Sewage and rain water mains

[mufi]

I live in a house built in 1935 and I know that the suface water goes into the same pipe as the sewage. I have a friend who lives in a 1960 built house. Is this likely to have the same set up or will it have a separate main for surface water. What is the current practice on new builds. Thanks - Mufi.

[New Forester]

In the UK roof water usually goes to soakaways, and I think private driveways will often do so too. However, there is generally only one public drainage system, so if it's going to a proper pipe, it'll be the public sewer. More houses off the public drainage will have a septic tank and will keep rainwater out of it. Road drainage in the countryside usually goes into local surface drains and ditches. Newer ones will have oil skimmers and perhaps balance ponds (those square pits you see beside motorways) to cope with sudden storms. Current best practice uses porous materials ("Grasscrete" etc) for driveways and residential access roads, so most rainwater soaks straight in. I think some places in the world have a parallel "grey water" drainage system for baths, roofs etc, with a "black water" sewer for proper sewage.

[sddsddean]

Nowadays, accepted practice is usually to have 2 seperate systems, although there are obviously still a lot of older properties that use combined sewers. A lot depends on where you live. In towns, you are much more likely to have a 2 sewer system, although a lot of houses will still use soakaways for storm water. Unless you know how your foul and storm systems work (ie have you got soakaways or are you connected to the main storm sewer) it is almost impossible to tell without digging along the line of the downpipes or their gullies. With respect to your house and your friends you could have the same sort of set up, or you might not. There is no hard and fast rule. My house is 5 years old and I have 2 seperate pipes going into the 2 seperate sewers, but there are plenty of new build houses that are built using soakaways.