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Sewage dumping

Dumping of raw sewage in rivers & sea

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Bob Mc24/10/2021 10:05:16
199 forum posts
19 photos

I am trying not to be political but I am asking this question since I am not fully conversant with the treament of sewage and perhaps a forum member could provide some information as to the reasoning behind a news item that an ammendment to reduce the amount or stop raw sewage being dumped into rivers & the sea has been defeated in Parliament.

Perhaps there is an engineering principle which cannot be achieved with the treatment of sewage at present.


JasonB24/10/2021 10:11:06
21613 forum posts
2490 photos
1 articles

Basically lack of capacity to treat it all at times of high volumes so it effectively "overflows" It would need a lot of investment to get the treatment plants large enough to cope with these peaks that may only happen on the odd occasion.

Simple engineering principal is you can't fit a litre into a pint pot

Edited By JasonB on 24/10/2021 10:12:30

Ady124/10/2021 10:21:10
4810 forum posts
717 photos

Politics is unavoidable

Private companies can't pay out large dividends if they invest in decent utilities infrastructure

So everything hangs on by its fingernails

water and power being good examples

That's why they nationalised our utilities after the war, to make them fit for purpose

Mark Rand24/10/2021 10:30:26
1076 forum posts
12 photos

The issue tends not to be a systematic one, but is often caused by surface water that is discharged into foul drains. This shouldn't happen, but does in older properties that did not have separate storm and foul drains and also happens with illegal/incorrect newer building work.

The foul water flow should be pretty much independent of the weather but if surface water is allowed into the sewers, then the treatment plants get overloaded in stormy weather.

This opinion is worth almost as much as it cost. blush

David Jupp24/10/2021 10:31:39
789 forum posts
17 photos

In many locations surface runoff water goes into the same sewer system as foul water (sewage). Heavy rainfall can lead to huge flow rates, many times more than the usual sewage flows.

Dave Halford24/10/2021 11:00:17
1816 forum posts
19 photos

Like Mark I used to believe in the separate drains system, however at least for SevernTrent it appears to be an Urban myth. If road drains are still separate then all the oil, brake and tyre dust goes straight to the river.

Whats wrong is when water companies discharge straight to the river in times of low rainfall to keep costs down.

J Hancock24/10/2021 11:48:40
773 forum posts

You and me ADY1 , the only ones to 'tell it like it is' .

Rockingdodge24/10/2021 12:11:23
292 forum posts
53 photos

The River Wye was in the news last week because the phosphate levels are waaaay over the legal limits and while land runoff from chicken farms poo being spread over fields near the river or tributaries the water company dumped raw sewage for 40,000 hours in 12 months!!!

It's a shame as we had otters coming back into the area and a couple of pairs of Kingfishers but with the minnows dying from the pollution we will lose them, also salmon caught in the river is down to low double figures this year.

Welsh Water are now saying they are 'looking into the issue' (probably because the issue has been highlighted). Before anyone says about profit, WW is a not for profit company.

It's such a shame to see the river deteriorate so much over my 70 years here.


Tim Stevens24/10/2021 12:16:30
1490 forum posts

The system will not be changed until it causes the death of the children of rich folk. For evidence supporting this view look at the delayed response to the Cholera epidemics in victorian times.

Which actually is when most of our sewer systems were built. Now, they are well overdue for a rebuild, and the population has grown significantly.

Cheers, Tim

JA24/10/2021 12:16:47
1245 forum posts
73 photos

The drains of the main road near my home go straight to the adjacent river. Flooding of the road has been a problem with river water flowing back through the drains. Two years ago non-return valves were fitted.

Six miles away, downstream, the same river suffered badly for many years from overflow of local sewage. The sewage company finally layed a large diameter drain for about eight miles to cure the problem. The work took a year and a half.

I would like to think the river is cleaner but nothing suggests that.


The main problem is probably farm and small industrial premises run-off.

