Exploring wastewater alternatives

Environmental management students from Te Wananga o Aotearoa have participated in a Gisborne District Council project by planting rows of low cost, low maintenance, native grasses known as purei in the plant medium."Ecological treatment solutions are appealing because of their low capital and running costs" says Te Wananga o Aotearoa environmental management teacher Ian Ruru. http://www.gisborneherald.co.nz/   / gisborneherald      / gisborneherald   "Our next step is to introduce more diversity with native fish which will help to improve the water quality and the mauri of the area."The grasses will send down metre long roots over an eight month period. Wastewater that has already been through the treatment plant's biological trickling filter system enters the floating wetland and circulates around the roots. Remnant particles of suspended solids are eaten by minute aquatic life such as worms, leeches and snails. "The floating wetland creates its own ecosystem," says Gisborne District Council projects manager David Wilson. "This is a natural way of treating water. "We have been working with iwi and wananga to determine the native grasses we use. Iwi are involved to ensure any solution we work with is culturally acceptable." Exploration of alternative means to treat wastewater is a requirement of GDC's resource consent. This is one of a number of projects investigating alternative options for use and disposal of Gisborne's waste water. The miniature floating wetland will run for 12 months. It is commissioned by the waste water technical advisory group who in turn report to the fresh water advisory group, The ability of the wetland to filter the water will be monitored and reported back to GDC with a recommendation as to whether further investigation is warranted. Mr Wilson says wastewater treatment alternatives to the outfall at sea have to be considered by 2020. "To get to that stage we have to look at what we can do with the water at the other end." An open day which will give the public an opportunity to see the floating wetland is planned for next month. A GDC survey to gauge perceptions about the quality of the water in Gisborne's bay and river mouths. GDC is particularly interested in public feeling about waste-water treatment since the new treatment plant was commissioned in December 2010. Filmed and Edited by Ben Cowper SUBSCRIBE! http://www.youtube.com/subscription_c...