A cross connection is the diversion of stormwater into the wastewater network, or wastewater into the stormwater system.
A common source of cross connections is a downpipe diverted into the gully trap (a drainage vent usually covered with a small grating and located against the outside of a house, near the kitchen, laundry or bathroom).
Stormwater in the wastewater network increases the volume at the treatment plant by up to five times dry-weather levels. It can overload the plant, leading to a discharge to sea of only partially treated water.
Wastewater connections to stormwater pipes have an equally harmful impact. Due to a faulty connection or leaks, wastewater can overflow and end up in the stormwater system, which transports directly into our streams, rivers and the sea.
One way to help keep our streams, coast and harbours clean for generations to come is to ensure there are no cross connections on your property, as they are illegal.
It is the homeowner’s responsibility to ensure their drainage pipes connect to the right system. If you are getting drainage work done for an extension or new development, ensure your drainlayer is 100% confident your pipes are going where they should.
The authority on sustainable building, Level, has some more information about the compliance requirements for drainage on properties, click here for more information.