The water pollution control and abatement plan shall include but not be limited to:

(1) Introduction (includes statement of purpose and intent, acknowledgments, summary of findings, and base map).

(2) Basis for planning

(a) Physical environment

(i) Topography - General description

(ii) Soil and drainage characteristics - Adequate interpretation of soil types and surface grades to determine suitability for septic tank filter fields

(iii) Hydrology - A brief summary of stream discharge records to include maximum, mean and minimum annual flows and 7-day 10-year low-flow; areas where low-flow establishment is needed; where applicable, a brief summary of information pertaining to the water table and flood plains (100 year floods)

(iv) Water quality - A brief summary of available water quality data; classification by interstate and intrastate water quality standards

(v) This section is to include maps of topography, soil and drainage characteristics, flood plains, watercourse classification and water quality problem areas, and location of sampling stations for quantity and quality.

(b) Social and economic growth

(i) Economy - To include a brief summary of commerce and industrial development

(ii) Population - To include trends, projections, and population densities based on census tracts or their equivalent for each planning level

(iii) Land use and zoning - Based on (i) and (ii) above summarize existing and projected zoning and land use for each planning level

(iv) This section is to include maps of present and future land use and population densities

(3) Inventory of existing facilities and sources and characteristics of wastes

(a) Collection systems - To include the delineation of service areas, operating authorities, the general location and capacities of interceptors, adequacy of facilities, population served, industries served, major commercial complexes served, and combined storm-sanitary sewers; also to include the numbers and general locations of individual waste disposal facilities.

(b) Treatment facilities - To include, for municipal treatment plants and industrial wastewater discharges, locations of treatment facilities, volumes and characteristics of wastes treated, degree of treatment, and adequacy of facilities; also for municipal treatment facilities the operating authority should be specified.

(c) Other water quality considerations - To include discussion and location of other water quality effect sources including but not limited to:

(i) Municipal wastes

(ii) Industrial wastes

(iii) Individual sanitary discharges

(iv) Storm runoff

(v) Soil erosion and land development runoff

(vi) Agricultural waste water, including irrigation return flow and animal feedlot wastes

(vii) Wastes from vessels and marinas

(viii) River impoundments

(ix) Log storage, including cold decking and rafting

(x) Dredging and dredging spoils

(xi) Solid waste disposal runoff and seepage water

(d) This section to include maps showing the general location of service areas and interceptors, municipal and industrial treatment facilities, and "other" water quality problem areas.

(4) Present and future water pollution control needs

(a) Collection systems - To include specification of immediate needs and, for each future planning level, delineation of service areas, operating authorities, general location and capacities of interceptors, population, industries, and major commercial complexes served, combined storm-sanitary sewers to be replaced by separate sewers, approximate number of connections, and percent of homes within the service area to be served.

(b) Treatment plants - To include specification of immediate needs, and for each future planning level, general location of treatment facilities, volumes and characteristics of wastes treated, and degree of treatment for municipal and industrial wastewater discharges; also for municipal treatment facilities the operating authority should be specified.

(c) Other water quality considerations - To include means of alleviating other water quality problems which now exist and to prevent such deleterious effects in the future.

(d) Recommended legal considerations - List and explain policy statements, ordinances, and legislation to prevent future water quality deterioration.

(e) This section is to include maps showing future service areas, general locations and capacities of interceptors and municipal and industrial treatment plants, and "other" water quality problem areas.

(5) Plan considerations

(a) Collection systems and treatment plants - To include factors not included in the previous section which would affect the logical and orderly implementation of the plan. Such factors should include interim and alternate measures and the criteria to govern the extension of sewer lines.

(b) Other water quality considerations - To include consideration of other phases of environmental quality such as water supply, solid wastes management, and air pollution as they might be affected by the water pollution control and abatement plan.

(6) Capital improvements program

(a) Approximate construction schedule - To include scheduling of immediate need items including those listed in the implementation and enforcement plans for interstate and intrastate waters and for ten years beyond the plan completion date.

(b) Cost estimates and financing - To include general construction costs of the various elements of the plan and a brief evaluation of the sewer service charges and financial considerations necessary to finance needed construction.

(7) Format and updating

(a) This outline is not necessarily meant to be used as a pattern for the plan format. Provisions to review this plan every five years or more often as development warrants and to update as necessary will be included.

(b) Ecology will designate, prior to August 1, 1970, which state, regional and/or federal documents should be used as references in forecasting social and economic trends. Such documents will include, but not be limited to, resource development, land use proposals, demographic data, industrial growth, and financial forecast documents.