Improvements at the Mogden Sewage Works

Dear Resident

As part of our upgrade works at Mogden, our contractors, Black & Veatch,are cleaning 13 of our sludge digester tanks in the south-west corner ofthe site. This work is underway, and the first three tanks have been done.

We plan to start working on the fourth tank on Monday 22 August 2011 and have itcompleted by Friday 2 September 2011. We are notifying you of this work as there is a small chance of an increasein odour during this time.

We would like to apologise in advance for anyinconvenience that this may cause. We will issue further notifications for the remaining 9 tanks, which willbe complete by the end of 2012. With kind regards

Dear Resident

We are now into our second year of construction to improve Mogden Sewage Treatment Works, and have already built more than half of the additional treatment tanks.

This puts us firmly on track to increase the site’s capacity by 50 per cent by March 2013, which will reduce the amount of sewage that overflows into the River Thames after heavy rain.

Our good progress has allowed us to start installing the machinery for two of the four key treatment areas being extended, which means they will be in use at the beginning of next year.

At the inlet works, we have installed screens that will remove from the incoming sewage items like nappies and other materials that should not be flushed down the toilet. The flow of sewage is then slowed in the primary settlement tanks, where we have put in place the equipment that will remove the heavy particles that settle to the bottom.

We have also built two of the five new aeration lanes, where we bubble air through the sewage to encourage bacteria to eat the organic matter.

In addition, we have recently started building the foundations for the ten new final settlement tanks, where any remaining solids are removed before the cleaned effluent is safely returned to the river. This activity will continue into the autumn, and can generate noise and vibration, as it involves hammering 1,700 concrete piles into the ground.

Working hours for the main construction activities will continue to be limited to between 8am and 6pm, Monday to Friday.


Thank you for bearing with us while we carry out this essential work. We apologise for any inconvenience it may cause.

On Thursday 25 August, from 5.30pm to 7pm, you can meet members of the project team, view our plans, and provide any feedback at our next informal drop-in session at Twickenham Stadium. Free parking will be available in the main car park. On arrival please report to reception at Rugby House Door A, situated in the South Stand.

We will continue to update you on our progress, but if you have any questions please call 0845 641 0030, quoting 'Mogden'. Our lines are always open.

Kind regards


If anyone fancies going down this Thursday, it is an open house

My wife and I went along to Twickenham Stadium yesterday and met a couple of people from Thames Water and a chap who was works for the primary contractor running the project to expand the site capacity. Amazingly, we were the only visitors there from 6 - 7 pm! These meetings are held monthly and intended as an update for local residents but if I had said we were coming they would have brought more materials of interest to us.

This left us free to get a good overview of how the plant works and what the expansion work involves. From the area and size taken up by the new expansion works, one would guess that it might increase capacity by 20-25% at best. But we were assured that being more modern and deeper the new facilities will increase capacity by 50%. They reckon that will be sufficient to deal with all domestic waste AND all storm surge events. The work will be complete and plant operational by March 2013.

How it works...
There are 2 sewage supplies to Mogden, the "shallow" one from the West comes down under the A4 arrives more or less at surface level and the "deep" one from the South which is over 30m down, they have pumps to lift this up to the first stage which is screening. Everything over 6mm diameter is removed here, branches, bricks, nappies, sanitary towels, you name it. Dental floss can be a bit of a problem as it can go through but not always. The screened material is skipped and sent to landfill, So bin all those things please folks, not down the loo - it will go to landfill eventually just the same!

Now we have watery sewage with grit, by running it through a tank at a precise flow rate over a certain distance, the grit drops to the bottom. These tanks are periodically scraped out, this grit is recycled as a material for building eg. roads.

Grit-free sewage now passes in to the airation tanks where air is bubbled up through to stimulate the breakdown of the organic matter by organisms such as bacteria, nematode worms and snails.

This passes to settlement tanks where the suspended treated substances are allowed to settle out to the bottom. The top layer is now clear treated water. Whilst not regarded as drinkable, it is of the quality of river water. It flows over a weir at the edge of the settlement tank, round in to a culvert and back out to the Thames at Isleworth Ait. This is what can be seen billowing up under the surface there continuously during normal operation.

