NR 811.39(2)(f)3.a.
a. A suitable air gap shall be provided which is at a higher elevation than the chemical solution tank.
NR 811.39(2)(f)3.b.
b. A dual head feeder with a small break tank located higher than the chemical solution tank shall be provided.
NR 811.39(2)(f)3.c.
c. A chemical feed pump discharging without any air gap or break box may be approved by the department on a case-by-case basis if the installation is provided with a spring opposed diaphragm type anti-siphon and back pressure valve device. The back pressure valve shall be installed as close as possible to the point of chemical addition. The spring opposed diaphragm type anti-siphon and back pressure valve device shall be installed in accordance with the requirements of par.
(e) 1. NR 811.39(2)(g)
(g) Makeup water lines. The makeup water supply lines to chemical feed tanks shall be protected from contamination by chemical solutions either by equipping the supply line with backflow or backsiphonage prevention devices, or by providing an air gap between the supply line and the top of the solution tank.
NR 811.39(2)(h)
(h) Chemical resistance. Materials and surfaces coming in contact with chemicals shall be resistant to the aggressiveness of the chemical solution.
NR 811.39(2)(i)
(i) Dry chemical feeders. Dry chemical feeders shall meet the following requirements:
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)(i)3.
3. Completely enclose chemicals to prevent emission of dust to the operating room.
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)
(3)
Location. Chemical feed equipment shall meet the following requirements:
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(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 Note
Note: 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 History
History: 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 811.40
NR 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:
NR 811.40(1)(a)
(a) Space shall be provided for at least 30 days of chemical supply, convenient and efficient handling, dry storage conditions, and a minimum of 1.5 truck loads storage volume where purchase is by truck load.
NR 811.40(1)(b)
(b) Covered or unopened shipping containers shall be provided for storage unless the chemical is transferred into an approved covered storage unit. Solution tanks shall have overlapping or threaded covers that provide sanitary protection for the chemical being stored. Large tanks shall be covered and those with top access openings shall have either threaded covers or the openings shall be curbed and fitted with overlapping covers. Grommets, pipe seals, or other sanitary means shall be provided to create a sanitary seal where tubes, hoses, and pipes pass through the walls or covers of chemical storage tanks.
NR 811.40(1)(c)
(c) Solution storage or day tanks supplying chemical feeders directly shall have at a minimum sufficient capacity for one day of operation. If the chemical solution is prepared from a powder or slurry, 2 solution tanks shall be required if necessary to assure continuity of feed.
NR 811.40(1)(cm)
(cm) Graduated lines may not be used to determine daily chemical usage when the daily use is less than 5 percent of the tank capacity.
NR 811.40(1)(d)
(d) Solution storage or day tanks supplying feeders directly shall have a maximum capacity such that daily chemical solution usage is a minimum of 5 percent of the tank capacity. The department may approve chemical container storage volumes that will allow daily chemical solution usage less than 5 percent of the tank capacity if supporting information is provided to the department and the chemical storage container is placed on a scale, or another department approved method is installed, to accurately determine daily chemical usage. Graduated lines shall not be used to determine daily chemical usage in cases when the daily use is less than 5 percent of the tank capacity. The maximum storage volume shall not exceed 45 days for sodium hypochlorite and 60 days for all other chemicals.
NR 811.40(1)(e)
(e) Storage facilities shall be constructed of, or lined with, materials compatible with the chemical being handled.
NR 811.40(1)(f)
(f) Mixing equipment shall be provided where necessary to assure a uniform chemical solution strength. Continuous mixing shall be provided to maintain slurries in suspension.
NR 811.40(1)(h)
(h) For non-bulk tanks, suction lines shall extend into the tank through the tank cover. Chemical feed pumps shall be installed at a height above the maximum liquid level in the chemical storage tank. Flooded suctions, for bulk tanks and if necessary to prevent loss of prime, may be approved by the department on a case-by-case basis.
NR 811.40(1)(i)
(i) Adequate means of draining tanks shall be provided, but there may be no direct connection between any drain piping and a sanitary sewer. Chemicals shall not be discharged directly to a storm sewer. Drain piping shall terminate at least 2 pipe diameters, but not less than 3 inches, above the overflow rim of a receiving sump, conduit or waste receptacle.
NR 811.40(1)(j)
(j) Overflow pipes, if provided, shall be turned downward, provided with a 24-mesh corrosion resistant screen, have a free air break discharge, and be located in a conspicuous location.
