biochar and remediation of saltwater spill in oil field

Thrilled to find a category for biochar here. Hope someone can help.

About 3 months ago a pipe busted upstream at an old well site from our land and spilled saltwater into our creek. Killed all the wildlife in the water, as expected, ran off the birds, ... killed off a lot of trees. They tell us we're lucky because it hasn't contaminated the ground water or gotten into our soil otherwise. (The creek is in a 18' deep channel.) They came in and flushed out the creek for a couple of weeks, hauled off all the water, etc etc.

Problem is there is still saltwater contaminate in the soil that is leaching into the spring fed water for the creek. They are supposed to be removing all that soil ... if this and that and the other happen. The landowner where the spill happened is balking at letting the oil company in to do remediation, wants to fight them, go to court, and essentially will delay this important part of the remediation.

We want to protect our portion of the creek from further damage and help clean up and residuals on our land. This is where we get to the biochar. I've read a couple of studies where it is being used to remediate heavy metals from stormwater runoff. I also know that it will suck up salt.

So our thoughts are to make some kind of net/sock filled with biochar that we can lay across the creek bed as the water enters our property and then, perhaps, repeat the filter at 3 or 4 more points along the creek as it runs through our property to help suck up the contaminates that were introduced during the spill. And then introduce some filter plants like cattails that can populate the entry point of the creek to help maintain a protection of sorts from upstream contaminants in the future.

We don't, however, have any experience with using biochar and, beyond the stormwater research, I can find no documents on using biochar in this manner for remediation of such an issue.

So, I ask, what are my potential issues with attempting this?
Is it feasible to try even if just as an experiment?
What type of biochar would work best in this situation?
And ... what the heck would I do with the biochar after sucking up all those salts and heavy metals in it? Can it be burned or used elsewhere?  

Thanks!

I can't answer your question but I would like to ask - how certain are you that you know exactly what the heavy metal contaminates are, and their severity? If you do know, this will be useful information for other people here.

Furthermore, I am unable to understand exactly what the connection with the oil company is.

EDIT: Sorry ignore that last part. By the time I finished reading your post I had forgotten your title said the spill was in an oil field.

Is it feasible to try even if just as an experiment?

 Yes.  I don't know of biochar's particular abilities with heavy metals or salts, but I do know that it has the ability to draw stuff into it.

It would be best to know exactly what sort of contaminants you are dealing with for your own sake and understanding, but it is likely not relevant to whether the char will draw materials into it.

I wrote 'char' instead of biochar, because I think that char is likely all that you need in the creek.  I might be wrong with that, but I don't think that you need to inoculate it with biology.  It could be, however, that certain biological communities will help draw more toxins from the water.  

It couldn't hurt, for instance, to include some fungal rich compost tea, which also has a remediating effect.  There are specific fungi that are used in heavy metal contamination remediation that you can search out.  I would focus, though, on getting your charcoal socks across the creek, probably held in place with stakes, and when you feel that they have drawn what they can of the toxins from the water, then either burn them and dispose of the waste ash appropriately, or attempt to further remediate with fungi on land.  

This process with the fungi locks the heavy metals into the biology of the fungi in complex molecules that help make the toxins inert.  It's not fool-proof, from what I understand, but it is vastly superior to doing nothing.  

If you were to burn the charcoal, then burn it in as high a temperature fire as possible, so as to eliminate as much of the harmful smoke as possible.  A rocket stove would be best for such purposes.  I don't know where you would dispose of the ash.  The authorities doing the clean-up might be the appropriate people to accept it.

And your idea of using plants to draw toxins out of the water/purify the water/filter the water is a good one, if the water is clean enough to support them in the first place.  Cattails, rushes, and things like watercress are all able to aid you in the process.  Any aquatic plant will do something to draw toxins.  The cattails and bullrushes are more proven.  You could also, in time, harvest these materials, and dry and char them to utilize them as much as possible for the full series of processes.  

The socks of char, and the plants, act as 'scrubbers' which will definitely help to clean the creek.  To what degree is likely related to your parts per million of the specific toxins per water volume, the volume of flow coming from the contaminated site onto your land, and time.

Good luck with the project.

At the moment we don't know the heavy metal loads in this water but I think I can find out. We are still working with the remediation team and environmental oversight people and the oil company who have, so far, told us everything we have asked. We know what the potential heavy metals are based on those generally found in the saltwater effusions in the oil field, but specifics depend on the type of rock the water was in contact with as it was drawn from the ground and oil. We do know that we still have 3500ppm of salts in the water, which is approaching the low end of salinity but not quite there yet.

