Idaho Administrative Code
Title IDAPA 58 - Environmental Quality, Department of
Rule 58.01.08 - IDAHO RULES FOR PUBLIC DRINKING WATER SYSTEMS
Section 58.01.08.503 - FACILITY AND DESIGN STANDARDS: PRELIMINARY ENGINEERING REPORTS

Universal Citation: ID Admin Code 58.01.08.503

Current through August 31, 2023

See the definition of Preliminary Engineering Report in Section 003. Preliminary engineering reports are required for all new water systems or material modifications to existing water systems that require plan and specification review and approval pursuant to Subsection 504.03. The preliminary engineering report shall be in conformance with the approved facility plan or shall describe any modifications to the facility plan. Preliminary engineering reports must be completed for all major water system projects including, but not limited to, source, pump station, pressure control, storage, and treatment projects. Preliminary engineering reports are not required for simple water main extensions that are approved in accordance with Subsections 502.01.a. or 502.01.b. (3-24-22)

01. Submittal to Reviewing Authority. Preliminary engineering reports shall be submitted to the Department for review and must be approved by the Department prior to the submission of plans and specifications. The Department may allow well construction plans and specifications to be submitted concurrently with a preliminary engineering report for these projects. (3-24-22)

02. Seal Required. Preliminary engineering reports submitted to the Department shall bear the imprint of an Idaho licensed professional engineer's seal that is both signed and dated by the engineer. The Department will accept the seal and signature of an Idaho licensed professional geologist on preliminary reports for well source, spring source, or infiltration gallery site reports, and for well construction. (3-24-22)

03. Preliminary Engineering Report Contents. The preliminary engineering report must include sufficient detail to demonstrate that the proposed project meets applicable criteria. The items included in Subsections 503.03.a. through 503.03.e., and all applicable issues and items specifically required in Sections 500 through 552, shall be addressed in detail. As required, a preliminary engineering report shall also identify and evaluate drinking water related problems, assemble basic information, present criteria and assumptions, examine alternative solutions with preliminary layouts and cost estimates, offer a conclusion with a proposed project, and outline official actions and procedures to implement the project. If specific items in Subsections 503.03.a. through 503.03.e. are not applicable to a particular design, then the designer shall state this in the preliminary engineering report and state the reason why it is not applicable. Items adequately addressed in the facility plan under which the project is being designed may be addressed by reference for purposes of the preliminary engineering report. (3-24-22)

a. All preliminary engineering reports shall include items in Subsection 503.03.a. and the applicable items from Subsections 503.03.b. through 503.03.e. (3-24-22)
i. General information. The preliminary engineering report general information shall include, but is not limited to: (3-24-22)
(1) Project description. A detailed description of the proposed project; (3-24-22)

(2) Site selection. A general description of the location of the project and justification of the site selection; (3-24-22)

(3) Access and utilities. A general discussion of adequacy of local roadways and availability of power or other utilities; (3-24-22)

(4) Surrounding land use. A general discussion of surrounding land use, including any potential sources of contamination; and (3-24-22)

(5) Security. A general discussion of planned security features such as fencing, lighting, alarm systems, etc. (3-24-22)

ii. Coordination with facility plan. The preliminary engineering report shall discuss or reference items provided in the Department-approved facility plan. These items include, but are not limited to: (3-24-22)
(1) Existing System. A general description of the existing system and how the project fits into the overall system and facility plan; (3-24-22)

(2) Size. The estimated system size based on number of persons, number of connections, or number of EDUs served or impacted by the project; (3-24-22)

(3) Water Quantity. Design data for domestic, irrigation, fire fighting, commercial and industrial water uses, including peak hour, maximum day, and average day demands; (3-24-22)

(4) Storage. How the project will affect various storage requirements. See definition of Components of Finished Water Storage in Section 003; (3-24-22)

(5) Operating Pressure. Pressure ranges for all flow conditions prescribed by these rules; (3-24-22)

(6) Hydraulic Analysis. A computer analysis of the hydraulics of the distribution system if requested by the Department; any analysis of an existing distribution system shall be properly calibrated. The type and sophistication of analysis shall be dependent on the type of system; (3-24-22)

