Mogden Sewage Treatment Works Residents Meeting 4 February 2014 - PowerPoint PPT Presentation

Mogden Sewage Treatment Works Residents Meeting 4 February 2014

Agenda • Review and actions of previous minutes • Operations and communications • Odournet report • Mosquito survey results • AOB

Operations and communications Update • Following the completion of the extension last year, Battery E had to be ‘run in’. This has been completed and the extra plant is fully optimised since November. • The Odournet olfactometry report has been received and shared with the London Borough of Hounslow. • The next Modgen Update newsletter including the mosquito awareness campaign is being prepared to be sent out in April.

100 Operational correspondence 10 20 30 40 50 60 70 80 90 0 Jan-10 Feb-10 Mar-10 Apr-10 May-10 Jun-10 Jul-10 Aug-10 Sep-10 Oct-10 Nov-10 Dec-10 Jan-11 Feb-11 Mar-11 Apr-11 May-11 Jun-11 Jul-11 Aug-11 Sep-11 Oct-11 Nov-11 Dec-11 Jan-12 Feb-12 Mar-12 Apr-12 May-12 Jun-12 Jul-12 Aug-12 Sep-12 Oct-12 Nov-12 Dec-12 Jan-13 Odour Odour and mosquitoes Mosquitoes Other LBH Feb-13 Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13 Sep-13 Oct-13 Nov-13 Dec-13 Jan-14 Feb-14

Odournet report Summary • Overall, the report considers Mogden to be within the normal operating parameters for a process of this type and size. • However the results show a higher level of odour than anticipated in our planning application. • We have put together an action plan to address the specific issues identified by Odournet – some of these activities were already in progress before their report was received.

Odournet report Recommendation 1 Replace the carbon in the East Side, West Side and Sludge Thickening Odour Control Units (OCUs) We had already started the process of replacing the carbon media due to the life expectancy of the media. It is important to note, however, that the OCUs are still operating within the Odour Management Plan’s trigger levels.

Odournet report Recommendation 2 Confirm that the current odour abatement performance of the Inlet PS OCU has improved to levels indicated by recent hydrogen sulphide monitoring data We consider the measurements obtained by Odournet during their survey to be unrepresentative of the normal performance of this unit. Our weekly monitoring showed that the unit was performing as expected shortly after, but this will be confirmed in Odournet’s follow up survey.

Odournet report Recommendation 3 Install a scum suppression system in the anoxic zone of Bank E to eliminate scum formation The accumulation of scum in the new activated sludge plant was not anticipated. Therefore, an automated spray system is to be installed to break-up the scum. The procurement of the equipment has started and the project is expected to be finished by the end of April 2014. In the meantime, the tanks are being manually hosed on a regular basis.

Odournet report Recommendation 4 Review the operational procedures around the storm channels to reduce retention of storm water in between storm events The operational procedures for the management of the storm tanks have been revisited as part of the six-monthly OMP review, and discussed with the London Borough of Hounslow. In summary, the storm tank feed channels will continue to be the subject of daily inspections, but their status will now be recorded on the daily storm tank check sheets.

Mosquito survey results Number of sites surveyed 400 350 300 250 Number of sites 200 150 100 50 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 Week 2010 2011 2012 2013 2014

Mosquito survey results Sites with any activity 50 % of sites with any activity . 45 40 35 30 25 20 15 10 5 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 Week 2010 2011 2012 2013 2014

Mosquito survey results Sites with any adults 50 % of sites with activity . 45 40 35 30 25 20 15 10 5 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 Week 2010 2011 2012 2013 2014

Mosquito survey results Sites with many adults % of sites with activity . 14 12 10 8 6 4 2 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 Week 2010 2011 2012 2013 2014

Mosquito survey results Sites with larvae % of sites with activity . 14 12 10 8 6 4 2 0 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 Week 2010 2011 2012 2013 2014

AOB

Proposed dates of future meetings • Wednesday 4 June 2014 • Wednesday 8 October 2014 • Wednesday 4 February 2015

Need to contact us about Mogden? Call the Mogden 24hr line: 0845 641 0030 Visit our website: www.thameswater.co.uk/mogden Write to us: Customer Feedback PO Box 286 Swindon SN38 2RA