*LATEST UPDATE * 18 September 2023 – Michael received a further update from Thames Water, which is copied below, and he will be meeting Thames Water next week to discuss compensating and making amends with the local community:
“I am pleased to say the second tank where the less odorous centrate was stored is now virtually empty too. The team have ordered scaffolding to be delivered to site and this will be then be assembled over the next few days. The final stage of the cleaning process will be starting on late Wednesday or Thursday morning. We will continue with the odour control equipment until the whole job is complete which we expect to be by the end of the month. As always, I will keep you posted with updates on progress until we are finished.”
8 September 2023 – Thames Water provided an update on the progress of its clean-up operation, which is copied below:
“Further to my update last Friday, I am pleased to say our contractors have pulled out all the stops and have finished the cleaning of the sludge tank. This has taken a huge amount of extra effort to finish it early but we know the impact it had when it was full and we really wanted to make sure we had this completed as soon as we could. I’ve included a photo of the tank taken at lunchtime on Thursday showing the cleaned tank as it is now. We still have some of the centrate in the other tank but this is being exported by tankers to other sites. I will let you know how soon this will be completed as soon as I can but it is a far less odorous process. Saying that, we will continue with the 24/7 odour control and this will continue until the whole site is returned to normal operation only. I hope this is helpful but please let me know if I can help further. In the meantime, I will send another update next Friday.”
4 September 2023 - Michael wrote to the Environment Agency on 3 and 18 August asking for an update following its visit on 2 August, and he has now received the following response regarding the new permit for Camberley STW. The new permit, due to come into effect by the end of September, will prevent any further importation of sludge for de-watering. This will ensure that the situation that has occurred this summer can never happen again.
Thank you for your email dated 18 August 2023 requesting an update on our investigation of Thames Water’s Camberley Sewage Treatment Works.
My officers visited the site on 2 August 2023. They found the odour impacting local residents is most likely from sewage sludge which had been brought to site from other works for dewatering.
Thames Water are using control measures to minimise the odour while this material is processed and we advised them of additional measures they need to implement. We have been told that the sewage sludge was removed from the site at the end of August.
We are working closely with Surrey Heath Borough Council on this matter. We have agreed that they will lead on the current odour investigation under their statutory nuisance provisions. Thames Water have informed us that the removal of the sludge is on track and expected to be completed next week.
You also asked for more information regarding a likely issuing of a new permit and impact on sludge processing at the site. After several years of discussions, Thames Water applied for a permit for the anaerobic digestion of sludge in March 2021. However, the application did not contain sufficient information for us to determine it. There followed a period of correspondence with Thames Water to obtain the necessary information so we could progress the permit application. With no further delays we expect the permit for this site to be issued at the end of September.
The permit will regulate the anaerobic digestion of sewage sludge. This is a different process to the dewatering of sludge. Because it is done in enclosed tanks, emissions can be better controlled. When the permit is issued the importation of sludge for dewatering will have to cease as it will no longer be allowed under the Environmental Permitting regulations. A change of permit would be needed to allow this activity to happen in the future. Thames Water have been made aware that the current exemption for the site will be deregistered when the new permit is issued. This was confirmed to them on the 9 August following our visit to the site.
Area Director – Thames
1 September 2023 - Michael received confirmation that the final stages of processing the imported sludge has been completed at Camberley Sewage Treatment Works.
Thames Water is now moving into the clean-up operation which may take up to a further two to three weeks to complete. Whilst Michael has been informed that this will be a much less odorous process than the previous work, they will maintain the 24/7 odour control throughout until completion.
“Following on from my note yesterday I am writing to update you on our progress with removing all the sludge from the tank at Camberley STW.
I am pleased to say we have now processed all the sludge from the tank through the centrifuge and this stage is now complete. From yesterday, as planned we are now moving into the clean-up stage where we be taking the final silt, rag and debris out of the tank which will be taken away from site.
To enable this the centrifuge has been taken away and a crane will be brought in on Monday to allow us to install some temporary equipment to allow the cleaning out work to commence. This final cleaning up is likely to take about 2-3 weeks and is a less odorous process than the previous work with the sludge itself. We will maintain full 24/7 odour control while this is carried out.
I hope this is helpful but please let me know if I can help further. In the meantime, I will send another update next Friday.”
Michael will continue to ask Thames Water for regular updates on progress and will keep pressing for this final stage to be completed as swiftly as possible.
31 August 2023 - Michael continued to chase Thames Water to see if they were on target to complete the processing of the imported sludge on time by the end of 31 August, and received the following response from which he was very relieved to learn that this situation and terrible odour is nearing an end.
“Our operations team are still working to have the last of the imported sludge removed from the tank today. The remaining sludge at the bottom of the tank is thicker than the rest and is taking longer to process but I can assure you we are still aiming to complete the operation on time. We have continued with the extra tankering to other sites and are employing an extra pump to help with the thicker sludge. This will involve working into the evening but we remain focussed.
