Monitoramento da qualidade das águas de poços comercializadas no município de Areia-PB

Abstract

Water is an natural resource essential for life maintenance and socioeconomic development. Although the planet holds 1.4 billion km³ of water, only 2.5% is considered freshwater. Brazil contains 12% of the surface freshwater, concentrated mainly in the northern region. However, the northeastern region faces significant challenges, with 23.2% of the population lacking access to treated water and relying on alternative sources that are not always safe. This scarcity on water access has led to increased use of groundwater, mainly from wells, which raises concerns about water quality and the importance of legislation to ensure potability and public health protection. This study aimed to monitor the physicochemical and microbiological quality of water from wells sold in the municipality of Areia-PB. Samples were collected from two wells: Well 1, a dug well located in the neighborhood named Mutirão, and Well 2, a tubular well located in the Macacos settlement. The samples were collected biweekly between July and October 2024, and analyses were conducted at the Analytical Chemistry Laboratory of the Centro de Ciências Agrárias and the Organic Matter Laboratory of the Department of Soils and Rural Engineering at the Universidade Federal da Paraíba. The pH, conductivity, turbidity, dissolved oxygen, carbon dioxide, total alkalinity, calcium hardness, total hardness, chloride, sodium, potassium, total phosphorus, sulfate, and salinity were evaluated following methodologies from the Standard Methods for the Examination of Water and Wastewater. Ammonia was analyzed according to the Standard Test Methods for Ammonia Nitrogen in Water (ASTM D 1426), and magnesium hardness was determined by calculation. The Colitest® chromogenic and fluorogenic substrate was used to detect total coliforms and Escherichia coli. The results indicated that water samples from both wells met the potability standards established by the Ministry of Health and Conama Resolutions. Although the pH and phosphorus levels were outside the recommended values, these results are not hazardous to human health. However, the elevated phosphorus level may indicate possible contamination, suggesting the need for continuous monitoring and investigation of contamination sources near the wells. For the salinity, the samples were classified as freshwater, and the bacteriological analyses were negative for total coliforms and Escherichia coli, indicating that the water is suitable for consumption and commercialization. In addition to quality analyses, the water use permit must be acquired to ensure proper and sustainable management of these resources.