Qualidade da água subterrânea que abastece Juazeiro do Norte – CE: relação com cobertura de esgoto e densidade populacional.

Abstract

Groundwater has been contaminated by agricultural, urban and industrial effluents, which have contributed to the elevation of nitrate levels (NO3-) to non-tolerable values, becoming the most frequent pollutant currently occurring in these water sources. The potential risk of a particular aquifer being contaminated is related to the type of use and its characteristics, such as lithology, hydrogeology, hydraulic gradients, among others. The greater or lesser susceptibility of an aquifer to contamination and pollution is called vulnerability. Groundwater pollution and contamination can be direct or indirect. Directly, it is released on the soil or water, when pollutants are released directly into the aquifer, through absorbent wells, without going through the soil layers (sewage, cemetery, agricultural activities, etc). Indirectly, it is when the pollutants are not released directly into the aquifer, but somehow, or at a certain time, reach the source. Both can be related to human activities and/or natural processes. Thus, the aim of this work was to evaluate the nitrate values of the 48 wells that supply the urban area of the municipality of Juazeiro do Norte, Ceará, in the period from 2013 to 2019, relating them to the coverage of the sewage system and population density. To determine the nitrate levels, results of tests performed in the laboratories of the Companhia de Água e Esgoto do Ceará - CAGECE are used. The analytical results are compared with the potability standards of Consolidation Ordinance No. 05/2017, annex XX, of the Ministry of Health, with the nitrate limit value being 10.0 mgNO3-/L. Information related to the sanitary sewage collection system in Juazeiro do Norte was provided by CAGECE and information related to population density by the Brazilian Institute of Geography and Statistics (IBGE). Final results indicate some cause and effect relationship between high levels of nitrate and the gaps in the coverage of the sewage collection system and the location of population settlements. Considering that water from wells is the only source of supply for the city, this work demonstrates the need to expand its sewage system, as well as other environmental sanitation measures, such as the proper disposal of solid waste and protection of exploitation points. In the ODS 2030 agenda, this dissertation is aligned and associated with items 6 and 12. Item 6 - Drinking water and sanitation and item 12 - Responsible consumption and production.