Indicadores sentinelas para a formulação de um plano de amostragem de vigilância da qualidade da água de abastecimento de Campina Grande (PB).

Abstract

The water characteristics in the public water supply system, considering the qualitative aspect, may be altered along the distribution system, which may be harmful to the population consuming that water. Aiming at knowing and evaluating the risks related to the quality of the water distributed to the population from Campina Grande, this work analyses the monitoring data from sentinel indicators in points distributed in the Pressure zone D in the city’s water supply system so that it may contribute to the formulation of a sampling plan to the vigilance of the water quality to have a preventive control avoiding the dissemination of illnesses through the water system in accordance to the order number 518, dated March 24, 2004, published by the Ministry of Health and the National guidelines for sampling plan of vigilance in environmental health related to the quality of water for human consumption. The results obtained during the six months of study show the vulnerability of the distribution system of water in the city and the risk of contamination due to the low free residual chlorine concentration and predominance of different kinds of combined residual chlorine in the monitoring points. Of the 236 samples collected for analysis, 28% was not in accordance with the legislation. Turbidity was found in 9.2% from a total of 239 samples. The results show that some corrective measures have to be taken considering that these indicatotrs are important to minimize the harms to public health. According to distribution of the points and the results we had, we conclude that unfavorable conditions related to the urban infra structure and factors related to the maintenance and operation of the system contribute to the results not to be in accordance to the rules and potability patterns, indicating vulnerable sectors in the distribution system that may contribute to the definition of sampling points in surveillance programs to the quality of water for human consumption. Monitoring systematically of water in public system as well as the alternative solutions found are very important as a measure of public health and essential to the development of surveillance actions on the quality of water for human consumption. The lack of commitment from the authorities in relation to the control and vigilance of the quality of the water for human consumption is present in most of the cities in Brazil and the same is present in Campina Grande. We may notice that the order number 518 is far from being implemented by the authorities in charge of the distribution system and few items of the legislation are considered.