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	Annual Toxics Summary Azusa 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
2025		*	*	*	*	*	*	0	*	*
2024		*	*	*	*	*	*	0	*	*
2023		*	*	*	*	*	*	0	*	*
2022		0.005	0.005	*	0.01	0.01	0.003	22	0.01	*
2021		0.005	0.005	*	0.02	0.03	0.007	24	0.01	*
2020		0.005	*	*	*	0.03	0.007	7	0.01	*
2019		0.005	0.01	0.019	0.03	0.15	0.026	30	0.01	2
2018		0.005	0.01	0.020	0.03	0.14	0.025	31	0.01	2
2017		0.005	0.01	0.017	0.03	0.08	0.016	30	0.01	2
2016		0.005	0.03	0.036	0.06	0.13	0.027	31	0.01	4
2015		0.005	0.03	0.031	0.05	0.07	0.016	30	0.01	4
2014		0.01	0.03	0.042	0.08	0.22	0.042	30	0.01	5
2013		0.005	0.02	0.031	0.06	0.11	0.024	31	0.01	4
2012		0.005	0.03	0.028	0.05	0.06	0.015	30	0.01	3
2011		0.005	0.03	0.029	0.05	0.07	0.016	30	0.01	3
2010		0.01	0.03	0.047	0.06	0.17	0.035	24	0.01	5
2009		0.005	0.03	0.033	0.08	0.10	0.025	31	0.01	4
2008		0.02	0.04	*	0.07	0.25	0.042	28	0.01	*
2007		0.01	0.05	0.052	0.08	0.16	0.032	27	0.01	6
2006		0.02	0.04	0.050	0.08	0.10	0.023	29	0.01	6
2005		0.02	0.06	0.076	0.13	0.24	0.052	29	0.01	9
2004		0.02	0.05	0.063	0.10	0.21	0.039	29	0.01	7
2003		0.03	0.08	0.109	0.16	0.34	0.071	28	0.01	13
2002		0.04	0.11	0.153	0.24	0.92	0.166	28	0.01	18
2001		0.03	0.15	*	0.28	0.40	0.089	26	0.01	*
2000		0.05	0.16	0.183	0.24	0.76	0.158	30	0.01	21
1999		0.17	*	*	*	0.17	0.713	1	0.01	*
1998		*	*	*	*	*	*	0	*	*
1997		*	*	*	*	*	*	0	*	*
1996		*	*	*	*	*	*	0	*	*
1995		*	*	*	*	*	*	0	*	*
1994		*	*	*	*	*	*	0	*	*
1993		*	*	*	*	*	*	0	*	*
1992		*	*	*	*	*	*	0	*	*
1991		*	*	*	*	*	*	0	*	*
1990		*	*	*	*	*	*	0	*	*
1989		0.29	*	*	*	2.5	0.713	9	0.01	*

	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.