NR 811.39(4)(4) Control. Chemical feeders shall be controlled in accordance with the following requirements: NR 811.39(4)(a)(a) Feeders may be manually or automatically controlled if the water supply pumps are manually controlled. Where pumps are automatically controlled, the feeders shall be automatically controlled. In all cases, automatic control shall be capable of reverting to manual control when necessary. NR 811.39(4)(b)(b) The operation of the chemical feed pumps shall be interlocked with the operation of the appropriate well or service pump. Any controlled electrical outlet used for any chemical feed pump shall be clearly marked. NR 811.39(4)(c)(c) Secondary control of chemical feed equipment shall be provided for fluoride chemical feed equipment in accordance with s. NR 811.51 (4) or when required by the department. NR 811.39(4)(d)(d) Feeders shall be designed and controlled to provide chemical feed rates proportional to flow and for variable flow rates shall be paced by a water meter. NR 811.39(4)(e)(e) Automatic chemical feed rate control in combination with residual analyzers which have alarms for critical values and SCADA system reporting or recording charts may be used. NR 811.39(5)(5) Solution tanks. The requirements for solution tanks, in s. NR 811.40 on storage and handling apply. NR 811.39(6)(6) Chemical use measurement. The determination of chemical usage when using chemical feeders shall meet all of the following requirements: NR 811.39(6)(a)(a) Weighing scales shall be provided for weighing cylinders at all plants utilizing chlorine gas. NR 811.39 NoteNote: It is recommended that indicating and recording type scales be used.
NR 811.39(6)(b)(b) Weighing scales are required for liquid solution feed unless comparable means for determining usage is approved by the department. NR 811.39(6)(c)(c) Weighing scales are required for volumetric dry chemical feeders. NR 811.39(6)(d)(d) Weighing scales shall be accurate enough to measure increments of 0.5 percent of load. NR 811.39(6)(e)(e) Graduated lines on chemical tanks shall be displayed in units of volume and be in maximum increments of 3 percent of tank capacity. NR 811.39(6)(f)(f) Radar and sonic level sensors that are programmed to display in pounds of chemical and that are accurate enough to measure increments of 0.5 percent of load may be used to determine chemical use. NR 811.39(7)(7) Feed lines. Feed lines shall meet the following requirements: NR 811.39(7)(a)(a) Be as short as possible in length of run, of durable, corrosion resistant material, easily accessible throughout the entire length, protected against freezing, and readily cleanable. NR 811.39(7)(b)(b) Slope upward from chemical source to feeder when conveying gases. NR 811.39(7)(c)(c) Introduce corrosive chemicals in a manner to minimize potential for corrosion. NR 811.39(7)(d)(d) Be designed consistent with scale-forming or solids-depositing properties of the water, chemical, solution, or mixture conveyed. NR 811.39(7)(e)(e) Not carry chlorine gas under pressure beyond the chlorine feeder room. NR 811.39(7)(f)(f) Include injection taps constructed of metal or SCH 80 PVC components and check valves. Removable injection quills shall be provided when application is into a pipe of adequate diameter. Injection quills installed in a horizontal section of pipe shall be installed up into the bottom half of the pipe. NR 811.39(8)(8) Service and carrier water supply. Water used for dissolving dry chemicals, diluting liquid chemicals, operating chemical feeders or as carrier water to deliver chemicals to injection locations shall be from a safe, approved source with appropriate backflow prevention provided. The department may grant an exception in cases where the finished water quality will not be affected by addition of the chemical mixed with untreated water. NR 811.39 HistoryHistory: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10; CR 22-074: am. (2) (e) (intro.), r. (2) (e) 2., renum. (2) (e) 3. to (2) (e) 3. (intro.) and am., cr. (2) (e) 3. a. to e., am. (2) (f) 1., (3) (d), r. and recr. (6) (intro.), am. (6) (a) to (d), cr. (6) (e), (f), am. (7) (f) Register January 2024 No. 187, eff. 2-1-24. NR 811.40NR 811.40 Storage and handling. Specific requirements regarding storage and handling are provided in the sections covering the particular chemical. Storage and handling installations shall meet the following general requirements: NR 811.40(1)(1) Storage facilities. Storage facilities shall meet the following requirements: