Environmental Engineering Reference
In-Depth Information
Seepage Meter Construction and Installation
What you will need:
• 208-L (55-gal) plastic storage drum
• Hand saw for cutting plastic drum
• Permanent marker
• Measuring device
• Power drill (battery-powered or electric)
• Drill bits appropriately sized for the hose-connection hardware
• Hose-connection fittings
• Rubber or cork stopper
• Plastic tub and lid to serve as a seepage bag shelter
• Plastic seepage bag (approximately 3-5 L)
• Tube and fittings to connect plastic bag to hose
• Hose to connect bag shelter to seepage cylinder
• Brick or suitable weight to place on top of seepage cylinder
A seepage meter can be made from many different readily available products.
The standard “half-barrel” seepage meter is described as such because it was made
by cutting the ends off of a standard 208-L (55-gal) storage drum (Lee
1977
).
Although many other cylinders have been used as seepage meters, such as coffee
cans, cut-off trash cans, trash-can lids, even wading pools, the half-barrel meter is
often used because it is rigid, durable, does not readily deform, covers a larger
surface area than many of the other devices, is still quite inexpensive, and can be
easily obtained from many industrial supply companies. A storage drum will be
used in this exercise. First, obtain a storage drum from one of a large number of
suppliers. Either metal or plastic drums can be used, but to simplify construction for
this exercise, you should obtain a plastic drum. Be sure to order a closed-top drum
to eliminate possibilities of leaks associated with an open-top drum where the top
can be removed, and order the larger 208-L (55-gal) drum because it covers a larger
surface area than the 114-L (30-gal) drum. You will make seepage cylinders from
the top and the bottom thirds of the drum.
Mark the side of the drum a consistent distance from one end of the barrel;
commonly, a length of 30-35 cm is used. Connect the dots (marks) by drawing a
line along the circumference of the drum. Use the hand saw to cut along this line to
remove one end from the drum. Repeat this process for the other end of the drum. If
vegetation on the wetland bed is tall and dense, you may instead simply cut the
barrel in half, essentially making two seepage cylinders, each approximately 45 cm
tall. A cross-cut hand saw can be used to cut the plastic drums whereas a cutting
torch or reciprocating saw (or a hack saw used with great persistence) are generally
required to cut a metal barrel. Carefully measure the diameter or the circumference
of the open end of the cut-off cylinder and calculate the area based on either
measurement. This open end of the cylinder will equal the area of the wetland
bed covered by the seepage cylinder. Most 208-L drums will cover an area of about
0.25 m
2
.