(7) Sources of Water. A general discussion of the adequacy, quality and availability of source of water. A water system that is to be served by a separate non-potable irrigation system must provide documentation to demonstrate the actual availability of water in sufficient quantity to ensure that the irrigation system will not compete with or in any way diminish the source of water for the potable water system; (3-24-22)

(8) Sewage. Describe the sewage collection system and sewage treatment works, with special reference to their relationship to existing or proposed water works structures which may affect the operation of the water supply system, or which may affect the quality of the supply; (3-24-22)

(9) Treatment wastes. Assesses and characterize all anticipated waste discharges generated by the project and any activities that could impact the water supply. The location of each waste handling area or discharge point shall be shown on a scale map; (3-24-22)

(10) Financing methods. Provide brief discussion of financing options investigated or planned; and (3-24-22)

(11) Flooding. Discuss mechanisms for protection of the system from flooding. (3-24-22)

iii. Code provisions. The preliminary engineering report shall include a summary of applicable codes and standards that apply to the proposed project. (3-24-22)

iv. Cost estimate. The preliminary engineering report shall provide, as applicable, estimated construction costs for public works projects or projects funded through public monies. (3-24-22)

v. Construction schedule. The preliminary engineering report shall include the proposed construction schedule. (3-24-22)

vi. Potential sources of contamination. Identify sources of contamination and describe how the drinking water sources will be protected. (3-24-22)

vii. Soils and ground water levels. Generally discuss soil, ground water conditions, and potential building foundation problems, including a description of: (3-24-22)
(1) The character of the soil through which water mains are to be laid; (3-24-22)

(2) Characteristics of the soil, water table, and geological substrate that may affect the design and construction of the foundations of proposed structures; and (3-24-22)

(3) The approximate elevation of ground water in relation to subsurface structures. (3-24-22)

b. Drinking water wells and spring construction projects. In addition to items listed in Subsection 503.03.a., a preliminary engineering report for source water construction projects shall include all items listed in Subsection 503.03.b., applicable items in Sections 510 through 514, and Sections 500 to 552 should be evaluated for their relevance to the project. (3-24-22)
i. Anticipated geology and hydrogeology. Include geological data and existing well logs. (3-24-22)

ii. Drilling methodology. Describe the anticipated drilling method and well construction. (3-24-22)

iii. Water quality. Anticipated potability and water quality including monitoring results required for new sources by these rules. (3-24-22)

iv. Water rights. Provide the appropriate documentation for the water rights for the drinking water source. (3-24-22)

v. Dimensions of the well lot and location of source. Include geographical coordinates of the source location. (3-24-22)

vi. Evaluation of surface water influence. For all new ground water sources, including but not limited to wells, springs, and infiltration galleries, systems shall supply information as required by the Department to determine if these sources are under the direct influence of surface water. (3-24-22)

vii. Provide a site evaluation report as required by Section 510 for wells and 514 for springs. (3-24-22)

c. Well and pump house construction projects. In addition to items listed in Subsection 503.03.a., preliminary engineering reports for well and pump house construction projects shall include all items listed in Subsection 503.03.c., applicable items in Sections 511, 541, 547, and Sections 500 to 552 should be evaluated for their relevance to the project. (3-24-22)
i. Well house. Include information on the anticipated construction and well house equipment such as heating, ventilation, interior lighting, and drain(s). (3-24-22)

ii. Water Level. Provide a brief description of the means for measuring the water level in the well. (3-24-22)

iii. Well pump. Include information on the proposed or planned pump, including the pump curve. (3-24-22)

iv. Controls. Describe the equipment and controls for the well and pump house. This includes but is not limited to system control and data acquisition, variable frequency drive, and other manual or automated controls within the well house. (3-24-22)

v. Piping and appurtenances including but not limited to sample taps, discharge piping, flow meters, check valves, and pressure gauges. Describe the receiving system for the pump to waste volume of water including an evaluation of the capacity of the receiving system and, if applicable, provide documentation that the system owner will accept the estimated volume of water and any limitations the owner places upon that acceptance. (3-24-22)