Edited By JA on 24/10/2021 12:21:06

Samsaranda24/10/2021 12:31:07
1244 forum posts
5 photos

I live in the Southern Water area and they were recently fined £90 million for illegally dumping raw sewage into rivers and the sea over many years, this practice was carried out because basically Southern Water instead of allocating funds to extend and improve their infrastructure over the years as the demand grew, they fed the cash to the shareholders. Complicit in this it appears was the Environment Agency because they should have been monitoring and prosecuting the offenders. If there are occasions when your system will be overwhelmed by abnormal rainfall etc. then it is common sense to provide storage so that the excess can be retained and processed when the event has passed this will be a not infrequent event as our climate changes, It would appear that other water companies are also guilty of inadequate provision of storage, Thames Water is one but has recently embarked on a programme that will go some way towards solving their problems. As for surface water being fed into the foul water system in the past the regulations allowed this so there are many older properties who are legally entitled to discharge rainwater into the foul system because of the legislation that existed at the time the properties were built. This practice is now illegal for new developments. I was born in Eastbourne and now live just outside of it, when I was a youngster, a long time ago now, you could stand on the seafront and somedays see that the colour of the sea close to the beach was a different colour, this was because in those days, the 50’s, the sewage was not treated but discharged through a very short outfall pipe direct into the sea. Nowadays the outfall pipe discharges some 3 kilometres out to sea and the discharge has been partially treated, they run it through screens to remove solids then blast it with uv light to minimise the bacteria content that is discharged. Recent housing developments in our area had no access to mains sewers, Southern Water were slow to invest in the necessary infrastructure, the houses were connected to communal septic tanks on the developments and these were serviced periodically. In the last two years Southern Water were forced to lay a new foul water sewer to service these new houses, the new drain is about 2 kilometres long and had to be laid trough the High Street of our village at a depth of about three metres, causing much disruption, and is adjacent to another foul water sewer that desperately needs to be replaced because of problems with frequent collapses, but there isn’t much prospect of that occurring due to Southern Waters abysmal investment policy. One can only surmise that the fact that the amendment in Parliament was defeated was due to pressure from the Water Industry, says it all really they are protecting their profits. Dave W

Bob Mc24/10/2021 12:31:33
199 forum posts
19 photos

Thanks to all who gave their information,

The overall situation then is that only in certain circumstances does actual raw sewage get dumped into rivers and the sea, I can understand that surface water may be contaminated and I would be surprised if the phosphate levels that Roger mentions are not classed as illegal.

What does surprise me is that there seems to be little in the way of surface water being checked for pollutants and that there does not appear to be any technology to make this automated rather than there being random tests.

What would be interesting is to see a map of where the sewage outflow pipes are so we can avoid those areas when visiting coastal areas or rivers.

From what I read of the ammendment, it was not just a case of stopping raw sewage but having the companies involved to pursue reducing the levels being dumped.


pgk pgk24/10/2021 12:42:13
2352 forum posts
293 photos
Posted by Rockingdodge on 24/10/2021 12:11:23:...

Welsh Water are now saying they are 'looking into the issue' (probably because the issue has been highlighted). Before anyone says about profit, WW is a not for profit company...


In 2016 it was reported that the CEO of WW earned £768,000
Not for profit, huh?


Peter Cook 624/10/2021 12:56:51
187 forum posts
53 photos
Posted by David Jupp on 24/10/2021 10:31:39:

In many locations surface runoff water goes into the same sewer system as foul water (sewage). Heavy rainfall can lead to huge flow rates, many times more than the usual sewage flows.

It's not just runoff in some places. I live in the Lambourn valley in the Berkshire downs, which are all chalk. In winter and spring the water table within the chalk rises to the surface in the valley. Any cracks or leaks in the sewer pipes then allow groundwater to flow into the sewer system frequently overwhelming it.

It has been a long standing problem, and causes sewers to overflow. Thames water have spent a lot of money lining the main sewers with continuous plastic pipe to minimise the inflows ( the main sewers are quite deep in places and well under the water table levels. But they haven't (can't) lined all the side drains from individual properties which still fill with groundwater when the water table rises.

J Hancock24/10/2021 13:48:51
773 forum posts

Anybody joining the dots here..................?

Too much demand on gas.........electricity...........sewage treatment............water next anyone.

Too much demand on rail , road.

Too much demand.

duncan webster24/10/2021 13:50:34
3581 forum posts
65 photos

Posted by Rockingdodge on 24/10/2021 12:11:23

​​​​​​....... the water company dumped raw sewage for 40,000 hours in 12 months!!


