Rule clarifications

Rule / Requirement

Rule / Requirement description

Rule / Requirement clarification

G1, G2, G3, G4, G17 (pages 17, 19) 

These rules are shown as monitoring rules. The compliance periods vary from rule to rule. 

These general rules are assurance rules, rather than monitoring rules. For more information on how to report against these rules, see Drinking Water Quality Assurance Rules - Guidance for Reporting. 

G5

Requires reporting to Taumata Arowai on the performance against all level 2 and 3 assurance rules annually within 40 days of the end of each calendar year.

The deadline for reporting may be interpreted to be "within 40 working days of the end of each calendar year." This aligns with the requirement of annual reporting against monitoring rules in rule G4.

Rule / Requirement

Rule / Requirement description

Rule / Requirement clarification

VP.3 and Tables 41 and 42 (pages 80, 81)

VP Increased monitoring for treatment plants and distribution zones have requirements for:

Duration between samples

The duration between samples means the duration must elapse before a supplier can take the next sample for compliance purposes.

Example for Tables 41 and 42: If a supplier takes a sample on Monday and the sampling frequency is daily with a duration between samples of 12 hours, they are required to take another sample on Tuesday.

These requirements should not be interpreted as limiting the number of samples taken in a day.

Rule / Requirement

Rule / Requirement description

Rule / Requirement clarification

TDWS.3, TDWS.4

These rules are shown as monitoring rules.

These rules are assurance rules.

Rule / Requirement

Rule / Requirement description

Rule / Requirement clarification

S1.1, S1.2

The reporting period for these monitoring rules is 1 year, however, there are samples which are only required every three years.

The reporting period is 1 year for these rules, even for those with 3 yearly sample requirements. For more information on how to report against these rules, see Drinking Water Quality Assurance Rules - Guidance for Reporting

T1.8 (page 26)

Water leaving the treatment plant must be monitored for the determinands and at the frequencies set out in Table 10. 

The current compliance periods stated in T1.8 and Table 10 are 6 months which is inconsistent with other references. 
 
The compliance periods in T1.8 and Table 10 should be 3 months to be consistent with G1 and Table 3. 

D1.1

There is a requirement to monitor for any other determinands identified in the supply's Drinking Water Safety Plan (including its Source Water Risk Management Plan).

The requirement mentioned may be reported under Reporting Rule ID "D1.1-chem" annually as per rule G4. This Reporting Rule ID has a compliance period of 3 months (4 compliance periods in the year).

Rule / Requirement

Rule / Requirement description

Rule / Requirement clarification

T2.1 and Table 14 (pages 30, 33)

Rule D2.1 and Table 15 (pages 34, 35)

T2 Treated water monitoring and D2 Distribution system monitoring have requirements for:

Duration between samples

The duration between samples is the period that must elapse before a supplier can take the next sample.

Example for Tables 14 and 15: If a supplier samples on Monday and must meet a requirement for an ‘At least 2 Days’ duration between samples, another sample must be taken on Wednesday or thereafter. The supplier must still meet the sampling frequency requirement.

These requirements should not be interpreted as limiting the amount of sampling done in a week. A supplier may take more samples than the sampling frequency, but at least two of those samples need to be taken within the specified duration between samples. 

T2.12, T2.14, T2.18, T2.20 (pages 31, 32) 

These rules are shown as monitoring rules with a 1 month compliance period. 

These rules are assurance rules, rather than monitoring rules. The compliance period for these rules is 1 year. For more information on how to report against these rules, see Drinking Water Quality Assurance Rules - Guidance for Reporting. 

S2.1, S2.2

The reporting period for these monitoring rules is 1 year, however, there are samples which are only required every three years.

The reporting period is 1 year for these rules. See the Drinking Water Quality Assurance Rules - Guidance for Reporting for more information on reporting Level 2 Source Water Rules. 

G2 and Table 4 (pages 17, 20)

Reporting requirements for Level 2 Supplies are shown in Table 4.

Additional clarification on the reporting requirements in Table 4:

The referenced rule numbers and parameters are inconsistent in some places. Table 4 is shown below with the correct references to rules and parameters highlighted in yellow.

Rule / Requirement

Rule / Requirement description

Rule / Requirement clarification

Source Water Protozoa Log Credit Treatment Requirements (page 36)

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 uppermost screen).

