Treatment Plant

The first sewers in the United States started in the late 1600s in Boston and served the purpose of draining water from flooded cellars, yards and streets into nearby surface waters. When there was a need to expand, provisions were made for distributing sewer costs and charging for their use.

Sanitary waste was allowed into the system in 1833 and just one year later, the city encouraged adding rainwater from roofs to the system to assist in flushing the sewers of sanitary waste. This flushing did not solve the problem; and health issues, related to water contamination such as cholera, typhoid and dysentery, began to increase among Bostonians.

Aerial View Today sewage isn't piped to flow straight to the river; there are many different types of treatment plants throughout the world.  In the City of Noblesville, our first treatment plant started up in 1949 and after many upgrades and expansions it has grown to what you see today.
The Utility has four Raw sewage pumps that pull from two 17,500 gallon wet wells. These ITT pumps have 150 HP motors and can pump around 7,000 gallons per minute. A 48" sewer pipe feeds the headworks with flow that gets screened before these Raw pumps send the 7.5 million gallons of average daily flow to grit removal tanks then on to the rest of the plant. Raw Sewage Pump
Aeration Tanks These aeration tanks treat the liquid flow after the sludge has been settled out and sent to the sludge processing facilities.  Each of the 12 aeration basins holds 65,000 cubic feet of wastewater and microorganisms that use the oxygen our blowers push into them to break down the remaining solids in the water. The basins work together in sets of three in a contact stabilization activated sludge process.
These large circular tanks are called Secondary Clarifiers.  After the microorganisms have done their job in the aeration tanks, they are allowed to settle out in the bottom of one of four clarifiers. The clear water travels over weirs at the top of the tank and on to the UV tank for final disinfection before entering the West Fork of the White River. Secondary Clarifiers
Boiler After the sludge is settled out in our primary sludge tanks it is pumped to our circular anaerobic digesters that are 60' in diameter and 30' deep. The sludge is sent across a belt press for dewatering. The process of anaerobic digestion requires the digesters to maintain a temperature around 95 degrees Fahrenheit.  Microorganisms inside the anaerobic digesters break down sludge and in doing so form Methane gas. This boiler allows us to reuse that same methane gas, burning it in the boiler to maintain the required heat in the digesters where the bugs are working.