Dominique Strong holds up a sign during a city council meeting in Flint, Mich., on Feb. 3. (Brittany Greeson/The Washington Post)
Stuart H. Smith is a New Orleans-based environmental lawyer and author of “Crude Justice: How I Fought Big Oil and Won, and What You Should Know About the New Environmental Attack on America.”

News keeps getting worse in Flint, Mich., where bureaucratic bungling exposed thousands of residents to highly toxic lead pollution in their tap water. With more than 150 parts per billion — above what common filters can extract — children in particular are at a heightened risk of developing irreversible conditions including lower IQs and behavioral problems. It’s a crisis of government negligence.

So how can people who live there hold officials to account? Sue.

We know people in Flint were poisoned. It’s a lawyer’s job to prove that they suffered because officials failed in their obligations, and class-action lawsuits are almost certainly the way to go. Two such suits, both focusing on the actions of the Department of Health and Human Services, have been filed against the state of Michigan, its agencies and the governor. The question is: Will they succeed?

As an environmental lawyer with years of experience suing oil companies for polluting working-class communities in the Deep South, I’ve watched Flint with a sense of déjà vu. What I’ve learned is that in these cases, bad actors, including government, will continually obfuscate until citizens and their lawyers or doctors are able to gather the evidence needed to prove their clients have been harmed. Just look at the misinformation that was put out to the public during the BP oil spill in the Gulf of Mexico about the flow rate of the leak and the safety of seafood harvested from surrounding waters.

Too often, a courtroom is not only the best but the only place where victims can win fair compensation. And their vehicle is a civil suit where the standard, unlike a criminal trial, isn’t “beyond a reasonable doubt.” Instead, lawyers must prove that a “preponderance,” or majority, of the evidence demonstrates liability. If defendants are held responsible, they’re required to compensate their victims financially.

What makes things more complicated in Flint is that unlike an action against an individual or corporation, allegations of mismanagement are directed at state, local and perhaps federal officials. And because governments write the legislation, they, unlike private entities, can shield themselves from aggrieved citizens seeking compensation. Even when citizens can sue the state, the bar they must clear is frequently higher.

In Michigan, residents wishing to recover from a public agency are required to prove not merely negligence, as they would in a typical case, but gross negligence, defined as “conduct so reckless as to demonstrate a substantial lack of concern for whether an injury results.” The question is whether officials in Flint, the governor’s office, the Michigan Department of Environmental Quality or the Michigan Department of Health and Human Services were grossly negligent, according to that standard.

It shouldn’t be too hard to get over this hurdle. Already, it’s clear that state officials knew about the crisis and took action to protect themselves, if not the people they served: providing state government workers in Flint with bottled water long before publicly acknowledging to everyday citizens that their water was tainted. The state sent 1,500 water filters to Flint in August, and Gov. Rick Snyder’s office issued a response plan in October — but at that point hadn’t warned residents to stop drinking the city’s water.

Still, cases like these are hard to win because it can be difficult to demonstrate a direct causal relationship between the defendant’s reckless disregard and the plaintiff’s injury. Besides passion, knowing the law and how to fight in court, the lawyers will need deep pockets, a team of recognized experts, and a solid understanding of chemistry and toxicology.

In the environmental cases I’ve litigated, environmental and medical testing, and providing the necessary experts, have cost millions of dollars. In the biggest cases, I have had to use large lines of credit and partner with other law firms. Similarly, this case is probably much larger than any small local law practice can handle. In what is known in the legal industry as a mass tort, as is the case here, lawyers from experienced firms will band together to share in the risks and the potential rewards. Given the circumstances, it’s the best course of action, and in Michigan the criteria are similar to those used in federal courts and in many states.

If the requirements for commonality (the plaintiffs’ claims against the defendants are common), numerosity (it’s impractical for every claimant to sue individually) and the adequacy of the class representatives (the named plaintiffs’ claims are similar to those of the class) are met, certain common questions of law and fact can be certified for one trial. Were the defendants grossly negligent? Was a contract breached? Were consumer protection laws violated? Was the water dangerous? Should the source be replaced? And by what percentage are the different defendants liable for the damages?

If liability is found in the class-action suits, individual damage claims probably will have to be litigated on their own merits, if there is no settlement, because different class members will have different categories of injury.

But first things first: Health is paramount, so anyone in Flint who has been drinking or bathing in the city’s water should see a doctor immediately. But another reason to seek treatment sooner rather than later is to get blood tests and any other relevant medical exams as quickly as possible, to document health problems caused by consuming Flint’s dirty water. Proof of rashes, hair loss or other maladies could become powerful courtroom evidence. I’ve found that clear-cut medical evidence is the best way for plaintiffs to prove they’ve been harmed by pollution, and to withstand challenges from aggressive defense lawyers.

And every cost that results from lead exposure must be accounted for, from medical expenses to the loss of future earnings for children who face diminished cognitive capabilities.

If my experience is a guide, the state will hire the best lawyers and experts money can buy to argue that Flint residents experienced insufficient exposure to lead and that their maladies come from another source or preexisting condition. Unfortunately, it is especially difficult to prove that a brain injury has caused cognitive dysfunction when no prior brain measurements exist. Almost certainly, everyone exposed to Flint’s poisoned water will need a lifetime of medical monitoring to watch for latent diseases that can take years to manifest. If and when that happens, another lawsuit might be in order. That is why potential plaintiffs should be cautious about any hastily offered settlement, which may require a waiver of future claims.

I hope that everyone in Flint has saved their water bills and other receipts as evidence of both the span of time during which they were consuming and paying for city water, and to demonstrate that the water crisis imposed a financial burden — including medical and pharmaceutical costs as well as the expense of buying large quantities of bottled water. This could become important later in establishing the length of exposure and damages to the person and the pocketbook.

Flint’s tap water may be orange and murky, but the way forward is clear: Government, like big business, works for the people only when the cost of doing wrong is shown to be greater than the cost of doing right. And for the people of Flint, the place to teach that lesson is in court.