Mogden Sewage Treatment Works Residents Liaison Meeting 7 December 2011 Thames Water
Agenda Review of previous minutes Operations and communications Mosquito talk and survey results Sewage Treatment Work Upgrade Project an update AOB Thames Water
Operations and communications Thames Water
Operations update The memorial garden dedicated to the five men at Mogden and Perry Oaks, who lost their lives during the Second World War, was refurbished last month. The rededication ceremony was held on 11 November and attended by Thames Water executive management team, exservices staff, Mogden site staff and Black and Veatch representatives. Thames Water
Operational Correspondence 2009 2011 100 90 80 70 Other Mosquitoes Odour and mosquitoes Odour 60 50 40 30 20 10 0 Jan-09 Feb-09 Mar-09 Apr-09 May-09 Jun-09 Jul-09 Aug-09 Sep-09 Oct-09 Nov-09 Dec-09 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 Thames Water
Notifications September Present September 2011 Notification of unplanned maintenance work on process tank Sludge export problem precautionary notice Mogden Upgrade construction update Mogden Upgrade digester cleaning odour notification Sludge export problem further notice October 2011 Primary tank drain down a precautionary notice Sludge export problem further notice update Mogden Upgrade construction update River Crane pollution odour notification November 2011 Mogden Upgrade construction update December 2011 Thames Water None
Communications update In November, we were invited by the Education Business Partnership to attend a careers fair at Lampton School in Hounslow. Both Thames Water and Black and Veatch took the opportunity to have stands and talk to the children about careers within their organisations. The next Mogden Update newsletter is in production and will be with residents in the New Year. Thames Water
Thames Water Mosquito Talk
Dr John W. Ismay B.Sc. F.R.E.S. Hon. Ass. Curator Oxford University Museum of Natural History & Barbara Ismay M.Sc. DPSI Entomological Consultants
Female mosquitoes need protein for their eggs use protein from blood, i.e. they bite eggs, larvae, pupae in standing water 1 egg batch contains ca. 250 eggs eggs to adult: min 10 days multiply very quickly!
In Britain we have 33 species of mosquitoes, 20 of which will bite humans. Others bite mammals, birds and reptiles and amphibians. Mosquitoes have a biting proboscis in front of the head, like a seventh leg. Only females bite.
C. pipiens pipiens overwinters as an adult female bites birds must have blood meal to lay eggs needs large space for mating C. pipiens molestus needs warmth to breed all year bites man can lay 1 batch of eggs without blood meal can mate in small space Identification
We survey about 60 sites (in winter) about 300 sites (in summer) for eggs, larvae, pupae, adults When we find mosquitoes we have the water drained or treated with pesticide We treat all mosquitoes found in Mogden as we cannot distinguish the two forms in a short timeframe best practice: prevention of breeding sites, not treatment
The key action that residents can do is to reduce breeding sites Cover water butts with tight lids Upturn containers such as buckets Introduce fish to garden ponds, they eat mosquito larvae
buckets wheel-barrows other containers
In 2009 we surveyed road drains and houses up to 4km N, S, E and W of Mogden. Samples were taken from: water bodies in gardens allotments cemeteries road drains Mogden
Culex pipiens pipiens Mogden and outside C. pipiens molestus Only in Mogden Anopheles plumbeus - in a water butt in an allotment 800m south Culiseta annulata in a water tank in an allotment 4km south
Percentage of properties with mosquitoes present per distance category 50 45 44.00 47.62 45.45 40 35 33.33 percentage 30 25 20 15 10 5 0 0-200m 1km 2km 4km distance to Mogden STW
70 60 4km 2km 1km Reports of biting: frequency per distance category (percentage) 56 62 50 0-200m 46 40 41 30 20 20 21 26 14 13 20 24 21 26 10 0 0 frequent: >weekly 4 7 infrequent: weekly-<monthly occasionally: >monthly no mosquitoes found or no bites reported
70 60 Reports of biting: total per distance category (percentage) 52 64 50 44 40 32 30 20 10 0 4km 2km 1km 0-200m
40 35 30 25 20 15 Road drains with mosquitoes present (percentage) 35.14 33.78 25.37 31.34 10 5 0 0-200m 1km 2km 4km
Thames Water Mosquito Survey Results
