button button button button button button button button button
USGS spacer
Patuxent Home button  
button button button button button button button spacer
button spacer


Supplies Needed:

1) SET - the instrument (including carrying case) - Costs run about $2000.

2) 3" PIPE - 20' long, 3" diameter aluminum irrigation pipe. We typically purchase this from an irrigation company. Be sure to order it without flared ends or coupling. These pipes are quite light and run about $25-30 each. You can get pipes in varying lengths. We have settled on 20' lengths. If they are too long they get difficult to transport and handle.

3) CEMENT - 60 LB bag of Mortar mix. Amount used depends on how deep you sink the 3" pipe and how much void space is in the pipe. You should be able to get at least 2 pipes per bag.

4) INSERT PIPE - 2' long, 2" diameter, schedule 40 aluminum pipe with 8 notches cut into it. These are custom built by a machine shop. Costs run about $30-50 each.

5) Hacksaw for cutting the 3" aluminum pipe.

6) Cement trowels and bucket, paper towels, duct tape.

7) Vibracorer or Pounder - used for sinking the 3" pipe.

8) Marker Horizon- We use Feldspar Clay in most circumstances.

9) ½" pvc pipe or fiberglass rods - for marking the feldspar plots


The general procedure for installing the SET Benchmarks is the following:

a) Build a platform
b) Drive the 3" aluminum benchmark pipe into the ground
c) Cement the aluminum pipe and insert pipe in place.
d) Take your baseline SET reading.
e) Lay out your Marker Horizons (optional).

Below are detailed instructions:

A) Step 1 - Establish a platform to work on:

Click here for a details on platform options

B) Step 2 - Install the SET benchmark pipe:

After the platform is built you will need to install the benchmark pipe which the SET attaches to. For installation it's good to have 2 planks as crosspieces since you will normally have two people standing up there (more if you're vibracoring).

Bayou Sauvage NWR, LA
Bayou Sauvage NWR, LA
Bayou Sauvage NWR, LA

1) Install the pipe into the marsh or pond using the pounder or vibracorer (more information). It's important to get the pipe installed as deep as possible since it is essentially going to be a benchmark. For example, a 20' pipe will only go in about 18-19' maximum because of the equipment that attaches to it when sinking it into the ground. In many environments, the pipe will stop moving long before it gets that deep

Everglades National Park
Everglades NP, FL USA

2) Cut the pipe about 12-15" above the marsh surface. NOTE: if you are in a pond the cut is typically 12-24" high (depends on the water depth of the pond).

C) Step 3 - Cement the Pipe:

Cementing the insert pipe.Rachel Carson NWR, ME USA

1) Fill the void space in the pipe with cement. We use "ready-mix" mortar mix (no stones). The amount of the void space to fill depends on the substrate you are working in. For example, in unconsolidated sediments there may be 8- 10' of void to fill. However, in very firm substrates there may only be a foot or two.

2) When there's about 6-12" of void space remaining, push the insert pipe into the top of the pipe and displace the cement up and around the outside of the insert pipe. Tap the outside of the 3" pipe to displace any air bubbles in the cement and help settle the insert pipe in place. Use paper towels to clean off the top of the insert pipe. Make sure the notches are free of cement.

Make sure you have the notches aligned properly which the cement is fluid. The directions of the SET will be permanent once the cement sets.

3) Use duct tape to secure the insert pipe in place. It will tend to float up and out of the 3" pipe if you don't tape it in place until the cement sets.

4) You are finished! Let the cement sit at least one night. We try to let the pipe sit for at least 1 week before taking the first SET readings (called the baseline reading). This may not be logistically feasible in some situations, but it is good to let the pipe and cement settle for a few days if possible.

D) Step 4 - Take your baseline SET reading.

Click here for details on how to take the first readings.

E) Step 5 - Lay out your Marker Horizon (optional)

Click here for instructions on how to establish the marker horizons.