Management of Catchment Water Quality Inspection and Rehabilitation of Private Sewers

Transcription

1 Management of Catchment Water Quality Inspection and Rehabilitation of Private Sewers 1

2 Outline Our Water Resources Managing Catchment Water quailty Plugging Used Water Leaks from Sewers Private Sewer Rehabilitation Programme Tightening of Water Test at BP Stage 2

3 Water from Local Catchment Punggol MacRitchie Reservoir Kranji Reservoir o Half of Singapore is already water catchment o Catchment area will be increased to two-thirds by 2009 Bedok Pond 3

4 Lower Pierce Reservoir Legend Upper Pierce Reservoir AngMo KioGRC Hougang SMC Catchment Boundary GRC Boundary MacRitchie Reservoir Bishan / Toa Payoh GRC Marine Parade GRC Kallang River Aljunied GRC Holland-Bukit Timah GRC Bukit Timah Canal Phase II Diversion Canal Sungei Whampoa Potong Pasir SMC MacPherson SMC Pelton Canal Joo Chiat SMC Tg Pagar GRC Rochor Canal Jln Besar GRC Geylang River West Coast GRC Alexandra Canal Stamford Canal Marine Parade GRC West Coast GRC Singapore River The Marina Catchment Highly Built-Up Catchment 1/6 of Singapore land area with 1 million population 4

5 Punggol- Serangoon Reservoir Punggol Reservoir Ang Mo Kio Pair Ris - Punggol Dam in place by end 2007 Punggol & Serangoon Reservoirs by 2009 Hougang Serangoon Reservoir Catchment highly urbanised Aljunied 5

6 Every drop goes straight into drains and the canals 6

7 Marina Reservoir 20 years in the making 2 key factors make the Reservoir possible :- 10-year river clean-up efforts - Cleaning up of rivers - Land use planning - Developing Infrastructure Technology - Advancement in membrane technology allows us to treat water from highly urbanised catchment 7

8 Cleaning up of Rivers Transformation of lifeless rivers into rivers of life Singapore River (Jiak Kim Street) Kampong Bugis (Kallang River) Singapore River (Robertson Quay)

9 Land Use Planning Drains for rain water only Solid Waste Mgt Public housing Construction of industrial workshops Separate sewerage and drainage system 9

10 Developing Infrastructure - DTSS ($3.6 bil) DEEP TUNNEL! Construction of tunnel completed! Changi WRP on schedule for completion in 2008 CHANGI WATER RECLAMATION PLANT 10

11 Developing Infrastructure - Rehabilitation of Public Sewers ($420mil) Phase 1 & 2 $270mil ( ) Phase 3 - $150mil (2006 -onwards) 11

12 12 Excerpts from 2-part documentary Reservoir in the City aired in Mar 2005

13 Uniquely 3-in-1 Marina Barrage water supply. flood control. major lifestyle attraction Critical 3P involvement to get the most out of this unique asset 13

14 Marina Barrage MARINA CHANNEL SEA Construction of drainage pumping station at Marina South Construction of barrage at Marina East 14

15 A major lifestyle attraction Uniquely 3-in-1 Marina Barrage water supply. flood control. major lifestyle attraction In water On land Vision an exciting & vibrant waterfront 15

16 Challenges Beautiful Waterways 16

17 Challenges Vibrant Basin and life style attraction Singapore River Raft Race Formula One Boat Races Wakeboarding Sailing 17

18 Uniquely 3-in-1 Marina Barrage water supply. flood control. major lifestyle attraction tidal flushing removes pollutants but ugly rivers and canals at low tide Tidal Flushing Urban Runoff 18

19 Uniquely 3-in-1 Marina Barrage water supply. flood control. major lifestyle attraction With Barrage in place by end 2007 no tidal flushing - pollutants accumulates stable water level - opportunity for aesthetic waterways and recreation Barrage Urban Runoff 19

20 Pollutants of Concern Used Water Leaks from sewers Silt Discharge from Construction Sites Water Treatable to drinking purposes Aesthetic & recreational use concerns Debris and Flotsam from Littering Nutrients & Sullage Water from urban activities Pollutive Runoff from Industrial 20 premises

21 Framework Strategies to Manage Catchment Water Quality Technology & International Experts! Water Quality Studies, Predictive Modeling of Water Quality! Evaluation of source control & mitigation measures! R&D on long term solution Source Control Mitigation Measures 3P Involvement! Engaging the community! Shared ownership of water resources! Public Education 21

22 Source Control : Brown silty water problems at construction sites No erosion control measures Unprotected earth slopes Undersized silt trap Undersized silt tank 22

23 Ang Mo Kio New Town how silt affect our waterways Turf City MacRitchie Reservoir Bishan New Town Kg Ubi Ind. Est Singapore Botanic Gardens Queenstown New Town Kallang Basin Marina Bay siltation Brown water 23

24 We are encouraging Source Control : Brown silty water good erosion control measures ECB protection concrete slope canvas protection effective sediment control progressive turfing Silt fence & cut-off drains Silt tanks 24

25 Source Control : Nutrients & Litters Pollutants from urban activities 25

26 Upper Peirce Reservoir Lower Peirce Reservoir Ang Mo Kio New Town how litters affect our waterways Turf City MacRitchie Reservoir Bishan New Town Kg Ubi Ind. Est Singapore Botanic Gardens Queenstown New Town Kallang Basin Marina Bay 26

