On 16th June HVDIG held its second Agencies Meeting with representatives from Thames Water, Bucks County Council and the Environment Agency to monitor progress on actions to deal with any future events similar to those experienced in 2001 and 2014.
Thames Water have carried out a lot of work on their network in Hughenden Valley, carrying out CCTV work, cleaning, lining and installing monitors in key places to get data on the water going through their network. They have set up a special reference number for Hughenden Valley to report a future event on their emergency phone line and have two pumps with sewage treatment systems at the Little Marlow depot allocated for Hughenden Valley to pump at a future event with their network set up for them to be quickly implemented – one system will be outside the Surgery in Valley Road and the other in Boss Lane and they will pump the treated water into the Hughenden Stream. All of this is being managed and documented in Thames Water’s “Hughenden Valley Drainage Strategy” that will be submitted to the Environment Agency. The draft of Stage 1: Initialise/Prepare was issued in November 2015 to Key Stakeholders for comment.
The mobile treatment works can be in place within days. Thames Water will use the information from the Environment Agency groundwater monitoring and the depth monitors in the sewer network to get an early warning of a likely event where the mobile treatment works may need to be “primed” – which takes two weeks – and deployed. They can still be effective if not fully primed in terms of screening the flow but may not be up to full biological treatment capacity. The mobile plant treatment won’t be as good as a full sewage processing works but will reduce bacteria by an estimated 40% and add oxygen. They rely on the flow to get the media working and there will be a filter which will have checks twice a day.
In October 2014 the Environment Agency issued a formal warning to Thames Water for the sewer discharges and over pumping into the Hughenden stream between 26 February and 05 June 2014. This activity was a contravention of Regulation 12 and 38 of the Environmental Permitting (England and Wales) Regulations 2010, causing polluting matter – sewage – to enter the Hughenden Stream.
Bucks County Council have allocated budget and are due to carry out maintenance work on their infrastructure in Hughenden Valley in February 2016. A potential blockage of one of the culverted pipes under Valley Road that flows into the drainage ditch forming part of the Hughenden Stream on the west side of Valley Road (in front of the Village Hall) needs CCTV investigation and the open section of the ditch needs to be dug out where silt is currently partially blocking the pipes that connect to it. The culverted section of the Hughenden Stream under Boss Lane also needs work done by Bucks County Council to make sure it is clear.