Another Angle on Flint Water

Well, why are there chlorides in the Flint River water? For the most part, the Genesee County Road Commission put them there.


It may seem that we’ve already heard all there is to hear about what went so wrong that Flint’s water system poisoned Flint residents. In reality, there’s much more to hear, and much more needs to be done to fix the issues that are fixable. Some problems, like children whose development is already damaged because of lead, can’t actually be fixed. Some, like corrosive water in the Flint River, can.

So whose fault is it? It’s the fault of the Genesee County Road Commission. This sounds completely illogical if you’ve never heard the idea before, but keep reading for a few short paragraphs and you’ll see why it’s true. 

Lead pipes supplying water to buildings in Flint have been in the ground for many decades. At least in recent decades, they were not causing a lead poisoning problem. That problem started when the city water system started using water from the Flint River. That water was more corrosive than water from the Detroit Water Department; 19 times more corrosive is a figure commonly cited in news stories.

What made the Flint River water corrosive? Chlorides is the answer. The water in the Flint River contains a higher concentration of chlorides. Before the switch, lead pipes in the water system were coated with a protective layer of chemicals to prevent leaching of lead into water coming out of the faucet. This coating was no doubt less than perfectly effective, but it was good enough that drinking the water was not, so far as we know, causing lead poisoning.

Well, why are there chlorides in the Flint River water? For the most part, the Genesee County Road Commission put them there. They are in fact proud of the good job they are doing while they are putting salt on the roads. They use around 15 thousand tons of road salt (bulk rock salt, i.e., sodium chloride) per year See p. 16 of the Genesee County Road Commission Performance Dashboard for 2014, downloadable at They also use some additional amount of calcium chloride, though the amount is not made clear in this report. Given that they measure rock salt in tons and calcium chloride in gallons, it’s a reasonable supposition that much more rock salt is used.

salt truck

All this salt, year after year, ends up in the soil around the roads and in the melt water or rain water that runs off the roads. The salts (both sodium chloride and calcium chloride are salts) dissolve in water, putting sodium, calcium and chloride ions into solution. That’s where the chloride ions in Flint River water come from. Now, some businesses and some individuals also use salt on their sidewalks, dirveways and parking lots. The Road Commission is not the only culprit here. However, the other contributors do not use 15 thousand tons a year, so the Road Commission is the main contributor.

Use of road salt is a prime example of short-term thinking over long-term thinking. Several tons of salt on the roads clears ice and snow for a day or two. If it snows again in a week, more tons of salt are spread on the roads. Again, the benefit lasts a day or so. However, once you get it into the local water, you can’t get it out. Sure, if the water evaporates, it leaves the salt behind. But until the water does evaporate, the salt stays in. Short term benefits are traded for long term damage. It’s good to think about this the next time you hear a TV announcer say about a snowfall, “… but don’t worry, the salt truck drivers will work all night to clear the main roads.” It’s really not good news.

Chlorides stay in the water. It is possible to produce chloride-free water by the very expensive process of reverse osmosis, but what that does is concentrate chlorides in the stream of waste water from the reverse osmosis process. Reverse osmosis is way to expensive to use on a municipal water system, and if used, the system would have to process 3-5 gallons of water for every gallon of chloride-free water.

Excessive chloride content in Flint’s water basically stripped the protective coating off lead pipes, allowing lead to leach into water before it gets to the faucet. This chain of causality is pefectly straightforward. Road Commission buys tons of salt and spreads it on roads. Melting snow and rain dissolve the salt, putting chlorides in solution. Drainage carries chloride-laden water into the Flint River. Chlorides in municipal water eat away at the pipes. People drink water with dissolved lead, which is particularly harmful to babies and children. Effects are permanent. Proper treatment afterwards helps compensate, but does not fix the children affected.

The Road Commission is at fault here. They are not the only ones at fault, but it is wrong to leave them out of consideration.

Further, we are at fault for demanding “safe” (free of ice and snow) roads in Michigan in the winter. Cars and trucks are just not great transportation choices when it snows heavily. It takes feet of snow, not just inches, to stop rail travel. If we had a good public transportation system using rails, then we would be much better adapted to Michigan winters without loading our water with chlorides. Beyond that, if we also accepted that travel should be be held to a strictly necessary minimum in bad weather, and adjusted our habits accordingly, we could get by without ruining our water sources with salt.

If the Genesee County Road Commission tried to get an EPA permit to dump 15 thousand tons of salt directly into Lake Huron every year, we would think they were insane – and of course, the EPA would be insane to give them such a permit. In fact, with an indefinite delay, Lake Huron is exactly where the 15 thousand tons of salt ends up. We all know that that the same pattern holds for many other counties in Michigan, some of which use lots more road salt. The runoff may go to different rivers and lakes, but the pattern is the same. It’s a widespread problem.

The water crisis in Flint has highlighted some of the terrible consequences of using road salt. There are many others, including our terribly potholed roads. If our car culture is addicted to road salt, then it’s an addiction that should be overcome for the same reasons that addictions to alcohol, heroin and sugar should be overcome.

Author: Art Myatt

Retired engineer and environmentally aware activist with Green Party of Michigan, Sierra Club and Alliance to Halt Fermi 3.

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