vi. Well vent. Describe the well vent if applicable. (3-24-22)

vii. Casings and well caps. Describe the anticipated casing and well cap type and materials. (3-24-22)

viii. Pitless adapters and units. Describe the anticipated pitless adapter for the well. (3-24-22)

ix. Soil and water conditions. Describe the soil and ground water conditions that may affect the design and construction of proposed structure(s). (3-24-22)

d. Reservoir and storage construction projects. In addition to items listed in Subsection 503.03.a., preliminary engineering reports for reservoir and storage construction projects shall include all items listed in Subsection 503.03.d., applicable items in Sections 544, and Sections 500 to 552 should be evaluated for their relevance to the project. (3-24-22)
i. Sizing. Describe the required storage capacity and the related components of finished water storage. (3-24-22)

ii. Overflow. Describe the anticipated overflow system for the water storage project and where the overflow will discharge. (3-24-22)

iii. Vents. Describe the venting system used for the water storage project if applicable. (3-24-22)

iv. Construction materials. Describe the construction materials used for the storage project. (3-24-22)

v. Protection from freezing. Describe the protection of storage facility features from freezing especially riser pipes, overflows, and vents. (3-24-22)

vi. Grading. Describe any site work or grading that may be necessary. (3-24-22)

vii. Corrosion prevention. Provide a discussion on methods to prevent corrosion such as coatings, cathodic protection, corrosion resistant materials, and encasement. (3-24-22)

viii. Disinfection. Describe the methods to be used to disinfect the storage facility and the testing to check for proper disinfection. (3-24-22)

e. Surface water and ground water under the direct influence of surface water (GWUDI) treatment construction projects. In addition to items listed in Subsection 503.03.a., preliminary engineering reports for surface water treatment and GWUDI construction projects shall include all items listed in Sections 503.03.e., applicable items in Sections 515 through 540, and Sections 500 to 552 should be evaluated for their relevance to the project. (3-24-22)
i. Intake structures. Describe the intake structures that will be used. (3-24-22)

ii. Off-stream raw water storage. If applicable, describe the proposed off-stream raw water storage. (3-24-22)

iii. Treatment methods. Describe the treatment methods and potential alternatives including the removal of pathogens, disinfection, enhanced disinfection, water quality monitoring, and redundancy provisions. (3-24-22)

iv. Treatment Wastes. Characterize the various wastes from the water treatment processes and, if applicable, their volumes, constituents, and proposed treatment and disposal. If discharging to a sanitary sewage system, verify that the system is capable of handling the flow to the treatment works and that the treatment works is capable and willing to accept the additional loading. (3-24-22)

v. Monitoring Results. Provide applicable raw water monitoring results as required by these rules including anticipated turbidity ranges, microbiological, physical, chemical, radiological, and other parameters as determined by the Department. (3-24-22)

vi. Potential contamination. An assessment of the degree of hazard to the supply by agricultural, industrial, recreational, and residential activities in the watershed, and by accidental spillage of materials that may be toxic, harmful or detrimental to treatment processes. (3-24-22)

vii. Waste discharge. Assess all waste discharges and activities that could impact the water supply. The location of each waste discharge shall be shown on a scale map. (3-24-22)

viii. Hydrological and historical stream flow data. Provide any available records and data. (3-24-22)

ix. Water rights and water quantity. A copy of the appropriate permit(s) or application(s) from the Idaho Department of Water Resources regarding authorization to appropriate public waters of the state of Idaho in sufficient quantity to meet the design requirements of the system. (3-24-22)

x. Turbidity. Anticipated turbidity range. (3-24-22)

xi. Watershed. Assessment of the degree of control the water system will be able to exercise over the watershed. (3-24-22)

xii. Projected future uses of impoundments or reservoirs within the watershed. (3-24-22)

xiii. Water quality. Submit source water sample data over a sufficient period of time to assess the microbiological, physical, chemical and radiological characteristics of the water. (3-24-22)

xiv. Stream characteristics. Provide consideration of currents, wind and ice conditions, and the effect of confluent streams. (3-24-22)

Disclaimer: These regulations may not be the most recent version. Idaho may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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