NR 811.54(5)(f)
(f) Catalysts shall be protected from foam, moisture and other impurities that may harm the catalyst.
NR 811.54(5)(g)
(g) The catalyst and heating elements shall be located where they can be easily reached for maintenance.
NR 811.54 Note
Note: In order to reduce the risk of fires, the use of units that operate at lower temperatures is encouraged, especially where high purity oxygen is the feed gas.
NR 811.54(6)
(6)
Piping materials. Piping materials used in ozone service shall meet the following requirements:
NR 811.54(6)(a)
(a) Only low carbon 304L and 316L stainless steel piping shall be used for ozone service. Alternative piping materials may be approved by the department on a case-by-case basis.
NR 811.54(6)(c)
(c) Rubber components may not be used in contact with ozone.
NR 811.54(7)(a)(a) Connections on stainless steel piping used for ozone service are to be welded where possible.
NR 811.54(7)(b)
(b) Connections with meters, valves, or other equipment are to be made with flanged joints with ozone resistant gaskets, such as Teflon or Hypalon. Screwed fittings and field-cut threaded connections may not be used.
NR 811.54(7)(c)
(c) A positive closing plug or butterfly valve and a leak-proof backflow prevention check valve system shall be provided in the piping between the generator and the contactor for pressurized ozone generation systems.
NR 811.54(8)
(8)
Instrumentation. Instrumentation shall meet the following requirements:
NR 811.54(8)(a)
(a) Pressure gauges shall be provided at the discharge from the air compressor, at the inlet to the refrigerator dryers, at the inlet and outlet of the desiccant dryers, at the inlet to the ozone generators and contactors, and at the inlet to the ozone destruction unit.
NR 811.54(8)(b)
(b) Each generator shall have a trip which shuts down the generator when the wattage exceeds a preset level. It is recommended that electric power meters be provided for measuring the electric power supplied to the ozone generators.
NR 811.54(8)(c)
(c) Dew point monitors shall be provided for measuring the moisture of the feed gas from each desiccant dryer. Where there is potential for moisture entering the ozone generator from downstream of the unit or where moisture accumulation can occur in the generator during shutdown, post-generator dew point monitors shall be used.
NR 811.54(8)(d)
(d) Air flow meters shall be provided for measuring the air flow from the desiccant dryers to each of the ozone generators, the air flow to each contactor, and the purge air flow to the desiccant dryers.
NR 811.54(8)(e)
(e) Temperature gauges shall be provided for the inlet and outlet of the ozone cooling water and the inlet and outlet of the ozone generator feed gas, and, if applicable, for the inlet and outlet of the ozone power supply cooling water.
NR 811.54(8)(f)
(f) Water flow meters shall be installed to monitor the flow of cooling water to the ozone generators and, if applicable, to the ozone power supply.
NR 811.54(8)(g)
(g) At a minimum, ozone monitors shall be installed and maintained to measure ozone concentrations in both the feed-gas and the off-gas from the contactor and the off-gas from the destruct unit. Monitors or a comparable testing method shall also be provided for measuring ozone residuals in water in accordance with subs.
(4) and
(5) (b). The number and location of ozone residual monitors shall be such that the amount of time that the water is in contact with the ozone residual can be determined.
NR 811.54(8)(h)
(h) Ambient air ozone monitors shall be installed in rooms where exposure to ozone is possible.
NR 811.54(9)
(9)
Alarms. The installation of alarm and shutdown systems shall meet the following requirements:
NR 811.54(9)(a)
(a) A dew point alarm and shutdown shall shut down the generator in the event the system dew point exceeds -60
°C (-76
°F).
NR 811.54(9)(b)
(b) An ozone generator cooling water flow alarm and shutdown shall shut down the generator in the event that cooling water flows decrease to the point that generator damage could occur.
NR 811.54(9)(c)
(c) An ozone power supply cooling water flow alarm and shutdown shall shut down the power supply in the event that cooling water flow decreases to the point that power supply damage could occur.
NR 811.54(9)(d)
(d) An ozone generator cooling water temperature alarm and shutdown shall shut down the generator if either the inlet or outlet cooling water exceeds the designated preset temperature.
