proposed;
(v) Topography and
				elevations. Topography showing pertinent ground elevations and surface drainage
				must be included, as well as proposed and existing streets;
(vi) Streams, lakes, and other bodies of
				water. The location and direction of flow of major streams, the high and low
				elevations of water surfaces at sewer outlets, and controlled overflows, if
				any. All existing and potential discharge locations should be noted;
				and
(vii) Water systems. The
				location of wells or other sources of water supply, water storage reservoirs
				and treatment plants, and water transmission facilities.
(e) The population trend as indicated by
				available records, and the estimated future population for the stated design
				period. Briefly describe the method used to determine future population trends
				and the concurrence of any applicable local or regional planning
				agencies.
(f) Any existing domestic
				or industrial wastewater facilities within twenty miles of the general plan
				area and within the same topographical drainage basin containing the general
				plan area.
(g) A discussion of any
				infiltration and inflow problems and a discussion of actions that will
				alleviate these problems in the future.
(h) A statement regarding provisions for
				treatment and discussion of the adequacy of the treatment.
(i) List of all establishments producing
				industrial wastewater, the quantity of wastewater and periods of production,
				and the character of the industrial wastewater insofar as it may affect the
				sewer system or treatment plant. Consideration must be given to future
				industrial expansion.
(j)
				Discussion of the location of all existing private and public wells, or other
				sources of water supply, and distribution structures as they are related to
				both existing and proposed domestic wastewater treatment facilities.
(k) Discussion of the various alternatives
				evaluated, and a determination of the alternative chosen, if
				applicable.
(l) A discussion,
				including a table, that shows the cost per service in terms of both debt
				service and operation and maintenance costs, of all facilities (existing and
				proposed) during the planning period.
(m) A statement regarding compliance with any
				adopted water quality management plan under the Federal Water Pollution Control
				Act as amended.
(n) A statement
				regarding compliance with the State Environmental Policy Act (SEPA) and the
				National Environmental Policy Act (NEPA), if applicable.