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	Annual Toxics Summary Simi Valley-Cochran Street FAQs Perchloroethylene parts per billion

Read About Estimated Risk

Year	Months Present	Minimum	Median	Mean	90th Percentile	Maximum	Standard Deviation	Number of Observations	Detection Limit	Estimated Risk
2023		*	*	*	*	*	*	0	*	*
2022		0.005	0.005	*	0.01	0.01	0.002	16	0.01	*
2021		0.005	0.005	*	0.01	0.02	0.004	23	0.01	*
2020		0.005	*	*	*	0.01	0.002	9	0.01	*
2019		0.005	0.005	0.007	0.01	0.02	0.003	30	0.01	0.8
2018		0.005	0.005	0.006	0.01	0.02	0.003	31	0.01	0.7
2017		0.005	0.005	0.006	0.01	0.03	0.005	30	0.01	0.7
2016		0.005	0.005	0.013	0.02	0.08	0.016	31	0.01	1
2015		0.005	0.005	0.011	0.01	0.09	0.016	28	0.01	1
2014		0.005	0.01	0.014	0.03	0.04	0.010	28	0.01	2
2013		0.005	0.01	*	0.02	0.07	0.012	26	0.01	*
2012		0.005	0.01	*	0.02	0.04	0.010	20	0.01	*
2011		0.005	0.01	0.030	0.03	0.56	0.098	31	0.01	4
2010		0.005	0.02	0.021	0.03	0.06	0.011	30	0.01	2
2009		0.005	0.02	0.017	0.03	0.04	0.010	31	0.01	2
2008		0.005	0.02	0.023	0.04	0.11	0.021	32	0.01	3
2007		0.005	0.02	0.029	0.05	0.09	0.019	31	0.01	3
2006		0.005	0.03	0.030	0.06	0.07	0.017	31	0.01	3
2005		0.005	0.03	0.038	0.07	0.14	0.030	30	0.01	4
2004		0.005	0.03	0.036	0.07	0.09	0.023	31	0.01	4
2003		0.01	0.04	0.042	0.07	0.08	0.018	31	0.01	5
2002		0.03	0.06	0.074	0.12	0.19	0.038	27	0.01	9
2001		0.02	0.06	0.078	0.12	0.24	0.047	27	0.01	9
2000		0.02	0.09	0.093	0.17	0.30	0.061	29	0.01	11
1999		0.04	0.12	*	0.19	0.21	0.051	14	0.01	*
1998		0.005	0.06	*	0.10	0.13	0.033	17	0.01	*
1997		0.01	0.05	0.067	0.12	0.19	0.044	29	0.01	8
1996		0.03	0.07	0.088	0.14	0.30	0.057	30	0.01	10
1995		0.02	0.09	0.125	0.27	0.44	0.110	31	0.01	15
1994		0.01	0.09	0.122	0.27	0.49	0.124	29	0.01	14
1993		0.02	0.10	0.111	0.20	0.58	0.108	28	0.01	13
1992		0.02	0.14	0.152	0.28	0.45	0.097	29	0.01	18
1991		0.04	0.19	0.192	0.31	0.67	0.136	28	0.01	22
1990		0.03	0.18	0.199	0.31	0.52	0.115	29	0.01	23
1989		0.07	0.19	0.352	0.42	4.8	0.982	22	0.01	41

	Notes:	Values below the Limit of Detection (LoD) assumed to be ½ LoD. Means and risks shown only for years with data in all 12 months. "*" means there was insufficient or no data available to determine the value.