Water Quality Assessment in an Area Degraded by Urban Solid Waste in Southern Brazil

Abstract

In most Brazilian municipalities, urban solid waste (USW) is disposed of in open dumps, with numerous sites now being closed, monitored, and rehabilitated. One location, the “old dump” area in the Portão municipality (southern Brazil), previously served as an irregular repository for USW and industrial solid waste (ISW). Its use continued until 1993 when it was closed for a natural remediation process. For this reason, this study aimed to assess groundwater quality in the Portão “old dump,” employing physicochemical, microbiological, and toxicity quality indicators. The study's scope was extended to encompass the Portão Stream as well. Notably, the second collection campaign revealed elevated dissolved aluminum (Al3+), iron (Fe2+), and nitrate levels in all groundwater samples (from PZi wells, i = 1–6), with the PZ3 monitoring well experiencing the most pronounced impact. Further quality indicators, such as total phosphorus, thermotolerant coliforms, BOD5, as well as Al3+ and copper (Cu2+) levels in the second water collection campaign from Portão Stream, were classified as Class 4, suggesting that the water is suitable only for navigation and aesthetic purposes. Conductivity analysis identified Portão Stream as another impacted area. Moreover, during the second collection campaign, the study uncovered an escalation in micronuclei (MN) frequency and chromosomal alterations in PZ5. Downstream water samples from Portão Stream exhibited similarly heightened MN levels. This study's investigation into water quality is a concrete example of the implications of improper USW management. These findings underscore the pressing need for effective waste management strategies to mitigate environmental degradation and protect public health.