I will be back in touch again tomorrow with a full update.”
Michael will continue to share any further updates from Thames Water as soon as they are received.
25 August 2023 – Michael received the following update from Thames Water, and efforts have been stepped up to clear the imported extra sewage sludge:
"At last week’s site meeting at Camberley I promised to follow-up with weekly updates on our progress with processing the raw sludge. Since then, we have continued using the centrifuge and have reduced the volume in the tank from 3,750m³ to 2,000m³. We are still aiming to have all the sludge processed by the end of the month and to help achieve this we have now also started tankering raw sludge from the site 6 times per day. Along with extra cake exports which we will now be running through the bank holiday weekend we have stepped up our efforts and will continue to do so until the tank is emptied. This comes with increased operational costs but we are happy to bear these to show our commitment to the community and get the job finished as soon as we can."
24 August 2023 - Michael wrote again to Thames Water as he has continued to receive complaints from constituents about the odour emanating from Camberley Sewage Treatment Works. During the meeting on 17 August, it was mentioned that Thames Water is around 45% of the way through the imported sewage sludge, and that it will be completely gone by the end of August. Michael explained that he is most anxious to ensure this happens, and requested an update on the progress being made.
18 August 2023 – Michael wrote again to the Environment Agency for an update, and asked further questions regarding the new permit for Camberley Sewage Treatment Works.
17 August 2023 – Michael visited the Camberley Sewage Treatment Works site with local councillors from Watchetts and St Michaels, together with Environmental Health Officers from Surrey Heath Borough Council for an update on the efforts being made to process the extra sewage sludge and to reduce the odour that has been plaguing Camberley residents for the past few weeks.
16 August 2023 – Thames Water responded to the additional questions Michael raised in his correspondence of 11 August, and please see attached below a copy of the letter that will be sent to approximately 5,500 addresses around the perimeter of the site:
"Thank you for meeting with us on Friday. I thought it was a very useful session and gave us the opportunity to discuss some very real concerns you have on behalf of your constituents.
Below I have given answer to your questions in your email of Friday evening along with responses to the points you raised in the meeting:
- Is there any further action or system that Thames Water can implement to eliminate the odour more quickly? We are de-watering the extra stored sludge as quickly as we can using the centrifuge we have brough to site. Also, we have our odour control units running 24/7 to minimise the impact on the community as much as we can. We will keep you briefed on our progress with processing all the sludge and returning the site to normal operation through August.
- Can the extra sewage sludge be exported to another Sewage Treatment Works that is more appropriate and not located in a populated area? We are treating the liquid sludge by processing into cake which is being exported to Basingstoke Sewage Treatment Works. We have statutory planned outages at the moment (for example at Chertsey Thermal Hydrolysis Plant) which restricts our liquid processing capacity. As and when we have spare capacity at other sites, plans are in place to export liquid sludge from Camberley in addition to cake removals. To facilitate the centrifuge operation, we are exporting centrate (the liquid from the centrifuge) which was initially planned to be processed at Camberley.
- Thank you for agreeing to share a copy of your future letter drop to residents in advance of it being sent out. Can you confirm whether there have been previous letter drops to residents, and if so, can you share copies with me? A copy of the letter is attached. It is with our delivery company for sending out now.
- What will Thames Water do to ensure constituents receive accurate and timely information in the future? Any future issues which we believe may have an impact on residents will be communicated to the Environmental Health team ay Surrey Heath BC. We will then jointly agree a communications plan for local elected stakeholders and for the local community.
- What action is Thames Water taking to avoid further imports of extra sewage sludge to Camberley STW? The tank currently being used to store the sludge is to be de-commissioned from its current function and is being re-purposed to become a storm water storage tank to give extra capacity at Camberley STW during intense rainfall events. Our site permit from the Environment Agency is also changing in September meaning that sludge imports will beno long be permitted as part of the site operation.
- Constituents have complained that the tanks are uncovered, which they believe is allowing odours to easily escape. Can the tanks be covered to mitigate the odour? The tanks cannot be easily covered without requiring major planned investment works, there is unfortunately no short term way to achieve this before the sludge is all processed and removed from site..
- What will Thames Water do to compensate and make amends with the local community? We are happy to talk with local representatives about how we can best give something back to the local community once the current event is over.
- Can we provide a copy of the latest Odour Management Plan? A copy of the Odour Management Plan from 2019 is attached. The plan was updated post-delivery of improvements carried out at Camberley STW. Following completion of the improvement work, the calculated odour emissions as a whole reduce by approximately 29,600 ouE/s to 90,300 ouE/s, a 25% reduction in total emissions from the site. The main factors which resulted in the decrease were the upgrade of the circular storm tanks pump out systems (initially identified as 14% of site total site emissions) and the decommissioning of the Viridor treatment tanks (initially 12%).
