Wastewater Treatment Plant
Frequently Asked Questions

Is the Wastewater Treatment Plant (WWTP) what smells in Moscow?

No. Offensive odors are indications that something in the treatment process is not working correctly. To ensure the treatment process is working correctly, Plant Operators make daily assessments of the system checking for potential odor causing problems.

Where does the water go?

In accordance with our EPA regulated National Pollutant Discharge Elimination System (NPDES) permit, the City of Moscow discharges the treated wastewater into Paradise Creek on the west side of Moscow.

What happens to the solid material?

The solids that are removed during the plant process are pumped to an onsite dewatering process. After dewatering the solids, then known as Biosolids, are trucked to an authorized processing facility for composting.

Where are you located?

Directly across from the Palouse Mall in Moscow ID, our buildings have distinctive, and very noticeable, blue roofs.

How long does it take to treat the wastewater?

Generally, the wastewater treatment process takes approximately 24 – 36 hours.

Do you use a lot of chemicals to treat the wastewater?

We use three different chemicals in our plant process. Chlorine is added to neutralize pathogenic, or disease causing organisms. After chlorination, sulfur dioxide is added to remove the chlorine before it is discharged into Paradise Creek. During the summer months we add a small amount of aluminum sulfate to coagulate, or capture, phosphorus that was not removed biologically in the treatment process. Phosphorus is an essential nutrient in plant growth yet excessive amounts can lead to eutrophication, an overabundance of plants and algae in a water body causing the depletion of oxygen needed for fish and other animals to survive.

How many people work at the wastewater treatment plant?

Currently, we have 4 Plant Operators, 1 laboratory Analyst, 1 Administrative Assistant, 1 Transport Driver, and the Plant Supervisor.

How many gallons of wastewater do you treat?

On average, we treat approximately 2 million gallons of domestic wastewater per day. Our plant is designed to accept and fully treat 4 million gallons per day if needed.

How does rain affect the wastewater treatment plant?

Rain water tends to thin out the domestic wastewater allowing certain unwanted bacteria to thrive. Plant Operators make adjustments in the plant process to curtail the unwanted filamentous bacteria. The City works to identify where rainwater is entering the sanitary sewer system so that the flows can be permanently redirected to the storm water collection system.

What type of education do you need to work here?

While most Plant Staff have college degrees, working in wastewater treatment can commence directly after High School.

How many "bugs" does the Aeration Basin have?

Millions and millions of microorganisms or "bugs" live in the wastewater treatment plant. They are essential for proper treatment and are directly responsible for pollution removal.

What do the "bugs" eat?

The microorganisms consume organic material such as fecal matter, ammonia, and other microorganisms. They cannot consume or break down inorganic material like metal, plastic, latex, or cinders.

Where do the "bugs" come from?

The "bugs" are natural living organisms in human and animal excrement.

How do the microorganisms reproduce?

The microorganisms reproduce themselves approximately every 20 – 30 minute by a process called mitosis.

What "bugs" do you look for?

We look for several different types of microorganisms in wastewater. Our Lab Analyst collects daily wastewater samples, and uses a microscope to identify the most prolific number and type of organisms present at that time. This information is used to calculate how much solids material is removed from the system or how much material can be used in the process again.

Is it acceptable to put grease, egg shells, and coffee grounds in my garbage disposal?

The City of Moscow Wastewater Division recommends that these items be disposed of in the garbage rather than being introduced to the sanitary sewer system. All of these materials, and in particular, a combination of the three can create opportunities for plugging private sewer services and public sewer mains. Grease is especially challenging as it solidifies within the mains or floats through the system and through the WWTP.

Contact Us

  • Engineering Division
    Kevin Lilly - Deputy Director - Engineering
    City Engineer
    klilly@ci.moscow.id.us
    208.883.7034
    Paul Mann Building
    221 E. Second Street
    Moscow, Idaho 83843
  • Streets & Fleet
    Water & Wastewater Divisions

    Tyler Palmer - Deputy Director - Operations
    tpalmer@ci.moscow.id.us
    208.883.7097
    650 W. Van Buren
    Moscow, Idaho 83843
  • Wastewater Treatment Plant
    Todd J. Swanstrom - Wastewater Supervisor
    tswanstrom@ci.moscow.id.us
    208.883.7091
    2221 Pullman Road
    Moscow, Idaho 83843
  • Special Projects
    Tom Scallorn - Special Projects Manager 
    tscallorn@ci.moscow.id.us
    208.882.3122
    201 N. Main Street
    Moscow, Idaho 83843