Taumata Arowai–Drinking Water Quality Assurance Rules 2022

Drinking Water Quality Assurance Rules Page 1 of 85 DRINKING WATER QUALITY ASSURANCE RULES 2022 Released 25 July 2022 Revised 29 November 2024 Page 2 of 85 Ko wai, Ko au, Ko tātou Ko te wai ahau, ko ahau te wai. He whakaaturanga tātou nō te wai. Ko te ora te wai ko te ora o te tangata. He taonga te wai me tiaki. Ko wai tātou. Ko wai tātou. I am wai, wai is me. We are reflections of our wai. The health of te wai is the health of te tangata. Wai is a taonga that must be protected. Ko wai tātou. We are wai. Wai is us. This document is a consolidated version of the Drinking Water Quality Assurance Rules 2022 including amendments made by the Drinking Water Quality Assurance (Very Small to Medium Drinking Water Supplies) Amendment Rules 2024. Page 3 of 85 Contents page List of tables ............................................................................................................... 5 1. Introduction .............................................................................................. 6 1.1 Rule objectives .................................................................................................. 6 1.2 Effective date of the Rules ................................................................................ 6 1.3 General guidance .............................................................................................. 6 1.4 Components of a drinking water supply .......................................................... 7 1.5 Categories of drinking water supply ................................................................. 7 1.6 Structure of the Rules ....................................................................................... 9 2. Drinking water supply categories and Rules modules ............................... 10 3. Application of the Rules modules ............................................................. 11 3.1 Compliance and reporting .............................................................................. 11 4. Compliance Rules Modules ...................................................................... 14 4.1 G General Rules Module ................................................................................. 14 4.2 VSC Very Small Communities Rules Module .................................................. 20 4.3 S1 Source Water Rules Module ...................................................................... 21 4.4 T1 Treatment Rules Module ........................................................................... 23 4.5 D1 Distribution System Rules Module ............................................................ 25 4.6 S2 Source Water Rules Module ...................................................................... 26 4.7 T2 Treatment Rules Module ........................................................................... 28 4.8 D2 Distribution System Rules Module ............................................................ 32 4.9 S3 Source Water Rules Module ...................................................................... 34 4.9.1 S3 Source Water Protozoa Log Credit Treatment Requirements .......... 34 4.9.2 S3 Sanitary Bore Head Requirements .................................................... 35 4.9.3 S3 Source Water Monitoring Rules........................................................ 36 4.10 T3 Treatment Rules Module............................................................................. 39 4.10.1 T3 Bacterial Rules................................................................................. 39 4.10.2 T3 Protozoal Rules ............................................................................... 45 4.10.3 T3 Chemical Rules ................................................................................ 62 4.10.4 T3 Cyanotoxin Rules............................................................................. 65 4.11 D3 Distribution System Rules Module ............................................................. 66 4.11.1 D3 Backflow Protection Rules .............................................................. 66 4.11.2 D3 New and Repaired Watermains Hygiene Procedures Rules .......... 67 4.11.3 D3 Facilities Operation, Maintenance and Disinfection Rules ............ 68 4.11.4 D3 Residual Disinfection, Disinfection By-product, and Plumbosolvent Metal Rules ..................................................................................................... 69 4.11.5 D3 Microbiological Monitoring Rules .................................................. 73 Page 4 of 85 4.12 WC Water Carrier Service Rules Module ............................................ 75 4.13 TDWS Temporary Drinking Water Supplies Rules (Revoked) ............. 77 4.14 VP Rules for Supplies with Varying Population Module ..................... 78 5. Definitions............................................................................................... 80 Page 5 of 85 List of tables Table 1. Rules Modules ........................................................................................................................................... 9 Table 2. Categories of drinking water supply and Rules that apply to them. ....................................................... 10 Table 3. Removed .................................................................................................................................................. 17 Table 4. Removed .................................................................................................................................................. 17 Table 5. Bacterial reporting requirements for level 3 Rules. ................................................................................. 18 Table 6. Protozoal reporting requirements for level 3 Rules. ................................................................................ 18 Table 7. Distribution zone reporting requirements for level 3 Rules. .................................................................... 19 Table 8. Removed .................................................................................................................................................. 22 Table 9. Removed .................................................................................................................................................. 22 Table 10. Removed ................................................................................................................................................ 24 Table 11. Removed ................................................................................................................................................ 25 Table 12. Removed ................................................................................................................................................ 27 Table 13. Removed ................................................................................................................................................ 27 Table 14. Removed ................................................................................................................................................ 31 Table 15. Removed ................................................................................................................................................ 33 Table 16. S3 Source Water Monitoring Determinands .......................................................................................... 37 Table 17. S3 Class 1, Class 2 and Class 3 Groundwater Source Monitoring Determinands ................................... 37 Table 18. S3 Raw Water Monitoring Parameters ................................................................................................. 38 Table 19. T3 Requirements for Drinking Water Disinfected with Chlorine ............................................................ 39 Table 20. T3 Requirements for Drinking Water Disinfected with Chlorine Dioxide ............................................... 41 Table 21. T3 Requirements for Water Disinfected with Ozone ............................................................................. 42 Table 22. T3 Requirements for UV Disinfection ..................................................................................................... 44 Table 23. T3 Requirements for Coagulation, Flocculation and Sedimentation without Filtration ........................ 46 Table 24. T3 Requirements for Coagulation, Flocculation and Direct Filtration ................................................... 48 Table 25. T3 Requirements for Coagulation, Flocculation, Sedimentation and Filtration ..................................... 50 Table 26. T3 Requirements for Second Stage Filtration ........................................................................................ 51 Table 27. T3 Requirements for Slow Sand Filtration ............................................................................................. 52 Table 28. T3 Requirements for Cartridge Filtration ............................................................................................... 54 Table 29. T3 Requirements for Membrane Filtration ............................................................................................ 56 Table 30. T3 C.t values (min.mg/L) for Cryptosporidium inactivation by ozone ................................................... 57 Table 31. T3 Requirements for Ozone Disinfection ............................................................................................... 58 Table 32. T3 Requirements for UV Disinfection ..................................................................................................... 60 Table 33. T3 Treatment Chemical Determinand Minimum Sampling Frequencies ............................................... 64 Table 34. T3 Possible Treatment Chemical Determinand Monitoring................................................................... 64 Table 35. D3 FAC sampling frequency ................................................................................................................... 71 Table 36. D3 Number of continuous monitoring analysers required in each zone ................................................ 71 Table 37. D3 Disinfection by-product sampling frequency .................................................................................... 72 Table 38. D3 Distribution zone for plumbosolvent metals .................................................................................... 72 Table 39. D3 Minimum Microbiological Sampling Frequencies ............................................................................ 74 Table 40. Removed ................................................................................................................................................ 77 Page 6 of 85 1. Introduction The Drinking Water Quality Assurance Rules (“Rules”) have been prepared by Taumata Arowai in accordance with section 49 of the Water Services Act 2021, including the public consultation requirements set out in section 53 of the Act. The Rules are secondary legislation and are disallowable by the House of Representatives under the Legislation Act 2019. 1.1 Rule objectives These Rules primarily impose requirements relating to drinking water supplier duties to: 1. supply safe drinking water 1 2. ensure that drinking water complies with the Water Services (Drinking Water Standards for New Zealand) Regulations 2022. 2 Aspects of the Rules also relate to drinking water supplier functions or duties, under other provisions in Part 2 of the Act. 1.2 Effective date of the Rules The Rules came into force on 14 November 2022 and the amendments in this revised version are in force from 1 January 2025. 1.3 General guidance This section provides some general guidance about the Rules. The Rules set out minimum compliance requirements and drinking water suppliers may use or undertake additional measures, including the management of risks specifically identified in relation to their supplies, to ensure that water provided to consumers is safe to drink. Definitions of technical terms and abbreviations used in the Rules are set out in the Definitions section (Section 5). Unless otherwise defined in Section 5, terms defined in the Act that are used in the Rules have the same meaning as in the Act. These Rules cover water quality operational requirements from source water abstraction to the point of supply to a consumer, typically at the boundary toby. In most situations, the Building Act 2004 regulates water supplies beyond this point. Compliance with the Rules is intended to ensure that water provided by drinking water suppliers does not exceed the MAVs for key determinands, as set out in the Drinking Water Standards. 1 Water Services Act 2021, section 21. 2 Water Services Act 2021, section 22. Page 7 of 85 Where MAVs cannot be (or are not) used to measure compliance, treatment efficacy is used as the surrogate criteria for demonstrating compliance. When surrogate criteria are used, the Rules specify operational requirements. Compliance with these provides confidence that a treatment barrier is working effectively. FAC and compliance with filter performance parameters such as turbidity are examples of surrogate criteria. These surrogate criteria have the important benefit of being able to be measured frequently, and even continuously, on-site so that near-real time feedback about treatment performance is available. The Rules do not set quality requirements for bottled water or water used solely for industrial or agricultural purposes as these are not covered by the Act. For people with certain medical conditions, or for uses of water for purposes other than drinking (e.g., kidney dialysis), additional or other water quality criteria may apply. 1.4 Components of a drinking water supply A drinking water supply comprises the infrastructure and processes used to abstract water from a source, and to store, treat, transmit, or transport drinking water to a point of supply for consumers or other drinking water suppliers. It will generally have one or more of each of the following components: 1. source water abstraction 2. water treatment plant 3. distribution system. Through the registration process, Taumata Arowai allocates unique identifier numbers to registered water supplies, sources, treatment plants, and distribution zones. 1.5 Categories of drinking water supply The Rules have been prepared for the following drinking water supply categories: 1. Very Small Communities Drinking water supplies of any configuration or arrangement (excluding domestic self-supplies) that provide drinking water to a population of up to 25 people. In circumstances when the population supplied fluctuates, the population supplied may increase to up to 50 people for up to 60 days in any 12 month period. 3 2. Networked Supplies Drinking water supplies that provide drinking water via a distribution system at a pressure and volume to meet consumer demand, or at a restricted flow and volume. These supplies may include storage facilities within the network to buffer demand. 3 Removed Page 8 of 85 The Rules have been prepared for Networked Supplies with the following population sizes: a) Small 26 – 100 people. Varying Population module requirements can apply to this drinking water supply category. b) Medium 101 – 500 people. Varying Population module requirements can apply to this drinking water supply category. c) Large >500 people. 3. Self-supplied Buildings Self-supplied Buildings are water supplies (excluding domestic self-supplies) which provide drinking water to up to ten buildings on one site (within the boundaries of one property, or within the boundaries of two or more properties with common ownership arrangements) and provide water to more than 25 people. The Rules have been prepared for Self-supplied Buildings with the following population sizes: (a) Small 26 – 100 people. Varying Population module requirements can apply to this drinking water supply category. (b) Medium 101 – 500 people. Varying Population module requirements can apply to this drinking water supply category. (c) Large >500 people. 