Canterbury's Medical Officer of Health is pushing for chlorination of the water in Christchurch's North west.

Council will discuss options available tomorrow - which includes temporary chlorination of several aquifers in the area.

Alistair Humphrey told Chris Lynch plans to accelerate a $16 million project to drill deeper into the shallow wells - which is causing the sub-standard water - is underway.

The project started in 2012 and was set to be complete by mid 2018.

"Essentially, they have to chlorinate the water. It's gone on too long," said Humphrey.

About half of Christchurch's water was chlorinated after the February earthquake until December 2011.

Meanwhile a Canterbury town awaits a decision on whether its drinking water will continue to be chlorinated - something residents have been fighting for nearly a decade.

Pegasus water has been chlorinated since its beginning in 2008.

The Waimakariri Council has consulted with the public, and Utilities and Roading Manager Gerard Cleary told Chris Lynch a majority want a more biological process.

"We've got that feedback, and the council is yet to make a decision. If it does it would probably take a couple of years still before we got down that path."