Section 58.01.08.503 - PRELIMINARY ENGINEERING REPORTSSee the definition of Preliminary Engineering Report (PER) in Section 003. PERs are required for all new PWSs or material modifications to existing PWSs that require plan and specification review and approval pursuant to Subsection 504.03. The PER must be in conformance with the approved facility plan or must describe any modifications to the facility plan.PERs must be completed for all major PWS projects including, but not limited to, source, pump station, pressure control, storage, and treatment projects. PERs are not required for simple water main extensions that are approved in accordance with Subsections 502.01.a. or 502.01.b.
01.Submittal to Reviewing Authority. PERs must be submitted to the Department for review and approval prior to the submission of plans and specifications. The Department may allow well construction plans and specifications to be submitted concurrently with a PER for these projects.02.Seal Required. PERs submitted to the Department must 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 for well source, spring source, or infiltration gallery site reports, and for well construction.03.PER Contents. The PER 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, must be addressed in detail or justification must be provided for any proposed deviations where specifically allowed. As required, a PER must 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 must state this in the PER 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 PER.a. All PERs must include items in Subsection 503.03.a. and the applicable items from Subsections 503.03.b. through 503.03.e.i. The general information must include, but is not limited to: (1) A detailed description of the proposed project;(2) A general description of the location of the project and justification of the site selection;(3) A general discussion of adequacy of local roadways and availability of power or other utilities;(4) A general discussion of surrounding land use, including any potential sources of contamination; and(5) A general discussion of planned security features such as fencing, lighting, alarm systems, etc.ii. The PER must discuss or reference items provided in the Department-approved facility plan. These items include, but are not limited to: (1) A general description of the existing PWS and how the project fits into the overall system and facility plan;(2) The estimated PWS size based on number of persons, number of connections, or number of EDUs served or impacted by the project;(3) Design data for domestic, irrigation, fire fighting, commercial and industrial water uses, including peak hour, maximum day, and average day demands;(4) How the project will affect various storage requirements. See definition of Components of Finished Water Storage in Section 003; (5) Pressure ranges for all flow conditions prescribed by these rules;(6) A computer model of the hydraulics of the distribution system based on flow demands and pressure requirements is required unless otherwise approved by the Department; any hydraulic model of an existing distribution system must be properly calibrated. The type and sophistication of hydraulic model will be dependent on the type of PWS;(7) A general discussion of the adequacy, quality and availability of source of water. A PWS 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;(8) Describe the wastewater collection system and wastewater 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;(9) Assesses and characterize all anticipated treatment waste discharges generated by the project and any activities that may impact the water supply. The location of each waste handling area or discharge point must be shown on a scale map;(10) Provide brief discussion of financing options investigated or planned; and(11) Discuss mechanisms for protection of the PWS from flooding.iii. Include a summary of applicable codes and standards that apply to the proposed project.iv. Provide, as applicable, estimated construction costs for public works projects or projects funded through public monies.v. Include the proposed construction schedule.vi. Identify sources of contamination and describe how the drinking water sources will be protected.vii. Generally discuss soil, groundwater conditions, and potential building foundation problems, including a description of:(1) The character of the soil through which water mains are to be laid;(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) The approximate elevation of groundwater in relation to subsurface structures.b. In addition to items listed in Subsection 503.03.a., a PER for source water construction projects using wells or springs must include all items listed in Subsection 503.03.b., applicable items in Sections 510 through 514, and Sections 500 to 552 are to be evaluated for their relevance to the project.i. Include geological data and existing well logs.ii. Describe the anticipated drilling method and well construction.iii. Anticipated potability and water quality including monitoring results required for new sources by these rules.iv. Provide the appropriate documentation for the water rights for the drinking water source.v. Dimensions of the well lot and location of source. Include geographical coordinates of the source location.vi. For all new groundwater sources, including but not limited to wells, springs, and infiltration galleries, PWSs must supply information as required by the Department for the Department to determine if these sources are under the direct influence of surface water. The determination of direct influence may be based on site-specific measurements of water quality, documentation of well construction characteristics and geology with field evaluation, a combination of water quality and documentation, or other information required by the Department.vii. Provide a site evaluation report as required by Section 510 for wells and 514 for springs.c. In addition to items listed in Subsection 503.03.a., PERs for well and pump house construction projects must include all items listed in Subsection 503.03.c., applicable items in Sections 511, 541, 547, and Sections 500 to 552 are to be evaluated for their relevance to the project. i. Include information on the anticipated construction and well house equipment such as heating, ventilation, interior lighting, and drain(s).ii. Provide a brief description of the means for measuring the water level in the well.iii. Include information on the proposed or planned pump, including the pump curve.iv. 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.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.vi. Describe the well vent if applicable.vii. Describe the anticipated casing and well cap type and materials.viii. Describe the anticipated pitless adapter for the well.ix. Describe the soil and groundwater conditions that may affect the design and construction of proposed structure(s).d. In addition to items listed in Subsection 503.03.a., PERs for reservoir and storage construction projects must include all items listed in Subsection 503.03.d., applicable items in Sections 544, and Sections 500 to 552 are to be evaluated for their relevance to the project. i. Describe the required storage capacity and the related components of finished water storage.ii. Describe the anticipated overflow system for the water storage project and where the overflow will discharge.iii. Describe the venting system used for the water storage project if applicable.iv. Describe the construction materials used for the storage project.v. Describe the protection of storage facility features from freezing especially riser pipes, overflows, and vents.vi. Describe any site work or grading that may be necessary.vii. Provide a discussion on methods to prevent corrosion such as coatings, cathodic protection, corrosion resistant materials, and encasement.viii. Describe the methods to be used to disinfect the storage facility and the testing to check for proper disinfection.e. Surface water and groundwater under the direct influence of surface water (GWUDI) treatment construction projects. In addition to items listed in Subsection 503.03.a., PERs for surface water treatment and GWUDI construction projects must include all items listed in Sections 503.03.e., applicable items in Sections 515 through 540, and Sections 500 to 552 are to be evaluated for their relevance to the project.i. Describe the intake structures that will be used.ii. If applicable, describe the proposed off-stream raw water storage.iii. Describe the treatment methods and potential alternatives including the removal of pathogens, disinfection, enhanced disinfection, water quality monitoring, and redundancy provisions.iv. 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.v. 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.vi. 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.vii. Assess all waste discharges and activities that may impact the water supply. The location of each waste discharge must be shown on a scale map.viii. Provide any available records and data regarding hydrological and historical stream flow.ix. 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 PWS.x. Anticipated turbidity range.xi. Assessment of the degree of control the PWS will be able to exercise over the watershed.xii. Projected future uses of impoundments or reservoirs within the watershed.xiii. Submit source water sample data over a sufficient period of time to assess the microbiological, physical, chemical and radiological characteristics of the water.xiv. Provide consideration of currents, wind and ice conditions, and the effect of confluent streams.Idaho Admin. Code r. 58.01.08.503