The Water Services Act 2021 has created a new regime for managing and monitoring private and public drinking water supplies.
“One of the main requirements for all drinking water suppliers is to develop and implement a Water Safety Plan (WSP), use it in the day-to-day operation of the supply and review it continuously”, says Maria Johnson, Water Sector Lead at GWE Consulting Engineers. “The WSP must also include a Source Water Risk Management Plan.”
As a drinking water supplier, you have a duty of care to provide safe drinking water to all consumers and take any remedial actions if the water becomes unsafe.
What is a Water Safety Plan?
A WSP is a multi-barrier risk-based assessment and management document that aims to ensure a safe and secure supply of drinking water to your customers.
The WSP covers every aspect of providing safe drinking-water, identifying the events that could cause water to become unsafe to drink (including not enough water) and developing plans to manage these. The water safety plan covers the three parts of your supply:
- Catchment and intake
- Storage and distribution
The WSP helps identify whether any of the following four barriers to contamination are missing:
- Minimising contamination of the source water.
- Removing particles from the water (where many of the pathogens hide).
- Killing or inactivating pathogens.
- Preventing recontamination after treatment.
The WSP helps to develop a plan to compliance:
- Barriers to contamination and Critical Control Points
- Improvement Schedule
- Contingency plans
Barriers to contamination and Critical Control Points
Identifying the barriers to contamination and Critical Control Points (CCPs), where hazards can be eliminated, minimized or isolated is a key element of the WSP.
A few preventative measures, one or more measures that you can operate as process controls, will be designated CCPs. These are able to control your water supply system, have defined limits and be able to be monitored. The CCPs are especially important in managing microbiological hazards and being able to supply water.
CCPs are areas within the supply where there is potential for contamination or a loss in water supply. The function of these CCPs is essential for protecting the water supply from hazards.
Presenting the barriers to contamination and CCPs can simply look like this figure below, with an accompanying table to state the critical limits. For example, if chlorine residual is one of your barrier to contamination for the reticulation, your CCP may be to ensure chlorine is dosed such that Free Available Chlorine (FAC) is between 1.5 to 2.0 mg/L as the water laves the treatment plant. Evidence will be via online FAC monitoring. Another example would be if UV treatment is your barrier to protozoa contamination, your CCP may be to ensure that all the water passes through the UV reactor and that the flow is restricted to the maximum design flow.
How to tailor your Water Safety Plan to your supply?
Your WSP is a risk-based approach to compliance and shall be relative to your supply size, risks and specific requirements. “If you are taking your first step to compliance, the WSP will be your guide. It will help identify the issues, help you prioritise and define the required monitoring and reporting to Taumata Arowai.”
“Tailoring your WSP to your supply simply implies developing a bespoke document that will be useful to all the stakeholders involved in the operation, maintenance and management of the supply.”
Planning your Water Safety Plan
Taumata Arowai will ensure that Councils and small drinking water supplies meet the requirements of the NZ Drinking Water Standards, as well as the expectations of the Water Services Act.
As a drinking water supplier, you have to comply with the following timeframes:
- Large supplies (serving >500 people) should already be registered with Taumata Arowai and have until 13 November 2022 to prepare and submit their WSP including Source Water Risk Management Plan.
- Smaller supplies have until 13 November 2028 to register with Taumata Arowai and a further 3 years to prepare and submit their WSP including Source Water Risk Management Plan.
You may already have a Water Safety plan in place, approved by your current Drinking Water Assessor at the District Health Board or due to be updated.
You don’t have to wait to ensure your customers receive potentially safer drinking water and reduce risk.
Recommendations and further Information
If you are supplying drinking water as part of your business or other private treaty arrangement, we recommend you start investigating what the WSP means for you in respect of delivering safe drinking water and complying with the new legislation.
“The most important aspect of the reform is the safety of drinking water and managing risks. The targets for water quality haven’t changed, it’s about getting it right, consistently. Small supplies have unique challenges, and the best thing you can do is start early so you understand the risks and plan to make the changes for a safe and reliable water supply, says Maria.”
For further guidance contact Maria or in the first place, read our 30-page practical guide, Water Services Act 2021: A Drinking Water Suppliers Guide to Compliance, dated April 2022. The guide has been developed as a comprehensive and easy to read document that provides detailed assistance to Drinking Water Suppliers on compliance with the new legislation.
To download your copy of Water Services Act 2021: A Drinking Water Suppliers Guide to Compliance, just click the image below.
For further information contact,
Maria Johnson, Water Sector Leader, GWE Consulting Engineers
p. 021 288 8782
About GWE Consultants Ltd
GWE is a growth company and a leading provider of professional engineering services to the infrastructure and land/property development sectors. We specialise in environmental services, geotechnical, land development, drinking water, wastewater engineering and stormwater management. We currently have a number of opportunities for graduate, mid-career and senior engineers and scientists. To find out more visit our careers page, https://gwe.co.nz/careers/