B3 Removing waste water safely
Waste water in the living environment can make people sick. If people come into direct contact with waste water, or if their water supply is contaminated with waste water, there is a greater risk of transmitting bacteria and virus that cause disease. These risks are also increased if animals, vermin or insects that have been in direct contact with waste water can pass bacteria on to people.
Removing waste water safely from the house and surrounding living area, and managing it safely at a community level, is important for people’s health. This section discusses essential items of waste water health hardware in the house and surrounding living area.
Communal waste water systems that take waste water from the surrounding living area and treat it at a central point are discussed in section C3 ‘Waste water’.
A household waste water disposal system must include the following components:
- a toilet
- drains from baths, showers, basins, sinks, laundry tubs and floors in these areas
- a floor drain and a grate to prevent objects going down the drains and blocking the pipes
- water trap or seal on each drain, which is a water-filled bend in the pipe under the drain to prevent bad smells spreading from the drain into the house
- drainage pipes that connect and fall to a main house drain located in the yard, which flows into a system for treating and disposing of the waste water
- inspection openings in the drainage pipes and house drain, for maintenance removing blockages
- vent pipes that discharge above the roof to remove bad smelling and volatile gases from the drain pipes
- an overflow relief gully for waste water to discharge into the yard and prevent overflow into the house if there is a blockage in the drain pipes.
These components need to be regularly maintained. Approximately 70 per cent of all maintenance funding used during Housing for Health projects over the past 12 years has been spent on fixing waste water drainage components.
Waste water from houses is described as ‘black water’ or ‘grey water’. Black water is waste water from the toilet. Grey water is waste water from the shower, laundry, basins and kitchen. Grey water can account for up to 90 per cent of the waste water from a house. Research10 has shown that grey water is not the ‘safe’ part of the waste water produced by the house as was commonly assumed. If grey water is not properly collected, treated and disposed of, it may have negative health effects on residents.
10Khalife, MA, Dharmappa, HB & Sivakumara, M 1997, Safe Disposal of Waste water in Remote Aboriginal Communities, University of Wollongong, Wollongong.