Appendix A. Quality Assurance and Control of U.S. Geological Survey 2007 and 2008 Geochemical Sampling

Quality assurance and control of geochemical sampling included the collection of duplicate and field blank samples for selected redox-sensitive analytes and Volatile Organic Compounds (VOCs). Field blanks were collected by pumping inorganic blank water and VOC-free water through new clean tubing to determine possible sampling contamination. Complete laboratory quality assurance and control data from TestAmerica (TA) Laboratories is on file with the U.S Geological Survey Washington Water Science Center in Tacoma, Washington.

Duplicate sample results compared favorably for all constituents (table A1). A duplicate sample was collected and analyzed by the National Water Quality Laboratory (NWQL) for organic carbon, manganese, nitrate and nitrite, sulfate, chloride, ethene, and ethane for well MW1-38 and piezometers P1-4 and P1-9. The duplicate results for these constituents agreed within 13 percent. Duplicate samples were collected and analyzed for VOCs at piezometers P1-4 and P1-9 and the concentrations agreed within 30 percent (table A1).

Filtered chloride was detected at an estimated concentration of 0.06 mg/L in the blank sample collected in 2007 (MW1-38), which is small compared to filtered chloride concentrations in environmental samples that were measured at 4.3 mg/L or higher. Dissolved organic carbon was detected at the method reporting limit concentration of 0.40 mg/L in the blank sample collected in 2008 (associated with site 1MW-1). Chloroethenes, chloroethanes, and benzene, toluene, ethylbenze, were not detected in the field blank samples (associated with wells MW1-38 and 1MW-1). Xylene was detected at an estimated concentration of 0.48 µg/L in the field blank sample in 2007 (MW1-38), which is comparable in magnitude to many total BTEX concentrations in environmental samples. No ethene, ethane, or chloroethene, or choroethane compounds of interest were detected in the laboratory method blanks. No changes were made to the dataset based on these quality control data.

Table A1. Quality assurance data collected by the U.S. Geological Survey at Operable Unit 1, Naval Undersea Warfare Center, Division Keyport, Washington, June 2007 and June 2008.

[Well or piezometer No.: D denotes duplicate sample; FB denotes field blank sample. Volatile organic compounds (VOCs): PCE, tetrachloroethene; TCE, trichloroethene; cis-DCE, cis-1,2-dichloroethene; trans-DCE, trans-1,2-dichloroethene; VC, vinyl chloride; TCA, 1,1,-trichloroethane; 1,1-DCA, 1,1-dichloroethane, CA, chloroethane; 1,1-DCE, 1,1-dichloroethene; BTEX, benzene, toluene, ethylbezene, and xylene; CVOCs, sum of all chloroethenes and chloroethane concentrations shown in table. Abbreviations: mg/L, milligrams per liter; nd, not detected; mg/L, micrograms per liter; nd, not detected. Symbols: <, actual value is less than the value shown; –, not analyzed]

Well or piezometer No.	Date sampled	PCE (µ/L)	TCE (µg/L)	cis-DCE (µg/L)	trans-DCE (µg/L)	VC (µg/L)	Ethane (µg/L)	Ethene (µg/L)	111-TCA (µg/L)	1,1-DCA (µg/L)	CA (µg/L)	1,1-DCE (µg/L)
P1-4	06-19-07	<40	<40	1,500	24	280	E11	E29	<40	<40	<80	<40
P1-4D	06-19-07	<80	E44	2,400	E28	470	E10	E28	<80	<80	<160	<80
MW1-38FB	06-21-07	<1.0	<1.0	<1.0	<1.0	<1.0	–	–	<1.0	<1.0	<2.0	<1.0
MW1-38	06-17-08	–	–	–	–	–	–	–	–	–	–	–
MW1-38D	06-17-08	–	–	–	–	–	–	–	–	–	–	–
MW1-5	06-18-08	–	–	–	–	–	E7.0	<50	–	–	–	–
MW1-5D	06-18-08	–	–	–	–	–	E6.0	E8.1	–	–	–	–
P1-9	06-18-08	<400	9,700	13,000	E80	2,000	12	160	<400	<400	<800	<400
P1-9D	06-18-08	<800	12,000	16,000	<800	2,700	11	150	<800	<800	<1,600	<800
1MW-1FB	06-18-08	<1.0	<1.0	<1.0	<1.0	<2.0	–	–	<1.0	<1.0	<2.0	<1.0

Well or piezometer No.	Date sampled	Total		Dissolved oxygen (mg/L)	Filtered NO2 + NO3 (mg/L)	Filtered (dissolved) organic carbon (mg/L)	Filtered manganese (mg/L)	Filtered iron (II) (mg/L)	Filtered sulfate (mg/L)	Unfiltered sulfide (mg/L)	Dissolved methane (mg/L)	Dissolved carbon dioxide (mg/L)	Filtered chloride (mg/L)
		BTEX (µg/L)	CVOCs (µg/L)
P1-4	06-19-07	66	1,800	<0.1	<0.06	7.1	0.35	3.2	4.70	<0.01	2,500	26	43
P1-4D	06-19-07	ND	3,000	<.01	<.06	7.4	.35	3.1	4.78	<.01	2,600	29	43
MW1-38FB	06-21-07	0.48	ND	–	<.06	<.40	<.20	–	<.18	–	–	–	E.06
MW1-38	06-17-08	–	–	.1	<.04	5.0	.04	.03	2.51	.02	620	<10	230
MW1-38D	06-17-08	–	–	.1	<.04	5.1	.04	.03	2.69	.02	–	<10	220
MW1-5	06-18-08	–	–	–	–	–	–	–	–	–	1,800	–	–
MW1-5D	06-18-08	–	–	–	–	–	–	–	–	–	1,600	–	–
P1-9	06-18-08	ND	25,000	<.1	<.04	10.5	.17	.07	7.89	<.01	740	<10	28
P1-9D	06-18-08	ND	31,000	<.1	<.04	11.4	.16	.07	8.04	<.01	730	<10	26
1MW-1FB	06-18-08	–	–	–	–	.40	–	–	–	–	–	–	–