Agenda and minutes

Apologies for absence were received from Mike Overall.

To agree the minutes of the meeting held on 12 April 2022 as an accurate record.

The Minutes of the last meeting were agreed as a correct record.

·         Little Marlow site performance update since March 2022.

·         Little Marlow sewage spill hours trend analysis over past five years.

·         Current capability on site to deal with asset redundancy.

·         Details of planned timings of capacity increases at the Little Marlow site.

·         Investment decision criteria used by Price Review Team

Andrew Scott from Thames Water provided the following update.

Site performance

·      Samples were taken in house on a regular basis for various quality parameters. The three graphs showed slightly different quality parameters to reflect site treatment. The first graph showed suspended solids and biochemical oxygen demand (this was important because it showed organic load and how much oxygen would be used up in the river). The higher BOD the worst impact on the river. Organic particulates could be turned into sludge and could generate green energy so it should not escape into the watercourse.

·      The second graph showed ammonia. Portable equipment was used including vials and daily samples were taken and sent away for analysis. It was well below the limits. In response to a question about who set the limits it was noted that these were permitted consents and they were below the level registering any concerns. There was also a phosphorous consent which related to the number of phosphates going into the river. The flight path was trending upwards through the year and this related to the availability of ferric sulphate (iron based salts used for precipitation). This helped coagulate or settle out the solids that the phosphorous was associated with.

·      On the whole the Works were performing well. There had been no compliance failures. All preventative maintenance was up to date and there was a stable site team. There had been a restructure but the site performance manager had not changed and the key people within the team.

·      A question was asked whether they were continuous measurements or a point in time. It was noted that in the main they were a point in time. On the first graph there was a turbidity reading which was continuous. Continuous readings were used for trending purposes as they were not as accurate as taking spot samples.

Spills

·      This was part of an ongoing investigation water company wide by the Environment Agency. The Event Duration Monitor which triggered the environment spill from storm tanks was only fitted at a certain time which showed the start of the graph. There were three levels. The first one was rainfall in the catchment to justify whether there had been a storm. A more sophisticated tool was being developed such as the Discharge Alert Management Tool. Another measure was the final effluent flow but this was not as good as the past forward flow so this could not be used to determine whether the full flow treatment had been met. It was representative of what the flow was at the back end. There was flow data which was sent to High Wycombe as part of the compensation flow.

·      The first graph showed the rainfall, the middle graph was the EDM meter and the bottom graph showed the outflow.

·      On the Event Duration Monitor anything above the red dash line showed that it would have impacted the environment. Further analysis could be undertaken on how those spills occurred. There could be some dry day infiltration  ...  view the full minutes text for item 3.

·         Update on why the July 2021 incident was considered not to require a Compliance Assessment Report.

·         Update on what new powers a review of the permit would bring to the EA.

·         Explanation of what the trend of “dry weather flow”, by year, is over the past 5 years.

Lucy Bee and Daniel Ophof provided the following update on behalf of the Environment Agency.

The Environment Agency was still investigating the Little Marlow Sewage Treatment Works incident so they were currently unable to report on that but would update the Committee once the investigation had been finalised. Lucy Bee reported that they had a programme of updating permits for sewage treatment works. The permit for Little Marlow had not been issued yet and some of the permit conditions would be more stringent but it was complicated around compensation flow issues. A timeframe could not be put on when the investigation would be finalised as it depended on what evidence was found.

On top of the local investigation there was a national investigation which was started earlier in the year which was looking at water companies across England and it wasn’t clear yet whether Little Marlow would be included in that national investigation. This was initiated due to public interest in storm overflows.

A question was asked about where residents could report any concerns and also how they would be notified if an event occurred. There was a 24/7 hotline for the reporting of any incidents which could be provided to the Committee including an enquiry email address. There was no methodology to inform residents when there were incidents apart from serious events where affected stakeholders would be notified e.g. Thames Water, local sailing club and this Committee. However, there were no notifications about routine incidents. With regard to the incident that was under investigation there would have been a notification released. A representative commented that the Parish Council had not been informed and should be added to the list of stakeholders notified of incidents. The notification should be undertaken as soon as possible after the incident occurred to inform river users. If there were any serious threat stakeholders like the sailing club would be contacted. A representative asked if there was a procedure for this and the Environment Agency said that they would check this. He also suggested that if there was no procedure one should be written. Lucy Bee reported that there could be pollution incidents that they were not aware of. If Thames Water were aware of any incidents they should be contacting stakeholders to inform them.

The representative from Thames Water reported that if there was an incident there was a process that was followed. Key stakeholders would be informed and vulnerable residents. Different communication techniques would be used according to who was being informed e.g. text alerts, a message board on the website or direct telephone calls. Going forward the EDRM trigger data for this AMP period could pick up information every one or two minutes (for AMP 6 the trigger data was not highly sophisticated and only picked up data every 15 mins). By the end of December Thames Water would enable website access so the public could view this information including discharge points and if there had been a spill. Historical data would  ...  view the full minutes text for item 4.

To review the Action Log (attached).

The Action Log would be updated and circulated.

An opportunity for public and Member questions.

Please send questions, in advance of the meeting, to Clare Gray at democracy@buckinghamshire.gov.uk

There were no questions.

To be confirmed.

A further meeting would be arranged in March.