NR 811.62(2) (2) Pressure requirements. Storage facilities shall be designed to meet all the following requirements:

NR 811.62(2)(a) (a) Minimum and maximum pressures. The storage facilities shall be designed to meet the minimum and maximum pressure requirements specified in s. NR 811.66 (1).

NR 811.62(2)(b) (b) Fire flows and residual pressures. When fire protection is to be provided, the storage facilities shall be designed in conjunction with distribution system design to provide the minimum fire flows and residual pressures specified in s. NR 811.70 (6).

NR 811.62(2)(c) (c) Alternative means for maintaining pressure. A hydro-pneumatic tank, booster pumping facilities, or other reliable means shall be provided to maintain system pressure when a gravity storage reservoir or tank is not available.

NR 811.62(3) (3) Elevated storage requirement waived. The department may waive the requirement for elevated storage if the system is designed to serve less than 50 homes, if it is not economically feasible to provide elevated storage, if elevated storage facilities are proposed for a later development phase, or if service is proposed for domestic use only.

NR 811.62 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 811.63 NR 811.63 Location. Storage facilities shall be located in accordance with all the following requirements:

NR 811.63(1) (1) Floodway and floodplain.

NR 811.63(1)(a) (a) Floodway. Storage facilities may not be located within a floodway, as defined in s. NR 116.03 (22).

NR 811.63(1)(b) (b) Floodplain. If it is necessary to locate a reservoir in a floodplain, as defined in s. NR 116.03 (16), outside of the floodway, the lowest elevation of the bottom floor, including sumps, shall be a minimum of 2 feet above the regional flood elevation as determined in s. NR 116.07 (4). All projects shall conform to the requirements of that chapter.

NR 811.63 Note Note: Refer to ch. NR 116 for floodplain and floodway requirements.

NR 811.63(2) (2) Grading. The area surrounding structures shall be graded in a manner that will prevent surface water from standing within 50 feet of the structure.

NR 811.63(3) (3) Year-round access. Storage facilities shall be located in an area accessible during the entire year. If necessary, road improvements shall be installed to provide year-round dry land access. Storage facilities and access roads shall be located on property owned by the water supply owner or for which the owner has obtained easements.

NR 811.63(4) (4) Floor elevations. The department recommends that the lowest elevations of floors and sump floors of ground level reservoirs and standpipes should be placed at or above the normal ground surface. If the department allows the floor or sump to be below the normal ground surface, it shall be placed a minimum of 2 feet above the groundwater table. Borings shall be made to determine groundwater elevations if that information is not available.

NR 811.63(5) (5) Contamination sources.

NR 811.63(5)(a) (a) Sewers, drains, fuel storage tanks, standing water, and similar sources of contamination shall be kept a minimum of 50 feet from the ground storage reservoir.

NR 811.63(5)(b) (b) The department may approve gravity or force main sewers within 50 feet of a ground storage reservoir if the sewer or force main is constructed of water main class pipe meeting the requirements under s. NR 811.69 and is pressure tested in place to meet the requirements under s. NR 811.12 (5) (d) 2.

NR 811.63(6) (6) Roof surface above grade.

NR 811.63(6)(a) (a) The top roof surface of a ground level reservoir may not be less than 2 feet above normal ground surface.

NR 811.63(6)(b) (b) The department shall require a higher exposed elevation if high groundwater, poor surface drainage, or tight soils are encountered that will deter subsurface drainage or if necessary to provide positive pressures for pump intake or discharge lines in accordance with s. NR 811.37.

NR 811.63 Note Note: It is recommended that no more than one-half of the reservoir depth be constructed below grade.

NR 811.63(6)(c) (c) The department may except clearwells constructed under filters from the 2 foot requirement when the total design gives the same protection.

NR 811.63 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 22-074: am. (5) Register January 2024 No. 817, eff. 2-1-24.

NR 811.64 NR 811.64 Construction details.

NR 811.64(1) (1) Materials. Materials used in the construction of storage facilities shall meet all the following requirements:

NR 811.64(1)(a) (a) General requirements. The materials and designs used for finished water storage structures shall provide stability and durability as well as protect the quality of the stored water. Unless the design engineer can justify the use of other materials, the department shall approve only steel, fiberglass, or concrete for use in a water storage facility. Porous materials, including wood and concrete block, may not be used.

NR 811.64(1)(b) (b) AWWA standards. Structures shall be constructed in accordance with the AWWA standards D100, D102, D103, D104, D110, D115, D120, and D130 concerning steel; concrete or fiberglass tanks, standpipes, reservoirs, and elevated tanks in effect at the time of construction wherever they are applicable.

NR 811.64(2) (2) Protection. Storage facilities shall be constructed and maintained to protect the water supply in accordance with the following requirements:

NR 811.64(2)(a) (a) General requirements. All water storage structures shall have watertight roofs or covers which exclude surface water, rain, snow, birds, animals, insects and dust.