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Proposed National Environmental Standard for Human Drinking-water Sources

Acknowledgements

1 Summary

2 Introduction

3 Why Do We Need a National Environmental Standard for Source Water

4 The Proposed Standard

5 Supporting Information

6 Costs and Benefits

7 What Next?

Appendix 1: Definitions

Appendix 2: Types of Activities that Pose a Threat to Source Water Quality

References

The Proposed Standard

This section details the proposed subject matter of the standard and what the standard would require in practice.

The intent of the standard is to ensure impacts of catchment activities on drinking-water supplies are considered in regional council and territorial authority processes. The proposal is the result of consultation with stakeholders and consideration by the Ministry's technical working group and is believed to be the most appropriate tool for achieving the desired outcomes.

The Ministry for the Environment is investigating a supporting package to assist with implementation of this standard. This is outlined in section 5 of this document. The combination of the standard and the supporting package are expected to establish best practice management of human drinking-water sources in New Zealand.

4.1 Detail of the standard

4.1.1 Proposed subject matter of the proposal

A national environmental standard is a legally enforceable regulation. The exact wording of this standard will be legally drafted after government decision following this consultation. In essence, the proposed standard will say:

4.1.2 Grant of resource consent

The standard states that a consent authority shall not grant a resource consent that renders source water at the point of abstraction for a community drinking-water supply non-potable or unwholesome following treatment.

To achieve this, a consent authority must be satisfied that any adverse effects of an application for resource consent on community drinking-water supplies have been assessed and include how any such adverse effects are to be avoided, remedied or mitigated.

The intent of this part of the standard is to increase protection of human drinking-water sources, while retaining flexibility and encouraging local solutions to be reached, through consultation and negotiation. Where an activity is assessed as likely to have an adverse effect on a community drinking-water supply, alternatives may be negotiated between the water supplier, local authorities, the consent applicant and the community. If adequate mitigation cannot be offered or an alternative solution cannot be agreed upon, priority should be given to providing safe drinking-water to the community and the application declined.

Defining a specific level of treatment is problematic and doing so would set a bottom line for source water quality. Feedback on the previously proposed monitoring and reporting standard made it clear that setting such a bottom line was not acceptable. Also, in some situations, for example, Christchurch, water used for human drinking-water does not require treatment, and defining a minimum level of treatment would place unnecessary requirements on these communities. A definition for treatment is provided in Appendix 1 to reflect this intent.

In practice, this will require:

• resource consent applications within a drinking-water supply catchment shall specifically consider the potential impact of their proposed activity on water quality at the point of abstraction for a community drinking-water supply. This includes water supplies that have no existing treatment. Refer to Appendix 2 for examples of the types of activities that pose a threat to source water quality. [The catchment definition work being carried out by the Ministry for the Environment will provide further guidance on defining drinking-water supply catchments and activities that may adversely affect them.] This information will guide consent authorities in determining whether drinking-water suppliers are an affected party
• the impact on any down-gradient community drinking-water supplies shall be included in an applicant's assessment of environmental effects
• the water supplier will assess whether their water treatment plant is able to treat the proposed water quality. This assessment should also be undertaken in the event of there being no treatment. This assessment should consider the expected water quality at the point of abstraction as assessed by the applicant, the capacity of their water treatment plant, and comparing the expected treated water quality with the water-quality requirements specified in the Ministry of Health Drinking Water Standards
• prior to granting any resource consent within a drinking-water catchment, the consent authority must be satisfied that the appropriate level of assessment has been undertaken, and that a proposal will not render source water at the point of abstraction for a community drinking-water supply non-potable or unwholesome following treatment
• where a resource consent cannot be granted, after taking into account the existing treatment plant capacity, the applicant and the water supplier (and other affected parties) may negotiate alternatives to enable the proposed activity to go ahead
• an application is to be refused where the decision-making body is not satisfied that the activity will not degrade source water quality to a point that down-gradient community drinking-water supplies are unable to provide potable and wholesome drinking-water after treatment, and alternatives cannot be agreed upon
• location of drinking-water supply catchments will be identified by consent authorities and abstraction points will be made available through the Ministry of Health's Water Information New Zealand website.

