SER Water Treatment Plant Major Upgrades

Seminole County, FL

The Seminole County Environmental Services Department (SCESD) owns and operates the Southeast Regional Water Treatment Plant (SER WTP), which is the primary source of potable water serving its service area.

The ground water source for the plant had elevated concentrations of hydrogen sulfide and organics. The existing treatment at SER WTP did not target these parameters, resulting in disinfection byproduct levels that would be above the new Stage 2 Disinfectant/Disinfection Byproduct Rule (D/DBP) regulations.

In order to meet the Stage 2 D/DBP Rule as well as County goals for sulfide removal and disinfection byproducts (DBP) formation, major upgrades to the SER WTP were required. Following pilot studies performed by Reiss Engineering, Inc. (Reiss), the County selected the addition of ozonation treatment to oxidize the sulfide followed by granular activated carbon (GAC) treatment to reduce organics.

The SER WTP was the first WTP in Florida to use ozonation and GAC treatment to meet Stage 2 D/DBP requirements. Reiss designed the major upgrades, including the core components of ozone and GAC treatment, conversion from chlorine gas to sodium hypochlorite for disinfection, control system upgrades, and new electrical service with increased reliability. Final design and permitting services included obtaining multiple permits through FDEP, including an extension on the timing for Stage 2 compliance, Seminole County Planning and Zoning Development Review Committee and Building Department.

In addition to design, Reiss performed construction phase services and coordinated with SCESD and the contractor. Since this facility is the primary WTP for the service area, the construction was equenced such that the plant could remain in operation. Reiss served as the Engineer of Record for the construction phase including hands-on startup and certification services for the County.

Data Points

  • Size: 19.4 MGD
  • Scope: Design, permitting, and construction services
  • Duration: 41 months

Project Components

  • 19.4 MGD water treatment plant
  • Ozone treatment
  • GAC treatment
  • Stage 2 D/DBP compliance
  • Planning
  • Design
  • CMAR delivery method

Key Benefits

  • Made major improvements to the facility, resulting in a much more efficient system
  • Plant remained fully operational
  • Obtained Florida’s first Stage 2 D/DBP permit extension

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