3003 COLBY AVE COURTYARD BY MARRIOTT 2021-03-09

I Proposed Everett Hotel Property Environmental Site Characterization and IEverett, Washington Remediation Recommendations I cleanup indicated no detectable diesel- or motor-oil-range TPH in ground water sample EB-1, and diesel- and motor-oil-range TPH concentrations in the decon water sample were below the MTCA cleanup levels. Gasoline-range TPH and BTEX concentrations in the EB-1 ground I water sample were also found to be non-detectable. Detectable concentrations of gasoline-range TPH and xylenes were measured in the decon water sample, but these concentrations were below the MTCA cleanup level. The analytical laboratory results are I summarized below in Table 4. Copies of the analytical laboratory reports for the ground water testing performed are provided in Appendix B. ITable 4 Summary of Analytical Laboratory Tes ng- Ground Water ITPH(µg/L) BTEX (pg/L) Motor IWell Date Diesel Oil Gasoline Benzene Toluene Ethylbenzene Xylenes EB 1 1/22/09 <50 <250 <100 <1 <1 <1 <3 Decon 1/22/09 310* 280* 170 <1 <1 <1 3 I Water Decon 6/12/09 NT NT <100 <0.25 4.0 <0.25 0.40** Water 1 I Decon 6/12/09 NT NT <100 <0.25 15 <0.25 <0.75 Water#2 MTCA --- 500 500 800/1,000*** 5 1,000 700 1,000 t�/ I TPH = total petroleum hydrocarbons. NT-Not Tested. MTCA = Model Toxics Control Act Method A cleanup level(Chapter 173-340-900 WAC). I All results are presented in microgram per liter(µg/L)units; 1 µg/L is equivalent to 1 part per billion. Values preceded by "<" represent analyte concentrations below the method detection limit indicated. *Results following silica gel cleanup. **O-xylene only; m,p-xylenes were <0.50 ug/L. I ***The cleanup level for gasoline-range TPH is 800 µg/L if benzene is present or 1,000 µg/L if benzene is not present. II Waste Water Analysis Samples of the water generated during decontamination of the drilling equipment was also I collected and analyzed for disposal characterization purposes. At the time of sample collection, the "decon" water was stored on-site in steel drums. The suite of analyses conducted on the sample of decon water generated during our initial field exploration was I similar to that conducted on the ground water sample. Analyses conducted on decon water samples collected at the time of our June exploration were limited to gasoline range TPH and BTEX compounds. The initial analysis of the decon water sample collected at the time of our IJanuary 2009 study indicated detectable concentrations of diesel- and motor-oil-range TPH; however, the laboratory report indicated that the chromatographic patterns produced by the analysis were not consistent with those typical for these petroleum products. Re-analysis of August 24, 2009 ASSOCIATED EARTH SCIENCES, INC. I TJP/tb-KV090168A5-Projects120090168IKVIWP Page 9