Liquids Process Treatment Steps

Below are descriptions of the liquid treatment process listed in sequence, and following the flow of the schematic. The liquid and solid treatments processes are inter-related. Solids are derived from and separated from the liquids treatment process.

Influent Parshall Flume

As the influent wastewater flow enters the WWTF through our Headworks Building, it passes through an Influent Parshall Flume (IPF). The IPF is a fixed open channel, hydraulic structure that is placed in a flow stream to determine the flow of water. The flume accelerates flow by both a…

Mechanical Bar Screen with Washer Compactor

The first piece of equipment the wastewater meets is the Bar Screen. This is where solids that are larger than 3/8" are removed from the wastewater. Sticks, plastic gloves, rags, cans, and bottles are items commonly removed. The removal of this debris helps to prevent issues further down the…

Influent Dry-Pit Raw Sewage Submersible Pumps

After the wastewater is screened, it makes its way through the Influent Dry-Pit Raw Sewage Submersible Pumps. These 5 pumps are located in our Headworks Building and they pump the wastewater up to a higher elevation to the next treatment step.

Pre-Aeration and Grit Settling Chamber

The Grit Settling Chamber is where non-desirable inorganic material, such as sand, gravel, and eggshells, settle out to the bottom of the chamber. It is then pumped into a grit classifier, washed, and later hauled to the landfill for disposal.

The Pre-Aeration is done in the same basin…

Primary Clarifiers

The wastewater flow is split at the end of the aeration process to provide equal flow into 2 Primary Clarifiers. These are circular tanks in which wastewater is held for a period of time to allow heavier solids, such as soil, coffee grounds, or other waste matter, to settle to the bottom as…

Trickling Filter

Trickling Filters are a non-submerged fixed film biological reactor that uses a random packed plastic media. The plastic media provides a location for the formation of the biomass which contain organisms that feed upon and remove wastes from the water being treated. Wastewater is applied at…

Rotating Biological Contactor

Rotating Biological Contactors (RBCs), is a biological treatment process that operates in a similar manner as the trickling filter. An RBC consists of a series of closely spaced circular disks of polystyrene or polyvinyl chloride that are attached to a horizontal shaft and are provided at a…

Final Clarifiers

The Final Clarifiers serve the same basic function as the primary clarifiers, in that light solids are allowed to float and heavy solids are allowed to settle. The dead and decaying or excess biomass that drops off of the media of the trickling filter and RBCs settles out in these 2 tanks and…

UV Disinfection

The UV Disinfection system is required during the summer season and sterilizes the micro-organisms with ultra violet light, before the effluent is discharged into the Big Blue River. The UV system is put into place May 1st through September 30th.