Ariz. Admin. Code § tit. 18, ch. 2, APPENDICES, app 2
The following test methods and protocols are approved for use as directed by the Department under this Chapter. These standards are incorporated by reference as applicable requirements revised as of June 30, 2017, and no future editions or amendments. These standards are on file with the Department, and are also available from the U.S. Government Printing Office, Superintendent of Documents, bookstore.gpo.gov, Mail Stop: SSOP IDCC-SSOM, Washington, D.C. 20402-9328.
A.40 CFR 50;
B.40 CFR 50, all appendices;
C.40 CFR 51, Appendix M, Section IV of Appendix S, and Appendix W;
D.40 CFR 52, Appendices D and E;
E.40 CFR 53;
F.40 CFR 58;
G.40 CFR 58, all appendices;
H.40 CFR 60, all appendices;
I.40 CFR 61, all appendices;
J.40 CFR 63, all appendices;
K.40 CFR 75, all appendices.
L.40 CFR 51.128, Appendix A(1)(B).
M. Silt Content Test Method. The purpose of this test method is to estimate the silt content of the trafficked parts of commercial farm roads, as defined in R18-2-610. The higher the silt content, the more fine dust particles that are released when cars and trucks drive on commercial farm roads.
1. Equipment:
a. A set of sieves with the following openings: 4 millimeters (mm), 2mm, 1 mm, 0.5 mm and 0.25 mm and a lid and collector pan
b. A small whisk broom or paintbrush with stiff bristles and dustpan 1 ft. in width. (The broom/brush should preferably have one, thin row of bristles no longer than 1.5 inches in length.)
c. A spatula without holes A small scale with half ounce increments (e.g. postal/package scale)
d. A shallow, lightweight container (e.g. plastic storage container)
e. A sturdy cardboard box or other rigid object with a level surface
f. Basic calculator
g. Cloth gloves (optional for handling metal sieves on hot, sunny days)
h. Sealable plastic bags (if sending samples to a laboratory)
i. Pencil/pen and paper
2. Step 1: Look for a routinely-traveled surface, as evidenced by tire tracks. [Only collect samples from surfaces that are not wet or damp due to precipitation, dew or watering.] Use caution when taking samples to ensure personal safety with respect to passing vehicles. Gently press the edge of a dustpan (1 foot in width) into the surface four times to mark an area that is 1 square foot. Collect a sample of loose surface material using a whisk broom or brush and slowly sweep the material into the dustpan, minimizing escape of dust particles. Use a spatula to lift heavier elements such as gravel. Only collect dirt/gravel to an approximate depth of 3/8 inch or 1 cm in the 1 square foot area. If you reach a hard, underlying subsurface that is < 3/8 inch in depth, do not continue collecting the sample by digging into the hard surface. In other words, you are only collecting a surface sample of loose material down to 1 cm. In order to confirm that samples are collected to 1 cm. in depth, a wooden dowel or other similar narrow object at least one foot in length can be laid horizontally across the survey area while a metric ruler is held perpendicular to the dowel. At this point, you can choose to place the sample collected into a plastic bag or container and take it to an independent laboratory for silt content analysis. A reference to the procedure the laboratory is required to follow is in subsection (10) below.
3. Step 2: Place a scale on a level surface. Place a lightweight container on the scale. Zero the scale with the weight of the empty container on it. Transfer the entire sample collected in the dustpan to the container, minimizing escape of dust particles. Weigh the sample and record its weight.
4. Step 3: Stack a set of sieves in order according to the size openings specified above, beginning with the largest size opening (4 mm) at the top. Place a collector pan underneath the bottom (0.25 mm) sieve.
Step 4: Carefully pour the sample into the sieve stack, minimizing escape of dust particles by slowly brushing material into the stack with a whisk broom or brush. (On windy days, use the trunk or door of a car as a wind barricade.) Cover the stack with a lid. Lift up the sieve stack and shake it vigorously up, down and sideways for at least 1 minute.
5. Step 5: Remove the lid from the stack and disassemble each sieve separately, beginning with the top sieve. As you remove each sieve, examine it to make sure that all of the material has been sifted to the finest sieve through which it can pass; e.g. material in each sieve (besides the top sieve that captures a range of larger elements) should look the same size. If this is not the case, re-stack the sieves and collector pan, cover the stack with the lid, and shake it again for at least 1 minute. (You only need to reassemble the sieve(s) that contain material which requires further sifting.)
6. Step 6: After disassembling the sieves and collector pan, slowly sweep the material from the collector pan into the empty container originally used to collect and weigh the entire sample. Take care to minimize escape of dust particles. You do not need to do anything with material captured in the sieves -- only the collector pan. Weigh the container with the material from the collector pan and record its weight.
7. Step 7: If the source is an unpaved road, multiply the resulting weight by 0.38. If the source is an unpaved parking lot, multiply the resulting weight by 0.55. The resulting number is the estimated silt loading. Then, divide by the total weight of the sample you recorded earlier in Step 2 and multiply by 100 to estimate the percent silt content.
8. Step 8: Select another two routinely-traveled portions of the unpaved road or unpaved parking lot and repeat this test method. Once you have calculated the silt loading and percent silt content of the 3 samples collected, average your results together.
9. Step 9: Examine Results. If the average silt loading is less than 0.33 oz/ft2, the surface is STABLE. If the average silt loading is greater than or equal to 0.33 oz/ft2, then proceed to examine the average percent silt content. If the source is an unpaved road and the average percent silt content is 6% or less, the surface is STABLE. If the source is an unpaved parking lot and the average percent silt content is 8% or less, the surface is STABLE. If your field test results are within 2% of the standard (for example, 4%-8% silt content on an unpaved road), it is recommended that you collect 3 additional samples from the source according to Step 1 and take them to an independent laboratory for silt content analysis.
10. Independent Laboratory Analysis: You may choose to collect 3 samples from the source, according to Step 1, and send them to an independent laboratory for silt content analysis rather than conduct the sieve field procedure. If so, the test method the laboratory is required to use comes from the from the following text: Procedures For Laboratory Analysis Of Surface/Bulk Dust Loading Samples, (Fifth Edition, Volume I, Appendix C.2.3 "Silt Analysis", 1995), AP-42, Office of air Quality Planning & Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina.
Ariz. Admin. Code tit. 18, ch. 2, APPENDICES, app 2