The CEO of the Great Lakes Water Authority detailed on Friday what went wrong at two Detroit pumping stations during the height of last weekend’s torrential rains and flooding.
Sue McCormick said power failures caused “operational issues” at two pumping stations on Detroit’s east side—Freud and Conner Creek. That area suffered some of the worst flooding in Metro Detroit after being pummeled with nearly seven inches of rain in several hours.
The problems began when Freud lost power because one of the substations powering it went offline for reasons that remain unclear. McCormick said Freud has a generator, but they’re only equipped to provide “redundancy” for one substation. As it happens, that was the substation that was still functioning. That meant it when it came time to energize the pumps for the rain event, there were several “trip events” that made them slow to come online.
Freud directs its flow to Conner Creek in wet weather, wastewater is discharged to the combined sewer overflow basin at Conner Creek. But that facility had its own problems. McCormick said that Conner Creek activated two pumps just before 1 a.m. on Saturday, but then lost “house power.”
“The Conner Creek pump station experienced a house power outage from a leaking vacuum priming pump that sprayed water on the circuit breaker within the pump station,” McCormick said. “Again, this did not impact the power to the first and second pumps, however it did delay the start of the remaining pumps.”
McCormick said contrary to suggestions that Conner wasn’t staffed during the storm, there were three GLWA employees onsite, including an electrician. However, when problems arose at Freud—which is operated remotely—the electrician was dispatched there, which delayed power restoration at Conner Creek. McCormick said it took the electrician more time than usual to return because of street flooding, but they were eventually able to restore power by re-setting the circuit breaker there.
McCormick said it’s unfair to suggest, as some people have, that Conner Creek “failed” during the storm. “That’s not true,” she said. “We were able to have two pumps on at all times, [and] we were able to get five pumps [out of six] on during the duration of the storm.”
McCormick called the storm unprecedented, saying, “We’ve never experienced anything like this.” But she promised to request that the GLWA board of directors retain an independent engineering firm to evaluate the regional water system’s performance during the deluge. “We believe that having the board use an independent expert will help to ensure public faith in the transparency of the process, and ultimately in its results and recommendations,” McCormick said.
Some Detroit area public officials, including Macomb County Public Works Commissioner Candice Miller, have requested such an investigation. They’ve also demanded to know why there continue to be problems at Conner Creek, which suffered similar issues during storms in 2014 and 2016, causing widespread basement flooding in surrounding communities. Detroit Water and Sewerage Department Director Gary Brown told the Detroit City Council this week that Conner Creek has had $30 million in upgrades since then.
McCormick said additional improvements to both Conner Creek and Freud are included in the GLWA’s 5-year, $1.7 billion capital improvement campaign. But she said there’s only one surefire way to really mitigate such events in the face of increasingly intense southeast Michigan rainstorms—replace itscombined sewer systems.“If you want a system that says, no matter what size rain event we’re not going to have sewer backups, we’ve got to separate all those sewers,” she said.
Combined sewer systems, which are typical in many older U.S. cities, are sewers that are designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same pipe. In heavy storm events, they can deluge water treatment plants and overflow into waterways—or in this case, the pump systems meant to prevent them. McCormick said replacing that whole infrastructure would cost an estimated $17 billion.
