3003 COLBY AVE COURTYARD BY MARRIOTT 2021-03-09

1 Proposed Everett Hotel Properly Environmental Site Characterization and Everett, Washington Remediation Recommendations typically constructed of steel. The magnetometer survey indicated the presence of a ferrous metal object near each of borings EB-1 and EB-2; however, both objects appeared to be relatively small. Although the presence of the USTs cannot be ruled out by the findings of the ' magnetometer survey, the apparent small sizes of the objects detected makes it appear unlikely .4---- that they are USTs. The findings of the Phase II ESA were presented in our report titled Phase II Environmental Site Assessment, Everett Hotel, prepared for Touchstone Corporation, dated February 5, 2009. Additional exploration for our current study was conducted in June of 2009 to further characterize the subsurface conditions and the extent of petroleum hydrocarbon impacted soil identified during the initial drilling event. Field screening techniques used and analytical testing results for both the Phase II ESA, and our current study are discussed in the following report sections. 2.2.1 Field Screening During drilling, a portion of each of the soil samples recovered from the borings was field- screened for the presence of volatile hydrocarbons using a photoionization detector (PID), as well as visual and olfactory observations. Field screening was conducted by placing the sample in a sealed zip-lock bag and allowing the sample to equilibrate to ambient temperature. The seal on the bag was then partially opened, the probe of the PID inserted inside the bag, and the air in the headspace of the bag screened for the presence of volatile organic compounds with the PID. The PID was calibrated using a 100 part per million (ppm) isobutylene gas I standard. Because petroleum products, such as gasoline, diesel, and motor oil, are composed of many different compounds, the values recorded by the PID do not provide a true quantitative measurement of volatile organic compounds in the headspace of the bag. However, they do provide a semi-quantitative measurement of the relative concentrations of volatile organics present. Volatile organic compounds detectable by the PID are limited to those having an ionization potential of less than 10.2 electron volts. This includes many of the compounds present in petroleum products. Natural background levels of volatile organic compounds (VOCs) detected by the PID are affected by such factors as temperature and humidity. Background PID values measured at the time of our January 2009 study generally ranged from 0 to 4 ppm. Background PID values measured at the time of our June 2009 study generally ranged from approximately 2 to 33 ppm. Elevated PID readings accompanied by a petroleum hydrocarbon odor were encountered in borings EB-5, EB-7, and EB-10. The depths over which elevated PID readings and/or petroleum hydrocarbon odors were observed are summarized below in Table 2. 1 1 August 24, 2009 ASSOCIATED EARTH SCIENCES, INC. 1 TJP/tb-KV090168A5-Projects1200901681KVIWP Page 6