Village Creek Water Reclamation Facility is dedicated to using its resources efficiently, and that includes recycling energy. Methane gas produced during anaerobic digestion is captured and used to generate electricity on site and to power blowers that provide air for the aeration basins.
About 90 percent of the energy required for aeration is produced by the generated power. Overall, 40 percent of the total plant's energy requirements are produced through the use of methane gas. Waste heat from the system is used to heat digesters that produce methane. Future construction will increase the energy produced from methane to more than 75 percent of the plant's total electrical needs.
Energy Recovery and Controls
Listed below are the specific areas where energy is recovered during the wastewater treatment process.
- Scum Incineration
All floating materials from the various treatment processes are moved to the scum holding tanks, then burned in a gas fired water grate incinerator.
- Blower/Engine Area
One 1,620-horsepower engine and one 1,760-horsepower engine run generators that produce electricity for use throughout the plant. Two 1,200-horsepower engines drive centrifugal blowers that provide compressed air to the aeration basins. The engines can be run on digester gas, natural gas or diesel fuel.
- Process Control
The plant processes are controlled through the plant process computer system, manually through control stations in the control room or manually in the field. Flows are split between the different process units, and a few pieces of equipment are started or stopped remotely as needed based on conditions occurring in the treatment processes and the results of lab data. Multiple computers are networked to provide for distributed controls ( DCS ) and operator interface. Process controls are available to many offices via the office network, which connects all portions of the Water Department.
The central control system acts as a focal point of plant operations. CRT displays provide windows into the plant process, offering operators opportunities to compensate for changes in plant processing and select control strategies while computers are left with the mundane tasks of making continual adjustments for control. In the process, computers also provides for equipment monitoring, alarming, data logging, database and statistical reporting.