GWD5_SP_Protecting Groundwater Sources

WASH Cluster – Groundwater Development and Drilling GWD5

Timetable

GWD1 - Occurrence GWD2 -

Characteristics of

Groundwater Systems

Session Plan

GWD5 – Protecting Groundwater Sources

GWD3 - Identifying

Potential

Groundwater Sources

GWD4 - Developing

Groundwater Sources

GWD5 - Protecting

Groundwater Sources

60 mins 1 hour 45 mins 40 mins 1 hour 45 mins 1 hour 10 mins

Session-at-a-Glance

Session Activities

Risks to Groundwater sources

Reduction of Groundwater availability

Water Quality

Groundwater Contamination

Maintenance of aquifers and well infrastructure

Protection of Spring sources

Monitoring

Approx.

Time

10

10

10

15

10

5

10

Total session time 1hr 10mins

Instructional Activity

QUESTION 1: and Plenary discussion with power point slides

QUESTION 2: and Plenary discussion with power point slides

Plenary with discussion and power point slides

Plenary and slides,

Exercise 1, 2 plenary and slides plenary and slides

Plenary and QUESTION 3,

Example

Session Aims

 This session is to demonstrate the potential impacts on groundwater that may affect security of the water source, the systems that must be put in place to determine whether the water supply is able to be sustained for on-going use, and what issues need to be understood to do so.

Session Objectives

By the end of the session participants will be able to:

 List at least three of the key risks to groundwater resources

 Explain the effect of pumping of groundwater from a bore on the continuity of supply

 Describe potential sources of naturally occurring and introduced contamination,

 Explain methods of management and rehabilitation of damaged groundwater sources

 List the parameters (yield, level and quality) needed to monitor in a groundwater project to maintain water supply

Session Materials

 Flip chart and pens

 Handout for Contamination migration (Exercise 1)

 Slide projector

1

WASH Cluster - Groundwater Development and Drilling GWD5

Key Learning Points

The key message is that even if a groundwater source has been identified and infrastructure is set up to extract groundwater, from the start of the emergency response the source needs to be protected from contamination or over-extraction to maintain security of supply to meet the water supply needs for the duration of the emergency and potentially longer.

Session plan

WASH Cluster – Water in Emergencies

GWD

Groundwater Development and Drilling

Protecting Groundwater Sources

GW D_4 WASH Cluster

– Water in Emergencies –


WASH Cluster

– Water in Emergencies

Session Aims

•Demonstrate the potential impacts on groundwater that may affect security of the water source,

•Discuss systems that must be put in place to determine whether the water supply is able to be sustained for on-going use, and

•Demonstrate what issues need to be understood to do so

GWD

1

FLIP CHART

Work through the session aims

Introduce participant issues / experience concerning poor water quality or quantity

What have been the problems caused by these issues – participants to advise

GW D WASH Cluster




Key Risks to Groundwater

GWD

QUIZ 3: What are some of the risks to the use of groundwater for emergency water supply?

2

•Reduction of groundwater availability / Depletion of aquifer yield

•Water quality contamination

•Protection of the bore itself

•Inadequate investigation and design

•Costs of pumping, maintenance of pumps and fuel supply

•Interruption to power or fuel supply

TRAINER: SEE QUESTION 1 (BELOW)Ask the question, answers on note below

Participants to identify the risks and the trainer to record on flip chart

Summarise participant risks and discuss participant responses and the slide

Note any additional issues not on the slide




WASH Cluster


Reduced Yield from a Well

GWD

QUIZ 4:

• What factors will affect the amount of water that can be extracted from a well?

• What will happen if the well is pumped at too high a rate

• What happens when the pump stops?

• Does this apply to all wells?

• What might the long term effect of this be?

WASH Cluster – Water in Emergencies –


GW D 4

3

WASH Cluster


Reduction in Availability

GWD

Relevance to Emergency

• Reduction of flow from well or spring related to the balance between the amount of water removed from an aquifer and the amount that recharges.

• Unless there is adequate seasonal recharge into the aquifer, the volume of groundwater stored in the aquifer will be reduced - ultimately unsustainable supply.