Criteria clarification: 

Groundwater sources that:

• draw water from a depth of greater than 10 metres below ground level (with depth measured from ground level to the top of the uppermost screen); and
• are not classified as Class 1 or Interim Class 1 source water.

Source Water Protozoa Log Credit Treatment Requirements (page 37)

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 uppermost 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.

Criteria clarification: 

Groundwater sources that draw water from a depth of 10 metres or less below ground level (with depth measured from ground level to the top of the uppermost screen), spring water sources and surface water sources.

S3.4

The reporting period for these monitoring rules is 1 year, however, there are samples which are only required every ten years.

The reporting period is 1 year for these rules. See the Drinking Water Quality Assurance Rules - Guidance for Reporting for more information on reporting Level 3 Source Water Rules.

Rule / Requirement

Rule / Requirement description

Rule / Requirement clarification

T3 Rules with requirements to meet a parameter for a percentage of a day (e.g., T3.2, T3.5, T3.8, T3.10, T3.13, T3.16, T3.24, T3.27, T3.31, T3.35, T3.39, T3.43, T3.47, T3.51, T3.60, T3.65, T3.81, T3.85, T3.86, T3.89)

Section 3.1 (page 14) states:

Drinking water suppliers only need to demonstrate compliance against the Rules for periods when a drinking water supply is operating.

Example: Rule T3.5 (page 41).

The turbidity of water leaving the treatment plant must be less than 1 NTU for at least 95% of each day.

Additional clarification for requirements to meet a parameter for a percentage of a day when a treatment plant or process does not operate for all of a day:

A treatment plant or process “is operating” when it is producing drinking water to be distributed to consumers.

Example: Rule T3.5 should be interpreted as:

The turbidity of water leaving the treatment plant must be less than 1 NTU for at least 95% of the time the treatment plant is producing drinking water to be distributed to consumers.

T3.7

This rule refers to Table 19

The rule should reference Table 20, not Table 19.

T3.15 and Table 22 (pages 45, 46)

UVT monitoring under T3 Bacterial Rules requires:

UVT is to be monitored for water entering or leaving the UV reactor(s).

The requirements of section 4.10.1.4 Table 22 are the same as the requirements of 4.10.2.13 Table 32 (footnote 56) (page 62): The requirement to monitor UVT does not apply to UV disinfection systems that automatically adjust the UV dose as the UVT of the water flowing through the reactor varies. The UV disinfection system may still require monitoring of UVT to meet the manufacturers’ validation criteria and requirements.

T3.15, T3.91

These rules refer to tables with multiple requirements. The compliance period is 1 day.

The requirement to undertake monthly UV sensor checks has a 1 month compliance period. This should be reported under Reporting Rule IDs T3.15-sens or T3.91-sens. There is no change to the reporting period, which is 1 year. See the Drinking Water Quality Assurance Rules - Guidance for Reporting for more information on reporting Level 3 Treatment Rules.

T3.16 (page 45) 
T3. 85, T3.86, and T3.89 (page 61) 

Level 3 ultraviolet light disinfection rules which contain "...at least (not less than) 95% of each day." 

If any reactor fails more than 5% of the time it operates during the day, then the whole process fails for the day. Alternatively, the compliant percentage of total production volume through all UV reactors may be used to calculate whether the whole process passes/fails the 95% criteria for the day.  

T3.25, T3.37, T3.41, T3.45, T3.49, T3.53, T3.72, T3.79, T3.91

These rules have process limitations.

The reporting period for the Reporting Rule IDs associated with process limitations or certification which have a suffix of "-lmts" or "-cert", respectively, are considered assurance rules with a reporting period of 1 year. See the Drinking Water Quality Assurance Rules - Guidance for Reporting for more information on reporting Level 3 Treatment Rules.

T3.29, T3.33, T3.37, T3.41, T3.45, T3.49, T3.62, T3.79

These rules have multiple requirements under process limitations.

The requirements to monitor the recycle stream may be reported under the respective Reporting Rule IDs with a suffix of "-recy". These are  continuous monitoring requirements, which have a 1 day compliance period. See the Drinking Water Quality Assurance Rules - Guidance for Reporting for more information on reporting Level 3 Treatment Rules.

T3.29, T3.33, (page 49), T3.74 (page 57) 

These rules are shown as assurance rules with 1 year or 1 day compliance periods. 

