Effluent treatment plants for activities with high pollutant-degradation potential: an analysis of compliance with legal requirements

Abstract

Sewage treatment plants (STPs), despite being fundamental for controlling environmental pollution, are also potential causes of environmental impact, therefore requiring an efficient self-monitoring plan to verify compliance with legal conditions. In this context, this research investigated the situation of Sewage Treatment Stations of enterprises that develop activities with high polluting degrading potential, located in Juazeiro do Norte – CE, in relation to compliance with legal guidelines. To guide this analysis, conditions were considered in resolutions from the Ceará State Environmental Council and municipal laws and decrees that deal with the matter under consideration. At the Municipal Environmental Authority of Juazeiro do Norte (AMAJU), data were collected from licensed enterprises that carried out high PPD activities, from the treatment technologies for effluents generated in each activity, from the STPs self-monitoring programs, and the types and locations of bodies receivers and the operating condition and physical flow of the AMAJU monitoring sector. The processing of data relating to the delivery of self-monitoring reports was carried out using percentages of 50 and 75%. From the analysis of the results, 48 ​​enterprises were identified that carried out high PPD activities, of which 4 were located in areas that had restrictions on this type of use. It was also verified that there was an important battery of public water supply wells surrounded by such projects. It was found that there are 70 high PPD projects that are under the jurisdiction of AMAJU and that the quality of liquid effluents from their STPs is, under specific conditions, in compliance with the release standards established by COEMA Resolution Nº 02/2017. However, it was found that the majority of the enterprises surveyed were non-compliant regarding the quantity and frequency of sending self-monitoring reports to AMAJU. These weaknesses were attributed to the reduced technical staff of the environmental agency and the absence of its minimum infrastructure for the development of the actions necessary for the implementation of an efficient environmental monitoring system. To contribute to the improvement of this system, it was suggested to strengthen AMAJU's technical, financial and institutional support, in addition to establishing a distinction in relation to the requirements regarding the frequency of analyzes and the periodicity of delivery of liquid effluent self-monitoring reports, for enterprises. with different types and classes.