• If extraction is too great on a particular day, the yield of the well on that day may drop off

• Changes due to pumping drawdown and recovery due to recharge need to be carefully monitored to make sure supply is maintained

WASH Cluster



GW D 5

FLIP CHART activity on water availability

Participants to identify what will reduce the yield of groundwater obtained from a well – record on Flip chart

Slide to prompt discussion

TRAINER: See QUESTION 2 Q & A

TRAINER: Discuss the points on this slide

The importance of this is that participants need to understand that once a well or spring is developed, the flow is not guaranteed and it has to be managed so that the volume taken can be balanced by the volume that recharges.

This applies to an emergency and longer term – in an emergency it can waste valuable time

Session Plan – GWD5 2


WASH Cluster


Water Quality Effects

Groundwater potentially protected by being below the surface

GWD

Potability can be influenced by:

– Natural variations in salinity

– Naturally occurring chemicals

– Man-induced contamination

Q & A:

What factors can influence the quality of drinking water – participants to answer

Refer to slide for general answer

WASH Cluster



GW D 6

GWD WASH Cluster – Water in Emergencies

Naturally occurring quality issues

• Salinity

– Potable (<1000mg/L) based on palatibility

• Turbidity

– Can be serious in hand dug wells and poorly constructed drilled wells

• Dissolved Iron

– Unpleasant taste and colour

• Dissolved Carbonate / bicarbonate

– Unpleasant taste, precipitation on pipes

WASH Cluster



GW D 7

WASH Cluster


Natural Toxicants

GWD

• High Fluoride and Arsenic occur in some groundwaters

• Can be naturally occurring

• Can be detrimental to health

• Tend to be due to long term exposure – but requires careful assessment

FLIP CHART ACTIVITY / NATURAL WATER QUALITY IMPACTS

Record on flip chart:

What have participants experienced in their area with water quality variations?

Compare with a list on the slides,

Any other things from participants......?

Trainer may need to provide some discussion on particular chemicals of concern for particular participants based on the notes provided eg There may be an issue with iron or some other chemical for the area where the course is held

GW D WASH Cluster – Water in Emergencies –



Contamination by Humans

GWD

8



WASH Cluster



GW D

WASH Cluster


GWD

Microbiological contamination

The bacterium Escherichia.coli is found in the intestines of warm blooded animals,

- present in the faeces of humans

Latrines can be a source of contamination with E.coli –

Bacteria and viruses have relatively short lives in groundwater

Latrine siting is important

- not in the groundwater flow path

GW D 10

9

Contaminants resulting from human activities

Q: What types of contaminants that might be a problem in an emergency - participants to prepare a list –

TRAINER to discuss answers

Spills of fuel , pesticides that might have been sprayed, waste dumps

Groundwater degradation with rapid impact on health results from microbiological contaminants (biological, bacteria and viruses ) is common in emergencies .

EXERCISE 1: Contaminant migration in Groundwater

Show slide and discuss

NOTE: people might suggest: that the pollutants can be diluted when they hit the water table – This can happen what if the water table is very deep – This is an advantage

for reducing impact

Q: What is the most common cause of contamination of water supplies in emergencies?

A: Latrines

Talk about the slide Refer to SPHERE standards which are meant to reduce this impact

Note also that burial pits and cemeteries may need to be considered also



WASH Cluster


GWD

Microbiological contamination

WASH Cluster



GW D


Protection of Well surrounds

GWD

WASH Cluster



WASH Cluster



GWD



GW D

GW D

Poorly maintained well head at pumping well with pathway for contamination down the well, Osire

Refugee Camp, Namibia

12

Filthy surrounds to shallow well and likely contamination introduced to a well by rope.

Note the broken hand pump has compromised the security of the well head. To access the well buckets are used.

Gassire, Eastern Chad

13

11

Based on the previous exercise participants to consider where would it be better to put a latrine to avoid contamination

EMPHASISE THAT THIS IS A REALLY COMMON PROBLEM

IN EMERGENCIES AND THERE IS OFTEN NO EASY

SOLUTION

THAT IS WHY YOU SHOULD UNDERSTAND THE

GROUNDWATER CONDITIONS

DO EXERCISE 2 (DETAILS BELOW)

Show the slide and point out the well in the groundwater flow path

TRAINER:

Handout Case Studies (4 in total) on maintaining a reliable water source

Break into groups (one group per handout)

Groups to discuss their handout and report to whole group.

Trainer to use the slides and make sure the key points are identified

What are the issues at this particular site?

The headworks around the well are poorly maintained and there is likely to be leakage done the side of the well.

Also, water vessels are left on the ground - ?hygienic?

What are the implications for this situation on the water supply?

