NR 811.64(13)(13) Turnover. Storage facilities shall be designed to facilitate turnover of water in order to prevent freezing and stagnant water conditions. Consideration shall be given to installing separate inlet and outlet pipes, diffusers, baffle walls, adjusting controls to temporarily reduce storage capacities, or other department approved means where necessary.

NR 811.64(14)(14) Internal catwalk. Every catwalk over a storage structure containing finished water or water to become finished water shall have a solid floor with sealed raised edges to prevent shoe scrapings, dirt, and other contaminants from falling into the water.

NR 811.64(15)(a)(a) Metal surfaces shall be protected by paints or other protective coatings. The paints or coatings may be accompanied by cathodic protection devices.

NR 811.64(15)(b)(b) Interior paint and coating systems and application procedures shall be consistent with AWWA standard D102 in effect at the time of application, have ANSI/NSF Standard 61 approval for use in potable water, and be approved by the department in accordance with s. NR 810.09 (5). Paint and coating systems shall be applied, cured, and used in a manner consistent with the ANSI/NSF approval. After curing, the paint or coating shall not transfer any substance to the water that will be toxic or cause taste or odor problems.

NR 811.64(15)(c)(c) Cathodic protection shall be designed and installed by competent technical personnel.

NR 811.64(16)(a)(a) Smooth-end sampling faucet. A smooth-end sampling faucet shall be installed in the connecting main or riser pipes of elevated tanks, standpipes, and reservoirs, if design permits. The sampling faucet shall be installed in accordance with the requirements of s. NR 811.37 (5) (b) 3.

NR 811.64(16)(c)(c) Valve vaults and above grade enclosures. Valve vaults and above grade enclosures installed at the base of storage facilities shall be protected against freezing and provided with floor drainage. Floor drains may be connected to a sanitary sewer, when available, if the floor elevation is at least one foot above the rim elevation of the nearest upstream sanitary sewer manhole. If a sanitary sewer is available but a manhole is not located nearby or the manhole does not comply with the upstream location or the one-foot requirement, the department may require installation of an additional manhole on the sanitary sewer main or on the sanitary building sewer. The facility may discharge to the ground surface by gravity, if possible, or else by a floor sump with a sump pump permanently installed. If constructed outside of the storage facility, the entrance to the vault or enclosure shall be locked to prevent unauthorized access.

NR 811.64(16)(d)(d) Condensate platform drains. Condensate platform drains shall not be directly connected to the overflow piping. The condensate platform drain shall be a minimum 2-inch diameter pipe and shall be brought down to within 12 to 24 inches of the ground surface and discharge downward facing with a free air break over a drainage inlet structure, splash pad, or riprap.

NR 811.64(17)(a)(a) Disinfection required. Water storage structures shall be disinfected before being put into service or before being returned to service following maintenance or repair work to the water storage structure. Detailed procedures for disinfection, equivalent to those outlined in AWWA standard C652 in effect at the time of disinfection, shall be written into the specifications by the design engineer or contractor as applicable.

NR 811.64(17)(b)(b) Bacteriological sampling. Disinfection and bacteriological sampling requirements shall meet the requirements of s. NR 810.09 (4). Detailed procedures for bacteriological sampling shall be written into the specifications by the design engineer or contractor as applicable.

NR 811.64(17)(c)(c) Allowable chlorine in wasted water. The amount of chlorine in any water wasted from a storage structure to the environment shall be assessed to prevent harmful impacts. Dechlorination prior to discharge may be necessary in some cases to prevent harmful impacts. Water wasted to surface water may not contain any substances in concentrations that adversely affect the water as determined under chs. NR 105 and 106. For chlorine, no total residual chlorine may be measured in water being discharged to a surface water.

NR 811.64 NoteNote: A copy of the AWWA standards is available for inspection at the central office of the department of natural resources and may be obtained for personal use from the American Water Works Association, 6666 West Quincy Avenue, Denver, Colorado 80235.

NR 811.64 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; correction in (11) (e), (f) made under s. 13.92 (4) (b) 7., Stats., Register December 2011 No. 672; CR 22-074: am. (1) (a), (3) (a) 2., 3., (4) (a) 1., 3., 5., cr. (4) (a) 6., 7., r. (4) (c) 1., renum. (4) (c) 2. to (4) (c), am. (4) (d) 1., (7) (a), (b), (8) (c), cr. (8) (f) 4., am. (10) (i), r. (16) (b), am. (16) (c), cr. (16) (d) Register January 2024 No. 817, eff. 2-1-24; correction in (4) (a) 6. made under s. 35.17, Stats., Register January 2024 No. 817.

NR 811.65(1)(1) Filter washwater tanks. Filter washwater tanks shall be sized, in conjunction with available pump units and finished water storage, to provide the backwash water required by s. NR 811.49. The design shall address the possibility of having to backwash more than one filter at a time, or several filters in succession.

NR 811.65(2)(a)(a) Clearwell storage shall be sized, in conjunction with distribution system storage, to relieve the filters from the strain of fluctuations in water use or peak demands.

NR 811.65(2)(b)(b) When water storage is used to provide proper contact time for disinfection, documentation, including tracer testing, shall be provided to assure adequate detention time under all operating conditions. The department may require the installation of baffle walls or additional reservoir capacity if necessary to prevent short circuiting and to obtain adequate contact times.

NR 811.65(3)(3) Basins and wet-wells. Receiving basins, pump cans, and pump wet-wells for finished water or water to become finished water shall be designed as finished water storage structures.

NR 811.66(1)(a)(a) Allowable head range. The maximum variation between high and low levels in storage structures which float on a distribution system may not exceed 30 feet during normal usage.

NR 811.66(1)(b)(b) Minimum and maximum pressures. The minimum and maximum pressure in service areas shall be 35 and 100 psi respectively at ground level.

NR 811.66(1)(b)1.1. In areas where a minimum of 35 psi cannot be maintained, a high pressure zone shall be established in the distribution system by means of booster pumps and related facilities or pressure boosting systems on individual service lines as required in subch. XI. The use of individual service line booster pumps shall be limited to the extent possible.