They must employ Dr Who, there are only 8760 hours in a year. However I do take the point, round here tots of driveways just direct rainwater onto the road, from where it goes into the foul sewer. I'd rather have road runoff in the river than sewage, is this a case of the best being the enemy of the good?

Phil Whitley24/10/2021 14:36:05
1383 forum posts
147 photos

Generally the only way to avoid this happening everywhere is to seperate surface water and sewage into seperate systems, and discharge the surface water directly into rivers and sea. As the planet warms (slightly) evaporation from the sea will increase, and there will be more rain, and it is impossible for any sewage treatment plant to cope with this amount of water appearing at their inflow point in storm conditions. There must be an overflow of some sort to act as a safety valve. If the treatment plant floods then the problem is massively compounded, there is no effluent grid, all water and sewage treatment is local. Once we have a seperate system, it must be kept clean, and the rivers that it discharges into must be dredged, something which has not happened for a long time!

We had this done in Driffield(Pop 13000) some time ago, it was a massive undertaking. took over a year, and involved a remote controlled hydraulically powered mole about 3ft diameter which drilled from point to point dragging a lining behind it. It was operated from towers built at about 200 yard intervals down the centres of the roads, which had to be closed. In short, disruption and expense on a grand scale. Since this was done, overflow discharges are now very rare, but still occasional.

Rivers and sea can cope with sewage up to a certain point, after all, all the aquatic life craps in it! What it cannot cope with is high phosphate and nitrate agricultural run off, and above all the worst pollutants are the detergents soaps, bleaches and other stuff that pours into the sewer from washing machines, dishwashers, the chemicals needlesly chucked down the toilet, and drain cleaners etc. These kill the bacteria that digests the sewage, and any septic tank owner should know that they can never use these products or their septic tank will stop working in a very short time, and need constant pumping out! Industrial outfalls are largely licensed and monitored to make sure that they are acceptable.

There is no easy answer to this, apart from the government legislating on the water companies to use their profits for upgrades rather than high salaries and shareholder dividends! Renationalising water, power and transport just throws the cost from the private companies onto the taxpayer, because governments have no money!


Edited By Phil Whitley on 24/10/2021 14:45:07

Rockingdodge24/10/2021 14:42:59
292 forum posts
53 photos
Posted by duncan webster on 24/10/2021 13:50:34:

Posted by Rockingdodge on 24/10/2021 12:11:23

​​​​​​....... the water company dumped raw sewage for 40,000 hours in 12 months!!




They must employ Dr Who, there are only 8760 hours in a year. However I do take the point, round here tots of driveways just direct rainwater onto the road, from where it goes into the foul sewer. I'd rather have road runoff in the river than sewage, is this a case of the best being the enemy of the good?

Umm no Duncan, if one outflow is opened for say 100 hours in a year and there are say 100 outflows then that is 10,000 hours of sewage, now the river Wye is one of the longest river in the UK so you see how the maths work and how the total can add up.

I don't know about your area but surface water, in the main, is separate to sewage here, the exception being where roof runoff at the rear of old houses do enter the sewage system.


Edited By Rockingdodge on 24/10/2021 14:47:32

derek hall 124/10/2021 14:49:36
178 forum posts


I used to work for Anglian Water some 27 years ago in the "lumpy water" department, in those days sewage treatment works were design to operate at a maximum of 3 x "dry weather flow". In other words once incoming flow had exceeded 3 x dwf then any excess ended up in the river....untreated...

Some larger treatment works did have storm water tanks that intercepted this extra high flow and then got treated when it was possible, but this was the exception and they did fill up quickly.

But this was a long time ago, probably different now.



not done it yet24/10/2021 15:13:44
6430 forum posts
20 photos

In the future, there will be a lot of down-stair loos that will back up and flood sewage into the property. If I was not living at the ‘top of the hill’, I would only install a pumped down-stairs loo, so that it fed into the soil pipe much higher than the usual loo. Most manhole covers are not sealed (ie bolted down) so flooding soon gets contaminated with sewage

Most sinks, basins and washing/dishwashing machines will only be OK until the out-door flooding exceeds 90cm, before feeding sewage back into the property.

The situation will only get worse over the next few years.

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