In this month’s blog post, we share a painting by Diana Almendariz, The Articulated Creek, that draws attention to the issue of mercury contamination in the Cache Creek watershed. This painting hangs in Diana’s living room when it is not part of a cultural exhibit. Diana says:
The painting represents how the Cache Creek was torn apart for its resources. Small rocks or aggregate are the new gold. Notice the red lower in the water, and its rising bubbles, which represents poisonous methyl mercury.
The painting is accompanied by an interview with environmental toxicologist Charles Salocks, who has been examining various issues related to toxic materials in the Yolo bioregion for over three decades. In this conversation with Salocks, he first introduces himself, and then introduces us to the various aspects of the mercury problem in the Cache Creek watershed.
What happens in the case of mining is not so much that you're creating new chemicals like you are with modern chemistry; what you're doing is that you are stirring things up... everything is locked up in the rock, and by physically breaking that up you are exposing that material to water and air and environmental factors that cause that material to break up and break down and mobilize, and start moving to places where it wasn't before.
As Salocks explains, the problem is not that mining introduces mercury into the watershed, for it is naturally occurring in this region. The issue is that mining makes the amount of mercury that is mobilized by weathering and exposed to anaerobic conditions in the deep, wet pits exponentially larger. In the following clip, he explains the kinds of weathering (or erosion) that work upon mercury and how that impacts the watershed.
Another issue specific to mining is the creation of highly toxic methyl mercury in the depths of mining pits where there is no oxygen available. In neighboring counties (such as Sacramento), mining pits are limited to a depth of 15 feet to prevent such methylization. In Yolo, however, mining companies are encouraged to go as deep as possible, and pits can be as deep as 150 feet or more. In the following segment, Salocks engages the issue of methyl mercury in greater detail.
The problem with methyl mercury is that it bioaccumulates in the small organisms that ingest soil particles… and as those organisms get consumed by other organisms further up in the food chain, it biomagnifies.
When I asked Salocks about mitigation measures, he offered a few possibilities. But all of these measures come with their own complications, as he explains in the following segment.
In the end, Salocks basically points to two pathways for mitigation: one, we need to find ways to clean up what is already here; and two, we need to stop proliferating more mercury in the watershed.
There are the natural sources like Cache Creek, which is actually one of the major sources of mercury to the delta. But there’s also the manmade sources, because all that mercury that was mined was transported over to the Sierra foothills and was used to extract gold… The amount of mercury coming down the rivers from legacy goldmines is just a huge amount.
Turning our attention back to Diana’s painting, how can we analyze this complex problem through the lens of environmental justice?
Yolo County is planning a 14-mile parkway linking together the former mining sites over the next thirty years. The Yolo County Natural Resources Department is working closely with the mining companies to convert the mined-out, deep pits into lakes for wildlife and recreation, but they don’t have a solution to the methylmercury problem. Next year, Yolo County will be reviewing the Off Channel Mining Plan that was established in 1996.
Should Yolo County continue permitting deep, open pit mines — and approve habitat restoration plans — even if methylmercury from the pits is bioaccumulating in the food web?
Should deep pits be turned over to the public for habitat and recreational use even if they are impoverishing this deeply impaired watershed?
Does maintaining a supply of aggregate to feed the demands of economic growth justify the release of even more mercury into the environment?