NR 811.54(9)(e)
(e) An ozone power supply cooling water temperature alarm and shutdown shall shut down the power supply if either the inlet or outlet cooling water exceeds the designated preset temperature.
NR 811.54(9)(f)
(f) An ozone generator inlet feed-gas temperature alarm and shutdown shall shut down the generator if the feed-gas temperature exceeds the designated preset value.
NR 811.54(9)(g)
(g) An ambient air ozone concentration alarm and shutdown shall sound when the ozone level in the building ambient air exceeds 0.1 ppm or a lower value chosen by the water supplier. Ozone generator shutdown shall automatically occur when the building ambient air ozone level exceeds 0.3 ppm or a lower value chosen by the water supplier.
NR 811.54(9)(h)
(h) An ozone destruct temperature alarm shall sound when the temperature exceeds the designated preset value.
NR 811.54(9)(i)
(i) Audible alarms and warning lights shall be installed and maintained to insure operators are alerted to improper operating or hazardous conditions.
NR 811.54(10)(a)(a) The maximum allowable ozone concentration in the air to which workers may be exposed may not exceed 0.1 ppm by volume.
NR 811.54(10)(b)
(b) Noise levels resulting from the operation of the ozonation system shall be controlled to within acceptable limits by special room construction and equipment isolation.
NR 811.54(10)(c)
(c) High voltage and high frequency electrical equipment shall meet current electrical and fire codes.
NR 811.54(10)(d)
(d) An exhaust fan shall be provided in the ozone generation and contactor rooms to remove ozone gas if a leak occurs and shall meet all of the following requirements:
NR 811.54(10)(d)1.
1. One complete air change per minute shall be provided when the room is occupied.
NR 811.54(10)(d)2.
2. The exhaust fan suction shall be located near the floor with the point of discharge located to avoid contamination of air inlets to other rooms and structures, to outside breathable air, or being blocked by snow or other obstructions.
NR 811.54(10)(d)3.
3. Air inlets shall be located near the ceiling and controlled to prevent adverse temperature variations.
NR 811.54(10)(d)4.
4. An exhaust fan switch shall be located outside of the entrance to the room with a signal light indicating fan operation when the fan can be controlled from more than one point.
NR 811.54(10)(e)
(e) A portable purge air blower that will remove residual ozone in the contactor prior to entry for repair or maintenance shall be provided.
NR 811.54(10)(f)
(f) A sign shall be posted indicating “No smoking, oxygen in use" at all entrances to the treatment plant. In addition, no flammable or combustible materials shall be stored within the oxygen generator areas.
NR 811.54 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10;
CR 22-074: am. (2) (d) 2. Register January 2024 No. 817, eff. 2-1-24. NR 811.55(1)(1)
Radium removal. Water treatment to remove radium shall meet the following requirements:
NR 811.55(1)(a)
(a) General. Radium may be removed by using the water treatment processes of zeolite softening, lime-soda softening, reverse osmosis, hydrous manganese oxides, and adsorptive resins. Other processes may also be used to remove radium as approved by the department on a case-by-case basis. The process design shall address the fate of radium in the treatment process including waste disposal. Where applicable, disposal of treatment plant wastes containing radium shall normally be to a sanitary sewer or wastewater treatment plant.
NR 811.55 Note
Note: It is recommended that measures be taken to protect workers from gamma radiation exposure and radon gas inhalation where applicable.
NR 811.55(1)(b)
(b) Finished water quality. Radium removal processes shall be designed to provide a finished water with a radium content as close to 0 picocuries per liter as practical while maintaining a finished water that is not corrosive. The department shall determine allowable plant outlet water quality, including radium concentrations, based on the raw water quality and the treatment process proposed. If corrosive water is produced during the radium removal process, a department approved method of corrosion control shall be provided.
NR 811.55(1)(c)
(c) Finished water sampling and reporting. For the radium removal processes listed in par.
