I watched with utmost respect to today’s interview with Erin Brokovich on the situation in Flint Michigan. Much of what the activist said was absolutely true, but some of it was not true, or at least exaggerated. Specifically, Erin laid part of the blame on this water contamination on a substance called chloramine. According to her, the chloramine contributed to the Flint River’s corrosive nature causing lead, copper and possibly other metals to be stripped out of the piping system, particularly the older pipes.
While chloramine is in fact aggressive on the metal parts it comes into contact with, historical water data shows us that this sanitant is not that aggressive. While I would have to go back and search for the sources, many other cities, including Denver, Boston and others have been using chloramine as far back as 1920, or perhaps before. If chloramine was as corrosive as Brokovich claims, those cities would have had the same problems with lead, copper and other metals leaching out of the pipes, long, long ago. But this has not happened, and for good reason.
The water that Flint was previously using was Detroit city water out of Lake Huron. Again, I have not pulled a water analysis, but have designed multiple water treatment systems over the years in that city. Memory tells me that this water is semi-hard water, mild at a hardness of about 6 grains per gallon, or roughly 100 – 120 parts per million.
At this hardness level, over the years the pipes in Flint would have been caked on the inside to a reasonable extent with calcium scale. This means that the residents were actually somewhat protected from metals leaching out because the water, in many cases, was coming into contact with the scale, and not the pipe.
The massive doses of metals that Flint residents suffered did not likely come from chloramine, but instead because the utility, the provider of drinking water, did not add chemicals to adjust the Langelier Saturation Index, or LSI. For that amount of metal to be released the water would have had to been aggressive enough to dissolve a lot of the old scale, and then begin attacking the pipes.
Please forgive me for the redundancy of having mentioned LSI in yesterday’s post, but this issue, these people do not deserve to be again abused by someone giving them what seems like a short, simple answer to their water problems. Brokovich is a champion of the consumer, but to my knowledge is not an engineer nor water quality chemist. She has passionately been arguing against the use of chloramine, but in this case, the issues are far too important to simply point to something convenient.
There is far more to this problem than chloramine.