High-Tech Sewage Management In Madison Heights
Thing is, after a rain as big as Sunday's, it'll be full of poop.
The George W. Kuhn Retention Treatment Basin begins just west of I-75 and extends for 2.1 miles to the east in the path of the Red Run Drain -- which was once an open cesspool after heavy rains.
The plant -- one of several similar centers in metro Detroit -- is run by the Oakland County Water Resources Commissioner's Office. It drains 27 square miles of suburban Detroit, including all or parts of Troy, Royal Oak, Madison Heights, Clawson, Ferndale, Berkley, Huntington Woods, Pleasant Ridge, Oak Park, Hazel Park, Royal Oak Township, Birmingham, Southfield and Beverly Hills.
On a dry day, the first five feet of seweage in its approach pipes are sent directly to the Detroit Water and Sewerage Department for treatment.
But overflow from a heavy rain used to go directly into the Red Run Drain, from there to the Clinton River, and into Lake St. Clair.
Blame metro Detroit's decision 70 years ago to build a combined sewer system -- sanitary sewers that work just fine to keep their discharge clean when the weather is dry, but which can overflow with millions of gallons of untreated sewage after a heavy rain sends stormwater runoff their way, since the region's street and parking lot drains are connected to the same sewer lines.
The Kuhn plant was built to get in the way of that overflow, storing it and treating it until it can be discharged to the Detroit sewer plant -- and, if an extreme storm requires it, discharging only sewage that has had at least basic treatment into the Red Run Drain. (The alternative? Letting all that sewage back up into everyone's basements. Water always wins, and it has to go somewhere, no matter what icky stuff is in it.)
The plant was built in 1974 and expanded in an $80 million project in 2006. It's essentially a concrete box, 25 feet high, 62 feet wide, and 2.1 miles long.
If overflow must be discharged to the Red Run Drain, the overflow is screened to remove solids down to a fraction of an inch, and the water involved is treated with sodium hypochlorite, better known as bleach.
The amount of bleach pumped into the water varies with the water volume. A series of variable frequency pumps, controlled from a computer console, controls the amount of bleach added to the water -- anywhere from seven to 1,200 gallons a minute.
Once the water recedes, small tracked vehicles originally designed for heavy snow scoop up the solid remains -- a dirty job if ever there was one -- for proper treatment.
John Stange, who manages the basin, said the plant has treated 27.8 billion gallons of overflow in the past 10 years in 292 events. Of that total, 19 billion gallons of waste stayed in the Kuhn plant and eventually went to the Detroit sewer treatment plant. There were, unfortunately, 73 discharges over the past 10 years when heavy rains overcame the system, sending 8.8 billion gallons of treated overflow to the drain.
"We manage things to minimize spills to the river," Stange said. "I don't want any spills to go to the river. Now, that's not possible, but we do everything we can to minimize it."
The plant saw 1.3 billion gallons of discharge pass through in a heavy rain in May that sent up to 4 inches of precipitation across metro Detroit. The plant used 160,000 gallons of chlorine -- and stayed within all its government permit limits. However, media accounts from the storm show there were overflow backups into the basements of some homes in Warren. Also, in late May and early June, Lake St. Clair beaches also closed due to high E. coli counts, but there were other discharges into the Clinton River after that storm as well, from Clinton Township, Fraser and Warren.
The Kuhn plant's control room looks like something out of a James Bond movie, a room full of computers and servers, its windows with metal shutters overlooking huge empty basins. (And in fact, the Kuhn plant was scouted as a location for a villain's lair in an upcoming Batman movie. Stange said the producers turned it down when told that they wouldn't be able to shoot on the days the plant was, well, busy.) On a dry day, there's still a bit of odor inside the plant -- a bit like the fertilizer department at the Home Depot next door or the Lowe's across the street. There's a huge air treatment plant attached, though, to prevent any smell from getting outside.
The computers control not only the Kuhn plant itself, but sewer valves, pipes and pumps up to 15 miles away, at 14 Mile and Inkster roads where Farmington Hills, Novi, and Bloomfield and West Bloomfield townships come together. In the not-so-good-old-days, sewage and runoff levels in those far-off pipes had to be checked manually, meaning sending staff out to pull up manhole covers and turning pumps on and off manually.
Ann Arbor-based Tetra Tech Inc. wrote the software to control the system, rendering them to look something like a simple video game.
For blackouts, the plant has two huge natural-gas-powered backup generators, either one of which can run the entire plant. The plant had diesel generators earlier, but learned in the blackout of 2003 that it's tough to get diesel fuel delivered in a long blackout, because diesel storage tanks use electric pumps.
The land on top of the former Red Run Drain is now a recreation area, boasting a nine-hole golf course, a wave pool and a soccer complex, better known as Red Oaks County Park.
"We've taken a cesspool and turned it into a recreation center," Stange said of the county's efforts.
For an in-depth look at how the plants work from the city of Detroit's perspective, visit www.dwsdoutreach.org/LinkClick.aspx?fileticket=9Rz5-Q6T1PI%3D&tabid=122.
