Chapter NR 810

Where:

LRVDIT= the sensitivity of the direct integrity test; Qp= total design filtrate flow from the membrane unit; Qbreach= flow of water from an integrity breach associated with the smallest integrity test response that can be reliably measured, and VCF = volumetric concentration factor. The volumetric concentration factor is the ratio of the suspended solids concentration on the high pressure side of the membrane relative to that in the feed water.

NR 810.45(2)(d)3.b. b. For direct integrity tests that use a particulate or molecular marker, the direct integrity test sensitivity shall be calculated according to the following equation:

LRVDIT= LOG10(Cf)-LOG10(Cp)

Where:

LRVDIT= the sensitivity of the direct integrity test; Cf= the typical feed concentration of the marker used in the test; and Cp= the filtrate concentration of the marker from an integral membrane unit.

NR 810.45(2)(d)4. 4. Systems shall establish a control limit within the sensitivity limits of the direct integrity test that is indicative of an integral membrane unit capable of meeting the removal credit awarded by the department.

NR 810.45(2)(d)5. 5. If the result of a direct integrity test exceeds the control limit established under subd. 4., the system shall remove the membrane unit from service. Systems shall conduct a direct integrity test to verify any repairs, and may return the membrane unit to service only if the direct integrity test is within the established control limit.

NR 810.45(2)(d)6. 6. Systems shall conduct direct integrity testing on each membrane unit at a frequency of not less than 3 times each day that the membrane unit is in operation. The department may approve less frequent testing, based on demonstrated process reliability, the use of multiple barriers effective for Cryptosporidium, or reliable process safeguards.

NR 810.45(2)(e) (e) Indirect integrity monitoring. Systems shall conduct continuous indirect integrity monitoring on each membrane unit according to the criteria in subds. 1. to 5. In this subsection, indirect integrity monitoring means monitoring some aspect of filtrate water quality that is indicative of the removal of particulate matter. A system that implements continuous direct integrity testing of membrane units in accordance with the criteria in par. (d) 1. to 5. is not subject to the requirements for continuous indirect integrity monitoring. Water suppliers for systems shall submit a monthly report to the department summarizing all continuous indirect integrity monitoring results triggering direct integrity testing and the corrective action that was taken in each case.

NR 810.45(2)(e)1. 1. Unless the department approves an alternative parameter, continuous indirect integrity monitoring shall include continuous filtrate turbidity monitoring.

NR 810.45(2)(e)2. 2. Continuous monitoring shall be conducted at a frequency of no less than once every 15 minutes.

NR 810.45(2)(e)3. 3. Continuous monitoring shall be separately conducted on each membrane unit.

NR 810.45(2)(e)4. 4. If indirect integrity monitoring includes turbidity and if the filtrate turbidity readings are above 0.15 NTU for a period greater than 15 minutes, or 2 consecutive 15-minute readings above 0.15 NTU, direct integrity testing shall immediately be performed on the associated membrane unit as specified in par. (d) 1. to 5.

NR 810.45(2)(e)5. 5. If indirect integrity monitoring includes a department-approved alternative parameter and if the alternative parameter exceeds a department-approved control limit for a period greater than 15 minutes, direct integrity testing shall immediately be performed on the associated membrane units as specified in par. (d) 1. to 5.

NR 810.45(3) (3) Second stage filtration. Public water systems receive 0.5-log Cryptosporidium treatment credit for a separate second stage of filtration that consists of sand, dual media, GAC, or other fine grain media following granular media filtration if the department approves. To be eligible for this credit, the first stage of filtration shall be preceded by a coagulation step and both filtration stages shall treat the entire plant flow taken from a surface water or GWUDI source. A cap, such as GAC, on a single stage of filtration is not eligible for this credit. The department shall approve the treatment credit based on an assessment of the design characteristics of the filtration process.

NR 810.45(4) (4) Slow sand filtration as secondary filter. Public water systems are eligible to receive 2.5-log Cryptosporidium treatment credit for a slow sand filtration process that follows a separate stage of filtration if both filtration stages treat entire plant flow taken from a surface water or GWUDI source and no disinfectant residual is present in the influent water to the slow sand filtration process. The department shall approve the treatment credit based on an assessment of the design characteristics of the filtration process. This subsection does not apply to treatment credit awarded to slow sand filtration used as a primary filtration process.

NR 810.45 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

subch. IV of ch. NR 810 Subchapter IV — Inactivation Toolbox Components and CT Tables

NR 810.46 NR 810.46 Inactivation toolbox components.

NR 810.46(1) (1) Calculation of CT values.

NR 810.46(1)(a) (a) CT is the product of the disinfectant contact time (T, in minutes) and disinfectant concentration (C, in milligrams per liter). Water suppliers for systems with treatment credit for chlorine dioxide or ozone under sub. (2) or (3) shall calculate CT at least once each day, with both C and T measured during peak hourly flow as specified in s. NR 809.563 (1), Table R.

NR 810.46(1)(b) (b) Water suppliers for systems with several disinfection segments in sequence may calculate CT for each segment. In this section, “disinfection segment” means a treatment unit process with a measurable disinfectant residual level and a liquid volume. Under this approach, water suppliers for systems shall add the Cryptosporidium CT values in each segment to determine the total CT for the treatment plant.

NR 810.46(2) (2) CT values for chlorine dioxide and ozone.

