The Water Treatment Process

Let's take a behind-the-scenes look at the technology and steps used to prepare raw water for use and consumption.  

The City of Marshall relies on technology, pumping and filtration systems in the water treatment process. Ongoing maintenance of this infrastructure is critical for year-round operational efficiency. The Water Treatment Plant is 76 years old and was built in 1949.

Over the next six years, the City of Marshall, will be making significant investments in its infrastructure at the Water Treatment Plant. These upgrades are vital to maintaining dependable year-around service. The treatment process is outlined below in six steps. 

Click here to go to Down the Drain: The Wastewater Treatment Process.



water treatment plant pipes
water treatment process steps

Step 1 occurs when raw water enters through screens to remove large debris like sticks, leaves and trash. It is then pumped to the City’s settlement basin, using four 500-horsepower vertical turbine pumps. The raw water then travels by gravity to the City’s Water Treatment Plant.

Step 2 is the coagulation process. Chemicals are added to neutralize the electrical charges of fine particles, encouraging these small particles to clump into larger, heavier masses.

Step 3 is the clarification process, also known as sedimentation, when water enters large clarifier tanks where it slows down. Gravity pulls the heavy sludge to the bottom, where mechanical scrapers collect it. The clearer water flows out over weirs or low barriers to the next stage.

Step 4 is filtration. The water passes through filters, a combination of sand and carbon media to remove remaining fine particles.

Step 5 is disinfection, when chlorine inactivates harmful bacteria and viruses. Several chemicals are used in the treatment of our water. For example, chlorine is used for disinfection, phosphate helps to control the corrosion of pipes and caustic soda is a water softener. Coagulant, polymer and ammonia are also used.

Step 6 is the final phase in the water treatment process. Treated water is stored in two 3-million-gallon clear wells and two 1-million-gallon elevated storage tanks. It is distributed to homes and businesses by way of the city’s high service pump station.