4. Water Carrier Services Drinking water supplies that involve the transport of drinking water in a vehicle or vessel with a water tank (e.g., a truck, trailer, or rail wagon) and supply to consumers or other drinking water suppliers, often to a storage tank on a property. Typically, Water Carrier Services provide drinking water to houses that have their own supplies but need the quantity of stored water to be augmented. Water Carrier Services can also augment other drinking water supplies, particularly during droughts and emergencies and provide water to planned events. Water Carrier Services that fill tankers from a supply that provides water specifically for Water Carrier Services, must ensure that supply is separately registered and complies with the Water Carrier Supplies Rules. 5. Water Carrier Supplies Water Carrier Supplies are drinking water supplies that provide water specifically to fill tanker vehicles that are owned or operated by a Water Carrier Service. 6. Community Drinking Water Stations Community Drinking Water Stations are drinking water supplies that provide drinking water from a single point of supply to a community who collect the water in containers. Public taps or container filling stations that are connected to a Networked Supply (e.g., community taps that provide water which is chlorinated and then de- chlorinated) are not considered to be Community Drinking Water Stations. Page 9 of 85 1.6 Structure of the Rules The Rules are structured as ‘modules’, with the main modules covering general rules, source water, treatment systems and distribution systems. Additional modules are provided for some specific drinking water supply categories or situations. The modules and module codes are: 1. General Rules Module (G) – including rules that outline the monitoring and assurance rules that water suppliers need to report their compliance against to Taumata Arowai and the frequency of that reporting, to Taumata Arowai, sample collection and calibration of analytical instruments. 2. Very Small Communities Rules Module (VSC) – includes microbiological monitoring requirements and additional requirements for when population limits are exceeded. 3. Source Water Rules Modules (S1, S2, S3) – three complexity levels dependant on the size of the supply, covering rules for source water sampling. 4. Treatment Rules Modules (T1, T2, T3) – three complexity levels dependant on the size of the supply, covering rules for bacterial compliance, protozoal compliance, chemical compliance and cyanotoxin compliance. 5. Distribution System Rules Modules (D1, D2, D3) – three complexity levels dependant on the size of the supply, covering rules for backflow prevention, preventing recontamination of stored water, hygiene practices for maintenance and upgrades, monitoring FAC, disinfection by-products and microbial water quality. 6. Water Carrier Services Rules Module (WC) – including Rules which cover the transport of drinking water. 7. Varying Population Rules Module (VP) – covers additional monitoring requirements that must be met when the usual base population of a drinking water supply increases for limited periods of time. The following table sets out the Rules modules and complexity levels. Subsequent sections set out which modules each supply category must demonstrate compliance against. Table 1. Rules Modules G VSC S1 S2 S3 T1 T2 T3 D1 D2 D3 WC VP Page 10 of 85 2. Drinking water supply categories and Rules modules Table 2 below outlines the drinking water supply categories, and the Rules modules that drinking water suppliers must demonstrate compliance against. Table 2. Categories of drinking water supply and rules that apply to them. 4 Removed 5 Where more than one building is supplied, chlorine must be used to demonstrate bacterial compliance. Categories of drinking water supplies Rules modules that compliance is demonstrated against 1. Very Small Communities 0 – 25 people and 26 – 50 people for up to 60 days in any 12-month period (includes flexibility for exceeding population limits) VSC 2. Networked Supplies Small (26 – 100 people) G + S1 + T1 + D1 + VP Medium (101 – 500 people) G + S2 + T2 + D2 + VP Large (>500 people) G + S3 + T3 + D3 3. Self-supplied Buildings Small (26 – 100 people) G + S1 + T1 + VP Medium (101 – 500 people) G + S2 + T2 4 + VP Large (>500 people) G + S3 + T3 5 4. Water Carrier Services Any population size G + WC 5. Water Carrier Supplies Any population size G + S1 + T1 6. Community Drinking Water Stations Any population size G + S1 + T1 Page 11 of 85 3. Application of the Rules modules Drinking water suppliers must select the Rules modules that apply to each of their registered supplies based on the category that best fits their drinking water supply. Drinking water suppliers must demonstrate compliance against those Rules modules for each registered supply. For example, if a Networked Supply serves 10,000 people, level 3 rules must be used for all source, treatment, and distribution zone compliance, regardless of the number of people served by any single source, treatment plant, or distribution zone. If a distribution zone in a community of 10,000 people serves only 450 people, that zone must still demonstrate compliance against the level 3 rules. Where population thresholds are provided, the population supplied should be calculated on the base population, the population that is normally supplied drinking water regardless of any seasonal increases. Any drinking water supplier can elect to demonstrate compliance with a higher level of source, treatment, or distribution zone Rules module if they choose. For example, a drinking water supply which is required to comply with the level 2 Rules modules for source, treatment, and distribution zone, may choose to demonstrate compliance against the level 2 Rules modules for source and distribution zone, but the level 3 Rules module for treatment if that is more suitable for them. In that case, the Rules modules that they would demonstrate compliance against would be G + S2 + T3 + D2 + VP. If a drinking water supplier chooses to comply with a higher-level Rules module e.g., T3, they must comply with all of the rules in that module. It is up to each water supplier to determine whether they will demonstrate compliance against a higher-level Rules module, and over which compliance periods. 3.1 Compliance and reporting Drinking water suppliers only need to demonstrate compliance against the Rules for periods when a drinking water supply is operating. Example 1: A bore may only be used during the summer period when there is a high level of demand. The source water requirements for that bore would only need to be demonstrated for the period that the bore is in operation. Example 2: A treatment plant may be off-line for several reasons, compliance does not need to be demonstrated for the period that the plant is not operating. However, if a treatment plant operates for only part of a compliance period, data/information must be reported for that compliance period. Example 3: A distribution zone is expected to be in operation continually, even when a treatment plant is not, so demonstration of compliance for the distribution zone will be continual. Drinking water suppliers must assess their compliance with the Rules and provide a report of compliance to Taumata Arowai. Page 12 of 85 Reporting requirements Drinking water suppliers submit compliance reports to Taumata Arowai at varying frequencies depending on the level of rules they follow. Compliance reports are reported in an approved form which Taumata Arowai makes available to suppliers. Reporting requirements are set out in the General Rules: G1, G2.1, G2.2, G3, G4, and G5. Each compliance report must indicate the number of compliance periods in the reporting period that the supply was non-compliant with and, where applicable, outline the reason for any non-compliance. Compliance periods are the length of time over which compliance is assessed for reporting purposes. Two types of rules are assigned a compliance period, monitoring rules and assurance rules. Some rules don’t have a compliance period, these are non- reporting rules. Monitoring rules Monitoring rules set out requirements to monitor the quality of source water and treated water. They cover determinands and parameters that need to be either continuously monitored, or regularly sampled. Monitoring rules have compliance periods of 1 day, 1 month, 3 months, or 1 year, which typically depends on the frequency of monitoring required in the rule. 1-day compliance periods A monitoring rule which requires a determinand or parameter to be continuously monitored or monitored daily, irrespective of the period of the day that the supply is operating, has a compliance period of 1 day, i.e. 24 hours (midnight to midnight). 1-month compliance periods A monitoring rule which requires a determinand or parameter to be monitored on a monthly or weekly basis, e.g. 2 per week, 8 per month, etc., has a compliance period of 1 month. 3-month compliance periods A monitoring rule which requires a determinand or parameter to be monitored at least every 3 months has a compliance period of 3 months. 1-year compliance periods All other monitoring rules have a compliance period of 1 year. Note: Where monitoring occurs at least every 3 years or at least every 5 years, the rule may be reported as compliant if the sampling frequency has been met by the end of the calendar year being reported on. Assurance rules Assurance rules cover activities that water suppliers need to undertake, for example the preparation of a backflow prevention programme or a distribution zone sampling plan. Assurance rules are not used to demonstrate compliance with the Drinking Water Standards but indicate whether water suppliers undertake activities that contribute to the provision of safe drinking water. Assurance rules have a compliance period of 1 year. Page 13 of 85 Non-Reporting rules Some rules are designated as non-reporting rules and water suppliers are not required to report on their performance against those rules, though they are still expected to comply with the requirements of the rules. Non-reporting rules have no compliance period as they do not have to be reported on. Page 14 of 85 4. Compliance Rules Modules 4.1 G General Rules Module Rule number Requirement Rule type Compliance period G1. Drinking water suppliers following level 1 Rules modules must report annually— (a) whether they complied with each monitoring rule requirement; and (b) the number of quarters for which each monitoring rule requirement was not complied with during each calendar year; and (c) the supply component ID, sample ID, sample date, and test results for all samples analysed by a laboratory during the year; and (d) within 40 working days of the end of each calendar year; and (e) in an approved form. Rule replaced on 29 November 2024 Assurance 1 Year G2. Revoked Rule revoked on 29 November 2024 G2.1 Drinking water suppliers following level 2 monitoring rules must report quarterly— (a) whether they complied with each monitoring rule requirement; and (b) the number of months for which each monitoring rule requirement was not complied with during each quarter; and (c) the supply component ID, sample ID, sample date, and test results for all samples analysed by a laboratory taken during the quarter; and (d) within 20 working days of the end of each quarter; and (e) in an approved form. Rule inserted on 29 November 2024 Assurance 1 Year Page 15 of 85 6 Removed Rule number Requirement Rule type Compliance period G2.2 Drinking water suppliers following level 2 assurance rules must report annually— (a) whether they complied with each assurance rule during each calendar year; and (b) within 40 working days of the end of each calendar year; and (c) in an approved form. Rule inserted on 29 November 2024 Assurance 1 Year G3. Drinking water suppliers demonstrating compliance against level 3 Rules must report to Taumata Arowai the water quality monitoring information set out in tables 5, 6 and 7. Assurance As set out in tables 5, 6 and 7 G4. Drinking water suppliers reporting against level 3 monitoring rules that are not included in tables 5, 6, and 7 must report annually within 40 working days of the end of each calendar year. Rule replaced on 29 November 2024 Assurance As set out in the relevant rules G5. Drinking water suppliers demonstrating compliance with level 3 rules, must report on their performance against all assurance rules annually within 40 days of the end of each calendar year. 6 Rule replaced on 29 November 2024 Assurance 1 Year G6. All samples collected from drinking water supplies for monitoring that are analysed by laboratories, must be labelled with the unique source, treatment plant, distribution zone, or Water Carrier Service identifier allocated by Taumata Arowai, to show where the sample was collected from and the time and date that the sample was collected. Assurance 1 Year G7. Drinking water suppliers must take reasonably practicable steps to ensure that samples for E. coli, total coliforms, or other microbiological contaminants are delivered to a laboratory within 24 hours of the sample being collected, and at a water temperature that is no higher than the water temperature at the time of sampling but above zero degrees Celsius. Assurance 1 year Page 16 of 85 Rule number Requirement Rule type Compliance period G8. All water samples that require laboratory analysis and are used to demonstrate compliance with these Rules must be: a. analysed by a laboratory accredited by IANZ for the type of analysis being undertaken; and b. collected according to any instructions and specifications provided by the laboratory. Assurance 1 year G9. Equipment used for the analysis of single samples (grab samples) by drinking water suppliers, to demonstrate compliance with any rule, must be calibrated/verified in accordance with the instrument manufacturer’s specified procedures and frequency. Assurance 1 Year G10. All work (planned or unplanned) on a water supply must be completed by suitably trained or experienced personnel. Assurance 1 Year G11. Drinking water suppliers must prepare a hygiene code of practice for people working on a water supply which must include: a. maintenance of personal hygiene at all times; and b. prohibition of people working on a water system who are experiencing any gastrointestinal illness; and c. protection of the work site, materials, and tools from contamination; and d. how all reasonable steps will be taken to minimise the entry of contamination into the water supply during any activity. Assurance 1 Year G12. Continuous on-line monitoring equipment used to demonstrate compliance with any rule must: a. be calibrated in accordance with the instrument manufacturer’s specified procedures and frequency; and b. have calibration verified in accordance with the instrument manufacturer’s specified procedures. Assurance 1 Year Page 17 of 85 Table 3. Removed Table 4. Removed 8 9 7 Separation between data records of up to five minutes is allowed for FAC analysers and fluoride analysers where the minimum cycle time specified by the analyser manufacturer exceeds 1 minute. 8 Removed 9 Removed Rule number Requirement Rule type Compliance period G13. For continuous monitoring equipment that is used to demonstrate compliance against treatment Rules (T1, T2, T3), the separation between data records must be no more than 1 minute. 