Distributed wastewater treatment offers an environmentally preferable alternative to conventional septic systems in Central Florida

Abstract

Wastewater management is a critical issue globally. In Florida, the importance of this issue is heightened by the proximity to sensitive ecosystems. Distributed wastewater treatment units (DWTU) are a recent, state-approved alternative to septic system conversions to centralized sewer infrastructure. In this study, the performance of a DWTU was tested at a new residence in Lake Hamilton, FL. A monitoring well was installed downgradient of the DWTU absorption field to establish baseline groundwater conditions prior to occupation of the residence. The residence was occupied, after which groundwater, DWTU influent, and effluent samples were collected. Many effluent parameters significantly decreased compared to influent, including ammonia (NH3; 97%), total Kjeldahl nitrogen (TKN; 95%), total nitrogen (TN; 88%), the TN:TP ratio (84%), fecal coliforms (92%), carbonaceous biochemical oxygen demand (CBOD; 96%), and total suspended solids (TSS; 96%). In the groundwater, nutrient concentrations initially increased compared to the baseline data, but eventually decreased, demonstrating that the DWTU was effective at improving quality of wastewater effluent. These systems could be especially effective in sensitive areas where advanced wastewater treatment has been mandated or is needed. HIGHLIGHTS A distributed wastewater treatment unit was installed and studied at a residence in Florida.; The distributed wastewater treatment unit significantly improved water quality of the residential wastewater effluent.; 97% of ammonia, 88% of TN, and 92% of fecal coliforms were removed from effluent.; Downgradient groundwater quality was better protected from wastewater contamination.;

Keywords

• fecal coliforms
• groundwater
• nutrients
• nitrogen
• wastewater
• water quality