LIVONIA, Mich. - Walking into the first floor of the Livonia Transmission’s Waste Water Treatment Plant (WWT), James Tucker is diligently measuring the PH level from a sample of water. The sample came from a 100,000 gallon batch tank that has cycled through the purification process, and when it tests clean, the water is sent back to the Detroit Water and Sewerage Department.
“If this sample water doesn’t pass the purity standard during the batch test, I add chemicals based on what is needed,” Tucker says. “Chemicals such as sulfuric acid and caustic balance out the PH levels, while polymer is used to help separate oil from water.”
The waste water treatment process is intricate to say the least. Built in 1970, it’s a 24/7 operation with one employee operating the facility on each of the three shifts. It takes several processes to make “dirty” water from the plant clean again to get sent back to the city sewerage systems.
The WWT Plant collects processed water from the plant in a batch tank. When the tank is full, the water is heated to 215 degrees Fahrenheit, which is the best temperature at which oil and water separate. Fumes from cooking the oil during the purification process go to the Scrubber Room, which treats and vents the fumes, making them safe to be released into the atmosphere.
The batch sits for a “quiet period” of 12 hours before the oil is “skimmed” or removed from the top of the tank. After the oil is removed, the water is treated for proper PH levels and the water/oil separation process is repeated until it tests at sufficient PH levels. Once the water has the proper PH balance, it is sent back to the Detroit Water and Sewerage Department.
The oil that is skimmed off of the top of the batch tank exists due to leaks in plant production processes. The oil is collected into an oil storage tank and eventually sold to an outside company. The proceeds from these oil sales are used to reduce about $100,000 a year in LTP’s scrap cost from Veolia, a waste management company. So far this year, 223,512 gallons of oil have been reclaimed using this process.
“The time it takes for a ‘batch’of water to cycle through the purification process varies based on the speed of the incoming flow from the plant, how much oil exists in the processed water and the weather,” said Matt Arnaudo, Powerhouse chief engineer. “If it rains outside, the batch tanks fill up much quicker, and sometimes water is sent to the equalizing tank, which is a 500,000 gallon overflow tank that holds water until it can be treated.”
Livonia’s WWT Plant plays a significant role ensuring that the environment is protected from manufacturing processes, and also reduces a substantial amount of scrap cost year over year. Just like the Powerhouse, the WWT Plant makes building transmissions possible.
View of a 100,000 gallon batch tank.
View of the top of a batch tank where oils are collecting at the top.
The three chemicals used to balance the PH of processed water from the plant.