Because the treatment cycle (airation plus settlement) is quicker than the lifecycle of the organisms doing the job, some of the sludge from the bottom of the settlement tank is pumped back round in to the airation tanks to maintain the numbers of them in those tanks. Otherwise they'd all eventually be washed out. The remainder of that sludge goes to a sludge tank where it is pasteurised at 70 deg.C, concentrated in centrifugal spinners, then pumped back to a sludge treament works at Colnbrook just beyond Heathrow Airport (it was previously located where T5 has now been built - BAA paid them enough for that land to build a new plant there!). The pipes for this actually run in the top of the main sewer under the A4, this has the benefit that if there is a problem (leak) the material simply comes straight back to Mogden via that sewer!
That material is further treated at Colnbrook to create something which can be used as fertilizer by farmers and spread directly on the land.

During the pasteurization cycle quantities of biogas (methane, ammonia, hydrogen sulphide) are given off. These are used to generate electricity, typically around 5MW. The plant needs up to 10MW to operate so that doesn't supply all its needs. In fact, because of the bizarre pricing of feed-in-tariffs they resell ALL the electricity they generate back to the grid and buy ALL that they need from the grid, they do better from it financially that way. Crazy but true!

The above is during normal operation of the plant. During a storm surge they simply cannot cope with the inflow. It still passes through the 6mm screens but then begins to fill storm tanks starting at Nos. 4 & 5 which are covered because of the odour and subsequently filling the others. After the storm these tanks are emptied by pumping back round to the start of the normal cycle. Organic matter should have settled somewhat in these tanks. Worst case is when there are repeated storms, if these tanks are already full there will be a discharge event. The EA monitor the output from Mogden and there is a unit which can add Hydrogen Peroxide to the waste before it leaves the plant in these circumstances.

They are confident that the increased capacity is sufficient that that they will be able to deal with such storm surges in future and those kinds of discharges will no longer be necessary. What that DOESN'T address is the CSOs (Combined Sewage Outlets) such as at Hammersmith which simply discharge unscreened untreated sewage directly. It MAY be that those discharges become less likely because more of that could be directed to Mogden but we'd need to seek clarification on this.

A very interesting and informative hour and raises a number of new questions. I swapped contact details with them so if we get something together we can get more answers. Also feel it is worth following up how TW / EA interface with one another, our guess is TW don't do anything extra unless the EA tell them to do so...

We visited the Kempton Steam Engine Trust yesterday. This is the large water-works pump house situated alongside the A316, http://www.kemptonsteam.org/
Inside the pump house are two giant steam pumping engines 4 stories high. They were installed by the Metropolitan Water Board in 1928. From 1929 until 1980 they ran 24 hours a day. The interesting part as far as we are concerned (I thought) was the explanation of the job they actually did (and which is now done by electric pumps situated on the same site).
This is the other side of our water system, before it becomes sewage. Water abstracted at Laleham is fed in to the Queen Mary resevoir. It flows from there by gravity down to the Kempton filter beds where it passes through screens (to remove leaves, sticks, dead animals etc.) then through gravel, sand and charcoal filter beds. Finally it is chlorinated which renders it good enough for drinking. The water is too low down to supply London directly, the water has to be lifted up about 200 feet so it will run out of the taps in all the houses in North-West London. The pumps push it all the way up to resevoirs at Cricklewood, about 19 million litres a day. Any filtered sludge is pumped to Mogden for treatment.
There is another pumping station at Kew Bridge (now Kew Bridge steam museum), it originally abstracted water directly from the Thames nearby. As we all know the water down there is filthy. In 1852 an Act of Parliament was passed which said that water abstracted for drinking may only be taken from the non-tidal river. So abstraction just upstream of Teddington Lock began, a new pipeline was laid from Teddington Lock to Kew in order to keep that water works running.

This is what they do with the sludge after Mogden has finished with it.
http://www.bbc.co.uk/news/uk-england-berkshire-15058397

Dear Customer

January is an important month for the team improving Mogden Sewage Treatment Works, as it heralds the start of our final year of construction and installation work.

We continue to work hard to increase the site’s capacity by 50 per cent by March next year, which will reduce the amount of sewage that overflows into the River Thames after heavy rain.
The focus of our work in the next month will be pushing ahead with the mechanical and electrical work for the new inlet works, where sewage enters the site and is screened to remove large objects. We will also be working on the new odour control plant, and some of the new primary tanks, where heavy particles are removed from the sewage.

Together, these elements will be commissioned in the spring as part of the first phase of putting the site into full operational service.

You may have noticed recent work to install the chimney of the odour control plant, located at the northern end of the site. This will mostly be hidden from view once we have completed work on the embankment and associated planting.

Our workforce will shortly start removing the earth temporarily placed on the mound, meaning the embankment will be back to its original height by the end of this year.


Thank you for bearing with us while we carry out this essential work. We apologise for any inconvenience it may cause.

On Thursday 26 January, from 5pm to 6.30pm, you can meet members of the project team, view our plans, and provide any feedback at our informal drop-in session. This will be held at a new venue − the BridgeLink Centre in Summerwood Road, Isleworth, TW7 7QR. Free parking will be available in the centre’s car park.

We will continue to update you on our progress, but if you have any questions please call 0845 641 0030, quoting 'Mogden'. Our lines are always open.

We would like to take this opportunity to wish all our neighbours the very best for 2012.

Kind regards

hi all will the disaster on june 6th 2011 be prevented from happening again? will they continue to dump raw sewage into the thames but not as much? 50% is a big improvement is this wishful thinking? sorry for all the questions however from fishing barnes twice and the strand once i would like to know.

Keep firing the questions mate, happy to answer if we can.

Mogden will make a difference as is the last sewage outlet on the western end of the tideway. In terms of how much it pumps out compared to the bigger picture, the figures below are from the last 6 months

Hammersmith
1,995,150

Mogden
2,117,300

Western (Albert Bridge)
2,326,525

Lots Road (SW6)
1,044,140

So it will remove a significant amount which is excellent but bigger picture, is only a fraction of the whole river.

Bear in mind these are only the monitored pumping stations out of 54 CSO's in total.

What it will mean is that the impact is no longer seen as upstream as before which is very good news.

In terms of a big fish kill, if we have a dry spring again then a storm in late May/June, sadly pictures maybe the same. Reason being is that all the sewage sits festering and just doing its normal thing. A big flush spews it into the river, the warmer weather means the oxygen levels are much lower, so hence the impact much higher.

Saw sewage being pumped out the other night in Kingston town centre from the car park just down from the Slug and Andy Shaw has seen it coming from right by Kingston bridge on the other side, where the futuristic silver houseboats are. Despite my involvement with the club, I didn't realise sewage was being pumped into the non-tidal like that. Gutted

And this was when there was zero rain for the last day or so.

Steve I think what you saw would have been as a result of mis-connections - properties connected to an overflow or surface run-off drain instead of the proper foul drain.
There hasn't been a great deal of rain so don't think it would have been as a result of main sewer overflow, but if there was a little it would cause standing matter to be flushed out.
Should be reported to Thames Water and the EA really, then they can make the owners fix it.
If you can get photo's and post them up on Google/Picasa with a precise map location marked it helps (so long as you're OK giving away the location of the swim ha ha!).

Mogden newsletter.

http://www.thameswater.co.uk/cps/rde/xbcr/corp/community-relations-residents-newsletter-feb-2012.pdf

The Mogden sewage plant is getting a 50% increase in capacity.

Serious question....does that mean instead of it dumping millions of litres of sewage into the river when we get 2mm of rain, that it will now take 3mm of rain before it dumps millions of litres of sewage?

Should dump anything mate, thats the plan.

BUT, these will for at least the next 10 years, and just a fraction of the problem

http://rivertac.org/thames-sewage-events/

omg dave i did'nt realize just how serious it really was but now when you look at those stats it highlites just how bad it really is. we need that super tunnel now !!!!!!!!!

i only wish i lived closer to london to give more support.

keep up the good work guys & tight lines

David Harvey wrote:

http://rivertac.org/thames-sewage-events/

What a good web page - nice work Dave.

So since June our beloved tidal river has already had 7,504,295 cubic metres of sewage dumped into it.....and that's just the numbers from 4 of the 57 pumping stations

Take a look at these sludge gas graphs
http://www.thameswater.co.uk/cps/rde/xchg/corp/hs.xsl/923.htm
Why don't TW publish the same style reports for sewage discharges, correlated with rainfall?

Dear Resident

This month marks an important milestone for the Mogden upgrade project, as we are now entering the final year of work to increase the site’s treatment capacity by March 2013.

With just months left before all the structures are finally formed, work to provide power to the extension is ramping up.

This will allow us to bring half of the new works into service in May, along with a new odour-control plant.

Work to reduce the height of the embankment is now into its second month, and we are working hard to keep dust down for people living nearby by watering the haul routes in this area. We are very aware of the need to conserve water supplies, particularly in the current drought. We are therefore dampening the embankment with some of the cleaned water we pump back into the River Thames at the end of the treatment process.

To find out more about the drought, including tips on how to use water wisely, please visit: www.thameswater.co.uk/drought.

Thank you for bearing with us while we carry out this essential work, which will significantly reduce the amount of sewage that overflows into the Thames after heavy rain.

Come and meet the team
On Thursday 29 March, from 5pm to 6.30pm, we will be holding an informal drop-in session, where you will be able to discuss the improvement work at Mogden with members of the project team. This will be held at the Ivybridge Link Centre in Summerwood Road, Isleworth. Free parking will be available in the centre’s car park and refreshments will be provided.

We will continue to update you on our progress, but if you have any questions please call 0845 641 0030, quoting 'Mogden'. Our lines are always open.

Kind regards
------------------------------

If anyone can get along on Thursday and check out the progress, be good to get a report back.

Dear resident,

With less than a year to go before we increase Mogden’s treatment capacity by 50 per cent, preparations for the commissioning of the new works are ramping up.

This involves a rigorous testing process, which is currently underway to ensure the new structures are fully watertight and all the new equipment operates correctly before we start to use it.

This process is nearly complete on the new inlet works and primary settlement tanks – where we will remove grit, rags and the heaviest solids from the large volume of sewage that enters the site.

Next in line are the recently completed aeration lanes – where we pump air into the wastewater to encourage naturally occurring micro organisms to break down the organic matter.

In order to conserve as much drinking water as possible we are using treated water from the works, known as final effluent, for the testing process. This final effluent will be reused to test each of the five aeration lanes, cutting water usage by around 80 per cent – equivalent to the daily water use of around 1 million people.

Elsewhere, work to reduce the height of the western embankment is entering its fourth month, with soil being removed at a steady pace as we continue to fill around the recently completed tanks. We are also using final effluent here, to damp down the soil on the western embankment where necessary to minimise dust.

Thank you for bearing with us while carry out work to improve Mogden, which will reduce the amount of sewage that overflows into the River Thames after heavy rain.

Dear Resident

After months of preparation, September saw a major milestone in Mogden’s £140m extension.

We have now switched on around half of the new works, including the new inlet area and primary tanks - where solid and heavy particles are removed.

This step has allowed us to start taking the existing uncovered primary tanks on the west side of the works out of service so that they can be upgraded, and then covered to control odour.

We are now gearing up to gradually switch on the remainder of the new works by the end of March 2013. At this point the site's treatment capacity will have been boosted by 50 per cent so it can cope better following heavy rain.

As we get closer to reducing the embankment to its final height by the end of the year, there will be an increase in activity in this area, particularly at the northern end as we remove our construction offices. You may notice some vibration as a result.

We are committed to minimising this as best as we can but we are sorry for any disruption you may experience.

By the end of this month we will be returning to our normal working hours, between 8am and 6pm for the main activities. This follows weeks of working on the embankment until 7pm to recover time lost as a result of this year's unusually wet weather.

Thank you for bearing with us.

Come and meet the team
On Thursday September 27, from 5pm to 6.30pm, we will be holding an informal drop-in session where you will be able to discuss the improvement work at Mogden with members of the project team.

This will be held at Twickenham Stadium. On arrival please report to reception at Rugby House Door A, situated in the South Stand. Free car parking is available in the main car park and refreshments will be provided.

We will continue to update you on our progress, but if you have any questions please call 0845 641 0030 and quote ‘Mogden’. Our lines are always open.

Kind regards

Dear Resident

We are now into the final phase of Mogden's £140 million upgrade.

This involves gradually bringing more of the new treatment plant into
service and landscaping the site's western embankment.

We are already just weeks away from reducing the embankment to its final
height.

Over the coming months, people living nearby are likely to see an increase
in earth-moving machinery working close to their properties. This will be
particularly noticeable at the northern end of the site – the area
previously occupied by our construction offices.

Section by section, we will carefully be shaping the mound. This will then
be finished with a layer of good quality topsoil, currently reserved in
piles at the foot of the embankment. Unfortunately the nature of this work
will involve some noise and vibration. We are sorry for any disturbance you
may experience, and will do our best to minimise this as much as possible.

Early next year, the embankment will be fully shaped and ready for us to
start planting a range of native trees such as English oak and hornbeam,
and shrubs including holly and hawthorn – encouraging biodiversity and
local wildlife.

Meanwhile, over the embankment, the team are gearing up to bring the next
set of treatment tanks into operational service.

Thank you for bearing with us during this important project. On completion
in March 2013, we will have increased the site's treatment capacity by 50
per cent. This will significantly reduce the need to discharge
partially-treated sewage into the River Thames.

Come and meet the team
On Thursday November 8, from 5pm to 6.30pm, we will be holding an informal
drop-in session where you will be able to discuss the improvement work at
Mogden with members of the project team and view our landscaping plans.

This will be held at Twickenham Stadium. On arrival, please report to
reception at Rugby House Door A, situated in the South Stand. Free car
parking is available in the main car park and refreshments will be
provided.

We will continue to update you on our progress, but if you have any
questions please call 0845 641 0030 and quote 'Mogden'. Our lines are
always open.

Kind regards
Emily

Emily Goren
Communications Advisor

Sent on behalf of: Sonia Rana, Communications Executive, and Matt
Warburton, Delivery Manager.

Thames Water Customer Services - Mogden Line (24hr/day): 0845 641 0030

Mogden is the second largest Sewage Treatment Works in the UK, serving 1.9
million people.  For more information please visit our website at
thameswater.co.uk/mogden

To register for Mogden news email bulletins, email mogden@thameswater.co.uk
with ‘Mogden – Register for news’ as the subject line.  To unregister for
Mogden news email bulletins, email mogden@thameswater.co.uk with ‘Mogden –
Unregister’ as the subject line

David Harvey wrote:

and ready for us to start planting a range of native trees such as English oak and hornbeam...

No mention of ash tree!


Richard

Dear Resident,

Mogden’s £140 million three-year construction project is drawing to a close.

At the end of March, we will have increased the site’s treatment capacity by 50 per cent so it can cope better during heavy rain. In the run up to this, the project team will continue working hard to switch on each part of the new works – a meticulous and complex operation which began in the autumn.

Over the next few months we also plan to complete the landscaping of the embankment. Although recent adverse weather conditions have affected progress, the shaping of the embankment is almost complete, with the north-west corner of this area following closely behind.

Weather-permitting, we plan to start planting the embankment next month, working from the south to the north of this area. We will be introducing a selection of young native species. This includes trees such as English oak, Scots pine, birch and hornbeam, shrubs such as holly, hazel, blackthorn and hawthorn, and herb-rich grassland – encouraging biodiversity and wildlife.

After March, a reduced number of the project team will remain on site for a short period to get the new part of the works ready to hand over to the day-to-day operations team. During this time we will carry out a number of checks and minor activities, including paving new footpaths, re-surfacing roads, and finishing off any remaining landscaping work that may be delayed by the weather.

Thank you for your ongoing support and patience throughout this project – we really do appreciate it.

Come and meet the team
Our next monthly drop-in session will be held on Thursday 31 January, from 5pm to 6.30pm, for you to discuss the improvement work with members of our project team and view our landscaping plans.

This will be held at Twickenham Stadium. On arrival, please report to reception at Rugby House Door A, situated in the South Stand. Free car parking is available in the main car park.