(a), a minimum of 4 consecutive quarters of finished water sampling for radium shall be required after the plant becomes operational to demonstrate treatment effectiveness. For other proposed radium removal treatment methods, the required radium monitoring program shall be established by the department. The sampling shall be conducted under worst case conditions. Radium analyses shall be performed by a U.S. environmental protection agency approved laboratory. The laboratory shall forward a copy of the radiological analyses to the department in an electronic format. Water hardness monitoring equipment shall be provided to monitor for hardness breakthrough when softening is used for radium removal. Daily water hardness measurements shall be reported on the monthly operating report submitted to the department. Use of hardness monitoring to substitute for radium analyses shall only be allowed if demonstrated effective by simultaneous radium and hardness sampling conducted for one year.
NR 811.55(1)(d)
(d) Water softening. Treatment for radium removal using standard water softening processes shall comply with the requirements of s.
NR 811.57.
NR 811.55(1)(e)
(e) Hydrous manganese oxides. Water treatment using hydrous manganese oxides for radium removal shall meet the following requirements:
NR 811.55(1)(e)1.
1. Each installation shall be individually pilot tested on-site under a department approval unless the pilot testing requirement is waived by the department based upon documentation of successful similar treatment performance at wells with similar water quality.
NR 811.55(1)(e)2.
2. Pre-mixed or on-site mixed hydrous manganese oxide chemicals shall conform to the applicable NSF/ANSI Standard 60 and AWWA standards as required by s.
NR 810.09 (1) (c).
NR 811.55(1)(f)
(f) Adsorptive resins. Water treatment using adsorptive resins for radium removal that will continuously accumulate radium on the resin shall meet the following requirements.
NR 811.55(1)(f)1.
1. Each installation shall be individually pilot tested on-site under a department approval unless the pilot testing requirement is waived by the department based upon documentation of successful similar treatment performance at wells with similar water quality.
NR 811.55(1)(f)2.
2. The radiation protection section of the department of health services shall be contacted to obtain a radioactive material license to operate pilot and full scale installations prior to constructing or operating the systems.
NR 811.55(1)(g)
(g) Other treatment. Other radium removal treatment processes may be approved by the department on a case-by-case basis using information obtained from department approved on-site pilot studies conducted on the water to be treated.
NR 811.55(1)(h)
(h) Waste disposal. Disposal of radium removal treatment plant waste shall comply with subch.
XII.
NR 811.55(2)
(2)
Radon gas removal. Water treatment to remove radon gas shall meet the following requirements:
NR 811.55(2)(a)
(a) Radon may be removed using aeration or pressurized granular activated carbon filters. The process design shall address the gamma radiation and disposal concerns associated with the use of granular activated carbon filters.
NR 811.55(2)(b)
(b) The design of radon removal equipment shall be based on a department approved on-site pilot study conducted on the water to be treated. The department may approve manufactured radon removal equipment without pilot study on a case-by-case basis if adequate treatment effectiveness is demonstrated to the department.
NR 811.55(2)(d)
(d) Radon gas shall be vented to the atmosphere at an elevation and location to prevent elevated radon gas air concentrations in inhabitable areas.
NR 811.55(2)(e)
(e) Granular activated carbon filters for radon removal shall comply with s.
NR 811.53. Disposal of carbon filters used for radon removal shall comply with s.
NR 811.859.
NR 811.55(2)(f)
(f) A minimum of 4 consecutive quarters of finished water sampling for radon gas shall be required after the plant becomes operational to demonstrate treatment effectiveness. The sampling shall be conducted under worst case conditions. Radon gas analyses shall be performed by a U.S. environmental protection agency approved laboratory. The laboratory shall forward a copy of the radiological analyses to the department in an electronic format.
NR 811.55(3)
(3)
Uranium removal. Water treatment to remove uranium shall meet the following requirements:
NR 811.55(3)(a)
(a) The designer of any proposed uranium removal equipment shall contact the department prior to the final design of the equipment to allow for department input on design requirements. The design shall be based on information obtained from department approved on-site pilot studies conducted on the water to be treated. The process design shall address the fate of uranium in the treatment process. Disposal of water treatment plant wastes containing uranium shall be in accordance with written department guidance. If applicable, disposal of treatment plant wastes containing uranium shall be to a sanitary sewer or wastewater treatment plant as approved by the department. The discharged water treatment plant wastes and spent media shall be analyzed for radionuclide content as required by the department. The disposal of spent media containing residual radionuclides shall be as approved by the department.
