Lead and copper

MS0700011 , Town of Walnut

Every monitoring period on record is listed here. This page applies no date range. The same list limited to the last two years.

Lead and copper 90th-percentile sample summaries for Town of Walnut, 32 summaries, every one on record. The agency records no date of receipt for any of them.
Analyte	Monitoring period	Samples	90th percentile	Facility	Data quality
Copper	Jan 1, 2021 – Dec 31, 2023	10	0.468 mg/l	DS000	Accepted
Lead	Jan 1, 2021 – Dec 31, 2023	10	0.0006 mg/l	DS000	Accepted
Copper	Jan 1, 2018 – Dec 31, 2020	10	0.4741 mg/l	DS000	Accepted
Lead	Jan 1, 2018 – Dec 31, 2020	10	0.001 mg/l	DS000	Accepted
Copper	Jan 1, 2015 – Dec 31, 2017	10	0.4339 mg/l	DS000	Accepted
Lead	Jan 1, 2015 – Dec 31, 2017	10	0.001 mg/l	DS000	Accepted
Copper	Jan 1, 2012 – Dec 31, 2014	10	0.0805 mg/l	DS000	Accepted
Lead	Jan 1, 2012 – Dec 31, 2014	10	0 mg/l	DS000	Accepted
Copper	Jan 1, 2009 – Dec 31, 2011	10	0.1736 mg/l	DS000	Accepted
Lead	Jan 1, 2009 – Dec 31, 2011	10	0.0013 mg/l	DS000	Accepted
Copper	Jan 1, 2008 – Dec 31, 2008	10	0.2648 mg/l	DS000	Accepted
Lead	Jan 1, 2008 – Dec 31, 2008	10	0.004 mg/l	DS000	Accepted
Copper	Jan 1, 2007 – Dec 31, 2007	12	0.3206 mg/l	DS000	Accepted
Lead	Jan 1, 2007 – Dec 31, 2007	12	0.001 mg/l	DS000	Accepted
Copper	Jan 1, 2006 – Dec 31, 2006	11	0.2675 mg/l	DS000	Accepted
Lead	Jan 1, 2006 – Dec 31, 2006	11	0.0012 mg/l	DS000	Accepted
Copper	Jan 1, 2004 – Dec 31, 2004	10	0.49 mg/l	DS000	Accepted
Lead	Jan 1, 2004 – Dec 31, 2004	10	0.0006 mg/l	DS000	Accepted
Copper	Jan 1, 2000 – Dec 31, 2000	38	0.401 mg/l	DS000	Accepted
Lead	Jan 1, 2000 – Dec 31, 2000	38	0.004 mg/l	DS000	Accepted
Copper	Jul 1, 1997 – Dec 31, 1997	5	0.08 mg/l	DS000	Accepted
Lead	Jul 1, 1997 – Dec 31, 1997	5	0.007 mg/l	DS000	Accepted
Copper	Jan 1, 1997 – Jun 30, 1997	20	0.341 mg/l	DS000	Accepted
Lead	Jan 1, 1997 – Jun 30, 1997	20	0.011 mg/l	DS000	Accepted
Copper	Jan 1, 1996 – Dec 31, 1996	10	0.239 mg/l	DS000	Accepted
Lead	Jan 1, 1996 – Dec 31, 1996	10	0.041 mg/l	DS000	Accepted
Copper	Jan 1, 1995 – Dec 31, 1995	10	0.484 mg/l	DS000	Accepted
Lead	Jan 1, 1995 – Dec 31, 1995	10	0.009 mg/l	DS000	Accepted
Copper	Jan 1, 1994 – Jun 30, 1994	30	0.184 mg/l	DS000	Accepted
Lead	Jan 1, 1994 – Jun 30, 1994	30	0.008 mg/l	DS000	Accepted
Copper	Jul 1, 1993 – Dec 31, 1993	22	0.345 mg/l	DS000	Accepted
Lead	Jul 1, 1993 – Dec 31, 1993	22	0.002 mg/l	DS000	Accepted

No date of receipt is recorded for any of these summaries.

This system’s violations

What the 90th percentile is

The 90th percentile of all samples collected from the distribution system is the standard that the US Environmental Protection Agency has chosen for determining compliance with the Lead and Copper Action Level under the federal Lead and Copper Rule. The 90th percentile is determined by ranking all sample results from lowest to highest and finding a result that is 90% of the number of sample results from the top. For example, if there are 10 sample results, the 90th percentile would be the 9th sample result from the top.

From the help text published with these pages.