The Christchurch City Council will spend up to $3.8 million to seal and re-bury thousands of tonnes of asbestos found underneath QEII Park.
The toxic material - discovered during the demolition of the former swimming and athletics complex - was believed to have been there for about 40 years.
The council had considered digging it up and trucking it to a landfill but decided the cheapest and safest option was to encapsulate it and bury it on-site.
QEII Park will soon be the new home of two high schools damaged in the earthquakes, as well as a rebuilt swimming pool.