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 173-240-060 - Engineering report

Current through Register Vol. 24-14, July 15, 2024
(1) The
				engineering report for a domestic wastewater facility shall include each
				appropriate (as determined by the department) item required in WAC
				173-240-050 for general sewer
				plans unless an up-to-date general sewer plan is on file with the department.
				Normally, an engineering report is not required for sewer line extensions or
				pump stations. See WAC
				173-240-020(13) and 173-240-030(5).
				The facility plan described in federal rule  40 C.F.R. 35  is an "engineering
				report."
(2) The engineering report
				must be sufficiently complete so that plans and specifications can be developed
				from it without substantial changes. Three copies of the report must be
				submitted to the department for approval, except as waived under WAC
				173-240-030(5).
(3) The engineering report shall include the
				following information together with any other relevant data as requested by the
				department:
(a) The name, address, and
				telephone number of the owner of the proposed facilities, and the owner's
				authorized representative.
(b) A
				project description that includes a location map and a map of the present and
				proposed service area.
(c) A
				statement of the present and expected future quantity and quality of
				wastewater, including any industrial wastes that may be present or expected in
				the sewer system.
(d) The degree of
				treatment required based upon applicable permits and rules, the receiving body
				of water, the amount and strength of wastewater to be treated, and other
				influencing factors.
(e) A
				description of the receiving water, applicable water quality standards, and how
				water quality standards will be met outside any applicable dilution
				zone.
(f) The type of treatment
				process proposed, based upon the character of the wastewater to be handled, the
				method of disposal, the degree of treatment required, and a discussion of the
				alternatives evaluated and the reasons they are unacceptable.
(g) The basic design data and sizing
				calculations of each unit of the treatment works. Expected efficiencies of each
				unit and also of the entire plant, and character of effluent
				anticipated.
(h) Discussion of the
				various sites available and the advantages and disadvantages of the site or
				sites recommended. The proximity of residences or developed areas to any
				treatment works. The relationship of the twenty-five-year and one hundred-year
				flood to the treatment plant site and the various plant units.
(i) A flow diagram that shows general layout
				of the various units, the location of the effluent discharge, and a hydraulic
				profile of the system that is the subject of the engineering report and any
				hydraulically related portions.
(j)
				A discussion of infiltration and inflow problems, overflows and bypasses, and
				proposed corrections and controls.
(k) A discussion of any special provisions
				for treating industrial wastes, including any pretreatment requirements for
				significant industrial sources.
(l)
				Detailed outfall analysis or other disposal method selected.
(m) A discussion of the method of final
				sludge disposal and any alternatives considered.
(n) Provision for future needs.
(o) Staffing and testing requirements for the
				facilities.
(p) An estimate of the
				costs and expenses of the proposed facilities and the method of assessing costs
				and expenses. The total amount shall include both capital costs and also
				operation and maintenance costs for the life of the project, and must be
				presented in terms of total annual cost and present worth.
(q) A statement regarding compliance with any
				applicable state or local water quality management plan or any plan adopted
				under the Federal Water Pollution Control Act as amended.
(r) A statement regarding compliance with the
				State Environmental Policy Act (SEPA) and the National Environmental Policy Act
				(NEPA), if applicable.