By Sara QuamLuverne Council members were knee-deep in sanitary sewer information as a part of their regular Tuesday meeting. They took a detour from City Hall to learn about the city’s Wastewater Treatment Plant, which was changed to an A Grade, so it has to meet stricter standards than before.The purpose of the facility is to treat sanitary sewer water (essentially toilet flushes) so that it’s safe enough to discharge the material to the Rock River.Senior operator Verlyn Van Batavia said, "Everything we do is under permit and we follow national guidelines, so we have to meet those limits every day."The process involves low-tech solutions, such as stirring the water to catch solids, as well as high-tech lab work that ensures a safe chemical balance.Van Batavia said he enjoys the work. "I am interested every day," he said, "from what we have coming in, to how we treat it, to what we have going out."There are the typical mis-flushes such as keys, small toys, coins and even a set of dentures one time. But the plant also has to filter feminine hygiene products, paper towels, condoms and other things that are regularly flushed even though they shouldn’t be.Van Batavia said, "One time we were cleaning, and there was a $20 bill stuck to a pipe. That hadn’t happened before."Operations A typical day has the plant treating about 800,000 to 1 million gallons of wastewater.That can reach to as much as 3 million gallons, but March 14, for example, brought in 719,000 gallons.The flow increases with precipitation, because older sewer pipes allow water from the ground into the system.Supervisor Al Lais said, "Some pipes on the outskirts of town can take a few hours to reach us."The city’s plant was built in 1956 with an addition in 1987, and it still has some of the original pumps. The average number of gallons treated is 312 million per year through the last 32 years.The peak monthly average for 2004 was 1.3 million gallons per day in July.Lais points out that 99 percent of what comes to the plant is water. But it’s dirty enough to have to go through a complicated filtering process.First, there is a grid chamber that takes out inorganic matter. Then, everything left over is pumped to a wet well, a trickling filter and an oxidation ditch. The oxidation helps naturally break down organic matter.A clarifier then slows down the process and solids settle. Then, the wastewater travels over layers of rocks inside a tank. The rocks are covered with bacteria, which helps naturally break down the organics.There is another clarifying step, and then chlorine is added to kill pathogenic bacteria. After a couple more steps of filtering, the chlorine has to be neutralized with another chemical before it is discharged into the river.The leftover "sludge" that can’t be discharged is heated to 95 degrees and kept in a tank so bacteria continue to break it down. A local farmer used 600,000 gallons of it for fertilizer last year.Methane gas produced through the sludge process, is burned as fuel for the boiler system that heats the building and the tanks.The wastewater plant occupies 3 acres and is working at all times. Staff members take turns being on call in case of problems, but they complete the required lab work and testing during regular hours.