Flint water crisis. Any pool chemistry similarities?

[gworrel]

I've been reading about the Flint water crisis and it sure sounds like the people running the water treatment plant did not understand some of the basic water chemistry that the people on this forum deal with all the time. I am sure methods of treatment are different, but it sounds like the ph of the water from the Flint river was too acidic and because it was not adjusted properly with the right additives, it corroded the protective layer that forms over the lead in the water lines and copper pipe lead solder. The result was that lead leached into the water that people were drinking.

I am far from an expert on any of this. Any of the chemistry geeks on here have any insight into the matter?

 

[Patrick_B]

From what I've seen on TV, it looks like some of the water has a severe Iron problem as well. Likely a result of the same issue of lower pH. Not much to say about it really, but it's a disaster for Flint on several levels. It's my humble opinion that there is more than a low pH issue here, but I don't have enough facts to back that up. It's a little shocking that they didn't foresee these potential problems and more than a gross oversight again, IMHO. Pools are the least concern really, but I'm curious if we see any results from this show up here. If we do, the advice will be much the same as always-metals are tough, and there are only a couple of things that usually help much.

 

[JoyfulNoise]

Even though people get freaked out by lead solder joints, the fact is that 50/50 Pb-Sn solder is completely stable as long as the pH of the water is maintained in a normal range. When the pH and alkalinity are both too low, the stable lead oxide and lead carbonate passivation layers get disrupted and then lead levels spike. There are many, many, MANY old eastern cities with lots of old copper and cast iron water pipes that are perfectly stable and deliver safe drinking water. Thankfully newer construction uses Sn-Ag or Sn-Sb solders which actually out-perform 50/50 solders.

There is a very up-to-date Wikipedia entry on the water crisis that goes into a lot detailed history regarding how the city of Flint handled it's water supply and the history of the crisis. It's a very good read.


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[gworrel]

Thanks, Matt. There is so much misinformation out there on this. I have looked at the wikipedia entry. I am surprised that the city of Flint did not have someone knowledgeable enough to manage the water treatment properly. Apparently the EPA and the Michigan Department of Environmental Quality were in disagreement about the need to add orthophosphate to the water to reduce the corrosivity.

 

[Patrick_B]

No surprise there.

 

[BuckeyeChris]

Would it literally be easier to just build a new town, instead of repiping every single drinking water supply pipe?

 

[Patrick_B]

What a mess this is turning into....some really screwed up on this one.

 

[JoyfulNoise]

Another good source of info from the head researcher that sounded the alarm, Dr. Marc Edwards -

Flint Water Study Updates | Up-to-date information on our collaborative research and citizen science work with the residents of Flint, MI in light of reported water quality issues

drinking water | Flint Water Study Updates


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