You know how fracking is so controversial, because applying high pressure to deep formations might cause hydrocarbons to migrate upwards and contaminate shallow drinking water aquifers? Texas has got the next best thing. This article calls it “fracking for uranium” which is just plain wrong. Fracking relies on high pressure to break apart rocks holding oil and gas. Uranium harvesting relies upon geochemistry to leach uranium out of rocks – no high pressure needed – and it has relatively low water requirements. Unfortunately, it does have one other difference that makes it way more controversial: uranium harvesting is occurring within drinking water aquifers.
Here’s how it works. Uranium is naturally present at trace levels in certain rock formations. A company in Texas is injecting oxygenated water into underground aquifers that are normally anoxic. This exposes the rock formations to different geochemistry and induces the uranium to dissolve into solution. Extraction wells recover the uranium-laced groundwater and precipitate out the uranium.
I’m sure the process works, but at what cost? Injection typically acts like a “bubble” that expands outward, with some mixing at the fringes. In other settings, like aquifer storage and recovery, it has already been shown that it’s virtually impossible to completely recover the injected “bubble” due to the mixing at the fringes. If you’re just talking about water storage, as in aquifer storage and recovery, that’s one thing. But we’re talking about intentionally mobilizing a contaminant in a drinking water aquifer. The mixing at the fringes means that uranium is going to stay in the groundwater, and potentially be pulled into someone else’s well eventually.
Maybe it doesn’t seem like a big deal now, especially if the aquifer in question isn’t heavily used. But Texas is really running out of water. The drought hit Texas hard this year, and their response has largely been to push for further conservation, rather than to expand long-term plans for water recycling or desalination (the only two realistic long-term options). So even if energy is at stake, I’d be awfully hesitant to sign away aquifers for uranium leaching, given that there are many sources of energy, but Texas is running short of water sources.