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 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. ​

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. ​

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. ​

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! ​

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. ​

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. ​

In part two of Robert Hellawell's blog about Pollution on the Worth he talks about Combined Sewage Outflows which have been much in the news lately. He also touches on the issue of sewage litter which is major problem on the Worth.

-------------------------------------------

As discussed previously, we have two types of sewer systems in the UK, combined sewer systems and separate sewer systems. Here we look at how sewage can get into our rivers from combined sewer systems. ​

Combined Sewer Systems are designed to discharge sewage from Combined Sewer Overflows or CSOs as they are often referred to. They act as a safety valve, releasing storm water containing sewage into our rivers in times of rain. They are only allowed to discharge in this way when the volume of flow in the combined sewer reaches an agreed rate. This is usually during, or following, heavy rainfall. The precise details are given in the Discharge Consent Permit issued by the Environment Agency (EA) for each CSO. All Discharge Consent Permits are held by the EA and can be obtained free of charge by the public. ​

Pollution is said to occur when a CSO discharges outside the agreed limits of its permit. In this case, it will discharge well before the permitted, sewer flow rates in the discharge consent permit. So, if it is not raining now, and it has also been dry for a few hours, then there should be no sewage escaping from any CSO. Sewage escapes from CSOs in dry weather mean that there is a problem in the sewer system. Discharges from CSOs during dry weather conditions is considered to be pollution by the EA. ​

The sewage discharges which have made the news recently are largely from CSOs that serve as overflows to Wastewater Treatment Works (WWTW). Here the concentration and sheer volume of sewage discharged can have a detrimental impact on the health of our rivers. An unsightly aspect of CSOs is the substantial amounts of sewage litter which they discharge into our rivers. Much of this is plastic based such as wet wipes, nappies and other sanitary products, adding to our growing problem of plastic pollution in our seas. It is a sobering thought that anything which we flush down the toilet has a chance of ending up in your nearest beck or river. Sewage litter caught along the banks of our rivers is evidence of CSO discharges nearby. ​

Only the “Three Ps” should be flushed down your toilet! These are pee, poo and paper. Sadly, not everyone follows this guidance, and everyday all kinds of debris are flushed down our toilets that can lead to blockages in sewers. Pollution of our rivers can then follow as the CSO upstream of the blockage does its job and discharges sewage into the river instead of that sewage backing up and spilling out in our homes and streets.  ​

You can find out if you have a CSO, or other permitted discharge, near you by looking on the Rivers Trust sewage map which can be found on the Rivers Trust website. 
https://www.theriverstrust.org/key-issues/sewage-in-rivers 
 
In the next instalment we will look at pollution to our rivers from separate sewer systems and finally learn what a misconnection is. ​