APPENDIX A: STEP-BY-STEP TEST PROCEDURES USED IN
LABORATORY SILT FENCE TESTS FOR EAGLE RIVER FLATS, ALASKA
13. Repeat steps 11 and 12 until three samples
Silt fence test procedure
have been obtained.
(from ASTM standard D 5141)
14. Determine the TSS of the three samples ac-
1. Set flume at an 8% grade.
cording to ASTM D 5141.
2. Fasten geotextile across flume opening. Be
sure there are no wrinkles or loose sections.
Silt fence tests for
3. Wet the geotextile with 50 L of tap water.
4. Determine the water content of the soil, and
1. Set flume at a 1% grade, and ensure that the
weigh out 150 grams of dry soil. Record
top of the vertical barrier, located 23.5 cm
weight of the soil.
from the back of the flume, is fastened in
5. Mix the soil in the blender with 500 mL of
water: 10 seconds on low, 10 seconds on high.
2. Mix 9248 g of dry soil collected from ERF
Add the mixture to tap water to make 50 L
ponds in 46.6 L of water. The water should
of soil and water in the top container.
have a salinity of 4.5 ppt, and the soil should
6. Agitate the mixture with the stirrer (paint
be mixed in a blender with the water. The
stirrer on drill) for one minute.
entire mixture should be stirred for one
7. Immediately after stirring, release the mix-
minute and released to the flume. (Note that
ture. Release should take less than 10 sec-
this is a mixture of 16.7% by volume of soil
onds. Start timer at release!
8. Rinse the mixing container with 23 L of
3. Let the mixture stand in the back of the flume
water. Record the total amount of water
until a clear layer of water, 13 cm high, forms.
used. Calculate initial TSS based on the 150
This will take about two hours.
g of soil and the total volume of water.
4. Remove (all at once) the top portion of the
9. Time the flow of water through the geotextile
vertical barrier in the flume.
until no water remains behind the geotextile
5. Catch all of the water and sediment in a large
or 25 minutes have elapsed. If 25 minutes
container. At about eight minutes and 16
elapse, measure the distance from the geo-
minutes after release of the water, scrape the
textile to the edge of the water behind the
downstream side of the geotextile with a
geotextile. Record the time of flow and the
spoon to induce water flow through it. After
distance, if appropriate.
25 minutes, stir the water and material in
10. Collect all of the mixture in a container.
the container for one minute and take three
11. Agitate the mixture with the stirrer for one
depth-integrated samples. Note that the gut-
ter may have to be cleaned out first.
12. After one minute of stirring, obtain a depth-
6. Determine TSS on the three samples accord-
integrated sample while continuing to stir
ing to ASTM D 5141.
the mixture. Record the volume of the sample