Take a magnet and see if the sand is attracted to it. If so, it is iron slag that is used for sand blasting. It is sometimes called Black Beauty. I would be a little concerned about heavy metal contamination from it though I don't have any info about that happening.

my mistake, black beauty (the name brand stuff) is coal slag not iron slag. Though I have seen black 'sand' that was iron slag and copper slag as well. One time I got some for an aquarium. ugh big mistake since you clean the glass with a magnet. Well super sharp iron slag, magnets, and a big glass box don't make a very good combination.

Likely placer deposit (aka black sand). I believe WA is known for having a fair number of these. Placer deposit black sand is often partially magnetic.

I suppose if it's magnetic it's due to magnetite (or hematite? not sure if that's magnetic). Magnetite is just an iron mineral that happens to be magnetic.

This is a much more likely scenario than a landscaper using toxic used blasting medium. Not that it couldn't happen. OTOH, when I Googled "Black Sand Washington" the first hit was a page about a project to remove and replace a black sand beach that was made up of granulated slag with high levels of metals.

Here is a link that might be useful: Black Sand Beach

tox,

Wouldn't that stuff go to a hazardous waste landfill?

It'a not used blasting sand. They get clean stuff. But I've seen it at rock yards all over the place being sold as black sand at an unreasonably attractive price. one of the reasons they use slag for sand blasting is because sand is in a way more dangerous because of silicidosis.

Like I said, placer deposits - I believe there's a lot of it the NW. It's one of the things the gold prospectors look for.

Now, my experience with the stuff is only in the SW. Sand, gravel, etc are very local products and placer deposits might be cheaper and more available in the NW than the slag. I would definitely ask first though. However if you see Black Beauty, that is a brand name for coal slag.

In addition to asking, a small strong rare earth magnet (they're cheap!) should move the stuff if its "black sand" from a placer deposit - the stuff is mostly mixed iron oxides and is considered partially magnetic.

If you get lucky maybe you'll find some gold, or platinum in it ;-)

I also don't think it's too crazy to think that landscapers are putting slag places when you can go into any BBS and buy a bag of mine tailings loaded with heavy metals beng sold as fertilizer (ironite).

wow tox that beach project was crazy. I did a little more digging to find out how that happened. 90 years of dumping 450 tons of slag a day into the river created that beach. crazy.

Here is a link that might be useful: black sand beach history

tox,

thanks for explaining that - makes sense. I never dealt much with the inorganic solids processing world. Where I've worked in the U.S. pretty much everything fell under RCRA HW, except office waste paper. If it could be burned, it went to our six 9's-plus incinerator which was the preferred method, selected and highly controlled waste water streams went to our HW-water treatment facility. The incinerator was water scrubbed and the water went to the ww facility, then the ash went tour our in-perpetuity HW landfill. Rainfall went into a separate storm sewer that went to HW-waster treatment. The sludge from ww went to the incinerator. Construction debris went to the HW landfill. Round and round it all went. Nothing left the system, save office stuff. The intent was a completely closed system, save air emission (highly permitted and regulated), and outflow form tertiary ww (again, highly permitted and regulated).

Hence, when I read the description of the black sand beach and how it was being handled, it sure seemed like HW to me.

I wonder if it's as simple as just sand mixed with top soil? There's no organic material that I can see.

Ordinary sand mixed with a dark soil or dark organic matter will, upon close inspection, look like a salt and pepper mix. If it's placer deposit black sand it will look fairly uniformly black, and it will readily settle from water to form a black sandy layer on the bottom of a container (the stuff is very dense, like 2X the density of quartz).

Around here, many years ago, landscapers used to sell people spent foundry sand as "topsoil" (hey, its black isn't it?). Today we have a company that dredges the organic matter (tree leaves primarily) from the bottom of one of our lakes, mixes that with sand and some lime (they have MSU test it for pH and call it "state tested") and when it is delivered it looks like decent black dirt. After a light rain, however, the organic matter is washed out and you see the light tan sand.
Sandy soils, because of the very large particles, drain quite well, almost too well, but do not hold nutrients at all and so sand needs lots of organic matter so both moisture and nutrients can be held in the plants root zone. Sand varies in color from light tan (almost white) to black depending on the source. Sand is the largest of the soil particles.

kruise - a simple test for you. Take a "clean" sample of the stuff (don't dig down and get a bunch of dirt). Put it an test tube, bottle, jar or glass, about 1/10th to 1/5th the depth. Add clean water to near the top, then shake or stir to suspend all the stuff in the water, The set it down to rest undisturbed and watch. Sand particles are denser and will settle quickly, and the color will be self evident - silica sand will be pale, placer "black sand" will be black and will settle very quickly.

From the simple soil tests I frequently post.
1) Soil test for organic matter. From that soil sample put enough of the rest to make a 4 inch level in a clear 1 quart jar, with a tight fitting lid. Fill that jar with water and replace the lid, tightly. Shake the jar vigorously and then let it stand for 24 hours. Your soil will settle out according to soil particle size and weight. For example, a good loam will have about 1-3/4 inch (about 45%) of sand on the bottom. about 1 inch (about 25%) of silt next, about 1 inch (25%) of clay above that, and about 1/4 inch (about 5%) of organic matter on the top.

TX, you must have worked at a really serious industrial facility! I'd be curious to know at least the type of industry (if you don't want to name the employer).

I would say the vast majority of waste with chemical contaminants in the US is not HW in the strict RCRA sense. Overseeing the cleanup of contaminated sites, I'd say well over 90% of what gets treated or hauled away ends up in the local sanitary landfill as Special Waste.

tox - like stated over on the sludge thread*, chemical industry, one of the big guys. I don't doubt that most of the stuff hauled off somehow escapes RCRA. In the industry, however, once you are significantly on the RCRA side of things it is probably just easier to live life that way. But to do so, you must have the facilities. The other part had to do with our own ethics and sense of responsibility - we believed in cleaning up after ourselves and not creating problems for others. The biggest issue(s) are typically ancient history, before anyone knew any better.

Then of course there was SARA, CERCLA, TSCA, etc., etc. It always seemed to us that the goal of regulatory agencies was to keep chemicals out of the hands of chemists. :-/

*very nice, and accurate reply to the dialogue on who can throw what into a POTW stream. Two things many forget - the initial generic restrictions without regard to HW classifications (there are a number of them back up at the start of 40 CFR 403, even before you get to HW, and many provide all that is needed to restrict), and state/local POTW ability to restrict.

oops - looks like I departed from gardening topics.
"never mind".

One of the lessons learned from Love Canal and the toxic waste sites we have around here is that chemicals dumped into the ground often combine there and even of they are inert when dumped they combine wit others and create new and very toxic substances. It has taken around 45 years to get enough of these toxins out of the lakes around here so they are in the process of being removed from the EPAs list of hot spots.
We have far too many people that are unaware of history so we are going to repeat the errors of the 1960s and create more hazardous waste sites that will need Superfund cleanup again.

>>The biggest issue(s) are typically ancient history, before anyone knew any better.

And that, in fact, is what I do for a living. Some of my sites have gunk under them that dates back well over a century.

tox - as a good friend of mine once said, "waste is a terrible thing to mind". ;-)

Haha, that's a new one, however surprising that sounds.

Re: creating new contaminated sites, it's certainly happening in many parts of the world. Waste control in the US is a lot better than many places and we don't have the burial of drums and pits full of gunk that we had just a few decades ago. Plenty of job security in places like Asia and Africa and Eastern Europe, though. I've heard some scary stories, and I shudder to think how bad it actually is close up.