Each Sunday we will feature a project going on within the city, happenings within a department or someone who works hard to provide services to the community. Today we're talking to Don Slawnikowski, Portage Wastewater Treatment Plant superintendent, about the operations at the plant.
You've finished washing the dishes or completed a load of laundry or flushed the toilet -- but do you ever wonder where the wastewater goes?
After traveling through some 175 miles of sanitary sewer pipes that traverse the city, the waste ends up at the city's Wastewater Treatment Plant on the north side of Portage.
On an average day some 3 million to 4 million gallons of waste flows to the plant, said Don Slawnikowski, the plant's superintendent. There it undergoes a series of treatments strictly adhering to the Indiana Department of Environmental Management and U.S. Environmental Protection Agency permit requirements before it either empties into Lake Michigan or is used as fertilizer on a farmer's field.
When waste enters the plant, it begins the process by going through a mechanical bar screen, which removes larger objects and proceeds through a washer to wash all the organics and then into the preliminary treatment tank where solids are suspended. The highly technical process continues through a secondary biological treatment process before going into a final settling tank for tiersery treatment. From April 1 through Oct. 31, it also goes through an ultraviolet disinfection process.
The wastewater is tested at the plant's lab several times during the process to make sure it meets all state and federal permit requirements.
The now clean water is emptied into the Burns Waterway where it mixes with Lake Michigan.
The solids captured in the process, now called sludge, are dewatered until it reaches a cake-like consistency. The sludge is stored until it is picked up by a farmer and land applied. The byproduct is used as fertilizer because of its high nitrogen levels.
While some 3 million to 4 million gallons of waste flows into the plant on an average day, Slawnikowski said, during the rainy season, the plant could see flows of 10 million to 12 million gallons per day. The excess is caused by a variety of things, including groundwater infiltration into the system and, in some of the older areas of the city, sump pumps are still tied to the sanitary system, causing storm water to flow to the plant.
The plant's capacity is rated at 5.3 million gallons per day.
Despite the occasional excess flows into the system, Slawnikowski said they haven't had any bypasses of raw sewage for at least two or three years.
While there hasn't been any recent expansions at the plant, which has been named an EPA-award winning facility, technological upgrades have increased the capacity a bit.
It takes 17 people to run the plant, which operates 24 hours a day, seven days a week.
Employees include five plant operators, three lab technicians, four maintenance personnel, an operations coordinator, a pre-treatment coordinator who closely monitors the industrial waste that flows into the plant, an administrative assistant and Slawnikowski.
"We have a good solid staff that is very experienced and that makes for a successful treatment plant," said Slawnikowski.