7 Assurance 1 Year G14. Generation of continuous monitoring data that is used to demonstrate compliance against T3 treatment Rules or D3 Distribution Rules, must not be interrupted for a period of more than 15 consecutive minutes, or for a total of more than 72 minutes in any one-day compliance period, for compliance to be achieved. Assurance 1 Year G15. For continuous monitoring equipment that is used to assess source water or to demonstrate compliance against distribution zone Rules, the separation between data records must be no more than 30 minutes. Assurance 1 Year G16. Continuous monitoring equipment used to monitor FAC in distribution zones must be appropriately pH and temperature compensated. Assurance 1 Year G17. Where continuous monitoring equipment that is used to demonstrate compliance (excludes source water monitoring) fails, or is not otherwise able to provide data, grab samples can be taken to substitute for continuous data if analyses of the parameters is undertaken for at least every 30-minute period that the continuous monitoring equipment is not operating. Monitoring Dependent on the parameter and circumstances Page 18 of 85 Table 5. Bacterial reporting requirements for level 3 Rules. Rule 10 Parameter Compliance Period Reporting period 11 If chlorine is the primary disinfectant T3.2 Chlorine C.t 1 Day 1 Month If chlorine dioxide is the primary disinfectant T3.8 Chlorine dioxide C.t 1 Day 1 Month If ozone is the primary disinfectant T3.13 Ozone residual 1 Day 1 Month If UV is the primary disinfectant T3.17 UV dose 1 Day 1 Month Table 6. Protozoal reporting requirements for level 3 Rules. Rule 12 Parameter Compliance Period Reporting period 13 For Coagulation, Flocculation and Sedimentation without Filtration T3.24 Turbidity 1 Day 1 Month For Coagulation, Flocculation and Sedimentation with Filtration, Second Stage Filtration, Slow Sand Filtration, Membrane Filtration or Cartridge Filtration Depending on process used, either: (T3.27 and T3.28) (T3.31 and T3.32) (T3.35 and T3.36) (T3.39 and T3.40) (T3.43 and T3.44) (T3.47 and T3.48) (T3.51 and T3.52) (T3.60 and T3.61) (T3.65 and T3.66) (T3.76 and T3.77) Turbidity 1 Day 1 Month For ozone T3.81 Ozone C.t 1 Day 1 Month If UV is the primary disinfectant T3.86 UV dose 1 Day 1 Month 10 Reporting is only required against one of the rules in this column depending on whether chlorine, ozone or UV is used as the primary disinfectant. 11 Report must be provided to Taumata Arowai within 10 working days of the end of each month. 12 Reporting is only required against one pair (in brackets) of the rules in this column depending on the process that is used to demonstrate an effective protozoa barrier. 13 Report must be provided to Taumata Arowai within 10 working days of the end of each month. Page 19 of 85 Table 7. Distribution zone reporting requirements for level 3 Rules. Rule Number Parameter Compliance period Reporting period 14 D3.19 FAC 1 Month 1 Month D3.29 E. coli, total coliforms 1 Month 1 Month 14 Report must be provided to Taumata Arowai within 10 working days of the end of each month. Page 20 of 85 4.2 VSC Very Small Communities Rules Module Rule number Requirement Rule type Compliance period VSC.1 Drinking water must be monitored at least every 6 months for the following: (a) E. coli: (b) total coliforms. Rule replaced on 29 November 2024 Non-reporting N/A VSC.2 All water samples taken for VSC.1 must be— (a) analysed by a laboratory accredited by IANZ for those tests; and (b) collected according to the requirements of that laboratory. Rule replaced on 29 November 2024 Non-reporting N/A VSC.3 When the population exceeds 25 people for more than 60 days in any 12-month period, the relevant Rules modules for Small Supplies set out in Table 2 must be followed, for the remainder of the calendar year. Rule replaced on 29 November 2024 Non-reporting N/A VSC.4 When the population exceeds 50 people for a planned event, the following requirements apply: (a) during the event, water must be— (i) filtered; and either (ii) disinfected with UV light; or (iii) chlorinated: (b) drinking water must be monitored in the week before the event and weekly if the event exceeds 1 week for the following: (i) E. coli: (ii) total coliforms. Rule inserted on 29 November 2024 Non-reporting N/A Page 21 of 85 4.3 S1 Source Water Rules Module Rule number Requirement Rule type Compliance period S1.1 Surface and groundwater sources must be monitored— (a) at least every 3 months for the following: (i) E. coli: (ii) total coliforms; and Monitoring 3 Months (b) at least every 3 years for the following: (i) arsenic: (ii) boron: (iii) nitrate: (iv) manganese. Rule replaced on 29 November 2024 Monitoring 1 Year S1.2 Roof water sources must be monitored— (a) at least every 3 months for the following: (i) E. coli: (ii) total coliforms; and Monitoring 3 Months (b) at least every 3 years for the following: (i) cadmium: (ii) copper: (iii) lead. Rule replaced on 29 November 2024 Monitoring 1 Year S1.3 Any chemical determinands that are identified as presenting a risk to the supply or are found to exceed 50% of their MAV in source water samples must be monitored at least annually until 3 consecutive results from source water samples are less than the 50% of the MAV. Rule replaced on 29 November 2024 Monitoring 1 Year S1.4 Samples collected under— (a) rule S1.1 must be collected at the abstraction point or treatment plant prior to treatment and/or mixing with other sources; and (b) rule S1.2 must be collected at the raw water storage tank outlet and prior to any treatment. Rule replaced on 29 November 2024 Non-reporting N/A Page 22 of 85 Table 8. Removed 15 Table 9. Removed 15 Removed S1.5 The following measures must be taken in relation to surface water intakes: (a) each month between October and May (inclusive)— (i) the water and area around and upstream of the intake must be inspected for the presence of benthic cyanobacteria mats and planktonic cyanobacterial growth; or (ii) water must be monitored for cyanobacterial cell count at the treatment plant prior to mixing and treatment: (b) if there is evidence of cyanobacterial growth, steps must be taken to evaluate the cyanotoxin risk to consumers: (c) if there is a risk of supplying water with cyanotoxins that exceed MAVs, abstraction of water must be discontinued, an alternative source used, or treatment installed, until the risk is no longer present. Rule replaced on 29 November 2024 Non-reporting N/A S1.6 Consumer taste or odour complaints, which have the potential to relate to cyanobacteria, must be— (a) recorded; and (b) investigated to determine the cause. Rule inserted on 29 November 2024 Non-reporting N/A Page 23 of 85 4.4 T1 Treatment Rules Module Rule number Requirement Rule type Compliance period T1.1 Water leaving a treatment plant must be monitored at least every 3 months for the following: (a) E. coli: (b) total coliforms: (c) turbidity. Rule replaced on 29 November 2024 Monitoring 3 months T1.2 Any additional determinand(s) which are identified as presenting a risk to the supply must be monitored at least every 3 months in water leaving a treatment plant until 3 consecutive results from treated water samples confirm the determinand(s) to be less than 50% of the MAV. Rule replaced on 29 November 2024 Monitoring 1 Year T1.3 All water, excluding groundwater abstracted from a depth of greater than 30 metres, must be filtered by a— (a) cartridge filter system that includes a 5 micron (nominal) or smaller pore size; or (b) back-washable media filter; or (c) slow sand (biological) filter; or (d) membrane filter. Rule replaced on 29 November 2024 Non-reporting N/A T1.4 Where filtration is used— (a) the filtration system must be operated within the manufacturer’s design specifications at all times; and (b) pumps must not be connected directly to the discharge side of any cartridge filter; and (c) where pumping occurs after filtration, the filtrate must first pass directly to a tank. Rule replaced on 29 November 2024 Non-reporting N/A Page 24 of 85 Table 10. Removed 16 17 18 16 Removed 17 Removed 18 Removed T1.5 All water passing through a treatment plant must be disinfected with UV light and UV units must— (a) deliver at least 40 mJ/cm2 (or equivalent) reduction equivalent dose (RED) of UV light; and (b) be installed, maintained and operated according to the manufacturer’s instructions; and (c) be certified to (and operate within the specifications of) at least one of the following standards unless purchased before 1 August 2022: (i) NSF/ANSI 55 Class A (NSF, ANSI n.d): (ii) Ultraviolet Disinfection Guidance Manual (USEPA 2006b): (iii) DVGW Technical Standard W294 (DVGW 2006): (iv) ÖNORM M 5873-1: 2020 01 01; or ÖNORM M5873 (Osterreichisches Normungsinstitut 2001): (v) DIN 19294-1:2020-08. Rule replaced on 29 November 2024 Non-reporting N/A T1.6- T1.8 Revoked Rules revoked on 29 November 2024 Page 25 of 85 4.5 D1 Distribution System Rules Module Table 11. Removed 19 19 Removed Rule number Requirement Rule type Compliance period D1.1 Water in a distribution zone must be monitored at least every 3 months for the following: (a) E. coli: (b) total coliforms. Rule replaced on 29 November 2024 Monitoring 3 Months D1.2 The following measures must be taken in relation to backflow: (a) each distribution zone must be assessed for backflow risks and cross-connections at least every two years: (b) a register of all points of supply where there is a medium or high backflow risk must be maintained: (c) a suitable backflow prevention device must be installed at any point of supply identified in the register: (d) every testable backflow prevention device must be inspected and tested at least every 2 years by a suitably trained and qualified person: (e) any faulty backflow prevention device must be remediated as soon as practicable: (f) records of backflow prevention device test results must be retained. Rule replaced on 29 November 2024 Non-reporting N/A Page 26 of 85 4.6 S2 Source Water Rules Module Rule number Requirement Rule type Compliance period S2.1 Surface and groundwater sources must be monitored— (a) at least every month for the following: (i) E. coli: (ii) total coliforms; and Monitoring 1 Month (b) at least annually for the following: (i) pH: (ii) turbidity: (iii) iron: (iv) manganese: (v) nitrate: (vi) arsenic: (vii) boron. Rule replaced on 29 November 2024 Monitoring 1 Year S2.2 Roof water sources must be monitored— (a) at least every month for the following: (i) E. coli: (ii) total coliforms; and Monitoring 1 Month (b) at least every 3 years for the following: (i) cadmium: (ii) copper: (iii) lead. Rule replaced on 29 November 2024 Monitoring 1 Year S2.3 Any chemical determinands that are identified as presenting a risk to the supply or are found to exceed 50% of their MAV in source water samples must be monitored at least annually until 3 consecutive results from source water samples are less than 50% of the MAV. Rule replaced on 29 November 2024 Monitoring 1 Year S2.4 Samples collected under— (a) rule S2.1 must be collected at the abstraction point or treatment plant prior to treatment and/or mixing with other sources; and (b) rule S2.2 must be collected at the raw water storage tank outlet and prior to any treatment. Rule replaced on 29 November 2024 Non-reporting N/A Page 27 of 85 Table 12. Removed 20 21 Table 13. Removed 20 Removed 21 Removed S2.5 Water sources must be categorised as either no, low, medium or high risk for the presence of cyanobacteria. Rule replaced on 29 November 2024 Assurance 1 Year S2.6 The following measures must be taken in relation to surface water intakes: (a) each month between October and May (inclusive)— (i) the water and area around and upstream of the intake must be visually inspected for the presence of benthic cyanobacteria mats and planktonic cyanobacterial growth; or (ii) water must be monitored for cyanobacterial cell count at the treatment plant prior to mixing and treatment: (b) if there is evidence of cyanobacterial growth, steps must be taken to evaluate the cyanotoxin risk to consumers: (c) if there is a risk of supplying water with cyanotoxins that exceed MAVs, abstraction of water must be discontinued, an alternative source used, or treatment installed, until the risk is no longer present. Rule replaced on 29 November 2024 Non-reporting N/A S2.7 Consumer taste or odour complaints, which have the potential to relate to cyanobacteria, must be— (a) recorded; and (b) investigated to determine the cause. Rule replaced on 29 November 2024 Assurance 1 Year Page 28 of 85 4.7 T2 Treatment Rules Module Rule Number Requirement Rule Type Compliance period T2.1 Water leaving a treatment plant must be monitored at least every month for the following: (a) E. coli: (b) total coliforms: (c) any chemical used in the treatment process (Fluoride and FAC have separate requirements, see rule T2.2). Rule replaced on 29 November 2024 Monitoring 1 Month T2.2 Water leaving the treatment plant must be monitored at least 8 times per month for the following: (a) turbidity: (b) FAC (not required for self-supplied buildings): (c) pH (not required for self-supplied buildings): (d) fluoride (only if added to the water). Rule replaced on 29 November 2024 Monitoring 1 Month T2.3 Samples collected for rule T2.2 must— (a) be evenly spaced across each month; and (b) use at least 3 different days of the week within each month. Rule replaced on 29 November 2024 Non-reporting N/A T2.4 Water leaving a treatment plant must be monitored for chlorate at least every 3 months if sodium hypochlorite (or calcium hypochlorite) is used as a disinfectant and this solution is not generated on-site from a salt brine solution. Rule replaced on 29 November 2024 Monitoring 3 Months T2.5 Any additional determinands which are identified as presenting a risk to the supply must be monitored at least every month in water leaving a treatment plant until 3 consecutive results from treated water samples are less than the 50% of the MAV. Rule replaced on 29 November 2024 Monitoring 1 Year Page 29 of 85 T2.6 Water leaving a treatment plant must meet the following limits while the plant is in production: (a) turbidity must be less than 5 NTU: (b) FAC must be at least 0.5 mg/L (not required for self-supplied buildings): (c) pH must be between 6.5 – 8 (not required for self-supplied buildings). Rule replaced on 29 November 2024 Assurance 1 Year T2.7 All water, excluding groundwater abstracted from a depth of greater than 30 metres, must be filtered by a— (a) cartridge filter system that includes a 5 micron (nominal) or smaller pore size; or (b) back-washable media filter; or (c) slow sand (biological) filter; or (d) membrane filter. Rule replaced on 29 November 2024 Assurance 1 Year T2.8 If cartridge filtration is used— (a) the final cartridge must have a pore size of 5 microns (nominal) or less; and (b) pumps must not be connected directly to the discharge side of any cartridge filter; and (c) where pumping occurs after filtration, the filtrate must first discharge directly to a tank; and (d) differential pressure must be measured across each cartridge filter and must not exceed the cartridge filter manufacturer’s specifications; and (e) the flow through any filters must be within the manufacturer’s design specifications for the treatment processes at all times. Rule replaced on 29 November 2024 Assurance 1 Year T2.9 All water supplied to consumers must be— (a) disinfected with UV light; and (b) disinfected with chlorine (not required for self- supplied buildings). Rule replaced on 29 November 2024 Assurance 1 Year Page 30 of 85 T2.10 The following requirements must be met for UV treatment: (a) UV units must provide at least 40 mJ/cm2 (or equivalent) reduction equivalent dose (RED) of UV light: (b) UVT must be monitored monthly or continuously: (c) UVI or UV dose must be recorded twice weekly or monitored continuously: (d) UV units must be certified to (and operate within the specifications of) at least one of the following: (i) NSF/ANSI 55 Class A (NSF, ANSI n.d): (ii) Ultraviolet Disinfection Guidance Manual (USEPA 2006b): (iii) DVGW Technical Standard W294 (DVGW 2006): (iv) ÖNORM M 5873-1: 2020 01 01; or ÖNORM M5873 (Osterreichisches Normungsinstitut 2001): (v) DIN 19294-1:2020-08: (e) water flowing through the UV unit/s must— (i) meet the limits of UVT specified by the manufacturer; and (ii) be restricted or monitored so that the flow rate does not exceed the flow rate specified by the manufacturer: (f) lamp usage must— (i) be recorded; and (ii) be alarmed if the UV unit has more than one lamp; and (iii) not exceed manufacturer's recommendations: (g) the duty UVI sensor must— (i) be referenced against a new sensor annually; and (ii) be replaced if the duty sensor reads levels different to the new sensor that are outside the manufacturer’s recommendation. Rule replaced on 29 November 2024 Assurance 1 Year Page 31 of 85 T2.11- T2.25 Revoked 22 23 24 25 26 27 