27 Source Control : Nutrients & Litters We are stepping up education and surveillance 27

28 Source Control : Industrial Discharges Poor housekeeping 28

29 Source Control : Industrial Discharges We are encouraging good housekeeping practices 29

30 problems of sewers Source Control : Used Water Leaks Joint displaced Hole in pipe Tree-root Intrusion in Sewer Cracked/crushed pipe Broken Pipe 30

31 Source Control : Used Water Leaks On-going Programme by Govt DTSS Public Sewers Rehabilitation Programme Relief Sewers Private Sewers by Owners Responsible for keeping private sewers in working order. Ensure usedwater does not contaminate run-off 31

32 Mitigation Measures Eg. Active, Beautiful and Clean (ABC) Waters Programme From utilitarian canals to vibrant streams and rivers Wetlands to remove harmful nutrients Waterwheels to improve aeration Beautiful waterways Water Sensitive Urban Design to slow down runoff 32

33 Private Sewer Rehabilitation Programme for Existing Buildings 33

34 The Used Water Network HIGH-RISE RESIDENTIAL COMMERCIAL PREMISES MANHOLE INDUSTRIES PRETREATMENT PLANT PUMPING STATION Water Reclamation Plants EFFLUENT OUTFALL SEA SEWER 34

35 Private Sewers (Drainlines) Rain water network Drains Canals Boundary Rivers Inspection Chamber manhole Reservoirs Used water network Private Sewers Belongs to owners Maintain by owners Public Sewers Owned by Govt Maintain by PUB 35

36 Studies by PUB and consultants Diffused used water leaks from sewers. Length of sewers in Marina Catchments Private sewers : ~1,000km Public sewers : ~1,000km 36

37 Private Sewer Rehabilitation Programme (2006) Rochor Canal Sub-Catchment ( ) Full scale work in Marina Catchments 37

38 Programme Features PUB investigate leak Premises Owners to rectify leak at his own cost Govt shelp: To pay part of the cost (min 5%) based on proportion of length of private sewer lying outside owner s premises Owner could engage PUB or list of contractors Technical assistance Financial Help Installment plan available for owners who engage PUB Private Sewers Belongs to owners Maintain by owners Public Sewers Owned by Govt Maintain by PUB Owner s share Inspection Chamber Govt fund Boundary manhole 38

39 How Govt will offer to pay part of repair cost If total length of private sewer is 10 m Length outside boundary is 2 m 10m Govt would help pay 20% of the rehabilitation cost Inspection Chamber Boundary manhole A minimum of 5 % but for some cases such as shophouses can be %. 2m 39

40 Stage 1 Pre Leak Test Create Awareness Door to Door Visits by PUB staff/representative Explain Private Sewers Explain need for the programme Arrange for free checks on private sewers Using letters, brochures and circulars 40

41 Stage 2 Leak Testing Carrying out free checks for owners Carry out the water test Let owners see the test Explain the problem of leaking sewers Explain help from PUB 41

42 Stage 3 Pre-rehab Helping owners Firming up the work Determine extent of rehabilitation required Advisory noteto owners if leaks are found Indicative quotation Sourcing for contractors List of contractors with Capped Rates Can engage PUB to carry out the work Technical help Hotline - Tel no

43 Stage 4 Rehabilitation work Helping Owners in implementation Minimize inconvenience to owner Minimize inconvenience to neighbors Provide technical support 43

44 Work impact on private owners Disruption Minimal 1-3 days work Trenchless With flow diversion - use of toilet and kitchens not affected. Exception, 1-2 hr disruption 44

45 Clip on Lateral Rehabilitation 45

46 For more info available on our website 46

47 Tightening of Water Test at BP Stage 47

48 Inspections & Water Tests Existing COP standards QPs to examine the water tightness of all new sewers and sanitary drainlines at new development before putting the sewerage system into use. Certification and documentation not required to be submitted Need for tests To ensure water tightness COP For All sanitary drainline and sewers (Dia 600 mm or less) shall be tested by filling with water pressure of1.5 metre head for 30mins before being surrounded and covered 48

49 Registration of BP /Sewerage detailed plan Clearance Certificate by CBPU, NEA Notify PUB to commence sewerage works Notify PUB to carry out sewer connection works BP submission (New Development or A/A works to Existing Buildings) PUB random witness sewer Connection QP submit Certificate of inspection and completion to PUB for TOP/CSC Clearance Audit inspection and water test by PUB PUB Sewerage Clearance for Compliance Certificate (TOP/CSC), 49

50 Revised Procedure (1 st Feb 07 onwards) Revised requirements: Clearance Certificate Require QP to check and witness the water test during pipe laying stage Certificate of Completion & Inspection for Sanitary/ Sewerage Works (Form C/QP) Certify that the water test requirements are met Submit and endorse water test results 50

51 Revised Procedure (1 st Feb 07 onwards) PUB will check compliance on water tightness for all new sanitary drainlines and sewers: Carry out own water tests on randomly selected projects when audit inspecting the completed sewerage works before TOP/CSC clearance, or when witnessing the sewer connection works If leaks are found, QPs/Owners will need to rectify leaks before issuing of CSC 51

52 Coverage For BPs submitted before 1 st Feb 07 PUB carry out water tests on randomly selected projects For all BPs submitted 1 st Feb 07 onwards QP submit new form to endorse water test results PUB carry out water tests on randomly selected projects 52

53 Water Test Water level drop Inspection Chamber Leak Plug 53

54 Everyone can play a part in Keeping the catchment clean Keeping the waterways clean 54

55 Thank You 55