An Auckland-based company is pioneering a new way of identifying water quality issues that may provide a "tonic" to
local councils nationwide.
Harrison Grierson Consultants Limited manager John Parker says recent research work has produced a new and
cost-effective method of measuring water quality in water distribution systems that has great export potential, as well
as application in communities throughout New Zealand.
University of Auckland engineering student Mary Wood did the leading-edge research work under the Technology for
Industry Fellowship scheme operated by the Foundation for Research, Science and Technology.
Ms Wood says the new approach involves developing a new technique - iso-concentration mapping (ICM) - for assessing
water quality.
Traditional water-quality modelling entails the prediction of chlorine concentrations - which is important because
chlorine remains in the water after being applied at water treatment plants and provides disinfection protection to the
pipelines. But this system can be subjective and is not always reliable or greatly informative.
"In one small town that had water quality concerns, we sampled water from 16 fire hydrants,' Ms Wood says. "We developed
maps that showed an unexpected decrease in chlorine concentrations near the treatment plant, which was likely to be from
accumulated sediments. This information could not be gained from the normal water-quality model."
The sampling also identified possible leaching from iron pipes that led to the council considering options such as
providing more targeted maintenance, improving treatment processes and upgrading or replacing pipes with non-corroding
materials such as plastic.
The fellowship scheme allowed Ms Wood to work with a business in a practical way and she is using the project as a
component of her thesis towards her masters degree in engineering. She may be able to do a PhD on a related subject. "It
is very satisfying doing a thesis that has such a practical application," she says.
The mapping tool has been developed and applied to other reticulations and the company is also looking at exporting the
system. "It particularly benefits small towns that would not otherwise be able to afford to develop a water quality
model," Ms Wood says.
"It is quicker and more cost-effective than the traditional modelling system and council staff will find it much easier
to use."
-ends-