covering a hugel with sand?

Real quick, I can arrange for the local canal maintenance dept. to dump truck loads of sand onto the property for free. With the overall intention of creating a sound-break from the traffic on the highway, my question is if covering a hugel with sand is a waste of time and a definite no-no? Other than that I assume it would just be a much slower working process, which is still ok with me. Since my main hope is to create an enormous barrier, I think in the long run it would be worth my time to arrange this, any thoughts? There are several sawmills in the area and I am sure they could contribute to the primary pile of biomass but the dominant material in this enormous mound would be sand. Thanks!

If I was able to get free sand delivered and I needed to create a berm sound barrier, then I would go with it, unless it was possible to get the native dirt for free.

I would then add as much wood chips & biomass as I could get my hands on.

If you have access to dig out the dirt where you would like your hugel berm and put this dirt on top of your berms, then most of your plants would likely be quite happy with the lower levels of the berm with sand and the upper layers of woodchips and natural soil. You might like to test the ph of your berms to make sure your plants like the ph level of your berms.

If you are unable to dig out the natural dirt and lay that on top of your sand berm, then continue adding wood chips and if you can get access to your native dirt.  The wood chips and other biomass are key to making any dirt or sand a great growing medium.

The thing I like about permaculture is that one can always improve the dirt, soil or sand with wood chips or other biomass to make things grow in them.  Just choose your plants in accordance.

Some of the most poisonous substances used by humans, are in antifouling paint, which covers the bottom of Commercial and Military ships. These things accumulate in the bottom mud of canals, and around marinas.

I can't think of any other location more likely to produce contaminated soil, than in the bottom of a ship canal. There are likely to be heavy metals, petroleum and any other product that has ever been dumped into that canal.


Edit.
I just left a mobile view for a minute, so that I can see where you are. I doubt that Idaho has the type of ships I was talking about. Are these canals, or drainage ditches, or some other type of trench?

This canal is diverted from a river and used for hydroelectric. A giant inflatable dam diverts water into the canal, and when it accumulates too much sand, the dam is deflated and heavy machinery goes in to remove the material, it is quite the maintenance project. Upstream lies about a couple hundred miles of river to the headwaters in the mountains. I expect the ick in the sand to consist primarily of runoff from agricultural (alfalfa) and livestock (cattle). You do bring up a good point though, I should get a sample of this sand tested before I bring any on the property.

My property is on glacial sand.  We built huglebeds 4 years ago when we first moved in.   The sandy drains so well that the huglebeds dry out fast and we are struggling to get the organic matter up high enough to solve this problem.   They are home to lots of little critters that wipe out about a 1/3 to half of my garden every year.

It is good to test the sand for chemicals etc... But since a lot of the water is coming from the mountains, the sand might not be so bad.

Having a berm out of sand verus the whole land sandy is quite different.  If you dig out a swale under the berm then the sand berm will actually trap moisture because there is a hidden swale. I am assuming that your land is mostly clay.  So you may not have as much issues with water retention in your sand berm.  Plus, you can always plant the water hungry plants lower in the berm and the more drought resistant plants higher.  Plus you have access to large quantities of wood chips.    Make sure that you have a cover crop growing as it retains moisture in the ground.  

We have done lots of work with small berms.  In our case it was to raise our sea buckthorn shrubs above the water table.  We then layered about 4 to 6 inches of wood chips from a local firewood harvester.