Examining Flint, MI Water Supply

CEE assistant professor Philip Larese-Casanova examines the drinking water crisis in Flint, Michigan.

Source: News @ Northeastern

The city of Flint, Michigan, has been engulfed in a drinking water crisis in recent months. In April 2014 the city tem­porarily switched its source from Lake Huron to the Flint River, and it was later dis­cov­ered that the dis­trib­uted water con­tained very high levels of lead. This month, Michigan’s gov­ernor declared a state of emer­gency and acti­vated the National Guard to help dis­tribute water fil­ters, test kits, and bot­tled water to res­i­dents. And Pres­i­dent Barack Obama has signed an emer­gency dec­la­ra­tion that could pro­vide Flint with up to $5 mil­lion in fed­eral funds.

What’s behind the crisis? In part it’s water chemistry—the chem­ical reac­tion of the water and the pipes it’s flowing through—according to Philip Larese-​​Casanova, assis­tant pro­fessor in the Depart­ment of Civil and Envi­ron­mental Engineering.

Larese-​​Casanova is an envi­ron­mental chemist who studies the chem­ical processes of water pol­lu­tants, par­tic­u­larly metals. In a phone inter­view last week, he explained that the water supply in Flint was not treated with an anti-​​corrosive agent, which can bind to the sur­face of the metal pipes and form a pro­tec­tive layer that pre­vents corrosion.

The water from the Flint River was found to be highly cor­ro­sive, and causing lead and iron from the pipes to leach into the water supply.

“The water chem­istry allowed the iron and lead to dis­solve freely from the pipes,” he explained. “In my research I look at how dif­ferent water qual­i­ties can cor­rode or oth­er­wise react to pol­lu­tants that we release—either acci­den­tally or through indus­trial waste processes.”

The water chem­istry allowed the iron and lead to dis­solve freely from the pipes
— Assis­tant pro­fessor Philip Larese-​​Casanova

He added: “We need to replace a lot of the pipes in (nation’s) infra­struc­ture. They’re just too old. We need to replace them with safer mate­rials. In order for that to happen, cities need a lot of money and they need a lot of time to dig them up and put new pipes in. That will solve a lot of problems.”

Health and envi­ron­mental experts point to the dan­gers of lead to plants, ani­mals, and humans. The EPA says lead is par­tic­u­larly dan­gerous to chil­dren because their growing bodies absorb more lead than adults do and their brains are more sen­si­tive to lead’s dam­aging effects. The Cen­ters for Dis­ease Con­trol and Pre­ven­tion, mean­while, says that no safe blood lead level has been identified.

At North­eastern, Larese-​​Casanova and his research team examine how pol­lu­tants can react in cer­tain water con­di­tions, and they run exper­i­ments to uncover the mech­a­nisms and fac­tors behind these reac­tions. One project is focused on metallic nanopar­ti­cles, which he says are increas­ingly being used in a range of com­mer­cial prod­ucts, from TVs to creams and sham­poos. Like the lead ions leaching from lead pipes in Flint, metallic nanopar­ti­cles can leach their toxic metals under cer­tain water con­di­tions. He is cur­rently exam­ining how cad­mium and zinc ions leach from the smallest of nanopar­ti­cles, called quantum dots, which are now used in light emit­ting diodes such as those in TV dis­plays. Another project involves inves­ti­gating how nat­u­rally occur­ring metals, like sele­nium, behave in ground water and sur­face water. He is studying how sele­nium can bind with min­eral sur­faces and essen­tially remove itself from the water supply.

“If we can under­stand how metals behave when they enter ground water, we can assess whether they are a danger or threat to drinking water sources,” he said.

What can average res­i­dents do to ensure their drinking water is safe?

Larese-​​Casanova advises that people be alert to changes in the color, taste, and odor of their drinking water. He also sug­gests reading the drinking water reports that their munic­i­pal­i­ties release. If res­i­dents wish to be more proactive—and have the means to do so—he says they could even peri­od­i­cally send out drinking water sam­ples to get lab workups that iden­tify levels of metals and other contaminants.

Related Faculty: Philip Larese-Casanova

Related Departments:Civil & Environmental Engineering