- Out of the overall sludge event, how much was Camberley affected compared to other sites? During the sludge event, 17,850m3 was exported from Hogsmill STW to the below sites:
Camberley STW’s capacity to take extra sludge was 6000m3 which was filled and therefore Camberley’s support to the event was approximately 33%.
- What were the nature of the complaints we had and when did they come in? Complaints that we can tie to this event started to come in to our Operations Call Centre from 23 June. We have 30 complaints logged but several of these are from the same individuals. All the complaints are of a very similar nature and refer to sewage odours from our treatment works. We acknowledge that there are other complaints that have gone to Surrey Heath BC and are working with officers to improve reporting processes in the future.
I hope this is helpful and look forward to meeting you tomorrow at midday at Camberley Sewage Treatment works."
11 August 2023 - Michael held a meeting with representatives from Thames Water and was grateful for the opportunity to learn more about the particular nature of what led to these unacceptable circumstances, and to be able to continue to push Thames Water for a speedy resolution to the issue, to ensure the right measures are in place to mitigate against it ever happening again, and to raise the prospect of compensation for the community in light of the terrible situation they have had to endure. Following the virtual meeting, Michael wrote to Thames Water with additional questions.
8 August 2023 - Surrey County Council responded to Michael with the following update:
"Further to my email I have the following update for you.
One of our monitoring officers visited Camberley STW last week and had a tour of the site with the Site Manager and Regional Manager. They were shown the waste which is the subject of the complaint and the temporary odour management which was operating.
The import of additional sludge is permitted under planning permission SU92/0728 however, the temporary odour suppression units were only operating for 12 hours a day which was a breach of the approved Odour Management Plan.
Having insisted that Thames Water increased the odour management to 24/7, we have received an assurance that this is now in place.
The EA and district council will now work together to address the odour issues under their powers. If we receive anything further which falls within our remit of the site we will of course revisit.
I hope this is reflected on the ground."
3 August 2023 - Michael wrote again to Thames Water expressing his concerns that this issue has been going on for far too long, and also his disappointment that Thames Water could not provide a date of completion. Additionally, Michael raised the issue of compensation and requested a meeting to discuss this situation further and how Thames Water can make amends with the local community. Furthermore, Michael sent a follow-up email to the Environment Agency requesting an update following its inspection of Camberley STW.
2 August 2023 - Thames Water responded to Michael with the following email:
"As outlined in Nikki’s previous note, we are dealing with the extra sewage sludge at Camberley by using a special centrifuge unit which spins the material at high speed allowing the liquid to be separated from the solid matter. The solid waste is then sent on to one of our other sites for processing. The extracted liquid is then put through the sewage treatments process but because it is much more concentrated than the normal flow we get into the works it has to be put through gradually and not all in one go. This means the whole process takes time and won’t be completed until later in the month. I can’t give an exact date but please accept my assurance that the team are working as hard as they can to get this done as soon as possible. In the meantime, we have odour control measure up and running 24 hours a day which will help neutralise the smell.
To keep our customers updated with our actions we have put a statement on our website and have posted on both Twitter and Facebook. We will also be writing update letters to the residents, copies of which I will send you.
I will keep you updated with our progress but in the meantime please accept my apology for the inconvenience to your constituents."
1 August 2023 - Michael wrote again to Thames Water to ask for an update on the work Thames Water is doing to eliminate the odour as quickly as possible. Michael also wrote again to Surrey County Council to share the response he received from the Environment Agency.
31 July 2023 - Michael received a reply from the Environment Agency, and he was pleased to read that officers will now inspect Camberley Sewage Treatment Works as soon as possible to investigate the situation further. The Environment Agency’s response is copied below:
"Thank you for your email of 26 July 2023 to our Chief Executive, Philip Duffy regarding the odour issues your constituents have been experiencing at Thames Water’s Camberley sewage treatment works (STW). Philip has read your email and asked me to respond on his behalf. He will also receive a copy of this response.
I can confirm our regulatory responsibilities relating to this site.
Permitted water discharges from the Camberley STW are regulated by ourselves. These permits do not include conditions or objectives relating to the control of substances or emissions (odour). Therefore, odours arising from the STW are addressed under statutory nuisance and regulated by the Local Authority.
Sludge recovery on the site takes place under an Exemption, which allows the Operator to recover waste such as Sludge, at a wastewater treatment works. Although registered with us, exemptions are not routinely inspected as this work stream is considered an unfunded activity.
We have received five odour reports relating to Camberley STW since 21 June 2023. Our initial assessment was of these being attributed to odour from the STW, therefore regulated by the Local Authority. As per our protocol, the reports were forwarded to Surrey Heath Borough Council.
