The quality of drinking water is a vital element of public health and well-being. 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.
WHO guidelines on water quality term these approaches as water safety plans (WSPs), developed to organize, systematize and apply management practices in drinking-water quality.
The Hyderabad Metropolitan Water Supply and Sewerage Board (HMWSSB) is in the process of developing pilot Water Safety Plans (WSPs) for three sites. The development and verification of successful implementation of these plans, require health based targets, developed by taking into account the disease burden in the community, exposures that contribute most to disease and the socio-economic determinants of exposure to risks. Principal risks to human health associated with consumption of unsafe water in these areas are microbiological in nature, and there is no reliable data on them.
Therefore a cross-sectional household survey amongst a representative sample of population in three project areas was conducted in support of the WSP. The overall objective was to establish baseline information on water quality-linked health outcome indicators to guide and evaluate the implementation of the WSPs.
The risk factors assessed in the survey were:
- contamination of source water and stored water with with E.Coli and Coliforms,
- not having a metro domestic connection,
- not having a pit tap as main drinking water source,
- using utensils for retrieving water from container,
- treating water,
- sanitation status and
- respondents' perception about safe drinking water.
The survey covered 60 out of 176 enumeration blocks and 25 households under each block in the 3 sites. Slums constituted a significant part of the survey.
Findings indicate acute gastroenteritis as an important public health problem. Sewerage overflows, excreta in the vicinity and garbage accumulation in household premises pose a significant risk for gastroenteritis.
The magnitude of acute gastroenteritis is much higher than suggested by the surveillance system because of the health seeking behaviour of the people and the coverage of the surveillance system. Currently, the surveillance system covers only large public hospitals in the city. Also some people may not seek medical treatment if symptoms are not very serious or prefer private providers.
Finally, the findings indicate the need for making residents aware of basic hygiene practices and a double risk of gastroenteritis in slum areas.
Download Assessing Acute Gastroenteritis Risks Associated With Water Quality and Sanitation in Hyderabad City, a paper by The Institute of Health Systems (IHS).