Rules revoked on 29 November 2024 Table 14. Removed 22 Removed 23 Removed 24 Removed 25 Removed 26 Removed 27 Removed Page 32 of 85 4.8 D2 Distribution System Rules Module Rule number Requirement Rule type Compliance period D2.1 Water in each distribution zone must be monitored at least every month for the following: (a) E. coli: (b) total coliforms. Rule replaced on 29 November 2024 Monitoring 1 Month D2.2 Water in each distribution zone must be monitored at least 8 times every month for FAC. Rule replaced on 29 November 2024 Monitoring 1 Month D2.3 Samples for FAC, E. coli and total coliforms must be taken at regular sampling points that are representative of the geographical coverage of each distribution zone including— (a) exit points of storage reservoirs/tanks; and (b) end points of the distribution zone. Rule replaced on 29 November 2024 Non-reporting N/A D2.4 Monitoring for FAC in each distribution zone must— (a) be evenly spaced across each month; and (b) use different days of the week. Rule replaced on 29 November 2024 Non-reporting N/A D2.5 Water in each distribution zone must be monitored at least annually for the following: (a) antimony: (b) cadmium: (c) chromium: (d) copper: (e) lead: (f) mercury: (g) nickel. Rule replaced on 29 November 2024 Monitoring 1 Year D2.6 When sampling for metals, sample points must— (a) be flushed immediately prior to obtaining samples; and (b) not be disinfected, e.g. flamed, immediately prior to sampling for metals; and (c) be located near the end point of the system. Rule replaced on 29 November 2024 Non-reporting N/A Page 33 of 85 D2.7 FAC in each distribution zone must be: (a) at least 0.2 mg/L in 80% of samples taken; and (b) no less than 0.1 mg/L at all times. Rule replaced on 29 November 2024 Assurance 1 Year D2.8 The following measures must be taken in relation to backflow: (a) each distribution zone must be assessed for backflow risks and cross-connections at least annually: (b) a register of all connections where there is a medium or high backflow risk must be maintained: (c) a suitable backflow prevention device must be installed at any connection identified in the register: (d) every testable backflow prevention device must be inspected and tested annually by a suitably trained and qualified person: (e) any faulty backflow prevention device must be remediated as soon as practicable: (f) records of backflow prevention device test results must be retained for at least 3 years. Rule inserted on 29 November 2024 Assurance 1 Year Table 15. Removed 28 28 Removed Page 34 of 85 4.9 S3 Source Water Rules Module 4.9.1 S3 Source Water Protozoa Log Credit Treatment Requirements Drinking water suppliers must determine the level of protozoa treatment required for a drinking water supply based on the requirements set out in the source class classifications below. Treatment systems must provide a protozoa barrier equal to or exceeding the source water, log credit treatment requirements for the applicable source water class. Class 1 – Protozoa barrier not required. Criteria Groundwater sources (bore water) that draw water from a depth of more than 30 metres below ground level (with depth measured from ground level to the top of the upper most screen) and via a sanitary bore head in which E. coli and total coliforms have not been detected over a period of three years 29 (monthly samples with a maximum of 45 days between samples). If a groundwater source has demonstrated Class 1 status but any result for E. coli or total coliforms is positive, the groundwater source must assume Interim Class 1 status. Interim Class 1 If a drinking water supplier intends to demonstrate Class 1 status for a groundwater source (bore water) but does not have the required E. coli or total coliforms data, they may demonstrate Interim Class 1 status by monitoring E. coli and total coliforms in bore water 30 daily for 36 days, and then weekly until 52 weeks of data has accrued with no E. coli or total coliforms detected. If any sample for E. coli or total coliforms is positive, the process must begin again until 52 weeks of data has accrued with negative results. If Class 1 category cannot be established within 24 months of beginning sampling, the water source must be classified as Class 2. Class 2 – Protozoa barrier – 3 log Criteria Groundwater sources that draw water from a depth of between 30 metres and 10 metres below ground level (with depth measured from ground level to the top of the upper most screen). 29 Samples can be from individual bores or water combined from up to six bores if the water is from the same aquifer and has similar characteristics. 30 Samples can be from individual bores or water combined from up to six bores if the water is from the same aquifer and has similar characteristics. Page 35 of 85 Class 3 – Protozoa Barrier – 4 log Criteria Groundwater sources that draw water from a depth of less than 10 metres below ground level (with depth measured from ground level to the top of the upper most screen), groundwater sources that draw water from a depth of 10 or more metres below ground level without a sanitary bore head, spring water sources and surface water sources. Class 4 – Protozoa Barrier – 3 log Criteria Drinking water supplies that require a minimum protozoa treatment barrier of 4-log may reduce the level of protozoa treatment to a minimum of 3-log if the source water risk management plan for the supply provides evidence that the source water has a low risk of protozoa contamination. 4.9.2 S3 Sanitary Bore Head Requirements A bore head is considered a sanitary bore head if it meets all of the following criteria: 1. The bore head is installed above ground. 2. The bore is installed in an area of ground that is not below the surrounding ground level such that ponding could occur around the bore head during rainfall. 3. The annulus of the casing is sealed taking account of the formation that the bore has been installed in, to prevent the ingress of surface water via the outside of the casing and the bore is grouted below ground to an appropriate depth. 4. A concrete apron is installed around the bore head, extending a minimum of one metre in all directions from the casing and sloping away from the casing so that any water on the ground surface is carried away from the bore. 5. All apertures into the bore (for cables etc) are sealed and watertight to prevent access from water and vermin-proofed to prevent access by small animals etc. 6. All air vents and any other apertures that are not watertight must be screened to prevent access by small animals, face downwards, and be elevated at least 0.5 metres above the surrounding ground level. 7. Reasonable security measures are in place to protect the bore head from unauthorised access or interference. 8. If the bore head is in an area where farm animals are present, it must be fenced to exclude those animals from an area extending at least five metres in all directions from the bore head. 9. A mechanism prevents backflow at the bore head. 10. The bore head is inspected monthly for damage or defects and records kept of all inspections for at least five years. Page 36 of 85 4.9.3 S3 Source Water Monitoring Rules 31 Samples of raw water may be collected at the treatment plant for this purpose. 32 Samples should not be collected if there are health and safety risks to people collecting samples that are not appropriately eliminated or minimised. Rule Number Requirement Assurance/ Monitoring Compliance period S3.1 Water suppliers must determine the class of source water for each of the source waters that are used, based on the Source Water Protozoa Log Credit Treatment Requirements. Assurance 1 Year S3.2 A drinking water supplier demonstrating Class 1 or Interim Class 1 groundwater must document whether or not the bore meets the requirements of a sanitary bore head. Assurance 1 Year S3.3 All source waters must be monitored for the determinands and at the frequencies set out in Table 16 and Table 18. Monitoring N/A S3.4 All groundwaters must be monitored for the radiological determinands set out in Table 17. Monitoring N/A S3.5 Additional monitoring of Class 2, Class 3 and Class 4 source waters must be undertaken either during or immediately after a severe or extreme weather event or other events which could adversely affect source water quality. 31 32 Monitoring N/A S3.6 Monitoring of source water must be undertaken for any determinand additional to those set out in Table 16 and 18 if the determinand has been identified in the drinking water supply Source Water Risk Management Plan as presenting a potential risk to the drinking water supply. Monitoring As determined by the Source Water Risk Management Plan S3.7 Water sources must be categorised as either low-risk, medium-risk or high-risk for the presence of cyanobacteria. Assurance 1 Year S3.8 When a water supply is categorised as medium or high-risk under rule S3.7, a cyanobacteria / cyanotoxin response plan must be prepared which includes vigilance levels for assessing the presence of cyanobacteria and alert levels related to the presence of cyanotoxins, monitoring for cyanobacteria/cyanotoxins and the action that will be taken to protect consumers. Assurance 1 Year Page 37 of 85 Table 16. S3 Source Water Monitoring Determinands Determinand Group Determinands monitored at each abstraction point 33 34 Sampling Frequency Bacterial E. coli and total coliforms 2 per Month Physico- chemical Iron, manganese, colour, nitrate Monthly Alkalinity, antimony, arsenic, barium, cadmium, calcium, chloride, chromium, copper, lead, magnesium, mercury, nickel, sodium, sulphate. Annually 35 Table 17. S3 Class 1, Class 2 and Class 3 Groundwater Source Monitoring Determinands Determinand Group Determinands monitored at each source 36 37 Sampling Frequency Radiological Gross alpha activity Gross beta activity Every ten years Chemical Potassium 38 Every ten years 33 Samples may be collected either at the source abstraction point or at the treatment plant before any form of treatment, if water is from a single source. If multiple sources are used, samples must be collected from each source at points before any mixing of source water occurs. 34 Where multiple bores access the same aquifer, one bore can be sampled to provide results that are representative of a number of bores if the water supplier can demonstrate that the bore that is sampled is representative of the bores that are not sampled. The representative nature of the sampled bore must be re- established every five years or after significant seismic activity. 35 Must be sampled monthly if the determinand exceeds 50% of its MAV. Sampling may return to annually after 12 consecutive samples are less than 50% of the MAV. 36 Samples may be collected either at the source abstraction point or at the treatment plant before any form of treatment, if water is from a single source. If multiple sources are used, samples must be collected from each source at points before any mixing of source water occurs. 37 Where multiple bores access the same aquifer, one bore can be sampled to provide results that are representative of a number of bores if the water supplier can demonstrate that the bore that is sampled is representative of the bores that are not sampled. 38 When samples are analysed for alpha and beta emitting particles a sample for potassium must also be analysed so that the potassium 40 contribution to beta emitting particles can be determined. S3.9 If a water supplier becomes aware of the presence of cyanobacteria in source water, monitoring to determine the level of cyanobacteria and/or cyanotoxin levels must be considered in accordance with the cyanobacteria/cyanotoxin response plan. Assurance 1 Year Page 38 of 85 Table 18. S3 Raw Water Monitoring Parameters Parameters monitored in raw water from each source or combined sources 39 Sampling Frequency Class 1 and Interim Class 1 Physico- chemical Conductivity, pH, Turbidity Monthly for 12 months Every 6 months if there is no significant variation in the initial 12 months of samples 40 Classes 2, 3 and 4 Physico- chemical Conductivity, pH, Turbidity Continuous 41 39 If water is abstracted from more than one source and combined at the treatment plant, only the combined water needs to be analysed and this can be done at the treatment plant before any form of treatment. 40 If a six monthly sample varies significantly from previous samples, sampling should return to monthly for 12 months. 41 Where continuous monitoring analysers fail or require maintenance, daily grab samples can be taken until the continuous monitoring equipment can be brought back into service. Page 39 of 85 4.10 T3 Treatment Rules Module 4.10.1 T3 Bacterial Rules One or more of the following options must be used to demonstrate bacterial compliance: 1. Disinfection with chlorine 42 2. Disinfection with chlorine dioxide 3. Disinfection with ozone 4. Disinfection with UV light 4.10.1.1 T3 Bacterial Rules for Water Disinfected with Chlorine Rule Number Requirement Assurance/ Monitoring Compliance period T3.1 All water passing through the treatment plant must be treated with chlorine and must be monitored in accordance with Table 19. Monitoring 1 Day T3.2 Treated water must achieve a chlorine C.t value of at least 15 min.mg/L for at least 95 % of each day. Monitoring 1 Day T3.3 Treated water must have a FACE of no less than 0.2 mg/L. Monitoring 1 Day T3.4 T10 contact time of at least 5 minutes must be demonstrated. Monitoring 1 Day T3.5 Turbidity of water leaving the treatment plant must be less than 1.0 NTU for at least 95% of each day. 43 Monitoring 1 Day T3.6 Turbidity must not exceed 2.0 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day Table 19. T3 Requirements for Drinking Water Disinfected with Chlorine Parameters that need to be continuously monitored and where they need to be monitored: Parameters: FAC Where it needs to be monitored: Water at a point after the prescribed disinfection contact time has elapsed. Parameters: pH Where it needs to be monitored: Water at a point after the prescribed disinfection contact time has elapsed. 42 For Self-supplied Buildings supplies that provide water to more than a single building chlorine must be used to demonstrate bacterial compliance. 