Last year, civil engineer Marc Edwards spent at least US$150,000 of his own money to prove that tap water in Flint, Michigan, was contaminated with lead. Over the past decade, Edwards has been documenting and exposing lead contamination in the Washington DC water supply and fighting to hold government officials accountable. Edwards explains how this work equipped him for the Flint case, which garnered international attention and shone a spotlight on similar concerns nationwide.

A mother's plea for help got you involved in the Flint crisis. Is it similar to the DC case?

In Flint, up to 12,000 children have been exposed to high lead levels. The DC-area case was much worse than Flint, in terms of harm done and number of children affected. Unfortunately, there was betrayal by government officials in both cases.

How did the DC case prepare you for Flint?

As a civil and environmental engineer at Virginia Polytechnic Institute and State University in Blacksburg, I researched corrosion in homes. In 2003, I started sampling water in DC homes and found outrageously high levels of lead. Ultimately, we discovered that the public had been misled by local and federal agencies. I've had to disprove falsified government reports, which my earlier work had not prepared me for. But without that experience, I would not have been able to help people in Flint.

How did the events in Flint unfold?

Flint was the exact opposite of DC in every respect. Once we confirmed the contamination and government oversight, we had sample kits going to Flint in less than a week. We knew we had to cooperate with anyone who wanted the truth about the lead, and fight anyone who tried to obfuscate matters. There is a line between science and activism, and it's one you cross only as a last resort. It's either that or, in this case, letting kids be hurt and a city destroyed. We used Freedom of Information Act (FOIA) requests — which invoke a federal law to access information from the government — to get the data about who knew what was happening with the contamination and when.

Your findings contradicted official reports. Were you concerned about credibility?

Only the paranoid could possibly survive something like this. If you make one mistake, you will never, ever recover. It makes you very careful not to say anything you are not prepared to back up 100%.

How have your efforts affected your workload?

I worked on the DC case for 30 hours a week as a volunteer, for 10 years. But I worked 70 hours a week to make money and produce papers, the things that count towards academic-career success. There's no way you'd put on your CV that you made FOIA requests and attempted to get falsified reports retracted.

How did you fund the Flint work?

I knew the day would come when another community would need help, so I donated my fees from consulting and other work into a fund in the department. It was put into a discretionary account. We did, eventually, get $33,000 from the US National Science Foundation, which gave us credibility.

Are you getting calls from people in other cities about more contamination concerns?

I get 20–30 communications every single day. I work 65 hours a week on Flint, so I don't have time to check these things out. But in the back of your mind, you say, what if they are valid?

Why do you maintain a website with Flint research updates?

I didn't want to be dependent on the few investigative reporters left to explain the science behind it. Every single major breakthrough came out on our blog first.

Do you have lasting concerns?

There was a time when engineers and scientists were the leaders of their generation. But we have created our own world, set apart from society, where we tell each other we're important. If we cannot get this fixed, we are destined to enter a new dark age.

This interview has been edited for length and clarity.