The Eastside Wastewater Treatment Plant was upgraded in 2004 from a 16 million gallons per day (mgd) Activated Sludge Treatment Facility to a 26mgd 5 Stage Biological Nutrient Removal Facility. The upgrade included a complete Plant expansion in order to meet new effluent standards for total nitrogen and phosphorus removal. As the flow comes into the Plant, it will go through many treatment processes before exiting as treated effluent to the new Randleman Reservoir.
The Treatment Process
Preliminary Treatment process consists of:
3 mechanical bar screens that remove rags, trash, and other debris
2 Vortex grit chambers that remove inorganic material such as sand and gravel
3 grit pumps with cyclone separators and classifiers that transport the grit to a dumpster
Pre-aeration for "freshening" the wastewater before the next treatment process
Primary clarification includes 5 primary clarifiers which remove solids, grease and some BOD (Biochemical Oxygen Demand).
Biological Process 5 Stage Biological Nutrient Removal (BNR)
The Biological Process 5 Stage BNR consists of:
These stages contain microorganisms that perform specialized functions to remove nitrogen, phosphorus and BOD
Final clarification or settling consists of 4 final clarifiers and 6 return sludge pumps. As the flow leaves the 5 stage BNR process it contains solids and microorganisms which will settle when it reaches the final clarifiers. Some of these biological solids will then be pumped back to the front of the 5 stage BNR process to keep the organisms in the system. A small amount will be pumped to the solids treatment process for disposal. The flow leaving the final clarifiers flows by gravity to final filtration. The flow is routed through 6 filters to remove the small amount of solids that still remain.
Ultraviolet Disinfecting consists of three UV channels. Each channel
has 2 banks of 42 ultraviolet lamps. The light from these lamps
disinfects the flow as it leaves the Plant and is pumped approximately
1.5 miles downstream to the Randleman Reservoir.