Table 1. Tritium, helium, and neon data, and tritium/helium-3 apparent ages for water from monitoring wells, Portland basin, Oregon, 1997–98.

[Local park or property name: Name of City of Portland park or property where well is located. Sample date presented in month/day/year. Helium-4 and Neon in cubic centimeters per 108 grams water at standard temperature and pressure. Helium-3 reported in percent (%) using standard delta notation. –, not analyzed in replicate]

Site No.	Site name	Local park or property name	Sample date	Tritum (tritium units)	Helium-4	Delta-Helium-3 (percent)	Neon	Apparent age (years)
Environmental Data
453523122433001	01N/01E-07AAC	North Gate	10/20/1997	4.03	5.95	-4.07	25.92	(1)
			04/09/1998	3.85	5.90	-3.72	24.46	(2)
453515122420301	01N/01E-09BCB	Trenton	10/10/1997	8.59	5.74	4.90	22.86	7.1
			04/06/1998	8.65	5.76	8.24	22.72	9.0
453458122412201	01N/01E-09DBB	Kenton	10/09/1997	8.31	5.48	0.05	22.36	3.8
			04/07/1998	8.79	6.88	2.18	25.08	9.6
453447122401501	01N/01E-10CDA	Faragut	10/08/1997	8.88	5.44	-0.62	21.01	6.3
			04/08/1998	8.06	5.45	-1.59	20.97	6.5
453356122372401	01N/01E-13DDB	Fernhill	10/22/1997	7.04	5.18	-3.90	21.24	2.4
			04/20/1998	6.71	5.05	-2.89	20.78	3.3
453419122391501	01N/01E-14BDB	Woodlawn	10/23/1997	7.79	6.25	-14.33	22.81	1.1
			04/22/1998	6.48	5.64	-10.64	21.42	2.6
453317122384101	01N/01E-23DAB	Vernon Tanks	10/24/1997	8.74	7.16	-21.31	22.05	5.6
			04/23/1998	7.98	7.13	-22.61	21.62	6.1
453037122373701	01S/01E-01ACA	Sunnyside	10/06/1997	13.64	5.90	72.87	22.16	20.2
			04/15/1998	12.69	5.84	74.84	22.16	21.2
453032122385201	01S/01E-02DBC	Ladd	10/07/1997	2.17	6.43	2.19	23.31	(3)
			04/16/1998	2.24	6.46	1.71	23.36	(4)
452950122382001	01S/01E-12CBB	Powell	10/21/1997	14.33	7.24	9.24	22.15	13.2
			04/21/1998	12.31	7.61	11.18	21.89	16.8
452927122374501	01S/01E-12DCC	Kenilworth	10/17/1997	7.37	5.90	8.36	23.24	10.2
			04/01/1998	6.26	5.93	4.32	23.54	8.8
452807122392901	01S/01E-23CBA	Sellwood	10/16/1997	6.85	5.83	8.09	24.40	7.0
			04/02/1998	6.14	5.94	6.31	24.90	6.2
Replicate Data (in addition to environmental analyses above)
453523122433001	01N/01E-07AAC	North Gate	04/09/1998	3.83	5.88	-3.26	24.37	(5)
			04/09/1998	–	5.98	-5.04	24.58	(6)
453356122372401	01N/01E-13DDB	Fernhill	04/20/1998	–	5.10	-3.66	20.70	3.6
453037122373701	01S/01E-01ACA	Sunnyside	10/06/1997	13.53	5.85	71.05	21.97	20.0
453032122385201	01S/01E-02DBC	Ladd	10/07/1997	2.12	6.48	2.01	23.33	(7)
			04/16/1998	–	6.51	1.32	23.36	(8)
			04/16/1998	2.26	6.41	3.11	23.42	(9)
			04/16/1998	–	6.46	2.55	23.46	(10)
452950122382001	01S/01E-12CBB	Powell	04/21/1998	11.71	7.60	9.11	21.81	16.9

¹Degassing during sampling; apparent age of -16.3 years reflects degassing.

²Degassing during sampling; apparent age of -1.2 years reflects degassing.

³Apparent age 24.8 years, but affected by mixing

⁴Apparent age 24.2 years, but affected by mixing.

⁵Degassing during sampling; apparent age of -0.4 years reflects degassing.

⁶Degassing during sampling; apparent age of -2.4 years reflects degassing.

⁷Apparent age 25.4 years, but affected by mixing.

⁸Apparent age 24.5 years, but affected by mixing.

⁹Apparent age 24.2 years, but affected by mixing.

¹⁰Apparent age 24.3 years, but affected by mixing.