Crystalline Substance on gravel in crawl space

Need some advice. Never seen this before. Inspected a crawlspace today. The dirt floor had been covered with a heavy 6mil plastic and then 2-3 inches of pea gravel was added.
The gravel over a considerable area of this floor was damp and had a crystal like substance on it. Looked like salt crystals. Any idea what this might be?

In addition, digging down through the gravel, the plastic itself was wet. Found no efflorescence on the concrete walls. The drainage around the house was positive. Any thoughts on why the gravel and topside of the plastic is wet?

Thanks for your help

Probably Salt Crystals

Not good!

Water getting onto plastic from
(1) condensation on floor framing then dripping down
(2) plumbing leakage (found a laundry drain never connected in a crawlspace of a realtor’s house in an upscale town near here.
(3) leakage from the exterior
(4) uneven ground with dips in grade in combination with a high water table in certain conditions

More info would help is it vented to the out side if so this could be the cause Cool floor warm moist air condences on colder floor .
A dehumidifer set at 50% drained to a sump could help .
Read this send me your phone and I will call … Roy

photos??

Is there a water softener and does it discharge into the crawlspace?

Here are a couple of pictures. Upon closer look, I noted a lot of moisture in the gravel around the sewer waste lateral connection in the crawlspace. The PVC connection to the cast iron appeared to be tight and I could not find any evidence of leaking or condensation along the PVC. There is also some “mold like” substance visible on the foundation wall by the pipe. Also found similar patches of “mold-like” material in other corners of the crawl and unfinished basement. The camera also picked up what appears to be some efflorescence on the galvanized ducts. There is definitely excessive moisture in the crawl space.
Possible contributors may be significant vegetation growing right next to the house on all corners of the crawl space. All downspouts discharge above grade on to short (12-14 inch) concrete splash guards, so water is not being properly diverted away from the house.
This area is not vented, but it does directly connect to the basement. The opening between the basement and the crawl has been finished with two doors (hatches) providing access to the crawl area. The majority of the wet gravel is on the right half of the crawl as viewed in the photo.

Thanks for any and all input.

I was going to say effervescence on the material the arrogate is made of.
Did you do a moisture reading of the earth or arrogate?
Sample of the joists.
The joists look like ceder. Is the home near salt water?