NR 811.55(3)(b)
(b) A minimum of 4 consecutive quarters of finished water sampling for uranium shall be required after the plant becomes operational to demonstrate treatment effectiveness. The sampling shall be conducted under worst case conditions. Uranium analyses shall be performed by a U.S. environmental protection agency approved laboratory. The laboratory shall forward a copy of the radiological analyses to the department in an electronic format.
NR 811.55(3)(c)
(c) Prior to constructing or operating the systems, the radiation protection section of the department of health services shall be contacted to obtain a radioactive material license to operate pilot and full scale installations when uranium will be concentrated on the resin or media to a level greater than 170 picocuries per gram at any time during use, including just prior to backwashing, regeneration, or disposal.
NR 811.55(3)(d)
(d) Disposal of uranium removal treatment plant waste shall comply with subch.
XII.
NR 811.55 History
History: CR 09-073: cr.
Register November 2010 No. 659, eff. 12-1-10;
CR 22-074: am. (2) (c) Register January 2024 No. 817, eff. 2-1-24. NR 811.56(1)(1)
Sequestration by polyphosphates. Sequestration by polyphosphates is suitable when concentrations of iron, manganese, or a combination of both, are 1.0 mg/1, or less. Polyphosphate treatment may be less effective for sequestering manganese than for iron. The following requirements shall be met:
NR 811.56(1)(a)
(a) Where phosphate treatment is used, chlorine residuals shall be maintained in the distribution system. In addition:
NR 811.56(1)(b)
(b) Polyphosphates may not be applied ahead of iron and manganese removal treatment. The point of application shall be prior to any aeration or oxidation and as far upstream as practical from the chlorine or other oxidant application.
NR 811.56(1)(c)
(c) Chemical feed installations shall conform to the requirements of subch.
VI.
NR 811.56(1)(e)
(e) Stock phosphate solution shall be kept covered and disinfected by carrying an approximate 10 mg/1 free chlorine residual unless the phosphate is not able to support bacterial growth, has a pH of 2 or less, and has not been diluted.
NR 811.56(1)(g)
(g) If polyphosphate sequestration is practiced, appropriate orthophosphate testing equipment shall be provided.
NR 811.56(1)(h)
(h) Possible adverse affects on corrosion shall be considered and addressed if necessary when phosphate addition is proposed for iron or manganese sequestering.
NR 811.56(2)
(2)
Sequestration by sodium silicates. Sodium silicate sequestration of iron and manganese is appropriate only for groundwater supplies prior to air contact. Sodium silicate addition is applicable to waters containing up to 2 mg/l of iron, manganese, or a combination of both. The following requirements shall be met:
NR 811.56(2)(a)
(a) On-site pilot tests are required to determine the suitability of sodium silicate for the particular water and the minimum chemical feed rate needed.
NR 811.56(2)(b)
(b) Chlorine residuals shall be maintained throughout the distribution system to prevent biological breakdown of the sequestered iron.
NR 811.56(2)(c)
(c) Rapid oxidation of the metal ions such as by chlorine or chlorine dioxide shall accompany or closely precede the sodium silicate addition. Injection of sodium silicate more than 15 seconds after oxidation may cause detectable loss of chemical efficiency. Dilution of feed solutions much below 5% silica as SiO
2 shall also be avoided for the same reason.
NR 811.56(2)(d)
(d) The amount of silicate added shall be limited to 20 mg/l as SiO
2. The combined amount of added and naturally occurring silicate may not exceed 60 mg/l as SiO
2.
NR 811.56(2)(e)
(e) Chemical feed installations shall conform to the requirements of subch.
VI.
NR 811.56(2)(f)
(f) Sodium silicate may not be applied ahead of iron or manganese removal treatment.
NR 811.57
NR 811.57 Softening. The softening process selected shall be based upon the chemical qualities of the raw water, the desired finished water quality, the requirements for disposal of sludge or brine waste, the cost of plant and chemicals, and plant location. The applicability of the process chosen shall be demonstrated and discussed in detail in an engineering report. For very hard water, the sodium levels in cation exchange softened water shall be considered in selecting the treatment process. Following are requirements for specific processes:
