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Sewage Discharge into the River Lambourn at East Garston

Update as of 21st June 2021

Recent developments from the battle front:

  • You may have seen in the Newbury Weekly News a few weeks ago, an article (“Sewer Scheme pays off”) praising the repair work done by Thames Water, and TW’s claim that the work eliminated the need for tankers in the early spring this year.
  • I wrote a letter (“We must do more to protect the river Lambourn”) to NWN to explain that the real reason that tankers were not needed was that TW continued to discharge untreated sewage into the river from the pumping station when groundwater flooded the network.
  • NWN wrote an article about it (“Utility firm denies sewage dump claim”) in which they included a statement from TW refuting my allegations of pollution and saying that no unfiltered sewage is discharged into the river, going on to explain how the ATAC filtration unit at Lambourn works, inferring that all discharges are treated in the same way.
  • This is, at the very least, disingenuous, so I wrote again to point this out, giving more details of the pollution TW are creating. NWN chose not to publish my second letter, saying they were going to work on a follow up article. Nothing has appeared yet.
  • You can see my second letter on Penny Post, together with an informative comment from Charlotte Hitchmough, of Action for the River Kennet, and yet another disingenuous comment from TW implying that the problem was storm water, and that they were operating legally under the terms of the EA permit (when it wasn’t, and they weren’t)

Permitted discharges in the River Lambourn – June 2021 – Penny Post

After asking some very specific questions after the first TW response, I have received some answers from a senior TW Engineer (rather than their Press Office) explaining exactly how the sewage discharged into the river is treated (or rather, not treated!)

Here is the relevant part of the response to my questions, and I have highlighted the key points. I’m sad to say, it’s even worse than I thought. Even I was shocked!

The Engineer wrote:

“In response to your questions -

Can you please explain how the sewage discharge from the EG pumping station is treated before it goes into the river?

The discharge at East Garston falls under the temporary discharge permit this means the water which discharges from the East Gaston Pumping Station (SPS) isn’t treated, the pipe is a direct pipe from the wet well to the river. There isn’t a requirement under the permit to screen the discharge from East Garston which means it doesn’t require pre-screening. It does advise that when a discharge occurs, a clean-up is required which I know have been carried out previously however I appreciate the location of the SPS and access to the watercourse is very limited to carry out a comprehensive clean-up. Because of this I have asked the team to review this process and if there is anything that can be done to make any improvements.

My understanding is that the normal sewage goes through a “sieve” to remove the solid stuff, and sits in a “settling tank” before being discharged into the river when levels get too high. But other than that, it is untreated sewage. Excuse my layman terms, but is that about right?

I’m unsure if you are referring to how waste water is treated via our Sewerage Treatment Works (STW) or how it is processed through a Sewerage Pumping Station (SPS) . As above where we have a the temporary discharge permit on the East Garston SPS this is not filtered before being discharged.

This water isn’t treated like it would be at a STW (PDF attached) from STW point of view we have a certain number of litres per second we need to treat through the full process, part of our permit from the EA. During storm conditions (high levels of rain fall) any excess goes to storm tanks, which are sized by the EA usually in accordance with the size of the catchment. During these times we hope that the storm passes quickly and that the flows from network reduce and we can return the storm tank flows to the STW inlet to be fully treated. However, In prolonged storm conditions or periods of infiltration the storm volumes are often exceeded, at this time we are allowed under our permit arrangements to discharge storm flows whilst continuing to treat our full flow to treatment. These are called storm discharges, storm flows are settled in the tank, flow through Copa sacks, and grills to the out-let pipes and discharged into either a feeder water course fur further dilution or directly into a river.

And what is the difference between that and an ATAC filtration unit?

The ATAC Filter has been designed as a deployable biological filter capable of filtering many different effluents - from ground water to raw sewage. The filter is designed to remove biological loading (solid waste) from wastewater influents, whilst also adding dissolved oxygen into the effluent flow.

If you are referring to the difference between East Garston pump station and ATAC filtration unit, as above – The SPS doesn’t have a filter/grill to prevent solids from entering the watercourse when it is discharging, however I am keen to highlight that the SPS generally only discharges when the network is infiltrated with ground water. This means the foul flows moving through the network are heavily diluted by the clean ground water, and when we have had the water tested independently at various points on the River Lambourn including in East Garston ammonia levels have been 0, NH4 (AMMONIUM ION) in the ranges of 0.01 and 0.2, with little to no impact to PH levels. This really highlights how diluted the water is when it escapes the network, or can’t be processed by the SPS.

The difference between a filtration unit and STW is very simple. A STW have a really robust system to treat water before it leaves us and enters the waterways. A ATAC filtration only removes the solids and adds dissolved oxygen as it passes through the filter. Then depending on the level of paper/rag/fat/grease/ and others items ( I’ve seen a whole lemon before) filtered out of the water depends on how often the filters are changed, usually weekly.”

So there we have it. TW are discharging untreated, unfiltered, sewage directly into the river, a Site of Special Scientific Interest, when the sewer is flooded with groundwater, and it has been going on for many years.

The other issue that comes out of this response is the validity of the permit granted by the Environment Agency for TW to discharge sewage in the case of emergencies.

Here the Engineer implies that the permit covers TW for discharging when groundwater floods the sewers. However, as I said in an earlier up-date, EA do not regard groundwater flooding as an emergency, and therefore TW does not have permission to discharge under the terms of the permit. How could it possibly be considered an emergency when it happens regularly and can be forecast? EA state that TW were in breach of the permit in 2020 for “discharging not due to an emergency”, so presumably they have been in breach again this year. No action has been taken by EA in respect of 2020 yet let alone 2021. The permit does allow sewage discharge in the event of storm flooding and mechanical breakdown, and no-one could sensibly argue with that.

But the good news is that our MP Laura Farris is absolutely determined to put a stop to it, here and everywhere else where pollution is occurring. She is hot on the case and has regular progress chasing meetings with TW, EA and others to keep up the pressure. Laura has spoken in Parliament on the issue of pollution by water companies and with another local MP, and Action for the River Kennet (ARK), has arranged an open consultation forum on pollution of chalk streams in our area. From the forum documentation, I learnt this:

Over the last year the frequency of untreated sewage being pumped into the Kennet at Marlborough more than trebled.
In 2020 Thames Water tipped untreated sewage into the Kennet for 2,872 hours. This compares with a total of 989 hours in 2019. This is not an isolated case, sewage treatment works across the catchment paint a similar picture of persistent pollution of the river.

This is having a devastating impact of the chalk stream wildlife, from plant life such as stream-water crowfoot to fish and freshwater invertebrate life.

Frightening, isn’t it?

All this throws up even more questions so I will now be submitting an Environmental Information Request (part of the Freedom of Information legislation) to try and put an end to all the waffle and spin we get from TW. But we have to accept that they are well practiced in the art, so I’m not expecting too much.

I will keep you updated on these and other related issues as and when things happen, (or possibly don’t).