43 Where lime is used for post-treatment pH adjustment, analysis may be undertaken before the lime is dosed. Page 40 of 85 Parameters: Turbidity Where it needs to be monitored: Water at a point after the prescribed disinfection contact time has elapsed. Parameters: Flow Where it needs to be monitored: Water leaving the contact tank unless there is a high-level outlet weir in which case water entering the contact tank is acceptable. A calculated outlet flow based on inlet flow and contact level change is also an acceptable approach. Water level in the contact tank (if used). Values that need to be continuously monitored: FACE. T10 Contact Time. C.t Page 41 of 85 4.10.1.2 T3 Bacterial Rules for Water Disinfected with Chlorine Dioxide Rule Number Requirement Assurance/ Monitoring Compliance period T3.7 All water passing through the treatment plant must be treated with chlorine dioxide and must be monitored in accordance with Table 19. Monitoring 1 Day T3.8 Treated water must achieve a chlorine C.t value of at least 15 min.mg/L for at least 95 % of each day. Monitoring 1 Day T3.9 T10 contact time of at least 5 minutes must be demonstrated. Monitoring 1 Day T3.10 Turbidity of water leaving the treatment plant must be less than 1.0 NTU for at least 95% of each day. 44 Monitoring 1 Day T3.11 Turbidity must not exceed 2.0 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day Table 20. T3 Requirements for Drinking Water Disinfected with Chlorine Dioxide Parameters that need to be continuously monitored and where they need to be monitored: Parameters: Chlorine dioxide Where it needs to be monitored: Water at a point after the prescribed disinfection contact time has elapsed. Parameters: FAC if used in combination with chlorine dioxide Where it needs to be monitored: Water at a point after the prescribed disinfection contact time has elapsed. Parameters: pH Where it needs to be monitored: Water at a point after the prescribed disinfection contact time has elapsed. Parameters: Turbidity Where it needs to be monitored: Water at a point after the prescribed disinfection contact time has elapsed. Parameters: Flow Where it needs to be monitored: Water leaving the contact tank unless there is a high-level outlet weir in which case water entering the contact tank is acceptable. A calculated outlet flow based on inlet flow and contact level change is also an acceptable approach. Water level in the contact tank (if used) 44 Where lime is used for pH adjustment, samples may be taken before the lime is dosed. Page 42 of 85 Values that need to be continuously monitored: FACE if chlorine is used in combination with chlorine dioxide. Total disinfectant T10 Contact Time. C.t 4.10.1.3 T3 Bacterial Rules for Water Disinfected with Ozone Rule Number Requirement Assurance/ Monitoring Compliance period T3.12 All water passing through the treatment plant must pass through the ozone contactor and must be monitored in accordance with Table 21. Monitoring 1 Day T3.13 C.t of at least 1.2 mg.min/L for more than 95% of each day must be achieved. Monitoring 1 Day T3.14 Turbidity must not exceed 5.0 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day Table 21. T3 Requirements for Water Disinfected with Ozone Parameters that need to be continuously monitored and where they need to be monitored: Parameters: Ozone Residual Where it needs to be monitored: Water leaving the contact tank. 45 Parameters: Turbidity Where it needs to be monitored: Water at a point immediately before or after the contact tank. Parameters: Flow Where it needs to be monitored: Water leaving the contact tank unless there is a high-level outlet weir in which case water entering the contact tank is acceptable. A calculated outlet flow based on inlet flow and contact level change is also an acceptable approach. Level of water in the contact tank (if used). Values that need to be continuously monitored: T10 Contact Time. C.t (Ozone x T10 Contact Time). 45 Additional monitoring sites may be used in addition to the contact tank exit point if the water supplier can demonstrate that they improve the accuracy of the monitoring information. Page 43 of 85 4.10.1.4 T3 Bacterial Rules for Water Disinfected with Ultraviolet Light Rule Number Requirement Monitoring/ Assurance Compliance period T3.15 All water passing through the treatment plant must pass through the UV reactor(s) and be within the reactor’s certified flow range and must be monitored in accordance with Table 22. Monitoring 1 Day T3.16 A reduction equivalent dose (RED) of not less than 40 mJ/cm2 (or equivalent) must be achieved for not less than 95 % of each day. Monitoring 1 Day T3.17 The RED UV dose must be not less than 40 mJ/cm2 for any consecutive 15-minute period. Monitoring 1 Day T3.18 Turbidity must not exceed 5.0 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.19 For UV units certified to Ultraviolet Disinfection Guidance Manual (USEPA 2006b) monitored UVI, UVT and flow must be used to calculate dose. Assurance 1 Year T3.20 For UV units certified to DVGW Technical Standard W294 (DVGW 2006) or ÖNORM M 5873-1: 2020 01 01 46 monitored flow must be used for UVI control or the reactor run at full power. UVI and UVT must be more than the validated value for the respective flow. Assurance 1 Year T3.21 For UV units certified to NSF/ANSI 55 Class A (NSF, ANSI n.d.); (for populations of up to 5000) – 3-log a fault must be generated when any parameter exceeds the certified value. Assurance 1 Year 46 Or UV reactors certified to öNORM M5873 (Osterreichisches Normungsinstitut 2001) Page 44 of 85 Table 22. T3 Requirements for UV Disinfection Parameters that need to be continuously monitored and where they need to be monitored: Parameters: UVT Where it needs to be monitored: Water entering or leaving the UV reactor(s). 47 Parameters: Turbidity Where it needs to be monitored: Water entering or leaving the UV reactor(s). Can include upstream filter monitoring if there is no other process between the filters and the UV reactors. Parameters: UVI or dose Where it needs to be monitored: The same point in the reactor as that used for certification/validation. Parameters: Flow Where it needs to be monitored: At a point representative of water entering or leaving the reactor(s). UVI sensor checking and standardisation: Duty UVI sensors must be checked at least monthly against the reference sensor. If the difference between the two readings exceeds the manufacturer’s specified limits, then the Duty UVI sensor must be replaced. The reference UVI sensor must be standardised at least annually in accordance with Ultraviolet Disinfection Guidance Manual (USEPA 2006b) or other traceable procedure. Alternatively, after 12 months the drinking water supplier can use the reference sensor as a duty sensor and purchase a new standardised sensor for use as a reference sensor. UV certification/validation: The equipment must be certified and operated to meet the RED dose of 40 mJ/cm2 (or equivalent) using at least one of the: Ultraviolet Disinfection Guidance Manual (USEPA 2006b). DVGW Technical Standard W294 (DVGW 2006) ÖNORM M 5873-1: 2020 01 01. 48 NSF/ANSI 55 (NSF, ANSI nd) for Class A systems (for populations of up to 5000) – 3-log. 47 Does not apply to UV units certified to NSF/ANSI 55 (NSF, ANSI nd) for Class A systems (for populations of up to 5000) – 3-log. 48 UV reactors installed before 1 January 2020 can be certified to öNORM M5873 (Osterreichisches Normungsinstitut 2001). Page 45 of 85 4.10.2 T3 Protozoal Rules Rule Number Requirement Assurance/ Monitoring Compliance period T3.22 Drinking water supplies must have a protozoa barrier that provides treatment equal to or exceeding the log level of the water class identified by the Source Water Protozoa Log Credit Treatment Requirements. Assurance 1 Year Treatment processes and log credit allocations The processes that can be used for protozoal treatment, and the log credits that can be achieved are: 1. Coagulation, flocculation and sedimentation process without filtration [0.5-Log] 2. Coagulation, flocculation and direct filtration [2.5-3.5-Log] 3. Coagulation, flocculation, sedimentation, and filtration [3-4-Log] 4. Second stage filtration [0.5-Log] 5. Slow sand filtration [2.5-Log] 6. Membrane filtration [up to 4.0-Log] 7. Cartridge filtration [2.0-Log] 8. Ozone [0.25 to 3.0-Log] 9. Ultraviolet light [up to 4-Log] The cumulative log credits of a process that includes filtration or sedimentation and a disinfection process can be calculated by adding the log credits of the qualifying processes that are used. If two filtration processes are used, the second filtration process is considered to be second stage filtration and can add only 0.5-Log to the cumulative log credits. Water suppliers must comply with the rules set out below that apply to the treatment process(es) they are using. Page 46 of 85 4.10.2.1 T3 Protozoal Rules for Coagulation, Flocculation and Sedimentation without Filtration [0.5-Log]. Rule Number Requirement Assurance/ Monitoring Compliance period T3.23 All water passing through the treatment plant must pass through the coagulation, flocculation and sedimentation process. Assurance 1 Year T3.24 The sedimentation process must achieve at least a 70% reduction in raw water turbidity each day, based on the arithmetic mean of the turbidity of the raw water and the water leaving the sedimentation process. Monitoring 1 Day T3.25 All of the monitoring requirements in Table 23 must be met. Monitoring 1 Day Table 23. T3 Requirements for Coagulation, Flocculation and Sedimentation without Filtration Parameters that need to be continuously monitored and where they need to be monitored: Parameter: Turbidity. Where it needs to be monitored: On the inlet and outlet of sedimentation process. Process Limitations: Sedimentation includes dissolved air flotation. Water from any treatment processes must not be added to the raw water and recycled through the plant. Page 47 of 85 4.10.2.2 T3 Protozoal Rules for Coagulation, Flocculation, and Direct Filtration [2.5-Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.26 All water passing through the treatment plant must pass through the coagulation, flocculation, and filtration process. Assurance 1 Year T3.27 Turbidity must not exceed 0.3 NTU for more than 5% of each day. Monitoring 1 Day T3.28 Turbidity must not exceed 0.5 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.29 All of the requirements in Table 24 must be met. Assurance 1 Year 4.10.2.3 T3 Protozoal Rules for Coagulation, Flocculation, and Direct Filtration [3.0-Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.30 All water passing through the treatment plant must pass through the coagulation, flocculation, and filtration process. Assurance 1 Year T3.31 Turbidity must not exceed 0.15 NTU for more than 5% of each day. Monitoring 1 Day T3.32 Turbidity must not exceed 0.5 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.33 All of the requirements in Table 24 must be met. Assurance 1 Year Page 48 of 85 4.10.2.4 T3 Protozoal Rules for Coagulation, Flocculation, and Direct Filtration [3.5-Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.34 All water passing through the treatment plant must pass through the coagulation, flocculation and filtration process. Assurance 1 Year T3.35 Turbidity must not exceed 0.1 NTU for more than 5% of each day. Monitoring 1 Day T3.36 Turbidity must not exceed 0.3 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.37 All of the monitoring requirements in Table 24 must be met. Monitoring 1 Day Table 24. T3 Requirements for Coagulation, Flocculation and Direct Filtration Parameters that need to be continuously monitored and where they need to be monitored: Parameter: Turbidity Where it needs to be monitored: On the outlet of each filter. Monitored when the filter is in service to supply, on any recycle streams to the plant inlet (if present). Parameter: Service State. Where it needs to be monitored: Each filter. Process Limitations: Filtration is of a rapid media design (pressure or gravity equivalent). Water treatment plants that recycle waste streams (excluding water from rapid media filters being diverted during restart after backwash, often called ‘filter to waste’) must return the recycle stream so that it undergoes the full treatment process and provide flow equalisation such that the instantaneous total return rate does not exceed 10% of the plant inflow. Turbidity monitoring is required to demonstrate that the recycle water has received effective solids/liquid separation. If instantaneous total return rate flows of greater than 10% of the plant inflow are recycled, separate treatment of the recycled stream is required to inactivate or kill protozoa and bacteria before the waste stream is returned to the plant inlet. Page 49 of 85 4.10.2.5 T3 Protozoal Rules for Coagulation, Flocculation, Sedimentation, and Filtration [3-Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.38 All water passing through the treatment plant must pass through the coagulation, flocculation, sedimentation, and filtration process. Assurance 1 Year T3.39 Turbidity must not exceed 0.3 NTU for more than 5% of each day. Monitoring 1 Day T3.40 Turbidity must not exceed 0.5 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.41 All of the monitoring in Table 25 must be met. Monitoring 1 Day 4.10.2.6 T3 Protozoal Rules for Coagulation, Flocculation, Sedimentation, and Filtration [3.5- Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.42 All water passing through the treatment plant must pass through the coagulation, flocculation, sedimentation, and filtration process. Assurance 1 Year T3.43 Turbidity must not exceed 0.15 NTU for more than 5% of each day. Monitoring 1 Day T3.44 Turbidity must not exceed 0.5 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.45 All of the monitoring requirements in Table 25 must be met. Monitoring 1 Day Page 50 of 85 4.10.2.7 T3 Protozoal Rules for Coagulation, Flocculation, Sedimentation, and Filtration [4-Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.46 All water passing through the treatment plant must pass through the coagulation, flocculation, sedimentation, and filtration process. Assurance 1 Year T3.47 Turbidity must not exceed 0.1 NTU for more than 5% of each day. Monitoring 1 Day T3.48 Turbidity must not exceed 0.3 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.49 All of the monitoring requirements in Table 25 must be met. Monitoring 1 Day Table 25. T3 Requirements for Coagulation, Flocculation, Sedimentation and Filtration Parameters that need to be continuously monitored and where they need to be monitored: Parameters: Turbidity. Where it needs to be monitored: On the outlet of each filter. Monitored when the filter is in service to supply, on any recycle streams to the plant inlet (if present). Parameters: Service State. Where it needs to be monitored: Each filter. Process Limitations: Sedimentation includes dissolved air flotation. Filtration is of a rapid media design (pressure or gravity equivalent). Water treatment plants that recycle waste streams (excluding water from rapid media filters being diverted during restart after backwash, often called ‘filter to waste’) must return the recycle stream so that it undergoes the full treatment process and provide flow equalisation such that the instantaneous total return rate does not exceed 10% of the plant inflow. Turbidity monitoring is required to demonstrate that the recycle water has received effective solids/liquid separation. If flows of greater than 10% are recycled, separate treatment of the recycled stream is required to inactivate or kill protozoa and bacteria before the waste stream is returned to the plant inlet. Page 51 of 85 4.10.2.8 T3 Protozoal Rules for Second Stage Filtration [0.5-Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.50 All water passing through the treatment plant must pass through the second stage filtration process. Assurance 1 Year T3.51 Turbidity must not exceed 0.1 NTU for more than 5% of each day. Monitoring 1 Day T3.52 Turbidity must not exceed 0.3 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.53 All of the monitoring requirements in Table 26 must be met. Monitoring 1 Day Table 26. T3 Requirements for Second Stage Filtration Parameters that need to be continuously monitored and where they need to be monitored: Parameters: Turbidity. Where it needs to be monitored: On the outlet of each filter, monitored when the filter is in service to supply. Parameters: Service State. Each filter. Process Limitations: A second filtration stage consists of media or granular activated carbon, other fine grain media in a separate stage after granular media filtration with preceding coagulation. Page 52 of 85 4.10.2.9 T3 Protozoal Rules for Slow Sand Filtration [2.5-Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.54 All water passing through the treatment plant must pass through the slow sand filtration process. Assurance 1 Year T3.55 The filter must not dry out. Assurance 1 Year T3.56 Disinfecting chemicals must not be dosed so that they leave a residual disinfectant upstream of the filter beds. Assurance 1 Year T3.57 Following filter maintenance, when a filter is brought back into operation, water must be discharged to waste until the filtration process has been demonstrated to be effective. Assurance 1 Year T3.58 The filters must be operated at a surface loading rate of less than 0.35 m3/m2/h. Assurance 1 Year T3.59 The temperature of the water entering the filter must not drop below 6°C at any time. Monitoring 1 Day T3.60 Turbidity must not exceed 0.5 NTU for more than 5% of each day. Monitoring 1 Day T3.61 Turbidity must not exceed 1.0 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.62 All of the monitoring requirements in Table 27 must be met. Monitoring 1 Day Table 27. T3 Requirements for Slow Sand Filtration Parameters that need to be continuously monitored and where they need to be monitored: Parameters: Temperature. Where it needs to be monitored: Water entering the filtration stage. Parameters: Turbidity. Where it needs to be monitored: On the outlet of each filter, monitored when the filter is in service to supply. Parameters: Flow. Where it needs to be monitored: On the outlet of each filter. Values that need to be continuously monitored: Surface loading rate. Process Limitations: Water treatment plants that recycle waste streams must return the recycle stream so that it undergoes the full treatment process and provide flow equalisation such that the instantaneous total return rate does not exceed 10% of the plant inflow. Page 53 of 85 Turbidity monitoring is required to demonstrate that the recycle water has received effective solids/liquid separation. If flows of greater than 10% are recycled, separate treatment of the recycled stream is required to inactivate or kill protozoa and bacteria before the waste stream is returned to the plant inlet. 