I'm trying to move this along quickly so we can do an actual scientific research project with it that can be written up. So I want information from the oil company on the presence of the toxins involved. Now I have to make some biochar quickly to have the volume I need for this project.

Any suggestions as to the type of material to use for the "socks"? Clearly it has to be water permeable and fine enough to retain the char but large enough to span the creek. Water flow is relatively light unless it rains which push a huge amount of water through the system. The creek is about 16 feet wide at the widest point on our property but only 6 to 7 feet wide where it enters our land.

Thanks for your inputs!  

I am in agreement with Roberto's thoughts on this issue your having to deal with Bernie and there are some things you can add to Roberto's ideas.

Fungi are capable of working with char socks (you could even add a mushroom slurry to the socks as you fill them).
Fungi will sequester just about all heavy metals and this would work in unison with all other methods you incorporate to limit/ remediate the possible damage as well as the damage already done.
One of the best documented species for this type of remediation is Oyster mushroom mycelium but all the ground living fungi also do this sort of remediation too, so the more species you can incorporate the better.

Keep us up to date and If I find some other things for you to try out I'll post them here with the how to.

For the socks I would try to find something fairly tightly woven but still permeable (cotton, nylon are probably the two fabrics that are easiest to find and procure, the environmental crew should have some other suggestions and may be able to provide those to you).

Redhawk

Seems like you've got a good plan with some good added advice from dr, redhawk and roberto. I would just add that there is a biological product sold under the names GrowPro and SeaGreen that was specifically designed to deal with saltwater intrusion into ag soils. The manufacturer also states that they believe it has watershed remediating capability. You could possibly use it as an inoculant in your char shock as well as applying it to the soil near the creek. It is a specialty compost extract designed to desalinate southern california farm land, so you may be able to make some version of it yourself but I suspect it will be much faster and easier to purchase it. Good luck

What you think of as saltwater or brine is probably not what the oil companies are referring to. Normal salt is sodium chloride, whereas they are likely using CaCl calcium chloride or KCl potassium chloride, so you may want to ask about that specifically.

While this may not directly answer your question, I have been doing some reading for a work-related application of biochar on saline affected soils for mining rehabilitation and found this interesting article;

http://www.jswconline.org/content/71/6/467

'Results showed that the biochar-amended columns discharged efflux 24 to 40 days earlier than that of the control without biochar (CK). Biochar addition saved 56 to 62 days for the EC values of the efflux to be reduced to 5 dS m−1.'
I don't have access to the full study, so can't really make any comment beyond my interpretation of the summary; biochar may provide a mechanism for increased leaching rates of sodium salts.

Heavy metals are a tricky one, it not so much as what can be done for their presence/removal, yet more a measure of their plant availability and mobility; which is largely driven by pH, modifying which ionic form is available and water solubility.
Biochar may have direct mechanisms for sorbing the charged ions to its surface, not so much changing their ionic form as chemically binding it in a bond stronger than osmotic pressure (I'm guessing, can't be bothered trying to back it up with science ) locking it up beyond plant availability.

Another benefit of biochar may be in its liming effect (depending on biochar); generally raises the pH of the soil, so if the soil is currently acidic it could prove to change bio-availability.

'According to relative heavy metals availability decrement, liming resulted in the strongest effect in extremely acid soils with the highest initial concentrations of available Zn, Pb, Cr and Cd. On the other side, the weakest relative liming effect on heavy metals availability decrement as recorded in moderately acid soils with the lowest initial concentrations of available heavy metals. Considering impact of initial humus content in soil, higher relative liming efficiency of heavy metals availability decrement was determined in soils with higher soil organic matter content and with lower initial concentrations of available heavy metals. '

I actually recall Dr. Elaine Ingham speaking about heavy metal concentrations and the soil food web, and I have read about it in Peter McCoy book Radical Mycology; fungi tend to lock up and bind heavy metals to their biomass, and can actively concentrate heavy metals in their fruiting bodies. So an interesting option could be to make swales, fill with lots of wood chips, and innoculate with some oyster mushroom/other species appropriate to your climate, and then harvest the mushrooms for incineration (wouldn't go eating them)/hazardous waste disposal...
Mycoremediation is a pretty new field of study, so it is an exciting area, which also makes it a bit experimental in nature - I would highly recommend Radical Mycology and read up about the bioremediation options. Also read up on Paul Stammets, has some great articles on bioremediation of hydrocarbon contamination.

Anyways that doesn't really help with your saline problem, but it sounds like biochar may assist in the leaching of salts through the profile, and chemically binding heavy metals; could probably just leave it in the soil, as it would likely have some benefit and the heavy metals may be immobilised. Don't quote me on that.

Not an expert, just a tinkerer.