Mosquito data - Number of sites inspected 400 350 300 Number of sites 250 200 150 100 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 Thames Water Average 03-07 2008 2009 2010 2011
Mosquito data - Percentage of sites showing any activity % of sites with any activity. 50 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 Average 03-07 2008 2009 2010 2011 Thames Water
Mosquito data - Percentage of sites showing 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 Average 03-07 2008 2009 2010 2011 Thames Water
Mosquito data - Percentage of sites with many 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 Average 03-07 2008 2009 2010 2011 Thames Water
Mosquito data - Percentage of sites with many adults (2) 10 % of sites with activity. 9 8 7 6 5 4 3 2 1 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 Average 03-07 2008 2009 2010 2011 Thames Water
Mosquito data - Percentage of sites with larvae activity 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 Average 03-07 2008 2009 2010 2011 Thames Water
Sewage Treatment Works Upgrade Project an update Thames Water
Mogden STW Upgrade
Key progress to date We have passed the peak of construction activity. We are half way to completing the work to increase the site s capacity by 50 per cent. All supporting foundations are now in place. The noisiest activity on site has finished.
Inlet works This is where we filter the sewage to remove grit and other large items. The main structure is now complete. The focus is now on mechanical and electrical installation and completion of the odour covers to bring the inlet works online.
Primary settlement tanks This is where solids settle to the bottom and are then removed. The main structure is now complete. The installation of sludge removal system is well underway. Odour control covers on the tanks are around 80 per cent complete.
Odour control unit 11 Odour control kit has been delivered to site. Installation will be complete around spring 2012. Commissioning of inlet works, primary settlement tanks and odour control around Spring 2012.
Aeration lanes This is where we encourage bacteria to eat the organic matter. All four tanks are almost complete. 1000 pre-cast panels are being installed to create the lanes, saving hundreds of concrete deliveries. We will soon start installing the interconnecting pipe work.
Aeration lanes (cont)
Final settlement tanks This is where the remaining solids are removed before the effluent is returned to the River Thames. We have now completed the foundations, using concrete piles measuring 11 miles end-to-end. This means our noisiest activity has now finished. Six of the ten bases for the new final settlement tanks will be complete before Christmas.
Sludge stream This is where the remaining sludge is broken down and turned into energy. Five new gas compressors are now operational. Nine of the 16 digesters have been refurbished. We have now built one of the new raw sludge holding tanks. This work will allow us to power up to 40 per cent of the new extension with renewable energy.
Looking forward Some interesting points as we pass the peak of construction activity: A 200-strong workforce remains on site, with their focus now moving towards mechanical and electrical installation. We have managed to keep 35,000 lorry loads off the roads by reusing or storing nearly 510,000 tonnes of earth on site.
Key statistics From spring 2012, we'll be removing the earth temporarily placed on the mound, meaning the embankment will be back to its original height by the end of next year. The embankment and surrounding area will be planted with native trees, shrubs, and herb-rich grassland, encouraging biodiversity and wildlife.
In the community Thames Water and contractors Black & Veatch joined forces at two careers fairs. The events at Isleworth & Syon School for Boys and Lampton School reached more than 1,000 local young people.
Thames Water AOB
Proposed dates of meetings: Wednesday 7 March 2012 Wednesday 6 June 2012 Wednesday 5 September 2012 Thames Water
Need to contact us about Mogden? Call the Mogden 24hr line (via the Thames Water Operations Contact Centre): 0845 641 0030 To subscribe to email notifications, email us at: mogden@thameswater.co.uk Visit our website: www.thameswater.co.uk/mogden Write to us: Customer Feedback PO Box 286 Swindon SN38 2RA Thames Water