Despite the 50m + depth of the well , contamination can leak down the sides; water supply can be considered to be polluted (this was suspected that there may have been impact of latrines that are some distance away)

What would you do to improve the situation?

Repair the earthworks to ground level; stop ponding of surface water around the well head; disinfect the well

What are the obvious problems ?

Filthy surrounds to shallow well including animal waste; likely contamination introduced to the well by rope.

Note the broken hand pump has compromised the security of the well head. To access the well buckets are used.

Volumes reduced because of too many people trying to use this limited resource that once for a small village

(100’s not 1000’s)


Pollution of source, limited availability


Clean and rehabilitate the well head, try to find another source, manage access if possible



WASH Cluster



GWD

WASH Cluster



GW D

Sanitary well conditions at the well head but a contamination source (pig pens) is immediately behind the fence

(Nias, Indonesia,

2006).

WASH Cluster


GWD

Maintenance of Aquifers and

Well Infrastructure

• Emergency can cause additional demand

– Increased drawdown on existing wells

– Over-extraction pressure on the aquifer

14

What are the good things about this well set up?

Solid, clean surrounds, cover to well, single bucket,

Community engaged by public health promotion (the young woman standing with thh older village lady),

Would you like to see any other features?

Perhaps fenced off so access is limited to only those collecting water

Are there risks here?

Behind the fence there is a piggery, that is potential contamination source!

Trainer: Discuss points on the slide

• Too many people at a well (eg open well) can lead to contamination




WASH Cluster


GWD

Repairing and disinfecting wells

13

Litter in well after Tsunami, Band Aceh, Indonesia

Rubbish removed from the base of an open well during well rehabilitation, Gassire, Chad

After rubbish removal, disinfection with a chlorine solution



GW D 14

WASH Cluster


Refurbishing well surrounds

GWD

Trainer: discuss slide

What is the issue concerning water supply here?

Direct introduction of contamination

How do you think this can happen?

Litter washed in by flood, Tsunami:

Ropes come loose dropping collection vessels into wells


Contamination of water, reluctance of community to use the well, In serious cases the wellhead is damaged

Eg Tsunami

In bad cases, well fills up and reduces available volume


Clean out and disinfect the well

NOTE: chlorine is a dangerous chemical, to be handled with gloves and care taken not to breath in, people in a well need to be securely lowered into the well

Chlorination is covered in the Water module.

Trainer: discuss slide

Original unsanitary well surrounds,

Rehabilitated apron with drainage point bottom left.



GW D 15



WASH Cluster


Repair of deep wells

GWD

Deep wells can be degraded by:

•Microbiological contamination

– can be disinfected with chlorine solution

•Casing and screen corrosion

– repair or replacement

•Build up of bacterial slime (fouling) on screens

– chemical treatments

Treatment / repair of existing wells needs careful assessment and specialist inputs

•Not a focus for first phase emergencies.

WASH Cluster



GW D 16


Spring Protection

GWD

Trainer to Emphasise:

Strong surrounds to prevent contamination from surrounding activities,

Dedicated bucket for collection at the site to prevent contamination from dirty buckets

GW D

Dedicated buckets and collection cell, Nias,Indonesia

17 WASH Cluster



WASH Cluster


Monitoring

• QUIZ 5: MONITORING QUIZ

GWD

TRAINER:

Do QUESTION 3: MONITORING QUESTIONS(BELOW)

• Why monitor?

• What to consider in a monitoring program

• What type of information is collected for a groundwater source?

WASH Cluster


Monitoring

GWD

Monitoring of water level, usage and quality is important fundamental to record and store the data

Data must be looked at and used to make best use of the groundwater resource

Talk to the slide

Note there is more detail on monitoring in the notes and a brief example of the importance of monitoring

Monitoring groundwater levels in new water supply well

END OF SESSION

DO A WRAP UP OF THE SESSION REVIEW OF INTRODUCTION

AND WHETHER EXPECTATIONS WERE ACHIEVED – REFER

BACK TO FLIP CHART PRODUCED IN INTRODUCTION

QUESTIONS TO WRAP UP

TRAINER TO TAKE QUESTIONS FROM PARTICIPANTS THAT

NEED TO BE ANSWERED AFTER THE SESSION BY OTHERS

SUCH AS GROUNDWATER SPECIALISTS.



GWD 5: Exercise and Quizzes

QUESTION 1: Risks to Groundwater sources

Q: What are some of the risks to groundwater resources?

