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Well... I've hauled about 250 lbs of scale infested cactus to the dump, pruned and white washed some fruit trees that were heavily neglected, and got back the results of my soil test for my new property.

Sadly my soil is in a city that is "worst" in the state for agriculture and on my property is harboring dangerous levels of lead, arsenic, and other heavy metals from tailings (mining runoff). So... I've decided on raised beds.

That being said, as I'll be carefully growing my food in Birdie raised beds, I still want to help remediate the soil. Does anyone have experience?

Obviously it's a multi year effort. I'm thinking laying mulch in the form of wood chips or straw between the beds, watering to help break down, then cover planting a plant that helps uptake the harmful chemicals / heavy metal and then removing to the dump and starting the process over? Thoughts?

Well... I've hauled about 250 lbs of scale infested cactus to the dump, pruned and white washed some fruit trees that were heavily neglected, and got back the results of my soil test for my new property. Sadly my soil is in a city that is "worst" in the state for agriculture and on my property is harboring dangerous levels of lead, arsenic, and other heavy metals from tailings (mining runoff). So... I've decided on raised beds. That being said, as I'll be carefully growing my food in Birdie raised beds, I still want to help remediate the soil. Does anyone have experience? Obviously it's a multi year effort. I'm thinking laying mulch in the form of wood chips or straw between the beds, watering to help break down, then cover planting a plant that helps uptake the harmful chemicals / heavy metal and then removing to the dump and starting the process over? Thoughts?

6 comments

[–] thelabwitch 9 points (+9|-0)

Hi. Chemist and hydrologist here. You could potentially have the soil washed, but its gonna cost you, and there's no guarantee it will solve the issue if the groundwater is contaminated. It will just seep back in. If its just the topsoil, you could just have it scraped off and replace it. None of these solutions are cheap though. Is the mine company at all liable? Sometimes there's remediation money held in a trust somewhere (rarely).

[–] Nasrin [OP] 3 points (+3|-0)

Sadly the mine is over 100 years old and my house is close to 100, the original mining company sold the mine and while the original company holds liability they have declared chapter 11 to avoid responsibility for remediation.

My soil is after three inches or so, caliche and rock with mine tailing contamination. This I'm hoping to uptake with plants to pull out the chemicals and heavy metal over time, hopefully building actual topsoil in the process. While that won't remove everything, I'm wondering if that will, over approximately 3-5 years result in viable soil I could use for vegetable planting that is safe to eat.

[–] thelabwitch 1 points (+1|-0)

Yeah that's one strategy. You'll want plants that are very water-thirsty. Indian mustard, sunflowers, willows, water hyacinth...things like that will get the job done fastest. Plant and sequester those every year for maybe 3 years and then retest to see if its making headway. If not, then more contaminants are upwelling from the ground and the area is effed.

[–] Nasrin [OP] 1 points (+1|-0)

Thank you so much for the advice!

Luckily we know that the tailings from the mine are now contained, it's just this horrible quest to fix it. Since I'm so rural (150 miles from the nearest city or other town) I'm really hopeful that if my method works out we can adopt it in the community and all collectively help rejuvenate the earth and make healthy dirt to grow the food we all desperately need.

[–] Chickpea 3 points (+3|-0)

I don’t have any direct experience but I had this article saved from my composting search that may be helpful. It sounds like it’s more of a bandaid fix than a permanent one but it could still be useful for keeping some metals out of the plants if using non-animal compost. It’s also a great way to recycle produce that would’ve been thrown out, so a win either way.

Article here

[...] inorganic contaminants such as metals cannot be broken down by composting instead they are transformed into a lesser bioavailable form (9). The humic substances and iron oxides present in compost binds to metals in soil and limit the availability of these metals for plant uptake (9).

Compost is a cost effective and natural way of restoring soils. It is environmentally friendly and more likely to gain public acceptance.[...] A study by researchers in Britain showed application of compost or fresh organic waste reduced the accumulation of Cu, Pb, Zn, and As in plants grown on metal polluted mine soils (8).

[–] Nasrin [OP] 4 points (+4|-0)

Thank you! If I'm understanding correctly it is in line Auth what I'm saying in regard to the inability to compost the cover crop because it won't assist in getting rid of the heavy metals and chemicals but would make them less likely to uptake into my food crop.

Since the levels are so insanely high my thought is to (sadly) take the cover crop and dispose of it for safety and keep pushing this process to help extract into the plants the harmful metals and chemicals over time.