I decided to delve into the subject because it covers 2 areas/fields that I am VERY interested in; water and mining. The water aspect is obvious and the mining aspect comes from a love of exploring old mines in southern AZ (as well as elsewhere) because my degrees are in geology. If I hadn't gotten into hydrology I would have probably gotten into something related to mining. So this story made my mouth water. I wanted to know what happened and just how full of shit the media coverage of the whole thing was. It was eye-opening/popping!
The whole thing started in 2009/2010 when it was determined that something had to be done with contaminated water flowing out of abandoned mines in SW Colorado. Water plus oxygen plus sulfate-rich rocks causes sulfuric acid to form. The acid leaches minerals from the rocks. Since the mines were built to extract metals, the rocks are rich in metals. The water that flows out of the mines is usually highly acidic and loaded with toxic metals. The streams below the mines are usually devoid of life because of this. This has been going on for over 100 years. Pollution of streams which we now consider "pristine" was rampant. Gradually the ore bodies played out and the mines were abandoned. Groundwater, however, continued to flow. Several mine tunnels were sealed off over the decades, but that only caused the water table to rise elsewhere. Finally water found an opening in the Red and Bonita Mines. As much as 500 gal/min spilled from the mine opening. The EPA decided to control the flow out of the mine and treat the water to raise the pH which would cause the metals to floculate in pools which could then be cleaned up. As they opened up a nearby mine, The Gold King, a surge of contaminated water rushed out and sent a toxic soup downstream.
Reports stated that 3 million gallons flowed out. I confirmed those calculations since there was a measuring station downstream. I came up with 2.5 million, but they probably rounded up.
I'm just amazed at all of the online rhetoric (but I guess I shouldn't be all that surprised). Most people want the EPA's head on a spike. Yeah, they screwed up, but a lot of it is a tempest in a teacup due to fear and ignorance. There were even people calling into the news stations here asking when the contamination was going to reach ABQ. Ummm...wrong river basin. I saw maps showing the contamination flowing all the way to Mexico. Sure, if you ignore Lake Powell, Lake Mead, and Lake Havasu. There also is this little thing cause dilution. Lake Powell currently holds 4.2 trillion gallons. So the contaminated water would equal 0.06%. Then there's settling/floculation. Probably a lot of the metals are attached to sediment particles. That sediment will settle out along the several hundred mile journey and especially when it hits the calm waters of the reservoir. Sediment contamination could be a concern, but considering there was 100 years of mining before where all sorts of things were dumped into the river, this weeklong event is a drop in the bucket to what is probably already there. There is also a concern for people with wells along the river. Generally groundwater flows towards the river not from it. I suppose you could develop a cone of depression that would suck in river water, but we're talking about taking a long time before river water made it to your well. Once again, dilution would take care of most contamination. Preliminary surface samples already show the river water to be at pre-spill levels.
So there's a lot of anger out there. Some is understandable like the rafting companies that couldn't send people out on the river for days. There's a lot more hysterics, though. The Navajo Nation wants to sue! Sue who?!? They said that their crops were damaged. Good luck proving that in a court. Unless you can show crops with elevated levels of metals in them and/or measurable crop losses, you don't have a case. They're claiming their way of life has forever been destroyed. Once again, what about 100 years ago when the river was in worse shape. You survived that just fine. It's like if a garbage truck overturns in front of your house. Sure, it will be messy and stinky for a day, but it will get cleaned up. You may find a plastic bag or a chicken bone over the later days, but your life will probably not be effected too much.