Kevin Johnson, 303-674-5694
The Evergreen Metro District wastewater department handles and treats the sewage in the Evergreen Metro, West Jefferson, and Kittredge Districts. The Wastewater Division is comprised of Treatment Plant Operations and Maintenance Operations. The Division operates and maintains three wastewater treatment plants, eleven pump stations, and approximately 300 miles of sewer lines. Operations of the treatment plants consist of sampling and testing, monitoring, evaluating and adjusting processes and equipment to meet discharge limits mandated by State and Federal regulations. Treatment Plant and Pump Station operations are monitored by computer and telemetry technologies.
How is wastewater treated?
Wastewater treatment involves several complex processes to transform incoming wastewater into clean effluent discharged into Bear Creek. The processes include physical, mechanical, biological, and chemical methods in a specific sequence to separate solids from liquid, breakdown organic material, and disinfect the remaining water prior to discharge. Waste materials (sludge) are aerobically treated to produce a material that is periodically disposed of by land application. The processes are constantly operating as wastewater continually flows into, through, and out of the treatment plant.
Evergreen Metro District Wastewater Plant
The processes below summarize those used at the EMD wastewater facility:
- Preliminary Treatment involves the removal of sand or grit and paper materials. Sandy material is removed by settling and paper materials are removed by cleanable racks that trap paper as it floats by. Flow is also measured in this process.
- Primary Treatment utilizes a settling tank (clarifier) to remove heavy organic material and a skimmer to remove floating grease.
- Secondary Treatment is comprised of two processes. In the first step, the organic material (known as Activated Sludge) is mixed in the Aeration Tank using fine-bubble diffusers, to provide oxygen for microorganisms that break down the material. In the second step, a Final Clarifier is used to allow solids to separate from the liquid slurry.
- Sand Filters (Tertiary Treatment) are used to remove fine particles that do not settle out in the final clarification process.
- Ultraviolet (UV) radiation is utilized as a disinfectant method to kill essentially all pathogenic bacteria. UV radiation kills disease-causing bacteria by destroying genetic material and preventing cell replication.
- Aerobic Sludge Digestion is a process used to break down waste organic material generated from the treatment processes into an inert slurry which can be safely disposed by a licensed contractor. Sludge, per state regulations, is land applied as a beneficial use.
West Jefferson Metro District Wastewater Plant
The West Jefferson Metropolitan District Wastewater Treatment Facility utilizes the following treatment processes:
The West Jefferson County Metropolitan District wastewater facility utilizes identical technologies as the Evergreen facility, with the exception of the Primary process. The disinfection process is accomplished with ultraviolet light. Filtered effluent passes through a chamber that houses a bank of ultraviolet lights. The energy from the lights kills the pathogenic bacteria. The main advantage to this process is safety. Hazards inherent with ultraviolet radiation do exist, but personnel do not handle more dangerous chlorinating or de-chlorinating chemicals and the possibility of those toxic chemicals being discharged into the receiving water is removed.
Kittredge Wastewater Plant
The Kittredge Wastewater Treatment Facility utilizes the following treatment processes:
The Kittredge wastewater facility utilizes identical technologies as the Evergreen facility with the exception of Primary Treatment. Sludge generated by the treatment processes is aerobically treated, removed by, and ultimately disposed of by a licensed contractor. The Kittredge facility also utilizes a polishing pond as a final filtering process prior to discharge into Bear Creek.