11

Water Quality Monitoring Water Quality Monitoring

through implementation of through implementation of

Water Safety PlanWater Safety Plan

Dr A Gunasekar WHO Country Office for India

22

Current situation and challengesCurrent situation and challenges

• 88% of India’s population is using improved drinking 88% of India’s population is using improved drinking water sources. (Urban – 96%; Rural – 84%); however water sources. (Urban – 96%; Rural – 84%); however water delivered at the taps may not always be safe to water delivered at the taps may not always be safe to drinkdrinkSource: World Health Statistics, 2011Source: World Health Statistics, 2011

• Diarrhoea is the 2Diarrhoea is the 2ndnd leading cause of death among leading cause of death among children; About 4 lakh children die in India due to children; About 4 lakh children die in India due to diarrhoea every year, that is one child dies due to diarrhoea every year, that is one child dies due to diarrhoea every 80 seconds diarrhoea every 80 seconds Source: Diarrhoea: Why children are still dying and what can be done, Source: Diarrhoea: Why children are still dying and what can be done, UNICEF/ WHO, 2009UNICEF/ WHO, 2009

• 88% of diarrhoeas can be prevented by safe water, 88% of diarrhoeas can be prevented by safe water, sanitation and good hygienesanitation and good hygiene

33

WHO Guidelines for Drinking water WHO Guidelines for Drinking water quality - Water Safety Plansquality - Water Safety Plans

The most effective means of consistently

ensuring the safety of a drinking-water

supply is through the use of a comprehensive

risk assessment and risk management

approach that encompasses all steps in

water supply from catchment to

consumer.

The approach is called Water Safety Plan

(WSP)

44

What is a Water Safety Plan?What is a Water Safety Plan?

• A documented plan that:A documented plan that:– Identifies Identifies hazards, assesses risks from hazards, assesses risks from

catchmentcatchment to consumer to consumer– PrioritizesPrioritizes risks – with focus on highest risks risks – with focus on highest risks– MitigatesMitigates risks through control measuresrisks through control measures

• Moving away from reliance on output monitoringMoving away from reliance on output monitoring - - i.e. measuring parameters in final wateri.e. measuring parameters in final water

• Move into input monitoringMove into input monitoring - i.e. measuring - i.e. measuring parameters which show that the system is workingparameters which show that the system is working

Consumer system

Distribution system

Water resources &

sourcesTreatment

Hazard, Hazardous event & Risk

• Hazard is a biological, chemical, physical or radiological agent that has the potential to cause harm

• Hazardous event is an incident or situation that can lead to the risk - what can happen and how? (e.g. heavy rainfall)

• Hazard identification - Desk studies & Site visits

• Risk is the likelihood of hazards causing harm in exposed populations including– Specified time frame– Magnitude of the harm – deaths, disease, financial cost

66

Why do we need WSPs?Why do we need WSPs?

Hazard (contaminant)

Salmonella

Hazardous event (cause)

Pigeons nesting on a water tank roof

Tank roof was not sealed and pigeon faeces were washed into the tank

Salmonella bacteria got concentrated in the sediment & the surface

During a flushing event, the bacteria got rapidly drained into the distribution system and chlorine residual was not enough

Effect

~ 500 ill from a town of 1,104

7 Dead

Gideon, Missouri, 1993Gideon, Missouri, 1993

77

Why do we need WSPs?Why do we need WSPs?

Milwaukee, Wisconsin, 1993• Hazard (contaminant)Hazard (contaminant)

– CryptosporidiumCryptosporidium cysts cysts

• Hazardous event (cause)Hazardous event (cause)– Runoff from heavy spring rains Runoff from heavy spring rains – Carrying sewage into Lake Michigan Carrying sewage into Lake Michigan

(from which raw water was drawn)(from which raw water was drawn)– Coagulation problems on the filtration Coagulation problems on the filtration

system in the water treatment plantsystem in the water treatment plant

• EffectEffect– 400,000 became ill from 1.2 million400,000 became ill from 1.2 million– 100 dead100 dead

Source: Presentation of Mr Asoka Jayaratne, Water Quality SpecialistYarra Valley Water,Melbourne, Australia

88

Why do we need WSPs?Why do we need WSPs?

Hazard (contaminants)Hazard (contaminants)E. coliE. coli O157:H7 O157:H7 Campylobacter jejuniCampylobacter jejuni

Hazardous event (cause)Hazardous event (cause) Heavy rainsHeavy rains Cow manure washed into a wellCow manure washed into a well Failure to chlorinateFailure to chlorinate Water supplied by local water utilityWater supplied by local water utility

EffectEffect– 2,300 ill 2,300 ill – 7 Dead7 Dead

Walkerton, Ontario, 2000

99

Why do we need WSPs?Why do we need WSPs?

