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APPENDIX B <br /> EXPLORATION LOGS AND FIELD PROCEDURES <br /> Underground Utility Locate <br /> Prior to drilling activities, an underground utility locate was conducted in the area of the proposed boring <br /> locations to identify subsurface utilities and/or potential underground physical hazards. The underground <br /> utility check consisted of contacting the public utility alert service (One-call) and hiring a private utility <br /> locating service. <br /> Groundwater Monitoring Well Installation and Development <br /> Soil borings were completed using continuous-flight, hollow-stem auger (HSA) equipment operated by <br /> Holocene Drilling of Puyallup, Washington. The exploration logs were completed based on discrete soil <br /> samples from selected depths obtained during hollow-stem auger drilling using a 2-inch diameter, 19-inch- <br /> long stainless-steel split spoon sampler driven with a 140-pound auto hammer dropped from a distance of <br /> 30-inches. <br /> A monitoring well was installed in each boring. The constructed wells were installed to depths of 40 feet <br /> below ground surface (bgs) and consisted of 2-inch diameter polyvinyl chloride (PVC) with 10 feet of <br /> 0.010-inch slot PVC screen installed between 30 and 40 feet bgs. The monitoring wells were developed <br /> using purge and surge methods and allowed to settle for 2 days after well development and prior to <br /> groundwater sampling. <br /> A representative from our staff observed and classified the soil encountered. Soil in the explorations was <br /> visually classified in general accordance with ASTM International (ASTM) D 2488-94. The boring logs are <br /> presented in Figures B-2 and B-3. <br /> The drilling and sampling equipment was decontaminated before each sampling attempt with a Liqui-Nox@ <br /> solution wash and a distilled water rinse.Soil samples were obtained from the split spoon sampler for field <br /> screening. <br /> Investigation Derived Waste <br /> Drill cuttings and decontamination/purge water generated during drilling activities was temporary stored in <br /> labeled and secured drums on site pending characterization results and removed for permitted off-site <br /> disposal coordinated by the City of Everett. <br /> Field Screening of Soil Samples <br /> Select soil samples obtained from the borings were screened in the field for evidence of contamination <br /> using: 1)visual examination; 2) sheen screening and 3)vapor headspace screening with a photoionization <br /> detector(PID).The results of headspace and sheen screening are included in the boring logs.Soil samples <br /> obtained from the borings for field screening were not submitted for laboratory chemical analysis. <br /> Visual screening consists of inspecting the soil for stains indicative of petroleum-related contamination. <br /> Visual screening is generally more effective when contamination is related to heavy petroleum <br /> hydrocarbons, such as motor oil or hydraulic oil, or when hydrocarbon concentrations are high. Sheen <br /> GEOENGINEER� January 24,2022 1 Page B-1 <br /> File No.0661-108-03 <br />