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Tuesday 28 July 1998 |
The Christchurch City Council organised community-based waste water working party recommending the future for Christchurch’s waste water infrastructure is recommending an upgraded sewage discharge in the sea instead of in the Estuary.
The Council is already upgrading the Christchurch waste water treatment plant at a cost of $30 million over eight years to increase the capacity to meet the needs of our growing City.
An additional requirement which was first foreshadowed in 1996, is the need to obtain resource consent from the Canterbury Regional Council for the effluent discharge the consent expires in 2001.
For this purpose the Working Party is recommending extra disinfection to kill most of the bacteria that remain, and to move the discharge point from the Avon-Heathcote Estuary to go instead direct to the open sea via a long underground ocean pipeline. This is subject to further research to prove the benefits of the proposal.
The Working Party which had three Councillors, three community board members, business representatives, residents, technical support, Friends of the Estuary, commercial fishing and surfing representatives has met for 18 months facilitated by Gay Pavelka. Working Party members included, Peter Townsend of the Employer’s Chamber of Commerce, Councillors Ron Wright, Carole Evans and Denis O’Rourke.
Council staff said that Christchurch’s sewage treatment system has led the way in New Zealand since the present plant was installed in the 1960’s, and staff are justly proud of what has been achieved, but times have changed and people rightly expect a better product than in the past. The cost of an ocean outfall is likely to be $47 to $57 million, spread over 10 years or more, and because of the good base to work from this is a small figure compared with what most New Zealand cities are having to spend.
In community meetings over the last 18 months people have asked that water be safe for swimming, sea lettuce problems reduced, shellfish safe for eating, no odours or visible effects, fish and bird habitat enhanced, etc. Apart from shellfish in the Estuary, which will still be affected by contaminants from rivers, the Working Party believes these outcomes will all be achieved with the solution that is proposed.
The investigation team looked at other options, particularly some land disposal possibilities, and even (briefly!) at recirculating treated effluent as drinking water. But in the end they felt the solution that best provided what people wanted in the long term was to produce a high quality effluent with further purification then put that out to sea.
Staff expect that the present high quality water on our beaches will not be compromised, and in fact would even be improved through there being less decaying sea lettuce and fewer pathogens to recirculate around the Brighton and Sumner beaches. Further research will be commissioned on the hydrodynamics of the estuary and nearby beaches to confirm expectations, but the Working Party has signalled the clear direction it believes the city should head, and expects the research will fine-tune details.
After the Council reviews the conclusions and reaches its own decision there will be a thorough investigation of all environmental effects before details are confirmed and an application lodged for a new consent in the middle of next year. The Council will continue to seek wide input from the public throughout this time to ensure it is hearing and responding to the concerns people have.
For further information contact:
Walter Lewthwaite 03 371-1367
Wastewater EngineerMike Bourke 03 371-1364
Liquid Wastes ManagerAndrew Nichols 03 371-1274
Waste Investigation Officer