Validation of the Feasibility of the New Bromodichloromethane Regulations in the City of Largo Wastewater Reclamation Facility

The City of Largo Wastewater Reclamation Facility (WRF) in Largo, FL is currently funding research to determine the optimum process improvements required to meet the United States Environmental Protection Agency (US EPA) and the Florida Department of Environmental Protection (FDEP) proposed standards for bromodichloromethane (BDCM) of 17 ppb and 7.4 ppb (annual average), respectively. In this regard, an evaluation of the plant was initiated via a dry season sampling event for water quality parameters such as total organic carbon (TOC), pH, and bromide at six sampling points to determine their individual and/or combined effect on BDCM formation. The results showed that BDCM formation was mostly triggered by bromide, residual chlorine, UVA, color and TOC. Therefore, control of bromide, TOC/color removal via coagulation and/or chlorine dose, and contact time optimization appeared as possible alternatives to reduce the BDCM formation in the plant. These alternatives will be narrowed with two additional sampling events.