If you have a sewage treatment plant or septic tank, you’ll probably have a soakaway system which takes the treated effluent from the tank and disperses it into the ground. The most common way of doing this is to use a herringbone layout of rigid, slotted pipework surrounded by drainage stone. 

Your could also have a reed bed is a product often specified in order to obtain an even higher level of water quality of a treatment plant before it seeps out into the surrounding land or watercourse. 

when it all goes wrong

soakaways have a limited lifespan which is heavily affected by the quality and volume of effluent dispersed through it. typically soakaways last up to 10-25 years. The main cause of soakaway failures failing to have regular desludges carried out on your septic tank or sewage treatment plant, which allows untreated waste to flow in to the soakaway and causes a binging effect on the surrounding crushed rock preventing the soakaway from working correctly, this is irreversible.