Ever wonder how Vermillion can deliver this life's necessity to thousands of people 24 hours a day, seven days a week?
It's not an easy process. At first glance, it appears to be something that Rube Goldberg dreamed up.
Despite being a bit complicated, though, the process has been proven to be effective.
Vermillion receives its water from five wells ocated along the north side of the Vermillion River in an area west of
Dakota Street. The wells are capable of producing 2,600 gallons per minute.
That means one well can be out of service for maintenance, and< the remaining four wells are capable of supplying the full design capacity of the treatment plant.
Water from the wells flows through a 16-inch pipeline to the plant.
The initial step in the treatment process is aeration to remove hydrogen sulfide and to aid in the removal of iron present in the water. Water then enters the solids contact basin for mixing with chemicals to react with minerals to be removed.
This is accomplished by adding lime, alum and soda ash at a controlled rate into the incoming raw water to react with the iron, manganese and hardness contents and form floc particles which settle to the bottom of the basin.
These are removed periodically in the form of sludge. The sludge is discharged by gravity to a sludge drying bed.
Clarified water is removed from the surface of the basin through what engineers call "launder troughs." This water then flows to the recarbonation basin.
In the recarbonation basin, carbon dioxide is added in solution to stabilize the water coming from the upflow basin. Water leaving the recarbonation basin flows through a 42-inch diameter pipe on its way to three gravity filters.
The gravity filters form the heart of the treatment plant and provide the final clarification of the water before delivery to the distribution system. Each filter has a capacity of 1 million gallons per day.
After passing through the filter bed, water flows to a clearwell storage located in the lower level of the plant. Chlorine is fed into the clearwell for final disinfection of the filtered water. Fluoride is also fed into the clearwell. Provisions are made for periodic backwashing of the filters. Water utilized for backwashing is reclaimed and recycled through the entire treatment process. From the clearwell, low head pumps transfer the water through a 16-inch treated water main to the 1.5 million gallon ground water storage reservoir located near the city library.
Treated water is supplied to the city's distribution system from the ground storage reservoir by three high service pumps.
These pumps are automatically started and stopped from the controls located in the treatment plant to fulfill the water demand from the distribution system.