Wastewater Treatment Plant Modeling

wastewater treatment plan view of equipment

The Town of Ticonderoga, NY was interested in understanding their wastewater treatment plant’s (WWTP) overall capacity of current unit operations, total phosphorus (TP) removal optimization options, and septage receiving capacity, especially under certain wet weather operating conditions. The Ticonderoga WWTP is a combined sewer overflow facility, which experienced difficulty meeting its 1 mg/L TP effluent limitation during wet weather events. TP removal was accomplished at the time using physical-chemical treatment.

wastewater treatment plan view of equipment


Fuss & O’Neill electronically modeled the WWTP and calibrated the model based on current operating data. Simulations under several conditions were run to determine optimization for phosphorous removal and the facility’s capacity to receive and treat septage.

The modeling was performed using Hydromantis’ GPS-X software. GPS-X is a wastewater modeling simulation software that allows mathematical modeling, control, optimization, and management of wastewater treatment plants.

Automated model calibration was utilized to determine model parameter values that provide the best fit between measured and simulated data. Septage influent was modeled as a trucked influent with daily and hourly septage volume controllers.

Dynamic analyses were performed on the model, and the effect on plant performance (including effluent concentrations and loading, as well as phosphorous removal efficiency) was detailed in the final report. Dynamic analysis included the following items:

  • influent or sidestream (supernatant, etc.) flow rate and loading
  • storm flow management (bypass, storage)
  • wasting, recycle, air flow, and chemical dose rate
wastewater treatment plan view of equipment

Workshop with the Town

At the conclusion of the first round of modeling, a web-based workshop with external stakeholders was held. The modeling and simulation results were presented and discussed. During the discussions, consensus was reached regarding the changes needed for the model, additional simulations, and edits to the existing simulations.

wastewater treatment plan view of equipment
wastewater treatment plan view of equipment
wastewater treatment plan view of equipment

Final Deliverable and Outcome

Based on the conclusions reached in the workshop, the modeling and simulations were adjusted and re-run. The information from the workshop and final simulation efforts was incorporated into a technical memorandum to provide a basis for current operational changes and for future plant upgrades.

The client incorporated the recommendations from the memorandum in their day-to-day operations. With these operation changes, new data is now being compiled for the design of the future process upgrades for the plant that will be made possible via U.S. EPA Clean Water State Revolving Fund support.

Related Projects