• Recontamination in the Recontamination in the distribution lines and at the distribution lines and at the household levelhousehold level

Components of WSP (1/3)

1. A system assessment to

determine whether drinking-water

supply chain as a whole can deliver

water of a quality that meets

requirements.

Components of WSP (2/3)

Identifying control measures in the system that

will control identified risks and ensure that the

health-based requirements are met.

For each identified control measure, an

appropriate means of operational monitoring

should be defined that will ensure that any

deviation from required performance is rapidly

detected.

Components of WSP (3/3)

Management and communication plans

describe actions to be taken during normal

operation or incident conditions and documenting

the system assessment, including upgrade and

improvement planning, monitoring and

communication plans.

Step-by-step risk management1. Assemble the WSP team

2. Describe the water supply system

3. Identify hazards and hazardous events and assess the risks

4. Determine and validate control measures, reassess and prioritize the risks

5. Develop, implement and maintain an improvement/upgrade plan

6. Define monitoring of the control measures

7. Verify the effectiveness of the WSP

8. Prepare management procedures

9. Develop supporting programmes

10. Plan and carry out periodic review of the WSP

11. Revise the WSP following an incident

1414

In simple terms, WSP means:In simple terms, WSP means:

Continuous Cycle

1. What are the risks?

1. What are the risks?

3. How do we know the risks

are under control?

3. How do we know the risks

are under control?

2. How do wecontrol the

risks?

2. How do wecontrol the

risks?

Describe the water supply system

• Source of water

• Changes due to weather

• Details of land use in the catchment

• Water storage

• Water treatment (processes and chemicals)

• Storage, distribution network

• Availability of trained staff

• Quality of documentation

Risk assessmentLikelihood Score

• Almost certain (once a day) - 5

• Likely (once a week) - 4

• Moderate (once a month) - 3

• Unlikely (once a year) - 2

• Rare (once every 5 years) - 1

Severity Score

• Insignificant / No impact - 1

• Minor compliance impact - 2

• Moderate aesthetic impact - 3

• Major regulatory impact - 4

• Catastrophic Public Health impact - 5

Likelihood score x Severity score = Risk score

Verify the effectiveness of the WSPTreatment works• pH - Daily• Chlorine dosing records - Weekly• Residual Chlorine - Daily• Turbidity - Daily

Distribution system• pH - Weekly• Chlorine levels - Weekly• Turbidity - Weekly• Sanitary inspection - Weekly

1818

Why do we need WSPs now?Why do we need WSPs now?

• Increasing risks of water quality – Increasing risks of water quality – microbiological as well as chemicals from microbiological as well as chemicals from industrial and agricultural activities (pesticides industrial and agricultural activities (pesticides and fertilizers) and fertilizers)

• Increased awareness among consumers on the Increased awareness among consumers on the need to have safe waterneed to have safe water

• Outbreaks (in many countries) - due to Outbreaks (in many countries) - due to (re)contamination of water, after treatment(re)contamination of water, after treatment

1919

Status of WSP implementationStatus of WSP implementation

• WSP piloted in over 40 urban and 100 rural WSP piloted in over 40 urban and 100 rural supplies in Asia - Bangladesh, Bhutan and Nepalsupplies in Asia - Bangladesh, Bhutan and Nepal

• WSP piloted in Hyderabad and Nagpur municipal WSP piloted in Hyderabad and Nagpur municipal water supplies in Indiawater supplies in India

2020

Outcomes of WSP:Outcomes of WSP:Improved water qualityImproved water quality

• Water source protection and preservationWater source protection and preservation

• Small problems are identified early and fixed, Small problems are identified early and fixed,

preventing bigger problems preventing bigger problems

• In water systems where WSP is carried on a In water systems where WSP is carried on a

continuous basis (24 x 7), water is found to be continuous basis (24 x 7), water is found to be

safer to drink with microbiological test results, safer to drink with microbiological test results,

before and after WSP, showing dramatic before and after WSP, showing dramatic

improvementimprovement

2121

Outcomes of WSP: Outcomes of WSP: improved managementimproved management

• Standard operating procedures improvedStandard operating procedures improved

• Clear roles and responsibilitiesClear roles and responsibilities

• Regular monitoring of water quality in treatment Regular monitoring of water quality in treatment plantsplants

• Promotes conversion to 24x7 supplyPromotes conversion to 24x7 supply

• Reduction in non-revenue waterReduction in non-revenue water

2222

ConclusionConclusion

• Water safety plan ensures water safety Water safety plan ensures water safety (improves health) and sustainability of (improves health) and sustainability of drinking water suppliesdrinking water supplies

2323

Thank youThank you