4.10.2.10 T3 Protozoal Rules for Cartridge Filtration [2.0-Log] 49 Exceedances of not more than 2% are allowable to take account of measurement accuracy. Rule Number Requirement Assurance/ Monitoring Compliance period T3.63 All water passing through the treatment plant must pass through the cartridge filtration process. Assurance 1 Year T3.64 Rapid pressure fluctuations on either side of the cartridges must be avoided. Pumps must not be connected directly to the discharge side of a cartridge filter. After filtration, the filtrate must pass to a tank if there is subsequent pumping. Assurance 1 Year T3.65 Filtered water turbidity does not exceed 1.0 NTU for more than 5% of each day. Monitoring 1 Day T3.66 Filtered water turbidity does not exceed 1.0 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.67 The filtrate turbidity from each filter housing must not exceed the turbidity of the cartridge feed water for the duration of any consecutive 15- minute period. 49 Monitoring 1 Day T3.68 The equipment is operated within the flow range for which it was certified at all times. Assurance 1 Year T3.69 Differential pressure across cartridges must be measured and kept within the manufacturer’s recommendations at all times. Assurance 1 Year T3.70 The minimum differential pressure must always exceed the differential pressure established at commissioning with a new cartridge and must be kept within the manufacturer’s recommendations. Assurance 1 Year Page 54 of 85 Table 28. T3 Requirements for Cartridge Filtration Parameters that need to be continuously monitored and where they need to be monitored: Parameters: Turbidity. Where it needs to be monitored: On the combined inlet to the process. On the outlet of each filtration housing. Parameters: Differential Pressure. Where it needs to be monitored: Across each filtration housing. Parameters: Flow. Where it needs to be monitored: On the inlet or outlet of each filtration housing. Parameters: Service State. Where it needs to be monitored: Each filtration unit. Cartridge Validation/ Certification: Each cartridge must have a certified Cryptosporidium (oo)cyst removal efficiency of at least 3-log and be certified to one of the following: 1. the USEPA (2010)’s Long Term 2 Enhanced Surface Water Treatment Rule: Toolbox Guidance Manual Part 8: Bag and Cartridge Filters. 2. the (oo)cyst reduction conditions of Drinking Water Treatment Units: Health effects, NSF/ANSI 53 (NSF, ANSI 2002). 3. The (oo)cyst removal requirements of a standard recognised by Taumata Arowai as being equivalent (e.g., AS/NZS 4348:1995 in conjunction with AS/NZS 3497:1998 (updated 2001)). T3.71 Individual cartridges must be able to be clearly identified in relation to the manufacturer and the part number that relates to the validation/certification. Assurance 1 Year T3.72 All of the monitoring requirements in Table 28 must be met. Monitoring 1 Day Page 55 of 85 4.10.2.11 T3 Protozoal Rules for Membrane Filtration [up to 4.0-Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.73 All water passing through the treatment plant must pass through the membrane filtration process. Assurance 1 Year T3.74 Direct integrity tests must be performed on each membrane filtration unit at least daily (midnight to midnight) if the membrane filtration unit has been in service at any point during the day. Assurance 1 Day T3.75 No membrane unit may be used while it has failed its direct integrity test. Assurance 1 Year T3.76 If the turbidity of the membrane filtrate exceeds 0.1 NTU for more than 15 consecutive minutes the membrane unit must be run to waste and not returned to supply until it has passed a direct integrity test. Monitoring 1 Day T3.77 Filtrate turbidity must not exceed 1 NTU at any time. Monitoring 1 Day T3.78 If the membrane unit has been out of service for maintenance or any other reason for more than 6 hours, a direct integrity test must be completed before the unit is returned to service. Assurance 1 Year T3.79 All of the monitoring requirements in Table 29 must be met. Monitoring 1 Day Page 56 of 85 Table 29. T3 Requirements for Membrane Filtration Parameters that need to be continuously monitored and where they need to be monitored: Parameters: Turbidity. Where it needs to be monitored: On the combined inlet to the membrane process, 50 and on the outlet of each membrane filtration unit (rack, train, or cell) when in service to supply and on any recycle streams to the plant inlet (if present). Parameters: Service State. Where it needs to be monitored: Each membrane filtration unit. Parameters that need to be non-continuously monitored and where they need to be monitored: Parameters: Membrane Integrity. Where it needs to be monitored: Each membrane filtration unit. Process Limitations: Membrane filtration includes microfiltration and ultrafiltration. Water treatment plants that recycle waste streams must return the recycle stream so that it is treated by the membrane filtration process and provide flow equalisation such that the instantaneous total return rate does not exceed 10% of the plant inflow. Turbidity monitoring is required to demonstrate that the recycle water has received effective solids/liquid separation. If flows of greater than 10% are recycled, separate treatment of the recycled stream is required to inactivate or kill protozoa and bacteria before the waste stream is returned to the plant upstream of the membranes. Membrane Validation/Certification: Membranes must be certified to comply with NSF/ANSI 61: Drinking Water System Components – Health Effects and NSF/ANSI 419 Public Drinking Water Equipment Performance – Filtration or equivalent. The maximum number of log credits (up to a maximum of 4.0) that a membrane filtration process is eligible to receive for protozoa removal depends on third party certification of the log removal that the filter plant can deliver. The manufacturer’s certificate (or validation) must specify the operational requirements under which the membrane units must be operated to meet the specification and the integrity testing procedure that the water supplier must carry out to demonstrate that the plant is operating at the claimed log credit rating at 3-micron resolution. Direct Integrity test requirements: The test is applied in such a manner that a 3 μm hole affects the response from the test. The test can verify the log removal value claimed for the membrane process. 50 This may be source water turbidity before coagulation when membrane filtration is the only process. It may be the average of turbidity from in-service pre-treatment units. Page 57 of 85 4.10.2.12 T3 Protozoal Rules for Ozone Disinfection [0.25 to 3.0-Log] Rule Number Requirement Assurance/ Monitoring Compliance period T3.80 All water passing through the treatment plant must pass through the ozone process. Assurance 1 Year T3.81 The C.t and water temperature required for the log credit claimed (Table 30) must be achieved for more than 95% of each day. Monitoring 1 Day T3.82 The C.t and water temperature must not be less than 80% of the values required for the log credit claimed ( Table 30) for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.83 Turbidity must not exceed 5.0 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.84 All of the monitoring requirements in Table 31 must be met. Monitoring 1 Day Table 30. T3 C.t values 51 (min.mg/L) for Cryptosporidium inactivation by ozone Log Credit Water Temperature (oC) 52 1 5 10 15 20 25 0.25 5.8 4.0 2.5 1.6 1.0 0.6 0.5 12 7.9 4.9 3.1 2.0 1.2 1.0 23 16 9.9 6.2 3.9 2.5 1.5 35 24 15 9.3 5.9 3.7 2.0 46 32 20 12 7.8 4.9 2.5 58 40 25 16 9.8 6.2 3.0 69 47 30 19 12 7.4 51 The C.t data in this table are valid for ozone concentrations in the range 0.2-5.0mg/L. 52 C.t values between the indicated temperatures may be determined by interpolation. Page 58 of 85 Table 31. T3 Requirements for Ozone Disinfection Parameters that need to be continuously monitored and where they need to be monitored: Parameters: Ozone residual. Where it needs to be monitored: Water immediately before or after the contact tank. 53 Parameters: Temperature. Where it needs to be monitored: Water leaving the contact tank. Parameters: Turbidity. Where it needs to be monitored: Water leaving the contact tank. Parameters: Flow. Where it needs to be monitored: Water leaving the contact tank unless there is a high-level outlet weir in which case water entering the contact tank is acceptable. A calculated outlet flow based on inlet flow and contact level change is also an acceptable approach. Water level in the contact tank (if used). Values that need to be continuously monitored: T10 Contact Time. C.t (Ozone x T10 Contact Time). 53 Additional monitoring sites may be used in addition to the contact tank entry or exit point if the water supplier can demonstrate that they improve the accuracy of the monitoring information. Page 59 of 85 4.10.2.13 T3 Protozoal Rules for Ultraviolet Light Disinfection [up to 4-Log as determined by the validation/certification of the reactor] Rule Number Requirement Assurance/ Monitoring Compliance period T3.85 All water passing through the treatment plant must pass through the UV reactor(s) and be within the reactor’s certified flow range for at least 95% of each day. Assurance 1 Year T3.86 The UV dose must meet or exceed that required to achieve the claimed log credit for at least 95% of each day. Monitoring 1 Day T3.87 The UV dose must not be less than that required to achieve the claimed log credit for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.88 Turbidity must not exceed 5.0 NTU for the duration of any consecutive 15-minute period. Monitoring 1 Day T3.89 UVT must meet or exceed 95% of the UVT for which the reactor has been certified for at least 95% of each day. 54 Monitoring 1 Day T3.90 UVT must not be less than 80% of the lowest UVT for which the reactor has been certified for the duration of any consecutive 15-minute period. 55 Monitoring 1 Day T3.91 All of the monitoring requirements in Table 32 must be met. Monitoring 1 Day 54 These requirements do not apply to UV disinfection systems that automatically adjust the UV dose as the UVT of the water flowing through the reactor varies. 55 These requirements do not apply to UV disinfection systems that automatically adjust the UV dose as the UVT of the water flowing through the reactor varies. Page 60 of 85 Table 32. T3 Requirements for UV Disinfection Parameters that need to be continuously monitored and where they need to be monitored: Parameters: UVT. Where it needs to be monitored: Water entering or leaving the UV reactor(s). 56 Parameters: Turbidity. Where it needs to be monitored: Water entering or leaving the UV reactor(s). Can include upstream filter monitoring if there is no other process between the filters and the UV reactors. Parameters: UVI or UV dose. For UV units certified to Ultraviolet Disinfection Guidance Manual (USEPA 2006b) monitored UVI, UVT and flow must be used to calculate dose. For UV units certified to DVGW Technical Standard W294 (DVGW 2006) or ÖNORM M 5873-1: 2020 01 01 57 monitored flow must be used for UVI control or the reactor run at full power. UVI and UVT must be more than the validated value for the respective flow. For UV units certified to NSF/ANSI 55 Class A (NSF, ANSI n.d.); (for populations of up to 5000) – 3-log a fault must be generated when any parameter exceeds the certified value. Where it needs to be monitored: The same point in the reactor as that used for certification/validation. Parameters: Flow. Where it needs to be monitored: At a point representative of water entering or leaving the reactor(s). UVI sensor checking and standardisation: Duty UVI sensors must be checked at least monthly against the reference sensor. If the difference between the two readings exceeds the manufacturer’s specified limits, then the duty UVI sensor must be replaced. Reference UVI sensor must be standardised at least annually in accordance with the Ultraviolet Disinfection Guidance Manual (USEPA 2006b) or other traceable procedure. Alternatively, after 12 months the supplier can use the reference sensor as a duty sensor and purchase a new standardised sensor for use as a reference sensor. Other instrumentation must be calibrated in accordance with the instrument manufacturer’s specified procedures and frequency. 56 These requirements do not apply to UV disinfection systems that automatically adjust the UV dose as the UVT of the water flowing through the reactor varies. 57 Or UV reactors certified to öNORM M5873 (Osterreichisches Normungsinstitut 2001). Page 61 of 85 UV certification/validation: The equipment must be certified to meet the required log credit using at least one of: 1. the Ultraviolet Disinfection Guidance Manual (USEPA 2006b) – variable log credits. 2. DVGW Technical Standard W294 (DVGW 2006). 3. ÖNORM M 5873-1: 2020 01 01. 58 4. NSF/ANSI 55 (2019) for Class A systems (for populations of up to 5,000) – 3 log. 58 UV reactors installed before 1 January 2020 can be certified to öNORM M5873 (Osterreichisches Normungsinstitut 2001). Page 62 of 85 4.10.3 T3 Chemical Rules Typical Value Range A drinking water supplier must sample the water leaving a treatment plant to determine the typical value range for specified chemical determinands to identify if any values exceed the MAV in the Drinking Water Standards and to determine the on-going monitoring frequency for those determinands. Standard typical range refers to a determined for which sample results are always less than 50% of the MAV. Elevated typical range refers to a determinand for which any sample exceeds 50% of the MAV but does not exceed 100% of the MAV. In the first 12 months of monitoring, 59 15 samples must be taken over a 12-month period (with no more than two samples collected in any calendar month) to determine the range of values for determinands in water leaving a treatment plant. Values must be identified for determinands in the water leaving the treatment plant if: 1. the determinand has a MAV; and 2. the determinand is: a) present in the source water at a concentration more than 50% of its MAV (as determined by the supply source water risk management plan); and/or b) a chemical added during treatment, or a possible contaminant in a treatment chemical; and/or c) formed as the result of a treatment process and is not expected to change in concentration beyond the treatment plant. Following collection of the first 15 samples to establish the typical range of a determinand, the determinand must be monitored at the frequencies set out in Table 33. Some of the determinands that may arise from treatment chemicals are listed in Table 34. Drinking water suppliers must test for determinands resulting from any other treatment chemicals that they use. If sodium hypochlorite is used, chlorate must be monitored weekly, regardless of the levels determined by sampling. 