NR 811.40(1)(k)
(k) If subsurface locations for solution or storage tanks are approved by the department, the tanks shall be free from sources of possible contamination and located to assure positive drainage for groundwater, accumulated water, chemical spills, and overflows.
NR 811.40(1)(L)
(L) Chemicals shall be stored in accordance with the following requirements:
NR 811.40(1)(L)1.
1. Each chemical shall be provided with its own secondary leakage containment.
NR 811.40(1)(L)2.
2. Each of the following chemicals shall be stored in a separate room with no other chemicals:
NR 811.40(1)(m)
(m) All buried chemical solution lines and gas lines shall be installed within protective conduit piping. Each chemical solution line shall be placed in its own protective conduit piping.
NR 811.40 Note
Note: When the chemical feed equipment will not be installed near the point of chemical application it is recommended that chemical solution piping be installed within protective conduit from the chemical feed equipment to the point of chemical application.
NR 811.40(1)(n)
(n) Gases from feeders, storage, and equipment exhausts shall be conveyed to the exterior of the building above grade and remote from air intakes to reduce the health and safety risk to operators and reduce corrosion of equipment and facilities from chemical vapors. Chemical vapor ventilation systems shall meet the following requirements as applicable:
NR 811.40(1)(n)1.
1. Fluoride and ammonia liquid storage tanks shall be vented to the exterior of the building but not through vents in common with day tanks.
NR 811.40(1)(n)2.
2. Chemical tank vents, when provided, shall be vented to the exterior of the building and terminate downward facing with a 24-mesh corrosion resistant screen. The tank vent shall terminate as high as practical, but a minimum of 24 inches above surrounding grade.
NR 811.40(1)(o)
(o) Permanent signs identifying the chemical for each fill tube shall be posted at chemical offloading areas. Permanent signs identifying the tank contents shall be posted adjacent to or on chemical storage tanks.
NR 811.40(1)(p)
(p) Compliance with local, state, and federal safety codes, including department of safety and professional services and OSHA codes, for other applicable chemical safety and handling requirements is required.
NR 811.40(2)
(2)
Handling facilities. Handling facilities shall meet the following requirements:
NR 811.40(2)(a)
(a) Equipment shall be provided for measuring quantities of chemicals used to prepare feed solutions.
NR 811.40(2)(b)
(b) Piping for chemicals shall be compatible with the chemical being conveyed.
NR 811.40(2)(c)
(c) The following equipment shall be provided for each installation where chemicals are handled:
NR 811.40(2)(c)1.
1. Where the eyes or body of any person may be exposed to injurious corrosive materials, suitable facilities for quick drenching or flushing of the eyes and body shall be provided as required in s.
SPS 332.15.
NR 811.40(2)(c)2.
2. Rubber gloves, protective clothing, and safety goggles that form a tight seal with the face shall be provided for each operator who prepares chemical solutions.
NR 811.40(2)(c)3.
3. A dust respirator of the prescribed type shall be provided for handling dry chemicals if required in the respective material safety data sheet or s.
SPS 332.15.
NR 811.40(2)(d)
(d) Provision shall be made for the transfer of dry chemicals from shipping containers to storage bins or hoppers in such a way as to minimize the quantity of dust generated. Control shall be provided by use of one of the following:
NR 811.40(2)(d)2.
2. Facilities for emptying shipping containers in special containers.
NR 811.40(2)(d)3.
3. Exhaust fans and dust filters which place the hoppers or bins under negative pressure.
NR 811.40(2)(e)
(e) Carts, elevators, or other appropriate means shall be provided for lifting chemical containers to minimize lifting by operators.
NR 811.40(2)(f)
(f) Electrical equipment shall be used which will prevent explosions, particularly when using sodium chlorite and activated carbon. Equipment shall comply with ch.
SPS 316.
NR 811.40(2)(g)
(g) Procedures for disposing of empty bags, drums, carboys, or barrels shall minimize exposure to dusts or chemicals.
NR 811.40(2)(h)
(h) Acids shall be kept in closed, acid-resistant shipping containers, or storage units. Transfer from shipping containers to solution or day tanks shall be through acid resistant hose or pipe by means of a transfer pump.
NR 811.40(3)
(3)
Chemicals. All chemicals used to treat or produce potable water shall meet the following requirements:
NR 811.40(3)(a)
(a) Shipping containers shall be fully labeled to include chemical name, purity, applicable NSF/ANSI standard approval in conformance with par.
(b), concentration and supplier name and address.
