5200 EVERGREEN WAY 2019-05-29 - Laserfiche WebLink

Former Brien Ford Property Everett, Washington Phase II Supplemental Site Investigation SCOPE OF SERVICES The purpose of this Phase II SSI was to delineate and characterize petroleum-affected subsurface soils at the Property in the vicinity of the former underground storage tank (UST) excavation area. The scope of services completed for our Phase II SSI included the following: • Complete 17 direct-push borings to depths of 15 to 20 feet each at the site. Four borings located in the former dry cleaning building and commercial sales area were completed utilizing a limited-access dolly mounted direct-push drill rig. The remainder of the borings were completed using a truck-mounted direct-push drill rig. • Obtaining soil and reconnaissance ground water samples from the borings for analysis of petroleum hydrocarbons and volatile organic compounds (VOCs). • Evaluating the resulting data with respect to the Model Toxics Control Act (MTCA) soil and ground water cleanup levels. • Preparing this letter-report summarizing the findings of the Phase II SSI. FIELD METHODS Subsurface explorations for collection of soil and reconnaissance ground water samples were completed on February 13, 2017 and March 9, 2016. Direct-push Geoprobe drilling services were provided by Cascade Drilling, Inc. of Woodinville, Washington. An AESI field representative observed drilling activities and collected soil and reconnaissance ground water samples for laboratory analysis. The approximate locations of the Geoprobe exploration borings are shown on Figure 2. AESI requested a public utility locate by contacting the Northwest Utility Notification Center. Prior to the start of exploration work for both drilling dates, private utility locating was performed by Applied Professional Services, LLC (APS). Locating was completed just prior to the start of drilling during each event. Eight of the 17 direct-push Geoprobe borings were advanced to a total depth of 15 feet below ground surface (bgs). Borings GP-16, GP-19, GP-24, and GP-25 were bored to 20 feet bgs due to the presence of petroleum-affected soils observed at 15 feet bgs. Boring GP-23 was only bored to 10 feet bgs due to refusal. Borings GP-18, GP-21, GP-28, and GP-29 were drilled inside the buildings utilizing a limited-access dolly mounted direct-push Geoprobe unit. These four borings were bored to 5 feet bgs due to refusal. The Geoprobe sampler was lined with disposable plastic sleeves that were removed and opened to reveal the sample for each 5-foot driven interval. Soil samples were described and March 31,2017 ASSOCIATED EARTH SCIENCES,INC. TWL/Id-20160594V002-2-Projects120160594VV\WP Page 2