59 Where coagulants are used intermittently, the water supplier must undertake an appropriate sampling programme to determine the range of values for determinands in water leaving the treatment plant. Page 63 of 85 Rule Number Requirement Assurance/ Monitoring Compliance period T3.92 Values for determinands in treated water that: 1. exceed 50% of their MAV in the source water, or 2. are added or formed in the treatment process (as well as impurities in treatment chemicals), must be identified by the collection and analyses of 15 samples over a 12-month period (with no more than two samples collected in any calendar month). Assurance 1 year T3.93 Determinands identified by the sampling programme outlined in rule T3.92 must be categorised as either standard typical range or elevated typical range and must be sampled at the frequency set out in Table 33. Monitoring 1 month T3.94 Samples must be taken from a point directly after the final treatment process (including chlorine contact tanks as they are part of the treatment process). Assurance 1 year T3.95 Containers used for collecting samples must be obtained from a laboratory and appropriate for the target determinand. Assurance 1 year T3.96 Event based monitoring (determined by the water supplier) must be undertaken for any event that may rapidly introduce high concentrations of health- significant chemical determinands into the water at the source or at the treatment plant. Monitoring As determined by the water supplier Page 64 of 85 Table 33. T3 Treatment Chemical Determinand Minimum Sampling Frequencies Minimum sampling frequency Standard typical range determinands (Typical value < 50% MAV) Elevated typical range determinands (Value range 50% - 100% MAV) Chlorate 60 FAC, Fluoride 61 Annually Monthly Weekly 62 Continuous Table 34. T3 Possible Treatment Chemical Determinand Monitoring Treatment Chemical Determinand to monitor 63 Aluminium based coagulants/flocculants Aluminium, antimony, cadmium, copper, chromium, lead, mercury, nickel Iron based coagulants/flocculants Antimony, cadmium, copper, chromium, lead, mercury, nickel Polyacrylamide (polyelectrolyte) Acrylamide EP-DMA (polyelectrolyte) Epichlorohydrin Sodium hypochlorite Chlorate, Bromate Ozone Bromate Permanganate Manganese 60 If sodium hypochlorite is used for disinfection. 61 If fluoride is added as part of the treatment process. 62 Sampling may reduce to monthly if 12 consecutive samples are below 50% of the MAV. If a sample exceeds 50% of the MAV, sampling must return to weekly. 63 Monitoring is only required for treatment chemicals that are used or formed in a treatment process. Page 65 of 85 4.10.4 T3 Cyanotoxin Rules Rule Number Requirement Assurance/ Monitoring Compliance period T3.97 If cyanotoxins are identified in treated water, cyanotoxin testing must be undertaken in accordance with the supply cyanobacteria/cyanotoxin response plan or at least twice weekly (whichever is more frequent) until cyanotoxins are not present. Monitoring 1 Month Page 66 of 85 4.11 D3 Distribution System Rules Module 4.11.1 D3 Backflow Protection Rules Rule Number Requirement Assurance/ Monitoring Compliance period D3.1 Drinking water suppliers must prepare and implement a backflow prevention programme to protect their distribution system against the risk of backflow. Assurance 1 Year D3.2 Periodic surveys of backflow risks to a distribution system to determine medium and high-risk sites must be undertaken by the drinking water supplier at least once every five years to assess the adequacy of backflow protection across the distribution system. Assurance 1 Year D3.3 Where backflow requirements at a point of supply are deemed inadequate, the drinking water supplier must notify the local authority with details of the situation and risk, determine the backflow device that should be installed at the point of supply and ensure that it is installed in a timeframe commensurate with the risk but as soon as reasonably practicable. Assurance 1 Year D3.4 Testing of all testable backflow prevention devices installed at a point of supply specifically to protect the network (generally boundary devices) 64 must be undertaken, at least annually. Assurance 1 Year D3.5 A drinking water supplier must maintain a register of the location of all point of supply testable backflow protection devices, device types, assessed risk level and the results of testing of all devices. Assurance 1 Year 64 Does not include devices that are installed downstream of the point of supply and/or within buildings that have the primary purpose of protecting building users. Page 67 of 85 D3.6 Access to a water network through use of a standpipe is not permitted except by Fire and Emergency New Zealand, other emergency services, the drinking water supplier, or authorised contractors to the drinking water supplier where it is reasonably necessary to access the network for the operation of the drinking water supply. Assurance 1 Year 4.11.2 D3 New and Repaired Watermains Hygiene Procedures Rules Rule Number Requirement Assurance/ Monitoring Compliance period D3.7 Before carrying out or commissioning repairs to pipes in a water distribution system, a drinking water supplier must undertake and keep records of a risk assessment to determine the risk of contamination of the network and the procedures required to minimise that risk. Assurance 1 Year D3.8 All materials used in construction and repairs must be free of visible contamination and remain protected from contamination until installation. Assurance 1 Year D3.9 All tools contacting the water supply or its parts, particularly cutting surfaces, must be adequately disinfected prior to commencing work and subsequently as necessary when tools contact soil or backfill material. Assurance 1 Year D3.10 Disinfection of mains (when required) must follow best management practices including but not limited to methods such as tablet, slug, spray chlorination, or equivalent as appropriate. Assurance 1 Year D3.11 Drinking water suppliers must develop and document standard operating procedures for planned, unplanned and emergency repairs. Assurance 1 Year Page 68 of 85 4.11.3 D3 Facilities Operation, Maintenance and Disinfection Rules Rule Number Requirement Assurance/ Monitoring Compliance period D3.12 Drinking water suppliers that have storage facilities within a distribution system must prepare a water storage management plan for the operation of storage facilities which includes the minimum and maximum operating levels, target turnover rates, inspection, and cleaning. Assurance 1 year D3.13 All storage facilities must be subject to an annual security and contamination inspection and assessment by the drinking water supplier. Assurance 1 Year D3.14 Drinking water suppliers must prepare and use written disinfection procedures for storage facilities that are consistent with industry best management practices. Assurance 1 Year D3.15 All new storage facilities, and existing storage facilities that have been drained for maintenance purposes, must be cleaned and disinfected and tested for E. coli prior to being brought (back) into use. Assurance 1 Year D3.16 Divers’ suits, rafts, remotely operated vehicles (ROVs) and other materials used during inspection, maintenance or other activities within storage facility interiors must be made from materials acceptable for contact with drinking water and suitable for disinfection. Assurance 1 Year D3.17 All equipment and materials entering storage facilities must be disinfected immediately prior to entry according to industry best management practices. Assurance 1 Year Page 69 of 85 4.11.4 D3 Residual Disinfection, Disinfection By-product, and Plumbosolvent Metal Rules Rule Number Requirement Assurance/ Monitoring Compliance period D3.18 A written sampling plan for determinands to be sampled in relation to disinfection, disinfection by-products and plumbosolvent metals must be prepared including a system map indicating sampling locations and response procedures to be followed when sample results do not meet prescribed levels. Assurance 1 Year D3.19 A FAC of at least 0.2 mg/L must be maintained in 85% of samples (or 85% of the time if continuously monitored). Up to 15% of samples (or 15% of the time if continuously monitored) may have a FAC of less than 0.2 mg/L but must be greater than 0.1 mg/L. Monitoring 1 Month D3.20 Samples must be collected for FAC at the frequencies outlined in table 35. 65 Monitoring 1 Monthly D3.21 Routine sampling sites must be located to adequately represent the distribution system and areas associated with higher risk of deterioration in drinking water quality and population exposure. 66 Assurance 1 Year D3.22 Analyses must be undertaken in each distribution zone according to the frequencies set out in Table 37 for the following disinfection by-products: 1. trihalomethanes: chloroform, bromodichloromethane, dibromochloromethane, and bromoform; and 2. haloacetic acids: dichloroacetic acid and trichloroacetic acid. Monitoring 1 Year 65 Demonstrating compliance with this rule (D3.20) is not required if FAC is continuously monitored according to rules D3.25 to D3.27. 66 Demonstrating compliance with this rule (D3.21) is not required if FAC is continuously monitored according to rules D3.25 to D3.27. Page 70 of 85 D3.23 Sample sites for disinfection by-products must represent both peripheral and central locations in the distribution system. Assurance 1 Year D3.24 Analyses must be undertaken in each distribution zone for the plumbosolvent metals outlined in Table 38. Monitoring 1 Year Alternative FAC Continuous Monitoring Rules for Distribution Systems Water suppliers may continuously monitor FAC in a distribution zone in accordance with rules D3.25 to D3.27 as an alternative to demonstrating compliance against rules D3.20 and D3.21. Rule Number Requirement Assurance/ Monitoring Compliance period D3.25 Continuous monitoring analysers for FAC must be installed in each distribution zone at the following locations: 1. At a point where water is provided to a distribution zone, e.g. a reservoir outlet or bulk point of supply. 2. At a supply main within the zone near to the centre or near to the extremity of the distribution zone. Monitoring 1 Month D3.26 Continuous monitoring analysers for FAC in each distribution zone must meet the requirements set out in Table 36. Assurance 1 Year D3.27 Confirmation of the representative nature of the continuous monitoring results must be undertaken by the collection and analysis of four FAC and pH grab samples (at least five days between samples) each month from within the distribution zone. Samples should be taken from the outer extent of the distribution zone at times of normal demand. Assurance 1 Year 67 67 Results from confirmation sampling do not need to be reported or notified for compliance purposes. Page 71 of 85 Table 35. D3 FAC sampling frequency Distribution zone population Number of samples per week Maximum interval between samples (days) Minimum number of days of the week used <25,000 3 4 5 25,001 – 50,000 4 3 6 50,001 – 100,000 5 2 6 (at least two Saturdays and two Sundays sampled each year) >100,000 6 2 7 (at least four Saturdays and four Sundays sampled each year) Table 36. D3 Number of continuous monitoring analysers required in each zone Zone population Number of analysers Up to 25,000 2 25,001 – 100,000 3 >100,000 4 Page 72 of 85 Table 37. D3 Disinfection by-product sampling frequency 68 Disinfection by- products sampling requirements Frequency Each distribution zone. 1 per quarter 69 Table 38. D3 Distribution zone for plumbosolvent metals Plumbosolvent metals Frequency Antimony, cadmium, chromium, copper, lead, mercury, nickel, zinc. Every 6 months 70 68 Additional targeted sampling should be undertaken in accordance with the sampling programme to understand the conditions and circumstances that lead to DBP formation. 69 After 2 years if consecutive samples are less than 50% of the MAV sampling may reduce to 1 per year. If any annual sample exceeds 50% of a MAV, sampling must return to quarterly. 70 Must be sampled monthly if the determinand exceeds 50% of its MAV. Sampling can return to 6 monthly after 12 samples are less than 50% of the MAV. Page 73 of 85 4.11.5 D3 Microbiological Monitoring Rules Rule Number Requirement Assurance/ Monitoring Compliance period D3.28 A written sampling plan for monitoring total coliforms, E. coli and any other determinands deemed necessary by the water supplier must be prepared, including a system map indicating sampling locations and a response plan for positive results. Assurance 1 Year D3.29 E. coli and total coliforms must be monitored in each zone of the distribution system according to the frequencies set out in Table 39. Reporting 1 Month D3.30 Routine sampling sites must be located to adequately represent water in the distribution system, including water leaving storage facilities, and entry points for water from another water supplier. Assurance 1 Year D3.31 Samples must be collected according to written sampling protocols prepared by the drinking water supplier or the laboratory undertaking the sample analysis. Assurance 1 Year Page 74 of 85 Table 39. D3 Minimum Microbiological Sampling Frequencies Distribution zone population Number of samples per week Maximum interval between samples (days) Minimum number of days of the week used <25,000 1 9 5 25,001–50,000 1 9 6 (at least two Saturdays and two Sundays sampled each year) 50,001–100,000 2 5 7 (at least three Saturdays and three Sundays sampled each year) >100,001 3 3 7 (at least four Saturdays and four Sundays sampled each year) Page 75 of 85 4.12 WC Water Carrier Service Rules Module Rule Number Requirement Assurance/ Monitoring Compliance period WC.1 All water to be transported must be sourced from a registered drinking water supply where the water is: 1. safe to drink; and 2. complies with the Drinking Water Standards; and 3. complies with the rules relevant to the supply. Assurance 1 Year WC.2 The water carrier must only take water from a point in a distribution system prescribed by the drinking water supplier. Assurance 1 Year WC.3 If water is sourced from a supply that provides water specifically for water carrier services, that supply must be registered and comply with the rules for Water Carrier Supplies. Assurance 1 Year WC.4 The operator of any vehicle used to transport water must ensure all tanks, and the equipment used for loading or unloading water, are only used for drinking water. Assurance 1 Year WC.5 The operator of any vehicle used to transport water must ensure all tanks, and the equipment used for loading and unloading water, are made from material that light cannot pass through, are kept clean and clear of any possible contaminants at all times, with all openings and connections sealed to protect them from possible contamination. The drinking water must be protected from contamination at all times during its loading, transit and delivery. Assurance 1 Year WC.6 If tanks and the equipment and fittings used for loading and unloading water are not used for the transport of drinking water for a period of 30 or more days, then before next being used to transport drinking water: 1. the tank must be disinfected by filling with drinking water containing at least 5 mg/L FAC for not less than 30 minutes before discharging safely to waste; and 2. equipment and fittings should be washed in water containing 5mg/L FAC. Assurance 1 Year Page 76 of 85 WC.7 The water carrier must ensure there is backflow prevention or an adequate air gap in place when discharging drinking water from their tank. Assurance 1 Year WC.8 When drinking water is delivered, a written statement must be supplied to the customer/consumer stating the: 1. Fill date and time. 2. Registered drinking water supply from which the tanker was loaded. 3. Delivery date, time, location and volume of water delivered. 4. Name and registration number of water carrier. 