Thank you for bearing with us during this important project which will increase the site’s treatment capacity by 50 per cent. This will significantly reduce the need to discharge partially-treated sewage into the River Thames.

We will continue to update you on our progress, but if you have any questions please call 0845 641 0030 and quote ‘Mogden’. Our lines are always open.

Kind regards,

Dear Resident

With construction almost complete, this month we will begin planting the
site's western embankment.

We will create a mixed grass and woodland area using a wide selection of
young trees and shrubs. In addition, there will be a meadow at the base of
the mound with a variety of herb-rich grasses and wildflowers such as
daisies and red campion.

To encourage wildlife we will also build several wood piles, and provide
nest boxes for bats and birds.

In preparation for planting, we have started spreading the area with the
topsoil stored at the toe of the embankment. Once complete, we will install
a shallow land drain in this location. Starting from the southern end, we
will gradually plant each section of the mound.

We have already started operational testing of a large part of the new
works and remain on target to complete the remaining construction work by
the end of March. Once everything has been tested and is running smoothly
we will have boosted the site's treatment capacity by 50 per cent so it can
cope better during heavy rain.

As is usual with work of this nature, some of the project team will remain
on site for a few months to complete the process of handing over the new
works to the site team. This includes optimising the performance of the new
equipment and completing any landscaping work that may have been delayed by
the weather.

Come and meet the team
On Thursday 28 February, from 5pm to 6.30pm, we will be holding an informal
drop-in session, where you will be able to discuss our work with members of
the project team.

This will be held at Twickenham Stadium and free car parking is available.
On arrival, please report to reception at Rugby House Door A, situated in
the South Stand, from where you will be directed to the meeting room.

We will keep you updated on our progress, but if you have any questions
please call 0845 641 0030, quoting 'Mogden'. Our lines are always open.

Kind regards
Emily

Mogden update as below folks.

This is fantastic news for the very upper tideway, at last the huge sewage spills will stop. If you have a look through This Data which we get from TW, its obvious just how significant theses upgrades are.

Of course its only part 1, not far way is Hammersmith pumping out millions of tonnes and so on down the river, the Thames Tunnel will stop these if approved but is at least 10 years off and many twists and turns ahead.

What this will do though is protect the nearest pound to the Richmond/ Teddington pound.

There is an open day/launch event in June and more to follow on that, its a real biggie for us even though 1st weekend of the new season.



Dear Resident

We are pleased to confirm that Mogden’s £140 million upgrade is now complete and the extension is up and running.

On behalf of the team, I’d like to say a big thank you for your patience and understanding throughout this important project.

This has boosted the site’s sewage treatment capacity by 50 per cent, which in turn will help to significantly improve water quality in the River Thames.

The project team are set to remain at Mogden until the end of June to carry out the necessary fine tuning of the new works. This is just to ensure it runs seamlessly with the existing site and to make any final tweaks.

You will notice that the embankment is nearly at its final shape. Unfortunately the past few months of wet weather has affected progress at the northern end of the mound, and this has meant a few temporary piles of soil have remained near the mature oak trees. Now the weather is looking better, we can finish off this work over the next few weeks.

We have been able to start seeding the embankment, and also plan to complete this by the end of the month. We will be introducing a variety of herb-rich grasses and native wildflowers such as daisies and red campion which will improve the look of the area as we enter the summer.

Overall, we have now planted all of the hedgerows on the embankment and a third of the trees and shrubs. This, again, has had to be delayed because of the weather. The remaining trees and shrubs will be introduced in November’s planting season to give them the best chance to get established.

Our last drop-in session

We will be holding our last informal drop-in session, where you can discuss the project with members of the team, on Monday 13 May, from 5pm to 6.30pm. As it’s the last session, we will have cakes available so please come and join us!

The drop-in will be held at Twickenham Stadium and free car parking is available. On arrival, please report to reception at Rugby House Door A, situated in the South Stand, from where you will be directed to the meeting room.

If you have any questions in the meantime, please call 0845 641 0030, quoting ‘Mogden’. Our lines are always open.

Finally, we will be marking the completion of this project with an open day on 22 June. For more details, please look out for our newsletter due out later this month.


Kind regards