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The computer scientists saw that an information problem was sitting atop the lead issue in the city. No one knew, exactly, who had lead pipes and who did not. The City had a variety of records: thousands of old cards describing parcels’ hookups, and also maps and small updates that had been filed into the system over the years. But a cataloging system is only as good as its maintenance, and the City of Flint had been starved of resources for decades.
Flint, you probably know, was a key chamber of the heart of the American automobile industry. Through the middle of the 20th century, General Motors had a variety of facilities in the area, employing some 80,000 people. As Flint’s position within the automotive industry declined, most white residents took the money they’d earned and
moved to the suburbs, taking their tax dollars and capital out of the city’s core. They created their own regional services in the wealthier Genesee County, while Flint’s residents suffered the repercussions of an economy that had moved on: budget cuts, failing schools, and, of course, post-industrial environmental problems. It is not a surprise, then, that before the crisis began, auditing and correcting water-department records from the early-20th century were not top of mind for city officials.
When Flint’s money woes got bad enough in the wake of the housing collapse, Michigan Governor Rick Snyder sent in an “emergency” manager to enact cost-cutting measures. Half of Michigan’s black residents have lived under an emergency manager,
according to a Michigan Civil Rights Commission report about Flint. It was Flint’s emergency manager who made the call to switch the water supply from the Detroit water system to the Flint River in April 2014 without putting in the right corrosion controls. That’s what started the problem.
Many cities share the lead-pipe problem and the informational obstacles layered atop it. The decay of infrastructure built decades ago is not only in the metal, but in the data cataloging that lets the city’s government and residents understand the state of the water system. For all the talk of “smart” cities, the real state of play in many older places is that no one even thinks of these things until there’s a disaster. People have been saying “
America is 1,000 Flints” since the city was booming, and it is still true. Just as there are thousands of lead service lines in Flint, there are something like 6 million lead service lines in America.
When Weaver launched the program to replace Flint’s lead service lines, Fast Start, in March 2016, suddenly the city’s maintenance debt came back up to the surface. General Michael McDaniel was picked to lead the program, with less than a handful of people working under him.
Some basic things were known about the lead-pipe distribution: The pipes were most likely to be found in postwar homes, built when Flint experienced major expansions, and least likely to be found in newer homes. In February 2016, Martin Kaufman at the University of Michigan at Flint built
some maps of nominal lead pipe placements in the city using City records. McDaniel’s team used them to prioritize initial excavations based on the age of homes and the Department of Environmental Quality’s rough sense of where the worst water problems were. Then they asked themselves who would be the most affected by lead in the water. “The very young, the very old, and those with compromised immune systems,” McDaniel told me. They determined which homes had kids under 5 years old and adults over 70.
Combining these sources gave them a rough sense of where to start. McDaniel set out to replace 600 lead pipes each in 10 small zones. “It was a matter of what was efficient and what was equitable across the city,” he said.
When Abernethy and his collaborator, the University of Michigan’s Eric Schwartz, got involved over the summer of 2016, they saw a familiar type of prediction problem: sequential decision making under uncertain conditions. The crews didn’t have perfect information, but they still needed the best possible answer to the question Where do we dig next? The results of each new dig could be fed back into the model, improving its accuracy.
Initially, they had little data. In March 2016, only 36 homes had had their pipes excavated. And even as the crews began to do hundreds of digs, they were looking for lead pipes, which meant that they were creating a decidedly unrepresentative sample of the city. Using just that data, the model was likely to overpredict how much lead existed elsewhere in Flint. So the University of Michigan team asked Fast Start to check lines across the city using a cheaper system called “hydrovacing,” which uses jets of water, instead of a backhoe, to expose pipes. The data from those cheaper excavations went back into the model, allowing the researchers to predict different zones of the city more accurately.
Read: How to prevent the next Flint
As they refined their work, they found that the three most significant determinants of the likelihood of having lead pipes were the age, value, and location of a home. More important, their model became highly accurate at predicting where lead was most likely to be found, and through 2017, the contractors’ hit rate in finding lead pipes increased. “We ended up considerably above an 80 percent [accuracy] for the last few months of 2017,” McDaniel told me.
In late 2017, Weaver announced that the City was awarding a $5 million contract to AECOM, the major national contractor, to run the project. In February 2018, the City held a community forum to “really introduce you to the company that’s going to accelerate Fast Start,”
as Weaver put it. Robert Bincsik, Flint’s director of public works, noted at the forum that the City was doing something nearly unprecedented. “There is not anybody else doing this as aggressively as we are,” Bincsik said. “Overall, I think we’ve done a wonderful job.”
