From the time man first lived in settlements, our waste products have posed a problem. It took many thousands of years to realise that befouling the oceans and rivers with waste made people ill and potentially sickened the environment.
The Christchurch Wastewater Treatment Planthas been built to operate in such a way as to be energy self-sustaining whilst safely disposing of effluent
Each year around 66 million cubic metres of effluent is processed through the effluent treatment plant. The complex process of treating this effluent is described in the Wastewater section.
At the Treatment Plant, wastewater is separated into sludge and water in primary sedimentation tanks. The sludge is diverted into digesters where the process of breaking down the organic material generates methane gas.
The methane gas is fed into 2.4 megawatt generators to produce electricity in a self-sustaining process. Waste heat from the generators is used to keep the digesters warm.
Most of the electricity produced is used at the plant; the remainder, approximately one million kilowatt hours a year, is fed into the national grid.
For further information about the treatment plant see our Facts and figures page.
The benefits of the project
The benefits of the project include:
- The plant generates sufficient electricity and heat to be energy self-sufficient in a sustainable manner.
- The plant exports additional power into the national grid for which the Council receives payment.
- The treatment process efficiently purifies the water, cleansing it by 99.99 per centof any organisms.
- The processed biosolids are suitable for use as fertiliser, soil conditioner or fuel for boilers.
Things to consider for your business or home
- Is there an area where waste heat is generated that could be used elsewhere in my factory/business?
- Can I generate power through solar panels or using waste material?
- Is there a market for material I presently throw away?