These rules are monitoring rules, rather than assurance rules. The compliance period for these rules is 1 day. For more information on how to report against these rules, see Drinking Water Quality Assurance Rules - Guidance for Reporting. 

T3.78 (page 57) 

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. 

If the membrane unit has been out of service for maintenance reasons which involve physical works, a direct integrity test must be completed before the unit is returned to service. Maintenance reasons may include, dismantling of a unit, membrane pinning, installation, and replacement of units, and do not include normal operational modes like stand-by and backwashes. 

T3.79 and Table 29 (pages 57, 58)

Membrane filtration process limitations under T3 Protozoa Rules require:

If flows of greater than 10% are recycled, the separate treatment of the recycled waste stream is required to inactivate or kill protozoa and bacteria before the waste stream is returned to the drinking water treatment plant upstream of the membranes.

Inactivating or killing protozoa includes processes that remove protozoa.

T3.86, T3.87

These rules refer to UV dose.

Where UV dose is referenced in the rule, UVI may be used as an alternative depending on the validation of the UV reactors being monitored.

T3.93

The compliance period is 1 month.

The compliance period is 1 year.

T3.93 and Table 33 (pages 65, 66)

Section 4.10.3 (page 64) states:

If sodium hypochlorite is used, chlorate must be monitored weekly, regardless of the levels determined by sampling.

Additional clarification for Section 4.10.3:

If sodium hypochlorite is used, sampling of chlorate must be weekly as per Table 33 unless footnote 62 (page 66) is met.

T3.96

The compliance period is determined by the water supplier.

The compliance period is 1 month.

Rule / Requirement

Rule / Requirement description

Rule / Requirement clarification

G14, G15, D3.19

G14 requires that generation of continuous monitoring data for demonstration of compliance against D3 Distribution Rules must not be interrupted for a period of more than 15 consecutive minutes. G15 contradicts this stating the separation between data records must be no more than 30 minutes.

For D3 Distribution System Rules, like D3.19, which may require the generation of continuous monitoring data, that data must not be interrupted for more than 3 consecutive hours in any 1 day compliance period, for compliance to be achieved

D3.20 and Table 35 (pages 71, 73)  

Rule D3.29 and Table 39

(pages 75, 76)

FAC and microbiological sampling under D3 Distribution System Rules have requirements for:

The maximum interval between samples.

The maximum interval between samples (days) means a supplier must take the next sample before the maximum interval has elapsed.

Example: If the supplier samples on Monday at 10 am and must meet a requirement for a 2-day maximum interval between samples, then another sample must be taken before the end of Wednesday.

D3.20 and Table 35 (pages 71, 73)  

D3.29 and Table 39

(pages 75, 76)

FAC and microbiological sampling under D3 Distribution System Rules have requirements for:

The minimum number of days of the week used.

e.g., For >100,000 zone population, the Minimum number of days of the week used is 7 (at least four Saturdays and four Sundays sampled each year)

The minimum number of days of the week used is assessed over the course of the year and reported on in the annual report by a supplier and is not required to be met for each monthly compliance period.

It refers to the spread of sampling days in a week, i.e. weekdays and weekends, to ensure the sample represents a spread of days and trends.

D3.25 (page 72) 

This rule is shown as a monitoring rule with a 1 month compliance period. 

This rule is an assurance rule, rather than a monitoring rule. The compliance period is  1 year.

D3.29 (page 75) 

This rule is shown as a reporting rule. 

This rule is a monitoring rule. 

Acceptable Solution 

Acceptable Solution for Roof Water Suppiles 

Part 2.4(f)(ix) 

End-point treatment system must be sized to comply with Building Code 

Probable simultaneous demand for dwellings can be found in section 3.2.3 and table 3.2.3 of the AS/NZS 3500.1:2021 standard. 

Acceptable Solution for Mixed-use Rural Water Supplies

Part 2.5(f)(ix) Footnote 12 

Part 2.5(f)(ix) "Probable instantaneous flow rates…" 

Should be probable simultaneous demand as referenced in section 3.2.3 and Table 3.2.3 of the AS/NZS 3500.1:2021 standard. 

Acceptable Solution for Spring and Bore Water Drinking Water Supplies 

Part 2.5(f)(ix) Footnote 12 

Part 2.5(f)(ix) "Probable instantaneous flow rates…" 

Should be probable simultaneous demand as referenced in section 3.2.3 and Table 3.2.3 of the AS/NZS 3500.1:2021 standard.