A:



Reduction of groundwater availability / Depletion of aquifer yield due to excessive drawdown, sustainability , interference from other bores



Water quality impacts - c ontamination in the catchment and near the bore -eg salt water intrusion, latrines, other pollutants

 Protection of the bore itself -eg animals, agricultural runoff, dirty equipment, including vandalism

 Contamination from upgradient contaminants, salt water intrusion



Set up costs, time lags, proper investigation and design



Costs of pumping, maintenance of pumps and fuel supply



Interruption to power or fuel supply (related to well infrastructure and delivery–session GW???)



QUESTION2: Reduction aquifer yield from a well

Q: Based on the previous discussion of geology and aquifer types and on well construction and pumping effects, what factors will affect the amount of water that can be extracted from a well?

A: Type of aquifer, rate at which water flows back into a well, depth of the well and the length of exposed area of screens/ well,

Q1: What will happen if the well is pumped at too high a rate:

A: There will be excessive drawdown and the well may dry out – risk then to the pump

Q2: What happens when the pump stops?

A: The water level is expected to recover to the pre-pumping level from flow of groundwater from the aquifer into the well

Q3: What can be inferred if the water level does not recover to the pre-pumping level?

A: The inflow from the aquifer is not sufficient to replace the water pumped out and the pumping rate is too high.

Q4: Does this apply to all wells?

A: Yes - if there is not sufficient groundwater inflow to the well to replace the volume that has been removed it will apply to any type of well (ie hand dug wells as well as drilled bores with carefully designed screens)

Q5: What might the long term effect of this be?

A: There will be a long term drawdown of the groundwater level in the aquifer and reduction in the groundwater resource available until recharge occurs



EXERCISE 1: Contaminant migration in Groundwater

TRAINER: HAND OUT FOR CONTAMINATION MIGRATION GIVE ONE TO EACH GROUP

– Aim is to have participants add to the drawing to understand how contaminants get into the aquifer

ASK PARTICIPANTS

Which way is groundwater likely to flow flowing

Where will the contamination go

ADD TO THE DRAWING

Flow direction arrows towards the stream

Draw down arrows and surface runoff

How will it get there

What if the water table is very deep

What will happen to the contamination when it reaches the groundwater?

Infiltration through seepage during recharge

NOTE: Some pollutants may be stopped in the soil

Draw the plume as in the slide –

Q: What factors affect how far the plume travels

A: the concentration of pollutant that reaches the water table, the distance to the stream, the permeability and hydraulic gradient



EXERCISE 2: LOCATING LATRINES AND WELLS

EXERCISE 11:- WHERE TO PUT WELLS and LATRINES – POTENTIAL SITE PLAN

What things need to be taken into account

When on a site, what would you do to protect the wells

Groups to consider a sanitary survey of possible impacts that looks at: location and distance of sources of pollution from wells, drainage – would wells be inundated in floods, are wells protected from leakage of contaminants into the well, how is water collected and how would the groundwater in a well be protected for contamination during water collection

Q: Where to put the latrines

A: As far away as possible from wells, in an area of deep water table, on the “up-side of the groundwater flow path



QUESTION 3: Monitoring quiz

Q1: Why monitor

A:To keep an understanding of the on-going availability from a well / bore both yield volume and quality.

Q2: What factors need to be considered in the design of a monitoring program

A: important thing about monitoring is to have a clear idea of the purpose of the monitoring, what parameters need to be measured and at what frequency.

Q3: What type of information could be collected in relation to a groundwater source.

A: Typically range of parameters:

Water level;

Well yield (or amount of water taken per day by a community),

Various water quality parameters – typically e.coli

and EC in first phase type situations, other


GWD5_SP_Protecting Groundwater Sources

GWD 5: Exercise and Quizzes

QUESTION 1: Risks to Groundwater sources

QUESTION2: Reduction aquifer yield from a well

EXERCISE 1: Contaminant migration in Groundwater

EXERCISE 2: LOCATING LATRINES AND WELLS

QUESTION 3: Monitoring quiz

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GWD5_SP_Protecting Groundwater Sources

GWD 5: Exercise and Quizzes

QUESTION 1: Risks to Groundwater sources

QUESTION2: Reduction aquifer yield from a well

EXERCISE 1: Contaminant migration in Groundwater

EXERCISE 2: LOCATING LATRINES AND WELLS

QUESTION 3: Monitoring quiz

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