Mogden Sewage Treatment Works

Transcription

1 Mogden Sewage Treatment Works Residents Liaison Meeting 7 December 2011 Thames Water

2 Agenda Review of previous minutes Operations and communications Mosquito talk and survey results Sewage Treatment Work Upgrade Project an update AOB Thames Water

3 Operations and communications Thames Water

4 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

5 Operational Correspondence Other Mosquitoes Odour and mosquitoes Odour 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

6 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

7 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

8 Thames Water Mosquito Talk

9 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

10 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!

11 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.

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13 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

14 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

15 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

16 buckets wheel-barrows other containers

17 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

18 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

19 Percentage of properties with mosquitoes present per distance category percentage m 1km 2km 4km distance to Mogden STW

20 km 2km 1km Reports of biting: frequency per distance category (percentage) m frequent: >weekly 4 7 infrequent: weekly-<monthly occasionally: >monthly no mosquitoes found or no bites reported

21 70 60 Reports of biting: total per distance category (percentage) km 2km 1km 0-200m

22 Road drains with mosquitoes present (percentage) m 1km 2km 4km

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25 Thames Water Mosquito Survey Results

26 Mosquito data - Number of sites inspected Number of sites Week Thames Water Average

27 Mosquito data - Percentage of sites showing any activity % of sites with any activity Week Average Thames Water

28 Mosquito data - Percentage of sites showing any adults 50 % of sites with activity Week Average Thames Water

29 Mosquito data - Percentage of sites with many adults 50 % of sites with activity Week Average Thames Water

30 Mosquito data - Percentage of sites with many adults (2) 10 % of sites with activity Week Average Thames Water

31 Mosquito data - Percentage of sites with larvae activity 50 % of sites with activity Week Average Thames Water

32 Sewage Treatment Works Upgrade Project an update Thames Water

33 Mogden STW Upgrade

34 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.

35 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.

36 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.

37 Odour control unit 11 Odour control kit has been delivered to site. Installation will be complete around spring Commissioning of inlet works, primary settlement tanks and odour control around Spring 2012.

38 Aeration lanes This is where we encourage bacteria to eat the organic matter. All four tanks are almost complete pre-cast panels are being installed to create the lanes, saving hundreds of concrete deliveries. We will soon start installing the interconnecting pipe work.

39 Aeration lanes (cont)

40 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.

41 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.

42 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.

43 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.

44 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.

45 Thames Water AOB

46 Proposed dates of meetings: Wednesday 7 March 2012 Wednesday 6 June 2012 Wednesday 5 September 2012 Thames Water

47 Need to contact us about Mogden? Call the Mogden 24hr line (via the Thames Water Operations Contact Centre): To subscribe to notifications, us at: Visit our website: Write to us: Customer Feedback PO Box 286 Swindon SN38 2RA Thames Water