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Pilot Study Workplan May 25, 2018
<br />Diamond Foods Inc. Page 7
<br />On February 15, 2017, injection activities were conducted in the vicinity of monitoring well MW-5.
<br />Three borings, I5-A, I5-B, and I5-C, were advanced to the target depth of 65 feet bgs. Each boring
<br />contained a five foot injection tool that was placed at total depth. A total of 588 gallons of CPS was
<br />injected into each borehole mixed with 725 gallons of water. After injection, a combined amount of 75
<br />gallons of water was introduce to flush the lines and injection manifold of remaining solution. The total
<br />volume of liquid injected on February 15, 2017 was 4,005 gallons.
<br />On February 16, 2017, injection activities were conducted in the vicinity of observation wells OBSW-S
<br />and OBSW-D, adjacent to well MW-3. A five foot injection tool was advanced at boring I3-A, to the
<br />target depth of 75 feet bgs. A second and third injection tool were each advanced at borings 13-B and
<br />I3-C to target depths of 65 bgs. A total of 588 gallons of CPS was injected into each borehole mixed
<br />with 725 gallons of water. After injection, a combined amount of 165 gallons of water was introduce to
<br />flush the lines, the injection manifold, and clean the holding tank of remaining solution. The total volume
<br />of liquid injected on February 16, 2017 was 4,107 gallons.
<br />Results were presented in ATC's We// Installation and Additional Pilot Study Injection Testing Report,
<br />dated May 1, 2017.
<br />3.0 NATURE AND EXTENT OF CONTAMINATION
<br />3.1 CONTAMINANTS IN SOIL
<br />In December 1988, Weiss Associates conducted the initial soil investigations in the vicinity of the
<br />previously referenced vaults to determine whether the vault contents had impacted the soil beneath
<br />the vaults.
<br />The samples collected beneath Vaults 1, 5, and 6 were analyzed for ethylene glycol and propylene
<br />glycol. Initial laboratory results reported ethylene and propylene glycol as detected beneath Vaults 1
<br />and 6. The samples collected beneath Vaults 7 and 8 were analyzed for soluble total chromium,
<br />soluble copper, total sodium, and total sulfate. Additionally the Vault 8 samples were analyzed for
<br />soluble hexavalent chromium, total calcium, and total chloride. All analytes were present at or above
<br />method detection limits beneath Vaults 7 and 8. Based on analytical data from soil samples collected
<br />beneath the vaults it appears that releases primarily occurred from Vaults 1, 6, 7, and 8.
<br />In January 1991, PC Exploration drilled three angle borings (B1-A, B6-A, and B8-A) and three vertical
<br />borings (B1-B, B6-B, and B8-B) in the vicinity of Vaults 1, 6, and 8 under the direct supervision of a
<br />Weiss Associates geologist. These borings were drilled in an attempt to define the extent of soil
<br />contamination and to determine if groundwater impact had occurred. Borings B1-A, B6-A, and B8-A
<br />were drilled to depths of 45.3, 37.6 and 40.8 feet, respectively. Borings B1-B, B6-B, and B8-B were
<br />drilled to depths of 91, 86, and 96 feet, respectively.
<br />In samples collected near Vault 1, glycols were detected in several soil samples collected from angle
<br />boring B1-A, but were not detected in the soil samples collected between 50.3 and 65.7 feet below
<br />grade in the vertical boring samples (B1-B). In Vault 6 glycols were not detected in the soil samples
<br />collected deeper than 33.4 feet in the angle boring (B6-A) and were not present in the vertical boring
<br />samples (B6-B). The soluble total chromium, total chromium, and total hexavalent chromium
<br />analytical results for the Vault 8 samples were below their respective DHS, STLC and TTLC limits.
<br />Although total sodium analytical results did not significantly exceed the sodium background
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