NR 811.39(2)(i)2.2. Provide effective dissolving and mixing of the chemical in the solution pot and provide gravity feed from solution pots, if possible.

NR 811.39(2)(j)(j) Direct sewer connections prohibited. No direct connection shall be made between any sanitary or storm sewer and a drain or overflow from any feeder or solution chamber or tank.

NR 811.39(3)(a)(a) Be located near points of application to minimize length of feed lines.

NR 811.39(3)(b)(b) Be readily accessible for servicing or repair and observation of operation.

NR 811.39(3)(c)(c) Be located and have protective containment curbs so that chemicals from equipment failure, spillage, or accidental drainage may not enter the water in conduits, treatment, or storage basins.

NR 811.39(3)(d)(d) Be located within a containment basin capable of receiving accidental spills, drainage, or overflows without an uncontrolled discharge outside of the containment basin. At minimum, the containment basin shall be sized to contain the volume of the largest tank that could fail. Chemical containment basins shall not be provided with floor drains. Trapped and vented floor drains discharging to sanitary sewers, holding tanks, or the ground surface in accordance with s. NR 811.25 (1) (h) may be installed for chemical rooms outside of containment basins. Chemical feed pumps shall be located within the containment basin. Piping shall be designed to minimize or contain chemical spills in the event of pipe ruptures.

NR 811.39(3)(e)(e) Be located above grade, except if this requirement is waived by the department.

NR 811.39(3)(f)(f) Be located in accordance with s. NR 811.48 (5) if gas chlorine feeders are used.

NR 811.39(3)(g)(g) Be located in accordance with s. NR 811.51 (2) if fluorosilicic acid is used.

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(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(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.