Drinking-water suppliers understand best the technical capabilities of their treatment facilities, and therefore the source water quality required at the point of abstraction. Therefore, to determine whether or not a proposed activity is likely to impact on a drinking-water supply, communication between the consent authority, the applicant and potentially affected drinking-water suppliers will be necessary.

Communication between these parties will ensure drinking-water suppliers have the opportunity to view the applicant's assessment on the potential impact of their proposed discharge on water quality at the point of abstraction. Water suppliers will then be able to assess whether a proposed activity is likely to affect their treatment process, and may advise on methods for avoiding, remedying or mitigating such adverse effects.

If the water supplier considers that their treatment plant may be unable to treat the drinking-water safely within the catchment as a result of the potential effects of the activity on source water quality, priority should be given to ensuring the quality of a proposed discharge is improved before considering an upgrade to treatment processes, to deal with a reduction in source water quality.

The standard formalises practices and procedures provided for already in order to minimise adverse effects on human drinking-water sources. The standard makes it clear that:

• drinking-water catchment management is addressed through the RMA and not through health legislation
• there is a responsibility under the RMA to ensure that water intended for human drinking-water is not adversely affected by the use, development and protection of natural and physical resources
• activities beyond the abstraction point are within the jurisdiction of the Ministry of Health and no attempt is made to direct these through the RMA.

4.1.3 Assessment of permitted activities

There is currently no specific requirement for local authorities to undertake a risk-based assessment on the impact of permitted activities on community drinking-water supplies.

The standard requires consent authorities to periodically assess whether existing or proposed permitted activity rules in plans present a risk to community drinking-water supplies. This may be during the review or renewal of an existing regional plan, or during a local authority's ongoing monitoring of the efficiency and effectiveness of their policies or rules (section 35(2)(b) of the RMA). To achieve this, councils should: consider existing water quality data from state of the environment monitoring to assess water quality to determine its suitability for treatment, carry out a risk assessment of existing permitted activities within the water supply catchment, and consider the impact of permitted activity thresholds.

In practice, this will require:

• for many, the existing state of the environment monitoring that councils do will be able to assess water quality to ensure permitted activities are not adversely affecting the existing drinking-water treatment plant. The Ministry for the Environment investigates developing guidance in the form of a monitoring framework
• where permitted or unregulated activities are identified as adversely affecting community drinking-water supplies, councils may need to revise their plan rules to avoid, remedy or mitigate these effects.

4.1.4 Communication protocols - unauthorised activities

There is currently no requirement within the RMA to ensure water suppliers are notified of unauthorised discharges that present a risk to the water supply.

The standard states that in the event of an unauthorised discharge from a consented activity within a drinking-water catchment, communication protocols should be in place to ensure water suppliers can take appropriate action to mitigate the risks to public health.

In practice, this will require:

• regional councils and territorial authorities to place a consent condition on any new resource consent that poses a potential risk to a community drinking-water supply, requiring notification of down-gradient community water supplies in the event of an unauthorised discharge to land or water
• regional councils and territorial authorities to include water suppliers in their list of agencies to notify in the event of an unauthorised discharge.

4.1.5 Response to emergencies

There is currently no requirement in the RMA that requires or empowers councils to respond to accidents and emergencies that may impact a drinking-water supply.

The standard states that a council has the ability to require a drinking-water supplier to take appropriate action, including ceasing to abstract water in the event of an accident or emergency that threatens the ability of the treatment facility to provide safe drinking-water to the community.

In practice, this will require:

• councils will have to include in all consents to take water for community drinking-water supplies, provision for councils to declare the source water unsuitable for treatment in the event of an accident or emergency
• in the event of an accident or emergency, the council must notify the drinking-water supplier as soon as practicable. The council and water supplier will determine the appropriate response to the event, which may include discontinuing abstraction until such time as the source water no longer presents a risk to drinking-water supply
• councils, drinking-water suppliers and civil defence and emergency management authorities could work together to identify scenarios that present a threat to drinking-water supplies and what the appropriate procedures should be for each of these scenarios.

4.2 What the standard does not require

The standard does not require:

• a quantitative water-quality standard. This would, in effect, set a national "bottom-line" receiving water-quality standard. Retaining flexibility, so water treatment plants are designed and operated to meet the water-quality needs in that particular catchment, is important
• upgrades to proposals for resource consents or water treatment plants - although these may occur as a result of discussions held during the resource consent process.