In light of the information you have shared with us from Thames Water, regarding the importing of additional Sludge giving rise to subsequent odours, my officers will inspect Camberley STW as soon as possible to investigate the situation further, assess compliance with permits and exemptions on site and address any next steps. We are liaising with Thames Water on their management of the odour and have informed them of our investigations.
Thames Water has applied for a new permit for the regulation of sewage treatment (anaerobic digestion) at the site. Once issued, we will have increased regulatory control with necessary permit conditions to effectively manage odour."
27 July 2023 - Thames Water responded to Michael with the following email:
"Thank you for your e-mail below. I do understand yours and your constituents’ frustration and appreciate that the odour must be unpleasant, particularly during the warmer weather. I have asked our Operational team for an explanation as to why we had excess sludge and why it was imported to Camberley which I hope you will find helpful.
We took the decision to import sewage sludge very reluctantly and only did so to avoid serious impact on the environment at other sites if the sludge had not been moved to Camberley for processing. Operational issues, at the sites we would normally use for the processing of this sewage sludge, meant that we had to find another location and Camberley Sewage Treatment Works (STW) was the only site with suitable storage capacity. Unfortunately we couldn’t remove the liquid sludge back out of Camberley to pass forward through the normal processing routes as quickly as we intended, leading us to instigate the recovery process we now have in place. This involves a temporary manned centrifuge which simply separates the ‘Cake’ from the liquid. We then transport the cake offsite and recirculate the non-odorous liquid through the works.
Prior to your constituents’ complaint earlier this summer, we were not aware that residents were being impacted by pre-existing odour issues at Camberley STW. We commissioned an independent odour investigation in 2019 (which we have shared with Surrey Heath BC and are happy to share with you), following a major upgrade to the works. The report states that prior to the upgrade, we only received odour complaints from 5 properties. The report also shows that the upgrade reduced the odour emissions by 25%.
The site has an odour management plan for its normal operations and has odour control equipment installed on the most odorous parts of the process. Before the current event, we have only received a small number of sporadic complaints – which is to be expected from a process which is inherently odorous and despite us applying best practicable means of control, will emit odours from time to time. However, during a recent meeting with Surrey Heath BC, one of the councillors told us d that residents have reported odours to them on an annual basis. We are working with officers at Surrey Heath to understand the number and frequency of these reports and will take whatever subsequent action is required.
I hope this helps to explain the situation and I apologise for the inconvenience this has caused the community. If you have any further questions, please let me know."
26 July 2023 - Michael pointed out to Thames Water that the situation is unacceptable and expressed his particular disappointment that Thames Water took the decision to import extra sewage sludge, despite knowing that residents were already impacted by the pre-existing odour issues. Michael asked Thames Water to explain to him why the extra sewage sludge was not sent to a different treatment works, in light of the situation in Camberley, and pressed for more to be done to eliminate the odour as quickly as possible.
On the same day, Michael also wrote to the Environment Agency and to Surrey County Council to ask for their assistance, and Michael is pleased that Surrey Heath Borough Council’s Environmental Health officers have been working on this issue too and have also been urging Thames Water to take more action.
25 July 2023 - Michael received further complaints that the odour had not improved and had in fact worsened, and on the evening of 25 July, Thames Water updated Michael with the following information:
"Due to a recent unplanned situation, we have had to import extra sewage sludge from other Thames Water sites and process it at Camberley. Due to the unplanned nature of the operation, we have not been able to fully control the odour from it. This is why the odour may have been more noticeable recently. We did not take the decision lightly to import the extra sludge and we will be ensuring that we do not have to do this again in the future. We have an odour suppression system in place and are quickly identifying means of running this 24/7 and are also processing the extra sludge as quickly as we can, so that it can be removed from the site. This will enable us to clean the sewage storage tanks over the coming weeks and will ensure odour levels return to normal.
We are carrying out a letter drop to residents to keep them updated on the situation."
10 July 2023 - Thames Water responded to Michael with the following email:
"I am writing to you in response to your email addressed to Nikki Hines, about the odour your constituents are experiencing from our sewage treatment works (STW). I fully understand how unpleasant this must be, especially in the warmer weather. I have investigated this matter on Nikki’s behalf. I trust you find the below information helpful.
An odour control system (OCS) was set up and commissioned on 12 July and is now being used. In addition, the tank which contributes to odour emanating, will begin a deep clean from 12 July and will take approximately three weeks to empty.
Our Bio Recycling Lead Planning Manager, is confident the level of odour will now decrease considerably, and your constituents should notice this by today onwards."
25 June 2023 - For a number of years, Michael has been aware that residents in Camberley have been periodically impacted by odours emanating from Camberley Sewage Treatment Works, but in June 2023, a number of constituents were in touch with Michael about the odour and he wrote to Thames Water to raise concerns.