Domestic wastewater includes grey water and sewage from domestic dwellings. Grey water is defined as wastewater that comes from sinks and washing machines, i.e. the wastewater that contains some bleach and detergents. The grey water from your household is treated in the same way as sewage whereby it is collected in a septic tank and undergoes treatment either in a percolation area or in a secondary treatment unit prior to being discharged via a polishing filter to ground. Rainwater is not classified as grey water and therefore should not be discharged into your wastewater treatment unit.
When houses are not served by a public sewerage system, the wastewater from a house should be treated by a septic tank and percolation area or advanced wastewater treatment system. With new houses the type of system used is determined by testing ground/soil conditions at planning stage.
A modern septic tank system includes a double chamber tank and percolation area. Wastewater is partially digested by bacteria in the septic tank and the effluent then passes through a percolation area where effluent is further treated.
YES – grey water should in all circumstances be directed to the wastewater treatment system. Grey water is also a pollutant and if directed to the rain water system may cause contamination of waters. Take care with house extensions or alterations – don’t connect any wastewater pipes to the rain water disposal system.
NO – Roof and yard waters should not be connected to your wastewater treatment system. Clean water should be collected and discharged separately to a local watercourse or soakaway.
Uncontaminated water should be disposed of by means of a soak pit/soakaway. The soakaway should be designed in accordance with the guidance provided in BS8301 and in BRE Soakaway Design (1991). It should not be located within 5m of any dwelling and as far away as possible from the percolation area (at least a minimum of 5m separation distances should be used).
Some signs that your wastewater treatment system may not be working include the following:
Yes it is possible. If you suspect that your wastewater treatment system is affecting your well you should have it checked. If you are concerned you should contact your local authority’s Environmental Section or local Environmental Health Officer for advice.
If you suspect contamination of your well you need to have a full assessment of your wastewater treatment system carried out by a suitably qualified person.