Friday, October 26

It's egg nog season!


Ah... sweet, sweet egg nog...

The Job.

Here's an illustrated guide to my new job.
The purpose of what I'm doing is to try and find locations of groundwater contamination from an industrial spill of some sort. Stone (my company) is subcontracted to collect the water samples from various depths: 50-500 feet down or so, in 10 foot intervals. In order to do that, we have to drive our probe into the ground. But we can only drive it so deep before we risk breaking something. The probe looks like this:

So a drilling company drills to a certain depth with hollow rods. We put our probe down through the insides of their rods, hammer it as far as we need to using a GeoProbe, and take a sample. As we're driving it down, it collects data as we go, which looks like this:

Once we get to a set depth (those 10' intervals) or a place where there's enough water flow to sample, we go into sample mode. At this point, the drillers get to take a break for a few hours while we work the magic "box". Basically, via stainless steel tubes, the water/gas/sample is collected from depth, and is run through the "box". See below:

Drill rig. Stainless steel tubes leading from rods to the "box".

The "box". Lots of tubing and valves and such... Whee!

A closer look at the various controls...
Basically, gas (nitrogen) is sent down the rods to the probe. Via some simple valves and things, the water in the probe is pressurized and sent back up the rods. Once it gets to the surface, we collect the water that has come up the hole. All this is done by turning those various knobs...
Once we begin to get a sample, the data shows up on a computer (via a HydroLab sonde). See below for that:

Once things have stabilized (e.g. all the drilling mud is out of the sample water), we record it on the computer, and also in a log, below:

After that, we collect the sample, give it to a guy, and repeat the process, every 10 feet or so down the hole. Collecting the sample can take as long as 2 hours if the flow is bad, so it takes quite a while to do an entire hole. When I started, we were finishing up a 510' deep one. This past shift, we started and completed a 380' hole, and moved to a new one (in the pictures) that will also be to 380'. So far, we're down to 120'. So I guess it takes a bit less than a shift (10 days) to do a hole. The site we're at now is sandwiched between a railroad and a garbage truck depot. Really nice pleasant place. Lovely...
Here's some other shots of the work site.

View looking out of the truck.

The Stone truck and a water truck (for drilling mud). Note the bundles of coiled stainless steel tubing...

View from the front.