TEMUKA WATER FILTER FOR ASBESTOS REMOVAL

In the closing moment of 2017 the Timaru District Council became aware of a fibre contamination in the Temuka water supply.  At this time of year in Temuka the ground often looks like it has had a light dusting of snow due to the large amount of seed fibre being shed by trees in the area.  Because of this it was initially assumed by many that this fibre had entered the water supply.

Analysis of the fibre removed from filters around the town soon however appointed to deterioration of the 7km Asbestos Cement main water pipe supplying the town of 4000 people.

Although public health experts confirmed that asbestos in drinking water does not present a significant health risk, following public feedback the Timaru District Council elected to install a centralised filtration plant where the main line entered the town to remove the fibre. The use of a centralised filtration plant also enabled the concentrated asbestos fibre removed by the plant to be dealt with and only handled by trained professionals rather than by members of the general public as they cleaned out filters in taps and home appliances.

One of the most significant challenges in installing the filtration plant was the timing. By the time a filtration plant was identified as the preferred management option, there were only a few working days left before all equipment suppliers closed down for the Christmas Holidays.

Fortunately national water treatment experts, Apex Environmental are based locally and were able to design a treatment plant that could handle the peak flows of the supply, remove the asbestos fibre, and be constructed in a matter of days.

After initial consultation on the design and desired outcomes, it was identified that both the council and contractor could make significant contributions to the delivery of the project and that a collaborative approach would provide the fastest and most comprehensive outcome for the people of Temuka.

In keeping with this approach, the Council organised cut-in to the existing water main and piping of the supply across the road to the site of the treatment plant and back, and provided filter housings that they had in storage from a previous project. While this was underway Apex sourced almost all suitable filter housings available in the country including diverting materials from other less urgent projects, secured almost all the suitable filter elements in stock in New Zealand, and began building the actual treatment plant.

By having several teams operating in parallel the filter plant was able to be bought online only 4 work days after design commenced.

The treatment plant was installed and operational one day before suppliers shut down for Christmas, Apex trained the councils staff on the operation of the plant, and provided sufficient consumables and spare parts to see the Council through the Christmas break during which supplies would be unavailable

As a result of the quick and collaborative action taken by council, the quantity of asbestos in the water supply throughout Temuka has been dramatically reduced and the plant will remain in operation as an interim measure while a new polyethylene pipe is installed to replace the failing asbestos concrete pipe.

With an estimated 6,000km of Asbestos Concrete water pipe installed throughout New Zealand, this quick and comprehensive resolution reached by the Timaru District Council is something that other councils around the country could learn from before they start seeing similar issues.