SOP No. EM - 6 Page 1 of 4

Collection of Soil Samples

Revision: #9 Replaces: 10/31/13 version Effective: 9/3/19

1. Purpose and Scope: Contamination of soil maybe associated with unintentional pesticide

releases such as spills. Sampling of such sites is usually designed to (a) delineate a

contamination plume and/or the intensity (i.e., the concentration) of the contaminant and (b)

confirm and document satisfactory clean-up or decontamination of residue at a site where prior

sampling indicated the presence of unacceptably high residue levels.

Pesticide residues in the soil also result from the intentional introduction of chemicals to control

insects, weeds or other pests. Soil samples for residues originating in this manner are usually

collected to: (a) confirm that an application was made correctly; (b) confirm that estimated

residue levels for environmental fate models used to conduct risk assessments were correct; (c)

complete one phase of an effort to track movement of residues in the environment (e.g., 

vegetation, soil, runoff); and (d) determine whether or not residues accumulate in soil. 

Review the instructions contained in an applicable Environmental Monitoring Plan (EMP) before

collecting soil samples. Program-specific sampling instructions in EMP will take precedence

over those contained in this SOP. 

2. Supplies Required: To request sampling supplies, contact the monitoring supplies 

coordinators, Lisa Mosser (305) 278 4902, or Richard King (305) 278 2905, Center for Plant 

Health Science and Technology, Miami, or email the Environmental Monitoring Supplies 

Checklist to lisa.k.mosser@usda.gov or richard.a.king@usda.gov.

2.1 hand garden trowel

2.2 aluminum foil

2.3 heavy-duty soil core sampler 

2.4 3-gallon, galvanized pail

2.5 1⁄4 inch mesh screen

2.6 sample containers consisting of heavy aluminum foil lined envelopes 

2.7 strapping tape 

2.8 field log book 

2.9 ice chest and either wet ice, dry ice or reusable ice packs (obtain locally)
SOP No. EM - 6 Page 2 of 4

Collection of Soil Samples

Revision: #9 Replaces: 10/31/13 version Effective: 9/3/19

2.10 APHIS Form 2060, Environmental Monitoring Forms 

2.11 indelible marker

2.12 sanitary wipes.

3. Sampling Soil at Spill Sites.

3.1 When collecting samples from spill sites, wear appropriate personal protective 

equipment (PPE) as noted on the pesticide label or in the Material Safety Data 

Sheet (MSDS).

3.2 When collecting more that one sample at a site where highly contaminated soil 

may be present, select sites along a transect that is perpendicular to the suspected 

concentration gradient. Sample outside the contaminated area first, and continue 

to sample from locations least likely to be contaminated to those likely to contain 

the highest residues. 

3.3 To prevent contamination, line a galvanized pail with aluminum foil. 

3.4 One soil sample consists of a composite of five soil cores (see Figure 1 for 

suggested core sampling pattern). Each core should be collected at the surface to 

a depth of three inches (7.5 cm). No one core should be more than 10 feet from 

any of the other four cores.
SOP No. EM - 6 Page 3 of 4

Collection of Soil Samples

Revision: #9 Replaces: 10/31/13 version Effective: 9/3/19

3.5 Each core should be placed in the foil-lined pail. If necessary, collect additional 

cores to ensure that sufficient soil is collected to fill the foil envelope to within 

two inches of the top. 

3.6 If muddy, place cores directly into a heavy foil envelope (do not attempt to sieve 

and mix samples, as described in 3.6 and 3.7, if a sample is too muddy to pass 

through the mesh of the sieve). 

3.7 Using a clean garden trowel, thoroughly mix the sample (the soil cores should be 

reduced to fragments small enough to pass through a 1/4-inch sieve). 

3.8 Sieve the sample (using the 1/4-inch wire mesh sieve) to remove twigs, leaves and 

other debris. If necessary, use a garden trowel to work the soil through the mesh. 

Use a doubled-over piece of aluminum foil approximately 18 x 18 inches or 

another galvanized pail lined with foil to catch the sieved soil. 

3.9 Fill the foil envelope, leaving about 2 inches of space at the top. Using the 

strapping tape, securely seal the foil envelope and then label it using the indelible 

marker with a code that will allow the sample to be matched with its 

documentation. 

3.10 Handle differently and separately from other samples because these samples have 

the potential to contaminate shipping containers, freezers and other samples. 

Place samples directly into a heavy cardboard box (not an ice chest) for shipping. 

Shipment in an ice chest could cause the Styrofoam to become contaminated. 

Unless directed to do so by the lab or the Environmental Compliance Team, it is 

not necessary to freeze samples from spill sites, so once samples are collected 

they should be shipped. Do not ship any other samples with these samples. 

Shipping with other samples could contaminate the other samples. 

3.11 Decontaminate all of the sampling equipment. Rinse equipment with a jet of 

water so that any adhering soil is dislodged and removed. Wipe the equipment 

with sanitary wipes. Discard the wipes after cleaning a single set of sampling 

equipment. 

4. Sampling Soil from Non-spill Sites.

4.1 Line a galvanized pail with aluminum foil. 
SOP No. EM - 6 Page 4 of 4

Collection of Soil Samples

Revision: #9 Replaces: 10/31/13 version Effective: 9/3/19

4.2 Measure or pace off a one acre plot (a square 209 feet on a side encloses one acre) 

and divide the plot into four quadrants. 

4.3 Using a core sampler, collect a composite sample consisting of at least four 3-inch 

deep soil cores, from four different randomly selected spots within each quadrant, 

for a total of 16 cores. Each core should be placed in the pail lined with 

aluminum foil. 

4.4 Follow procedures for soil sampling already described for sampling at a spill site 

(section 3). 

4.5 Store samples in an ice chest with ice, dry ice or frozen freezer packs until it can 

be transferred to a freezer for storage prior to shipping. 

5. Documentation:

5.1 Record observations in the field log book (see SOP EM - 12, Using a Field Log 

Book). Draw a site map, including an approximate scale and North arrow, 

showing the location of the sample collection site and its relation to the treatment 

site and any sensitive area that might be near by. A topographical map or aerial 

photograph annotated with the required information should be provided if 

possible as well as photographs and a video of the sample collection site. Be sure 

to record the type of and density of ground cover and any canopy over the site 

where the sample was collected. Determine the soil characteristics (e.g., clay, silt, 

sand), land slope and if apparent, the direction of surface run-off (see SOP EM - 

13, Taking Measurements for the APHIS 2060 Form) 

5.2 Complete an APHIS Form 2060 for each soil sample. 

5.3 Retain the pink copy for your records and distribute the remaining copies as noted 

on the bottom right hand corner of each copy of the APHIS Form. 

6. Packaging and Shipping:

6.1 Package and ship the soil samples as described in SOP EM - 17, Packaging and 

Shipping of Samples, except highly contaminated soil samples from spill sites 

which are packaged as described in section 3.10 above. Call Richard King or 

Lisa Mosser, above, before shipping highly contaminated samples so that they 

can prepare to receive them.