Key responses – Water Water treatment and Priorities in Different Settings

WASH cholera / AWD EP&R training

Key responses – Water

Water treatment and Priorities in Different Settings

Session 3.2WASH Cholera / AWD EP&R training


Learning Objectives

By the end of the session the participants• specify water treatment during a cholera / AWD

outbreak• describe basic principles of chlorination, its

limitations and advantages • suggest solutions to provision of water for

different settings at different stages of cholera / AWD response


IMPORTANT

During a cholera outbreak it is

advisable to use chlorinated water

only for drinking and cooking!!!


Bulk vs. household water treatment

• .


Work in pairs

Discuss advantages and

disadvantages of household and bulk

water treatment

10 min


Bulk vs. household treatment

+ -Bulk water treatment

• Can supply to large numbers of people

• Can provide drinking water quickly

• Can control water quality

• Can monitor changing water needs

• Not useful for dispersed populations

• High Operation & Maintenance inputs

• Water can be contaminated post - treatment (at source, during transport and storage)

Household water treatment

• More control by users

• More sustainable (if appropriate to situation)

• Less risk of contamination post treatment

•Good for dispersed populations

• Training needed for effective use

• More difficult to supply for large numbers of people

• Limited control on effective use

• Might be difficult to introduce quickly to communities if no prior knowledge


Water Treatment Chlorination

Most common water treatment is

chlorination because…..

1. It is easy to use and monitor

2. it is readily available

3. It has a residual effect

4. It is effective against most pathogens


Chlorination Limitation

• Chlorination works most effectively with low turbidity <5 NTU (max 20 NTU)

• Chlorination will require 30 minutes contact time under the conditions that:– pH<8– turbidity <5 NTU– temperature approx 20oC

• If pH higher, temp lower, turbidity higher then processes need to be adjusted


Chlorine Source Available Chlorine %

Remarks

High Test Hypochlorite (HTH ) Granules

70 Preferable for high chlorine content & stability.

Let the deposit settle & use only supernatant.

Strict air transport regulations.

Sodium Dichloro-isocyanurate (NaDCC)

60% powder

1g tablets

Preferable for high chlorine content & stability.

Completely soluble.

Usually more expensive than HTH.

Chlorinated Lime (Bleaching Powder)

30 Let the deposit settle & use only supernatant.

Sodium Hypochlorite Concentrate

15 Only use if manufactured very recently (<3 months) and if stored away from heat & light.

Sodium Hypochlorite (Bleach)

5 Only use if manufactured very recently (<3months) and if stored away from heat & light.

Antiseptic Solution – e.g. Milton, Javel

1 Keeps for a very short time after being opened


Handling & Storage of Chlorine

• Metal consumes chlorine - do not store chlorine solutions in metallic containers

• When in contact with air and especially humidity, HTH, chlorinated lime and NaDCC produce corrosive and toxic chlorine gas heavier than air. Stores should be ventilated at the bottom of the walls.

• Both powdered and liquid forms of chlorine reduce in strength over time. Store dry chlorine in sealed containers, away from heat & out of sunlight and keep liquid solutions in dark coloured bottles.

• Chlorine in corrosive – handle with care, avoid skin contact and when mixing chlorine solution, wear protective clothes and gloves, protect eyes and do not inhale fumes. In case of contact, rinse thoroughly with water.


Chlorination – important points

1. Training & on-going monitoring – check correct use regularly

2. Care when agencies using different makes - different instructions, package size and strengths

3. Check instructions – they can vary even for same product

4. Turbidity & type of water affects use – test samples & residuals before distribution

5. Work closely with hygiene promotion staff - ensure effective communication (e.g. why used, how used, taste) with users, training and support

Bucket Chlorination


Picture MSF


Bucket Chlorination

Water is treated with chlorine generating product at water

source at each individual water container

There are some issues you need to consider…….• Different sizes of water containers need different dose • Requires recruitment, training and close support

supervision of “chlorinators” • Could be expensive if there are many water points to

cover • Short term solution only • Effective and fast method if properly implemented


Exercise

Calculate how much HTH (70%) active

chlorine you will need to make 1 litre of 1%

solution.


Answer Exercise

PREPARATION OF A 1% SOLUTION

• 1% chlorine solution contains 10g of active chlorine per litre

• HTH is not 100% active chlorine but 70%

Calculation: calcium hypochlorite (HTH) at

70% active chlorine : 10 x (100/70) = 14.2 g

(which is about 14 g / l of solution)


16

Instructions for group work

In your groups discuss what would be your water prioritiesin this setting during the- First two weeks of a cholera / AWD outbreak response - After first two weeks up to 2 months - Beyond 2 months

Time 25 min

Make notes on your handouts. Choose who will to presentyour priorities in plenary


17

Nomadic communities


18

Rural area - spring


19

Peri Urban area


20

Urban formal setting with broken infrastructure


21

Established IDP Camp


22

New IDP camp


23

Rural setting - open wells


24

Urban informal settings


Learning Objectives

By the end of the session the participants

• specify water treatment during a cholera / AWD outbreak

• describe basic principles of chlorination, its limitations and advantages

• suggest solutions to provision of water for different settings at different stages of cholera / AWD response

Documents

Key responses – Water Water treatment and Priorities in Different Settings