De-mystifying Misconnections - Part 3 Separate Sewer Systems

So finally, in part three of Robert (aka Urban Pollution Hunter) Hellawell's sewage trilogy we find out about misconnections and how they are a danger for our river. But first we explore separate sewer systems. Read on............

Separate sewer system.

Separate Sewer Systems are a development of combined sewer systems. With the rapid expansion of our town and cities it was realised that the combined sewers built in Victorian times would soon struggle to cope with this growth. It was decided that removing rainwater from the combined sewers would help. This would reduce the number of spills from CSOs into our rivers when it rains. Essentially, all post-war housing in the UK has 2 separate sewers, one for the foul waste from toilets baths, sinks etc., and a separate sewer just for the run-off from rooves and road gullies when it rains. The foul sewer joins into the combined sewer and is transported to the wastewater treatment works for cleaning treatment before being returned to the river. The surface water sewer transports the rainwater directly to the nearest river or beck without any treatment. ​

Misconnections into surface water drains are all too commonplace. Having two sewer systems means that mistakes can be made where toilets, sinks and baths are plumbed into the surface water drain in separate sewer areas. The effluent from these misconnections flows straight into the nearest river or beck and causes low grade, diffuse pollution.  ​

New extensions of kitchens and bathrooms are often connected into the wrong sewer by unscrupulous or uninformed tradesmen. This causes avoidable pollution of our watercourses that is both difficult to trace and expensive to repair. If you are having work done, ask your plumber if he is “Water Safe” accredited and understands the risk of pollution from misconnections. ​

Domestic misconnection discharge recently spotted at Silsden Beck.

Are you Misconnected? We can all check to see if we are polluting our rivers from our own homes. Firstly, we need to figure out if our home is served by a separate sewer system or not. If your home was built after the second world war, then it is likely that you are on a separate sewer system. If you are on a separate sewer system, there will be two drainpipes connected to your home. One will take the rainwater from your roof, the other will take the foul effluent from toilets baths and sinks. There should be no connections from sinks, baths or toilets into the drainpipe that takes the rainwater from your roof. The ConnectRight website is extremely helpful in finding out if you are misconnected and to find a local plumber who is “Water Safe” accredited. ​

Click here for ConnectRight website

Not all misconnections are from extensions and alterations. There have been multiple instances of new build houses being connected into the surface water sewer by the developers! One such development which has recently been traced and rectified on Bradford Beck dated back 25 years. Other similar instances are much newer and are a source of acute embarrassment for the authorities who have passed off new build houses without checking where the effluent ended up. ​

25 year old misconnection of 1990's houses plumbed into Bradford Beck.

Not all misconnections are new. With our rich, industrial heritage being increasingly recognised, vacant, old industrial buildings are being repurposed. Many old buildings date from a time before there was any local sewage treatment. Marley wastewater treatment works, which processes the sewage from Keighley, was not constructed until the early 1900s. Before this time, all effluent was simply piped straight into the nearest river. Redevelopments of old buildings sometimes use existing drains not knowing that they take the sewage straight to the river just as they did in the old days! ​

Culverted Carr Mires Beck discharging sewage into the Aire at Shipley from redeveloped former mill.

redeveloped former mill.) 
Only rain down the drain please! In separate sewer areas, the gullies that drain our roads lead straight into the river. This means that when you wash your car on your drive, or the road, wash paint brushes out, or swill wastewater down the drain, this will all end up in the nearest river or beck. Please be mindful of what you are disposing of down the drains as there is a chance that you are polluting our river. ​

Bradford Beck Shipley after building work swilled off down road drain.

You can help by becoming a pollution spotter. If you value spending time by the river, then remember to always keep an eye out for any pollution. All the plants and aquatic insects and the fish, birds and mammals that rely on them as food, all require clean, unpolluted water to thrive. If you see pollution to our rivers and becks, then take pictures if you can, share with the River Worth Friends (contact us here) and always report pollution incidents to the Environment Agency on their free hotline 0800 80 70 60. Together we can make a difference caring for and protecting our rivers. ​