The Ocean Outfall fits into a much larger City Council jigsaw of works which will further improve the way Christchurch treats its wastewater, Mr Moore says.

The Ocean Outfall plans are running in parallel with the upgrade of the oxidation ponds at the Christchurch Wastewater Treatment Plant and with the city-wide Major Sewer Upgrade - a 10-year project which will reduce sewage overflow into Christchurch rivers during wet weather.

This means that, once the Ocean Outfall is completed in about five years time, people will enjoy far better water quality and beach grades than they do now, he says.

There will also be less sea lettuce growing in the Estuary. For many years, residents have had to bear the smell of rotting sea lettuce at low tide. At Scarborough and Sumner beaches especially, beach standards would improve.

Discharge plumes from the Estuary were now being carried out along the South Brighton spit on various tides, measuring up to 80 faecal coliforms per 100ml of water (80 FC/100ml), but this will be eliminated with the Ocean Outfall, Mr Moore says. Mr Moore's comments come as the City Council prepares relatively complex information on beach standards and water quality for a city-wide summer survey.

The survey aims to get residents' views about what beach grade and water quality outcomes they expect when the Ocean Outfall is completed. For example, it will ask if they want a recreational swimming standard in the ocean and a seafood-harvesting grade on the beach.

The survey's results will then be presented to the Council to help it decide which options to pursue in building the Ocean Outfall.

More information about the Ocean Outfall, the treatment plant and the major sewer upgrade is available on the Council website, at www.ccc.govt.nz/WasteWater