Soft on water? It?s quiet boring really

IF WANGANUI is lucky it will be able to solve the dual problems of hard water and an unreliable city supply bore at the same time. Wanganui District Council utilities manager Julian Reweti said the 75 percent referendum vote to investigate softening Wanganui water had sharpened his focus on that aspect of the city's water issues. Wanganui Mayor Michael Laws has said softer water is "do-able". Getting softer water was only one aspect of water planning for Mr Reweti. Others were to do with finding new, secure and plentiful sources of good water. Council was already engaged in water planning, because the city's No 1 bore, providing up to 25 percent of its water, was over 40 years old and liable to failure. The bore and the 15km of pipes linking it with the city had already failed several times. "It's at the end of its asset life, so it's slightly vulnerable. It can't be repaired and needs replacing. The big question is ? where do we replace it?" Mr Reweti said. That bore and two others ? the three providing 85 percent of the city's water - were close together at Kai Iwi. It would be safer to get the city's water from a bigger range of places. The two most recent bores sunk close to the city had had encouraging results. A Brunswick Rd bore found softer water than that from Kai Iwi. It was now providing 15 percent of the city's water and went to Aramoho and Wanganui East, with some also getting to Durie and Bastia hills. The latest pilot bore, at Lenihan St in Wanganui East, was very deep and also had softer water. But its water wasn't good drinking. It would need more treatment, to reduce temperature and remove ammonia. Tests were still being done, to see whether this would be economic. Further bores could be sunk near the city and might have similar results. Soft water could then be mixed with the hard Kai Iwi stuff, and dilute the lime content down to an acceptable level. This would solve the dual problems of unreliable supply and hard water. Mr Reweti said the groundwater resource below the city was in no danger of running out. "Hard" water was water with calcium carbonate (lime) in it, he said. All Wanganui's water now came from underground. That from the cluster of Kai Iwi bores passed through limestone rock and contained lime at the level of 200 parts per million (ppm). About 100ppm was considered acceptable, and 40 to 50ppm made for "soft" water. Rain water had no lime at all. Lime in water was invisible and had no taste. But it solidified when heated, sticking to jug and hot water cylinder elements. It could reduce electricity efficiency by five to 20 percent, and people with hard water had to use more soap and detergent to get the same effect. A thickly coated element could also cause electrical fuses to blow continually. For people in hard water areas (all of Wanganui except Aramoho, Wanganui East and Bastia and Durie hills) 18 months was a good length of time for a hot water cylinder element to last, though some lasted longer and shorter times. In towns with soft water, the elements could last five to 20 years. Replacing a hot water cylinder element cost $150 to $180, Wanganui plumber Mike Bates said. The element itself cost about $66. "Hard water is quite good business for plumbers. I didn't vote to have it softened."