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December 11, 2013 Project BL-13-05167 Marcus Zbinden Carver County Government Center Services Building 600 E 4th St Chaska, Minnesota 55318 Re: Double Ring Infiltrometer and Permeability Test Results Arboretum Compost Pads Highway 5 Chanhassen, Minnesota Dear Mr. Zbinden: We are pleased to report that the in-situ double-ring infiltrometer and laboratory permeability testing have been completed for the Arboretum Compost Pads project in Chanhassen, Minnesota. This letter documents the procedures we used, and the attached test report indicates the results of this testing.

Background Double Ring Infiltrometer The purpose of our testing was to provide an estimate of the soil’s infiltration rate as determined by the double-ring infiltrometer (DRI). Testing was performed in general accordance with ASTM International (ASTM) D 3385; Standard Test Method for Infiltration Rate of Soils in Field Using a Double-Ring Infiltrometer. A DRI test apparatus is composed of two metal cylinders, an inner ring 12 inches in diameter and an outer ring with a diameter of 24 inches. The rings are 18 inches in height and are driven partially into the ground, then filled to an approximate level of 5 centimeters with water. We then record the rate at which the water infiltrates into the soil. The test is performed using potable water and the flow rate is measured using a flow meter (course-grained soils) or a Mariotte tube (fine-grained soils) based upon soil type present at the test elevation. The infiltration rate is measured until saturation has occurred and the flow rate is relatively constant which varies based on soil type. The locations of the infiltration tests were given by Mr. Marcus Zbinden of Carver County. Excavations to reach the test elevation for DRI-2 were performed using a front end loader operated by a subcontractor provided by you.

Carver County Project BL-13-05167 December 11, 2013 Page 2

Laboratory Permeability Testing The purpose of the laboratory permeability testing is to provide an estimate of the soils coefficient of permeability as determined by the standard test method for permeability of granular soils constant head test. Testing was performed in general accordance with the ASTM International (ASTM) D2434-68 (2006). The permeability testing consisted of remolding of the sampled material to a density that is representative of the level of compaction as tested in the field with a nuclear density gage. The material is prepared in a soil specimen cylinder of known diameter with a porous stone placed at the top and bottom of the prepared sample. The head is maintained constant throughout the test by an overflow pipe at the inlet and a constant head chamber at the outlet. Water is run through the sample until saturation has occurred. The volume of water that flows through the sample after saturation has occurred is measured over a given time period at a constant head.

Results The results of the tests are attached to this report. A summary of the tests follows in Table 1 and Table 2 below. Laboratory permeability results are shown in the table in English units for comparability. Table 1: Summary of DRI Test Results

Test Location

Location Soils at test

location

Percent Passing

#200 Sieve Moisture

Average Infiltration

Rate

DRI-1 Main

Compost Pad GP-GM 15% N/A 0.19 in/hr

DRI-2 Native Soil MLS 50% 15% 0.78 in/hr

DRI-3 Test Pad 2 GP-GM 15% N/A

4.84 in/hr

Table 2: Summary of Laboratory Permeability Results

Trial # Relative Compaction

Temperature, Celsius

Head (cm)

Hydraulic Gradient

Velocity (in/hr)

Coefficient of Permeability (in/hr)*

1 90.6 15.3 .6 0.03 37.42 1261

2 90.6 15.0 1.4 0.08 66.33 878.7

3 90.6 15.2 1.8 0.11 77.95 807.9

4 90.6 15.1 2.2 0.13 96.80 822.0

*Average coefficient of permeability (@20°C) = 935.4in/hr