5. Name and signature of delivery person. The water carrier needs to keep records of this information for a period of 3 years. Assurance 1 Year Page 77 of 85 4.13 TDWS Temporary Drinking Water Supplies Rules (Revoked) Rules revoked on 29 November 2024 Table 40. Removed Page 78 of 85 4.14 VP Rules for Supplies with Varying Population Module Rule Number Requirement Rule Type Compliance period VP.1 If a supply operating under level 1 treatment or distribution rules exceeds 100 people, the following additional monitoring requirements must be met in the week before the population exceeds 100 people (if predictable) and continuing every week until the population reduces below 100 people: (a) water leaving a treatment plant must be monitored at least weekly for the following: (i) E. coli: (ii) total coliforms: (b) if the supply has distribution zones, water from each distribution zone must be monitored at least weekly for the following: (i) E. coli: (ii) total coliforms. Rule replaced on 29 November 2024 Non-reporting N/A VP.2 If a supply operating under level 1 treatment or level 1 distribution rules exceeds 500 people, the following additional monitoring requirements must be met from 1 week prior before the population exceeds 500 people (if predictable) and continuing every week until the population reduces to below 500 people: (a) water leaving a treatment plant must be monitored at least twice weekly for the following: (i) E. coli: (ii) total coliforms: (b) if the supply has distribution zones, water from each distribution zone must be monitored at least twice weekly for the following: (i) E. coli: (ii) total coliforms: (c) monitoring must continue in accordance with VP.1 where the population reduces below 500 people and remains above 100 people for any period of time. Rule replaced on 29 November 2024 Non-reporting N/A Page 79 of 85 VP.3 If a supply operating under level 2 treatment rules exceeds 500 people, the water leaving the treatment plant must be additionally monitored— (a) at least weekly for the following: (i) E. coli: (ii) total coliforms; and (b) at least daily for the following: (i) turbidity: (ii) FAC (not required for self-supplied buildings): (iii) pH (not required for self-supplied buildings). Rule replaced on 29 November 2024 Non-reporting N/A VP.4 If a supply operating under level 2 distribution rules exceeds 500 people, water in each distribution zone must be additionally monitored— (a) at least weekly for the following: (i) E. coli: (ii) total coliforms; and (b) at least daily from a range of sites across each distribution zone for FAC (not required for self-supplied buildings). Rule inserted on 29 November 2024 Non-reporting N/A Table 41. Removed 71 72 Table 42. Removed 71 Removed 72 Removed Page 80 of 85 5. Definitions Term Definition abstraction point See section 5 of the Water Services Act 2021. annulus The void between a bore hole and the bore casing. apron (bore) An impervious ground covering, typically concrete, which prevents ingress of surface water into the bore. backflow See section 5 of the Water Services Act 2021. backflow prevention device See section 5 of the Water Services Act 2021. backwash The process of cleaning a filter by reversing a flow of fluid which may contain air through it. barrier A process or infrastructure which prevents or reduces the likelihood of contamination of a drinking water supply. benthic cyanobacterial mat A collective mass of cyanobacteria that forms on the bottom surface of a water body. bore A piped or encased hole constructed to access groundwater. bore head A part of a bore infrastructure located above ground or within the accessible part of an underground access or inspection chamber. building As defined by sections 8 and 9 of the Building Act 2004. C.t value The product of the concentration (C) of a disinfectant and the contact time (t) required to control micro-organisms. calibration Comparing the accuracy of a measuring device to a known standard (which may be a reference device) and adjusting it appropriately. calmed bottom inlet A tank inlet pipe on the floor of a tank which is designed to prevent disturbance of sediment as water enters the tank. cartridge The removable component of a cartridge filter which is used to entrap particulate material. cartridge filtration A treatment which uses a disposable cartridge to remove particulate material from water. certification Written confirmation, usually by a manufacturer, that certain requirements or standards have been met. coagulation A chemical process to neutralise matter in water and which leads to floc formation. consumer See section 5 of the Water Services Act 2021. Page 81 of 85 contact time The hydraulic residence time of a disinfection process. T10 (contact time) The effective contact time, which is the time it takes 10% of the volume of a unit to pass through a tank. cross connection Any actual or potential connection between a drinking water supply and stormwater, wastewater, or other infrastructure. cyanobacteria A major group of micro-organisms capable of photosynthesis, sometimes referred to as blue-green algae. cyanotoxin A toxin produced by cyanobacteria. determinand See the Drinking Water Standards for New Zealand 2022. differential pressure The difference in pressure between two given points, e.g., on the inlet and outlet of a filter. direct filtration A treatment process which consists of coagulation, flocculation, and filtration, without a sedimentation process before filtration. direct integrity test A physical test applied to a membrane unit to identify and isolate one or more leaks that could result in contamination of the filtrate. disinfection The process used to kill or inactivate micro-organisms. disinfection by- product or DBP A substance formed in drinking water as a result of a disinfection process. dissolved air flotation A clarification process in which the flocs formed during coagulation and flocculation are floated to the surface by air bubbles. distribution system All components (e.g. buildings, storage tanks, electrical equipment, reticulation, pumps, instrumentation, etc) of a drinking water supply used to transmit drinking water to consumers or other drinking water suppliers. distribution zone All or part of a distribution system which contains water of a similar character, often defined as a bounded geographic area. Every drinking water supply with a distribution system has at least one distribution zone. domestic self- supply / domestic self- supplier See section 10 of the Water Services Act 2021. drinking water See section 6 of the Water Services Act 2021. Drinking Water Quality Assurance Rules (2022) or Rules See section 49 of the Water Services Act 2021. Page 82 of 85 Drinking Water Standards or Standards See the Water Services (Drinking Water Standards for New Zealand) Regulations 2022. Also see regulations made under section 47 of the Water Services Act 2021. drinking water supplier See section 8 of the Water Services Act 2021. drinking water supply As defined by section 9 of the Water Services Act 2021. duty (UVI) sensor The duty (on-line) UV sensor installed in a UV reactor that monitors UV intensity during UV equipment operations. Escherichia coli or E. coli A bacteria species used as an indicator of faecal contamination of water. The presence of E. coli almost certainly indicates pathogens harmful to human health are present. event based monitoring Monitoring of a drinking water supply to understand the effects of a specific event on its operation and the safety of drinking water. filtrate Water, other than wash water, leaving a filter. filtration A treatment process that physically removes particles from water by passing it through a medium such as sand or other suitable material. filtration housing The casing containing a cartridge filter or filter material. floating off take A device designed to extract water from the top of water storage infrastructure using a flotation device. flocculation A process that promotes the formation and growth of floc, which are loosely clumped masses of fine particles. free available chlorine or FAC The chlorine present in chlorinated water in the form of hypochlorous acid and hypochlorite ion. free available chlorine equivalent or FACE The free available chlorine equivalent, which is the FAC concentration that would have the same disinfecting power as the chlorine solution would have at pH 8. groundwater Water contained beneath the land surface. inactivate A mechanism which inhibits the reproduction of a micro-organism. instantaneous total return rate The amount of recycled water flow being returned to, and entering, the treatment system at a given point in time. log credit A method for determining a treatment level based on a log-scale control of the target micro-organism. maximum acceptable value or MAV See the Drinking Water Standards 2022. Page 83 of 85 media filter A filtration process which uses a media, e.g., sand, for the removal of particulate matter. membrane filtration A pressure or vacuum driven separation process in which particulate matter is rejected by an engineered barrier (membrane). microfiltration A filtration process, usually membrane filtration, with pore sizes in the range of 0.1-10 microns (100 - 10,000 nm). nephelometric turbidity unit (NTU) A unit of measurement for turbidity. (oo)cysts Collective term for oocysts and cysts. A Cryptosporidium oocyst is a thick-walled structure within which Cryptosporidium zygotes develop and that serves to transfer the organism to new hosts. operator See section 11 of the Water Services Act 2021. ozone contactor A vessel which facilitates the dissolution of ozone into water and provides sufficient contact time for disinfection. ozone residual Ozone remaining after disinfection has been achieved. pH adjustment The process of changing the pH of water using acidic or basic compounds. planktonic cyanobacteria Cyanobacteria which are freely floating in a body of water. point of supply See section 13 of the Water Services Act 2021. pore size The nominal or absolute size of the holes or apertures in a thin layer of continuous medium, e.g., a membrane filter. property Separate rating unit as defined by the Rating Valuations Act 1998 or a separate rating area under the Local Government (Rating) Act 2002. rapid media filter A media filter which can be pressure or gravity fed and is regularly backwashed. raw water See section 5 of the Water Services Act 2021. recycled water Water, usually discharged from a treatment process which that is returned to the start of the treatment process (i.e., recycled). reduction equivalent dose or RED A dose value for UV systems derived from a UV-dose response curve determined during UV reactor validation. reference (UVI) sensor A calibrated sensor used to check the validation of the duty sensor. registered water supply See subpart 7 of Part 2 of the Water Services Act 2021. Page 84 of 85 residual disinfection A disinfectant, typically chlorine, remaining in the water after it leaves a treatment plant to act as a barrier to recontamination of water in a distribution system. roof water The rain water collected from the roof off a structure. safe drinking water See section 7 of the Water Services Act 2021. sampling point / site A location / tap for the collection of water samples. sedimentation A treatment process in which solid particles settle to and are removed from the bottom of a clarifier or settling tank. slow sand filtration A filtration process that consists of a bed of fine sand, which is not backwashed and relies on a biologically active layer on top of the sand to remove and degrade particles. slug (disinfection) A disinfection method consisting of placing chlorine liquid in the main to achieve a target concentration when the main is full, completely filling the main to remove all air pockets and flushing the main. source and source water See section 5 of the Water Services Act 2021. source water risk management plan See section 5 of the Water Services Act 2021. spray chlorination (disinfection) A process of spraying chlorine solution to disinfect materials, equipment and fittings used in repairs and construction of water drinking supplies. spring A location where groundwater naturally emerges from the ground surface. surface loading rate The flow of water through a settling tank or clarifier, divided by the effective surface area of the clarifier. surface water A body of water that is open to atmosphere, whether running (streams and rivers) or quiescent (lakes, reservoirs, impoundments and ponds). tablet (disinfection) Disinfection of a pipe using chlorine tablets placed inside the pipe during construction to disinfect the mains once installed. target turnover rate The ideal amount of time that it takes for the volume of the water in a tank to be completely replaced. total coliforms Genera in the family Enterobacteriaceae that will grow on a specific selective medium when incubated at 35°C ± 0.2°C. turbidity A measure of the suspended particles in a sample that cause loss of clarity by scattering light. Page 85 of 85 ultrafiltration A filtration process, usually membrane filtration, with pore sizes in the range of 0.01-0.1 microns (10 - 100 nm). UV dose The amount of UV radiation emitted into water within a UV reactor calculated by the UV intensity multiplied by the exposure time, usually measured in mJ/cm2. UV intensity or UVI The intensity of UV radiation, usually measured in mW/cm2. UV transmittance or UVT A measure of the amount of ultraviolet light (typically measured at 254 nm) that passes through water. validation Confirmation that equipment or a process meets, or will meet, certain performance requirements or standards, typically referring to UV reactors or membrane filters verification Checking the accuracy of a measuring device against a known standard (which may be a reference device). waste stream A flow of water from a drinking water treatment plant that is not intended for further treatment or use as drinking water. water carrier See section 5 of the Water Services Act 2021. Water Services Act 2021 or Act See the Water Services Act 2021. List of tables 1. Introduction 1.1 Rule objectives 1.2 Effective date of the Rules 1.3 General guidance 1.4 Components of a drinking water supply 1.5 Categories of drinking water supply 1.6 Structure of the Rules 2. Drinking water supply categories and Rules modules 3. Application of the Rules modules 3.1 Compliance and reporting 4. Compliance Rules Modules 4.1 G General Rules Module 4.2 VSC Very Small Communities Rules Module 4.3 S1 Source Water Rules Module 4.4 T1 Treatment Rules Module 4.5 D1 Distribution System Rules Module 4.6 S2 Source Water Rules Module 4.7 T2 Treatment Rules Module 4.8 D2 Distribution System Rules Module 4.9 S3 Source Water Rules Module 4.9.1 S3 Source Water Protozoa Log Credit Treatment Requirements 4.9.2 S3 Sanitary Bore Head Requirements 4.9.3 S3 Source Water Monitoring Rules 4.10 T3 Treatment Rules Module 4.10.1 T3 Bacterial Rules 4.10.1.1 T3 Bacterial Rules for Water Disinfected with Chlorine 4.10.1.2 T3 Bacterial Rules for Water Disinfected with Chlorine Dioxide 4.10.1.3 T3 Bacterial Rules for Water Disinfected with Ozone 4.10.1.4 T3 Bacterial Rules for Water Disinfected with Ultraviolet Light 4.10.2 T3 Protozoal Rules 4.10.2.1 T3 Protozoal Rules for Coagulation, Flocculation and Sedimentation without Filtration [0.5-Log]. 4.10.2.2 T3 Protozoal Rules for Coagulation, Flocculation, and Direct Filtration [2.5-Log] 4.10.2.3 T3 Protozoal Rules for Coagulation, Flocculation, and Direct Filtration [3.0-Log] 4.10.2.4 T3 Protozoal Rules for Coagulation, Flocculation, and Direct Filtration [3.5-Log] 4.10.2.5 T3 Protozoal Rules for Coagulation, Flocculation, Sedimentation, and Filtration [3-Log] 4.10.2.6 T3 Protozoal Rules for Coagulation, Flocculation, Sedimentation, and Filtration [3.5-Log] 4.10.2.7 T3 Protozoal Rules for Coagulation, Flocculation, Sedimentation, and Filtration [4-Log] 4.10.2.8 T3 Protozoal Rules for Second Stage Filtration [0.5-Log] 4.10.2.9 T3 Protozoal Rules for Slow Sand Filtration [2.5-Log] 4.10.2.10 T3 Protozoal Rules for Cartridge Filtration [2.0-Log] 4.10.2.11 T3 Protozoal Rules for Membrane Filtration [up to 4.0-Log] 4.10.2.12 T3 Protozoal Rules for Ozone Disinfection [0.25 to 3.0-Log] 4.10.2.13 T3 Protozoal Rules for Ultraviolet Light Disinfection [up to 4-Log as determined by the validation/certification of the reactor] 4.10.3 T3 Chemical Rules 4.10.4 T3 Cyanotoxin Rules 4.11 D3 Distribution System Rules Module 4.11.1 D3 Backflow Protection Rules 4.11.2 D3 New and Repaired Watermains Hygiene Procedures Rules 4.11.3 D3 Facilities Operation, Maintenance and Disinfection Rules 4.11.4 D3 Residual Disinfection, Disinfection By-product, and Plumbosolvent Metal Rules 4.11.5 D3 Microbiological Monitoring Rules 4.12 WC Water Carrier Service Rules Module 4.13 TDWS Temporary Drinking Water Supplies Rules (Revoked) 4.14 VP Rules for Supplies with Varying Population Module 5. Definitions