Mussel farmers are warning plans to discharge partially treated sewage into the ocean, to deal with Christchurch's Bromley stink, could wipe out aqua culture

The City Council's planning to dump 30-percent of partially treated wastewater into the ocean to ease pressure on the poorly operating treatment plant.

Two thousand tonnes of green lipped mussels come from eight Aroma New Zealand farms in Banks Peninsula annually.

Company director Ben Winters says chlorine and sewage don't need to go to sea.

He warns if plans go ahead it could be a national disaster