Environmental Engineering Reference
In-Depth Information
Fig. 3.44 Half-barrel seepage cylinder showing ports installed both in the top and the side of the
cylinder. A section of garden hose with female garden-hose connectors on both ends (not shown) is
used to connect the bag shelter to the seepage cylinder
Next, you will need to drill a hole in the side of the drum, near the drum end, to
which a short hose will be attached (Fig.
3.44
). The short hose will extend from the
seepage cylinder to a seepage-bag shelter that will protect the bag from wind and
waves, curious animals, and diving ducks (Fig.
3.45
). The diameter of the hole will
depend on the hardware that you use to attach the hose to the seepage cylinder.
There are many different options available. Water flows through a seepage meter
under very low pressure. The fitting should not leak under small pressures but you
do not need to go to the expense of installing a water-tight bulkhead fitting either.
Lastly, drill a small hole approximately 0.5-1 cm in diameter at the highest point of
the seepage cylinder (vent hole identified in Fig.
3.1
). This will be the vent for
releasing any gas that is trapped during seepage-meter deployment. This hole will
be open during installation of the seepage cylinder and then plugged with a rubber
or cork plug during operation. If substantial amounts of gas are generated, a
common situation in many wetland settings, you may need to install a vent tube
that will extend above the water surface so that gas can be released to the atmo-
sphere during seepage-meter operation (Lee and Cherry 1978).
