Impacts of Irregular Dumping of Untreated Domestic Sewage into the Billings Reservoir, São Paulo-SP

Case of the Espanha Residential Condominium

Abstract

Objective – To evaluate water quality at a collection point near the DAVIDE-SABESP Sewage Pumping Station, in Jardim Apurá, adjacent to the Espanha Residential Complex, identifying environmental impacts caused by illegal sewage discharge into the Billings Reservoir.

Methodology – The study followed the Standard Methods for the Examination of Water and Wastewater and the National Guide for Sample Collection and Preservation. Samples were collected in sterile Falcon tubes, with laboratory analyses of physicochemical, microbiological, and parasitological parameters, as well as field measurements using a multiparameter probe.
Originality/Relevance – This research addresses an underexplored socio-environmental conflict in resettlement housing areas, highlighting risks arising from lack of oversight and urbanization in Environmental Protection and Recovery Areas (APRMs), directly impacting public health and aquatic ecosystems.

Results – Analyses revealed alarming contamination levels: physicochemical parameters such as ammonia, phosphorus, and sulfide far exceeded limits established by CONAMA Resolution 357/2005; moreover, microbiological contamination showed thermotolerant coliform counts 51,000 times higher than allowed, with pathogenic bacteria such as Escherichia coli, Salmonella spp., Providencia spp., and Pseudomonas identified.

Theoretical/Methodological Contributions – The study reinforces the importance of integrating physicochemical and microbiological indicators for water quality assessment in urbanized water sources, proposing continuous monitoring protocols.
Social and Environmental Contributions – The findings highlight the urgent need for more effective public policies to protect water sources and mitigate impacts of irregular urbanization, preventing risks to human health and aquatic biodiversity.