Kuhn Facility – Warren – Red Run
GWK basin keeps sewage out of Great Lakes
By Andy Kozlowski
C & G Staff Writer
In heavy rain, it’s deep underwater, and its access staircase is half-submerged.
The largest filtering facility in North America, GWK has screens several stories tall.
The screens rotate rakes up and down, carrying debris to a trough upstairs.
There, in a warmly lit corridor, one can peer over bright yellow railings
into the dizzying depths below.
“It’s like going to the moon,” said John Stange, supervisor of GWK
and three other basins in Oakland County under the jurisdiction
of the Water Resources Commissioner’s Office.
“When you’re here during a heavy rain, it sounds like lions roaring,”
as water first hits the structure.
It’s then that the basin’s all-important work begins.
“We’re here to protect Lake St. Clair,” Stange said.
In the nearly 40 years it’s existed, GWK has prevented billions
of gallons of raw untreated sewage from reaching the Great Lakes
via Lake St. Clair. Its sole purpose is to keep the Great Lakes,
one-fifth of the world’s freshwater supply, clean and pristine.
In dry weather, runoff from 27 square miles across 14 communities
is routed to the Detroit Wastewater Treatment Plant via a pipe
at 12 Mile and Stephenson. When heavy rain causes sewage
(over 90 percent storm water) to exceed capacity to Detroit,
the excess flow tops a weir and is diverted to the 2.2-mile-long
GWK basin. Here the solid waste is thoroughly separated and
the water pumped back to Detroit.
If the volume is so high that it tops the second weir,
the excess is disinfected by carefully controlled amounts
of sodium hypochlorite, similar to swimming pool chlorine
or household bleach. The chemical is dispensed through
plastic pipes and titanium pumps connected to eight tanks
in a secure room, with each tank holding 18,000 gallons.
From there the water, now clean, heads toward Dequindre.
If it tops the third weir, it’s back to Lake St. Clair
via the Red Run Drain, a tributary of the Clinton River.
And from there it’s off to the Great Lakes.
Before the basin went live in 1974, discharges went straight
to the lake, unfiltered and untreated. GWK originally cost
$30 million to build, paid for by federal funds and revenue
generated by the GWK Drainage District, which serves Berkley,
Birmingham, Clawson, Ferndale, Hazel Park, Huntington Woods,
Madison Heights, Oak Park, Pleasant Ridge, Royal Oak,
Southfield and Troy, plus the charter townships of Royal Oak
and Village of Beverly Hills.
An expansion in the early 2000s and in-system upgrades
cost an additional $127 million.
Now it can handle three million gallons of water per minute,
with the 16 fine screens (one-half-inch openings)
and four emergency screens (two-inch openings) filtering out
paper, rubber, rocks, organic matter and more, so that
the water can be chemically treated.
“We’re the last line of defense between combined sewage
and the Great Lakes,” Stange said. “We take a lot of pride
in our work, and we’re dedicated here to ensuring that
everything operates as it should.”
This is achieved, in part, with state-of-the-art technology
that has attracted visitors from as far away as Mumbai, India.
Everything is monitored from GWK’s administrative facility
at 1400 Ajax in Madison Heights, a red brick building among
rolling green hills. In the control room, seven computer monitors
track all activity at GWK and the three smaller basins in
Birmingham and Beverly Hills. They also keep tabs on the weather
and can be accessed by Stange remotely.
It’s intricate work, dealing with water levels that fluctuate
by the minute, taking frequent samples at both ends of the
treatment pipeline to make sure the right amount of chemicals
are being applied: enough to disinfect while leaving only
minimal residue. The heavy rain seems to hit most often
past midnight, requiring some odd hours.
At most, only a half-dozen people run the facility.
After a rain event, when the sewer levels are dropping,
a powerful pumping system purges the basin of water,
at which point the priority becomes cleaning the structure
for the next event. This involves special plow vehicles
to move solid waste, and cycling in four million gallons
of fresh water to clean out the basin over an eight-hour day.
There are also two auxiliary generators to ensure operations
continue in the event of a power outage, and odor control
apparatus to neutralize any foul smells.
“It’s such an impressive facility,” marveled Gary Nigro,
a basin operations engineer. “It’s a benchmark for retention
treatment basins around the world. Consultants across the country
catch wind of it and ask, ‘Can I come and see this basin,’
because there’s nothing else quite like it. When they try to
design similar facilities in their own communities,
this is the one they come to see how it’s done correctly.”
The positive impact can be seen right outside. Lush and green,
the banks of the Red Run Drain teem with life, everything
from pheasants to foxes. It wasn’t always this way.
“My father grew up in Warren,” Nigro said. “He can recall
when he was a kid walking along the banks of the Red Run Drain,
seeing toilet paper way up in the trees. That drain is normally
a foot or two deep, but when you get a big storm the water can
get 20 feet high. Back then, any combined sewage would flow right
down Red Run Drain before the basin was built. It was a big cesspool.
“But that’s not the case anymore,” Nigro said. “You can walk
along the Red Run Drain today and see an abundance of wildlife
— lots of turtles and even beavers. There are all kinds to see.”
You can reach Staff Writer Andy Kozlowski at
or at (586)498-1104.