Trade waste does not include wastewater from toilets or bathrooms but rather discharge from food processors, metal finishers, service stations, restaurants and chemical manufacturers.
Council controls the trade waste of Christchurch through the Trade Waste Bylaw 2006 which came into force in January 2007.
The level of contamination is governed by this bylaw, which sets limits for acceptable substances and lists prohibited substances.
Christchurch city’s growth and its increasing number of commercial and industrial operations results in a significant increase in the amount of trade waste discharged through the sewer network.
Currently, about 10 per cent – or 15,000 cubic metres per day – of the average daily volume of wastewater that is treated at the Christchurch Wastewater Treatment Plant comes from industry.
Trade wastewater is not necessarily toxic but can be harmful if discharged directly into the sewer without first having problem substances removed. Such substances can:
- harm people's health and safety as well as the environment
- corrode or block sewer pipes
- create odours
- put extra demands on treatment at the wastewater treatment plant.