NR 810.46(2)(a) (a) Public water systems receive the Cryptosporidium treatment credit for chlorine dioxide by meeting the corresponding chlorine dioxide CT values found in s. NR 810.56 for the applicable water temperature, as described in sub. (1).

NR 810.46(2)(b) (b) Systems receive the Cryptosporidium treatment credit for ozone by meeting the corresponding ozone CT values found in s. NR 810.61 for the applicable water temperature.

NR 810.46(3) (3) Site-specific study. The department may approve alternative chlorine dioxide or ozone CT values to those referenced in sub. (2) on a site-specific basis. The department shall base this approval on a site-specific study a water supplier for a system conducts that follows a department-approved protocol.

NR 810.46(4) (4) Ultraviolet light. Public water systems receive Cryptosporidium, Giardia lamblia, and virus treatment credits for ultraviolet (UV) light reactors by achieving the corresponding UV dose values shown in s. NR 810.62. Water suppliers for the systems shall validate and monitor UV reactors as described in pars. (b) and (c) to demonstrate that they are achieving a particular UV dose value for treatment credit.

NR 810.46(4)(a) (a) UV dose table. The treatment credits listed in the dose table in s. NR 810.62 are for UV light at a wavelength of 254 nm as produced by a low pressure mercury vapor lamp. To receive treatment credit for other lamp types, water suppliers for the systems shall demonstrate an equivalent germicidal dose through reactor validation testing, as described in par. (b). The UV dose values in this table are applicable only to post-filter applications of UV in filtered systems and to unfiltered systems.

NR 810.46(4)(b) (b) Reactor validation testing. Systems shall use UV reactors that have undergone validation testing to determine the operating conditions under which the reactor delivers the UV dose required in par. (a), also known as the validated operating conditions. These operating conditions shall include flow rate, UV intensity as measured by a UV sensor, and UV lamp status.

NR 810.46(4)(b)1. 1. When determining validated operating conditions, water suppliers for the systems shall account for the following factors: UV absorbance of the water; lamp fouling and aging; measurement uncertainty of on-line sensors; UV dose distributions arising from the velocity profiles through the reactor; failure of UV lamps or other critical system components; and inlet and outlet piping or channel configurations of the UV reactor.

NR 810.46(4)(b)2. 2. Validation testing shall include the following: Full scale testing of a reactor that conforms uniformly to the UV reactors used by the system and inactivation of a test microorganism whose dose response characteristics have been quantified with a low pressure mercury vapor lamp.

NR 810.46(4)(b)3. 3. The department may approve an alternative approach to validation testing.

NR 810.46(4)(c) (c) Reactor monitoring.

NR 810.46(4)(c)1. 1. Water suppliers for the systems shall monitor their UV reactors to determine if the reactors are operating within validated conditions, as determined under par. (b). This monitoring shall include UV intensity as measured by a UV sensor, flow rate, lamp status, and other parameters the department designates based on UV reactor operation. Water suppliers for the systems shall verify the calibration of UV sensors and shall recalibrate sensors in accordance with a protocol the department approves.

NR 810.46(4)(c)2. 2. To receive treatment credit for UV light, systems shall treat at least 99.9% of the water delivered to the public during each month by UV reactors operating within validated conditions for the required UV dose, as described in pars. (a) and (b). Systems shall demonstrate compliance with this condition by the monitoring required under subd. 1.

NR 810.47 NR 810.47 CT table for giardia when using free chlorine at 0.5°C or lower.

NR 810.47 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.48 NR 810.48 CT table for giardia when using free chlorine at 5°C.

NR 810.48 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.49 NR 810.49 CT table for giardia when using free chlorine at 10°C.

NR 810.49 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.50 NR 810.50 CT table for giardia when using free chlorine at 15°C.

NR 810.50 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.51 NR 810.51 CT table for giardia when using free chlorine at 20°C.

NR 810.51 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.52 NR 810.52 CT table for giardia when using free chlorine at 25°C.

NR 810.52 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.53 NR 810.53 CT table for viruses when using free chlorine.

NR 810.53 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.54 NR 810.54 CT table for Giardia lamblia when using chlorine dioxide.

NR 810.54 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.55 NR 810.55 CT table for viruses when using chlorine dioxide.

NR 810.55 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.56 NR 810.56 CT table for Cryptosporidium when using chlorine dioxide. 1

1Systems may use this equation to determine log credit between the indicated values: Log credit = (0.001506 ´ (1.09116)Temp) ´ CT.

NR 810.56 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.57 NR 810.57 CT table for Giardia lamblia when using chloramines.

NR 810.57 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.58 NR 810.58 CT table for viruses when using chloramines.

NR 810.58 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.59 NR 810.59 CT table for Giardia lamblia when using ozone.

NR 810.59 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.60 NR 810.60 CT table for viruses when using ozone.

NR 810.60 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.61 NR 810.61 CT table for Cryptosporidium when using ozone. 1

1Systems may use this equation to determine log credit between the indicated values: Log credit = (0.0397 ´ (1.09757)Temp) ´ CT.

NR 810.61 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.

NR 810.62 NR 810.62 UV dose table for Cryptosporidium, Giardia lamblia, and viruses.

NR 810.62 History History: CR 09-073: cr. Register November 2010 No. 659, eff. 12-1-10.