Wastewater Management in Swimming Pools: A Circular Economy Approach

Water is a vital resource for sustaining life; however, it is increasingly at risk due to escalating demand and heightened pollution levels. Swimming pool facilities generate diverse wastewater streams whose management offers opportunities for water recovery within a circular economy framework. The quantitative and qualitative analysis of research identifies five primary categories of wastewater: swimming pool basin outflow, filter washings, rainwater and meltwater, sanitary wastewater, and technological sludge, at a public swimming pool complex in Poland. Annual volumes were determined through direct measurements and calculations: pool basin outflow—2829.7 m3/year; filter washings—7179.2 m3/year; rainwater and meltwater—1172.6 m3/year; sanitary wastewater—5849.3 m3/year; and technological sludge—90.1 m3/year. Laboratory testing included physicochemical parameters (pH, redox potential, conductivity, COD, BOD, nutrients, heavy metals) and microbiological parameters (Escherichia coli, Pseudomonas aeruginosa, Legionella spp., Salmonella spp., Ascaris sp., Trichuris sp., Toxocara sp., Coagulase-positive Staphylococcus). The results showed that the filter washings, despite exceeding the limits for total suspended solids and combined chlorine, exhibited stable quality and significant volume, making them the most promising candidate for reuse after treatment. Rainwater quality was compromised by elevated heavy metal concentrations (Zn: 244.67 mg/L, Pb: 92.33 mg/L), while technological sludge exceeded the legal pollutant thresholds, classifying it as hazardous waste. The experimental conditions included year-round monitoring of operational flows, standardised backwash cycles every three days, and sampling under routine operational load. The findings support the development of targeted treatment systems that allow the recirculation of up to 7000 m3/year of water, thus reducing the demand for potable water and operational costs in swimming pool facilities.