Day 5: Cour de A'lene Superfund Site, Idaho

Today was dubbed Geology day as we drove from Starbuck into Idaho to meet with a couple geologists from the United States Geological Survey to tell us about the Cour de A'lene mining sites and how they have affected the area. The site was a main producer for lead and zinc minerals as well a silver, the ore was gathered from meta-sedimentary rock formed during the cretaceous period. Thee veins could go down nearly 5000 feet and forms a wave like pattern. We learned about the different methods used to extract the desired minerals for the ore which included flotation and crushing with flotation having a much higher efficiency as many particles tend to be lost while in the stamp mills. 

A display of minerals gathered from the mines

The first stop the geologists took us to was in Burke where the spring melt brings water down from the mountains that washes through the mines and drags lead and zinc particles from old tailings all the way into Cour de A'lene Lake. Tailing are excess particles that were extracted during mining but were never processed and pose hazards for nearby water sources.

Early mine entrances and water diversion systems 

The second site was in Woodland park where we viewed an enormous pile of tailing, this used to be where the miners would dump all the old tailings and they were never removed. Now the area is still contaminated and in an effort to keep the contamination from spreading the site was capped. Unfortunately there is not liner so the contamination can still move down but the hope is that the cap will prevent any surface water from passing through the contaminated tailing and leaching into groundwater. 

A pile of old tailings, capped with rubber and stone

The third site was in Kelogg where we visited the bunker hill trailing impoundment, a site that has been successfully re-mediated. The sides are lined with riff-raff and the top is covered and there are plans to turn the site into a golf course so that the area is not wasted. The hillside in the area was terraced as to help capture some of the contaminated sediment that washes down and growing conifers and grass to help absorb the metals. 

The fourth site was at the Cour de A'lene river delta where there were parts of the exposed river bank stained red from galleena tailings that had oxidized. We were told that every year this site gets dredged in an effort to help keep contaminated sediment from making its way into the lake. Unfortunately this helped to no avail as the tailings were still left in suspension and have been found in Lake Cour de Alene and the material that was dredged ended up contaminating the river bank as well. Funny enough as we were heading back to our vans we watched as a bunch of teenagers started jumping and swinging into the water, were not sure if they knew the story about the site or not but we didn't have time to explain it to them. 

The Cour de A'lene river as it flows downstream

The final site was in the Cour de A'lene River Valley where much of the contamination gets caught, the highest concentrations of contamination are along the rivers bends. There are fish in the area, the zinc concentrations are dilute enough for them to survive but large populations cannot be sustained. The geologists told us that the biggest hazard was the soil, people touching their face or eating without washing their hands and putting lead into their bodies. We bid farewell to the geologists and made our way to our KOA campsite located in Missoula, Montana. We were quite surprised comparing this site to our last KOA, this one made it feel like we were sleeping in someones backyard. Luckily there were showers and laundry so everyone got to relax a bit after dinner and there was breakfast in the morning to get everyone started the next day.