Whakapapa and Iwikau sewerage close to capacity

Ruapehu Bulletin, Volume 12, Issue 553, 13 September 1994, Page 9 (Supplement)

Whakapapa and Iwikau sewerage close to capacity

The way Whakapapa's sewage is dealt with has to change, and the Department of Conservation is still considering a number of options as to how to improve on the present system. The Tongariro/Taupo Conservation Board held a meeting and inspection on 1 September 1994. At this meeting the board noted that the current Whakapapa treatment plant, which has been in operation for some 30 years, was operating well, but close to capacity. However the discharge from the plant into a small stream was unacceptable. It appears that the effluent is changing the nature of the stream. Normally the stream contains plant life suited to low levels of nutrients. The effluent is permitting the growth of algae which are disturbing the plant life. A temporary discharge permit has been granted whilst various options to solve the problem are studied. According to the Department of Conservation (DoC)

the preferred solution would be to pipe effluent out of the park to an oxidation pond/wetland area at a lower elevation, This and other options have been presented to engineering consultants and an environmental impact study prepared for assessment. Presently there are four areas under consideration but only one of these seems immediately suitable to DoC. "Piping the effluent to an oxidation pond/wetland area established on existing farm land would be the easiest with least environmental impact," said conservation officer Don Bogie. Iwikau Most lodges have their own sewage treatment facilities, with the ski area utilising a reticulating sand filter system. Effluent discharge is by ground soak with sludge often being removed by helicopter. Apparently the discharge by ground soak is potentially a problem. Due to the low temperatures at higher altitudes

the effluent is often nutrient-rich. Nutrients can find a way into the streams and surface water, and it takes only a few parts per million of nitrates to change the balance of plant life in some streams. The local council has indicated that Ruapehu Alpine Lifts and the lodges will need to make improvements before discharge consents will be granted. DoC says the best option would be to reticulate and pipe off the mountain. The anticipated growth in visitor numbers would place the present systems under strain in the future. Lodge Permits The existing lodges on the mountain have been granted new leases. The leases are the maximum allowable under the National Parks Act, which is 60 years. Alterations and additions will have to conform to the department' s building code. Should a catastrophe such as fire destroy a lodge re-building would be permitted, but not necessarily on the same site, said Mr Bogie.