GROUNDWATER: THE GOOD, THE BAD AND THE UGLY. By: L van Zyl-Smit May 2016

Transcription

1 GROUNDWATER: THE GOOD, THE BAD AND THE UGLY By: L van Zyl-Smit May 2016

2 REDE ENGINEERING AND MANAGEMENT SOLUTIONS

3 A Brief Introduction to REDE Who are we? rede (riːd) an old Middle English word 1. to advise or counsel 2. an explanation What do we do as Consulting Engineers Water Supply and Sanitation; Mine Closure and Rehabilitation; Project Management Solutions;

4 GROUNDWATER

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6 Groundwater and the water cycle

7 GROUNDWATER THE GOOD

8 Water Balance Earth's Water Balance Saline Water Sea water Saline groundwater 97.5% 99.0% 1.0% Fresh Water Ice and Snow Groundwater Lakes and rivers Soil and wetlands Atmospheric water vapour 2.5% 70% 30% 0.25% 0.1% 0.04%

9 Water Balance Total Water Balance

10 Water Balance Total Fresh Water

11 Water Balance Total Fresh Water Excluding Ice

12 Why is Groundwater Important? Close to the need; Less subject to seasonal variation in availability; Groundwater is stable and of constant temperature; The relative Quality of groundwater is good; Simple treatment processes required; Relative simple supply solutions; Relative low Capital Expenditure; Reduced failure risk through diversification; Often the only resource available; SA is a water scarce country: Total mean annual Zambezi runoff = million m3 RSA Total mean annual runoff = million m3 Global average annual rainfall = 860mm RSA average annual rainfall = 465mm

13 Chris Hani DM - Surface Water vs Groundwater

14 Chris Hani DM - Surface vs Groundwater

15 GROUNDWATER THE BAD

16 Water: It s Taken for Granted We wash in it,

17 Water: It s Taken for Granted don t even think about drinking it...

18 Water: It s Taken for Granted and we play in it...

19 Water: Appreciation of Infrastructure We see the tap, but not the reticulation...

20 Water: Appreciation of Infrastructure Back then, conveyance infrastructure was showcase...

21 Water: Appreciation of Infrastructure Today conveyance infrastructure is hidden...

22 Groundwater: Typical Challenges Whose water is it? Groundwater quality; Turbidity Pollution Fecal Coliforms Iron and Metals Fluoride Manganese Hardness Low groundwater potential areas; Pump head limitations; Borehole yield limitations.

23 Groundwater: Typical Challenges Complex Team of specialists required Hydrogeology; Groundwater Exploration and Drilling; Borehole Testing; Water Quality; Electro-Mechanical; Institutional Social Development; Operation and Maintenance; Water use licensing; Resource management.

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25 Select the right tool for the job

26 Groundwater: Engineering Solutions Pump Technology Submersible vs Line shaft pumps

27 Groundwater: Engineering Solutions Pump Technology Positive displacement vs Centrifugal Pumps

28 Groundwater: Engineering Solutions Electricity Power Supply Electricity vs Generators

29 Groundwater: Engineering Solutions Green Power Supply Solar vs Micro Wind Turbine

30 Groundwater: Engineering Solutions Old School Solutions Diesel driven Lister type engines Windmill

31 Groundwater: Engineering Solutions Pump control philosophy and instrumentation; Security of infrastructure; Lightning protection.

32 GROUNDWATER THE UGLY

33 Groundwater has a Bad Name Technical Failures Disappointment after the exploration phase Poor selection of Pump infrastructure Poor selection of Power source Water Quality Operation and Maintenance Procurement Failures Complex procurement requirements Procurement sequencing Inadequate budgets Lack of Social Buy-in Land consent Resource management

34 Is your gun loaded or are you digging? Is your gun loaded, or are you digging?

35 What Can You Do? Client Education / Training Informed budgets / estimates Informed about Risks Procurement Management Operation and Maintenance Resource management Project Planning Design with the end in mind Turnaround time Turnkey solutions Early community involvement

36 Select the right tool for the job

37 Manual Disadvantage Fatal Fatal To be located close to need Low yields ( L/s) Low pump head (10 30 m) Pump on demand - no storage Limited pumping time Labour intensive Source quality Advantage No electricity Simple operation Easy maintenance Owner maintenance Low capital and operational expenditure Simple pumping mechanism Easy quick installation

38 Wind Power (Windmills) Disadvantage Fatal Fatal Fatal Wind dependant Low yields (< 0.4 L/s) Average pump head (< 90 m) Damage during extreme weather conditions Complex pumping system Operator intensive Safety risk to operators / maintenance High maintenance requirements Specialized maintenance requirements Advantage No electricity renewable energy Low operational expenditure Low risk of theft / pilferage

39 Wind Power (Micro Turbine) Disadvantage Low yields ( L/s) Damage during extreme weather conditions Difficult to automate control High capital expenditure New unproven technology Specialised maintenance Noise Fatal Wind dependant Variable supply Fatal Advantage No electricity renewable energy Simple operation Very low operational expenditure Very little maintenance Low risk of theft / pilferage Simple pumping system Distance between turbine and BH Distance between source / need High total pump head

40 Solar Power Disadvantage Advantage No electricity renewable energy Simple operation Very low operational expenditure Very little maintenance Distance between source / need Distance between panels and BH Fatal Fatal Solar dependant Variable supply Low yields ( L/s) Damage during extreme weather conditions High capital expenditure Specialised Maintenance Difficult to automate control Extreme risk of theft / pilferage

41 Electricity (Municipal) Disadvantage Advantage Stable electricity supply dependant Vulnerable to lightning and voltage spikes Specialised Maintenance Wide range of yields Wide range of pump heads Simple easy automation and control Very little maintenance Simple pumping system Low capital expenditure Fatal

42 Electricity (Generator) Disadvantage Fatal Fatal Generator required Servicing of generator Fuel supply required High capital expenditure Specialised Maintenance Extreme risk of theft / pilferage (Generator) Extreme high operating expense Advantage Wide range of yields Wide range of pump heads Simple pumping system Low capital expenditure

43 Fuel Engine Disadvantage Fatal Fatal Fatal Servicing of engine Fuel supply required Operator expertise critical Extreme high capital expenditure Extreme high operational cost Specialised Maintenance High risk of theft / pilferage of equipment and fuel Complex pumping system Operator safety risk Advantage No electricity required Very wide range of yields Wide range of pump head Tried and tested technology

44 OPEX Typical Analysis

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46 Select the right tool for the job

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48 Accelerated Schools Infastructure Delivery Initiative (ASIDI) October February 2014 Number of Production Boreholes developed 76 Hand Pumps - 13 Micro Wind Turbines - 19 Electrical Submersible - 43

49 Accelerated Schools Infastructure Delivery Initiative (ASIDI) February May 2016 Number of Production Boreholes developed 31 Hand Pumps -8 Micro Wind Turbines - 11 Electrical Submersible - 12

50 Accelerated Schools Infastructure Delivery Initiative (ASIDI) February May 2016 Average Implementation time 46 weeks Best Worst

51 Accelerated Schools Infastructure Delivery Initiative (ASIDI) Number of Production boreholes - 76 Successful installations to date - 35 Best implementation time 26 weeks Worst implementation time 76 weeks Average implementation time 46 weeks

52 Is your gun loaded or are you digging? Is your gun loaded, or are you digging?

53 QUESTIONS

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