Water Treatment for Small Supplies – Balancing Risks and Costs

Annual Conference

Over the last two decades New Zealand has made significant strides in the quality of its drinking water in our large and medium-sized supplies. There remains, however, a major backlog of small supplies that need to be improved to bring them up to compliance with the Drinking-water Standards for New Zealand, and achieve levels of risk acceptable to the communities they serve.

This paper draws on the authors’ 80 years of combined experience in the design and implementation of water treatment plants to help frame the industry’s thinking about how to cost effectively design water treatment for small supplies, while balancing the risks of non-compliance and waterborne disease outbreaks.

The paper includes a number of case studies of small water treatment plants from across New Zealand, and compare and contrast the wide range of capital costs for these plants. It will show what is included and not included in each of these plants, and how that has and could flow through into the public health and other risks to the communities served.

It also includes a review of how a design can be well integrated with, or at odds with, the operational and asset management capabilities of the owner of the supply. This is a subject that often does not receive nearly enough attention in the design process.

This paper highlights affordability as the prime reason why small water supplies are lagging behind larger supplies in terms of compliance. The reality is that for many small supplies if conventional approaches are taken the supplies are be not economically sustainable. Alternative approaches are discussed to enable small communities to achieve a water supply of an acceptable quality.

Conference Papers

2.00 Water Treatment for Small Supplies Balancing Risks and Costs.pdf

pdf
259 KB
06 Nov 2017

2.00pm A Watson.pdf

pdf
3 MB
06 Nov 2017