Tap Truth EPA drinking water records, in plain English

Public water system record

City of Lathrop

Serves Lathrop, San Joaquin County, CA · 35,080 people served

Federal records show no health-based violations and 2 monitoring/reporting issues for City of Lathrop in the last ten years.

  • CA3910015
  • LATHROP
  • CA
  • 35,080 served

System profile

Source water Purchased surface water
ZIP 95330
EPA system ID CA3910015

Verify this system on EPA ECHO →

Health-based violations, last 10 years
0
Resolved
0
Unresolved
0
Any acute record
No
Monitoring issues, last 10 years
2

Key facts

  • City of Lathrop draws water from 4 wells.
  • Most recent formal enforcement: compliance order (no penalty) by California, October 2018.
  • Record on file since 1985, with 42 health-based violations before October 19, 2016.
  • Lead pipe inventory: 0 lead and 0 unknown out of 11,099 service lines.

Check whether City of Lathrop serves your address

Address suggestions by Mapbox

Health-based violations

Since October 2016

Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.

None since October 2016.

Monitoring and reporting issues

Since October 2016

Missed tests or reports, not contaminants found above a limit.

Issue Start date Status
Haloacetic Acids (HAA5)
Monitoring and reporting
 Jul 1, 2018 Resolved
Total Trihalomethanes (TTHMs)
Monitoring and reporting
 Jul 1, 2018 Resolved

Full record since 1985

EPA's records for City of Lathrop go back to 1985. Before October 19, 2016 they list 42 health-based violations (42 resolved) and 6 monitoring or reporting violations.

Violations that began in Health-based Monitoring and reporting
1980s 0 2
1990s 4 3
2000s 13 1
2010 to October 18, 2016 25 0
October 19, 2016 to 2019 0 2

Most recent health-based violation before October 19, 2016: Combined Uranium, began April 2014, Resolved.

Show all 42 health-based violations before October 19, 2016
Contaminant Start date Status
Combined Uranium
Contaminant limit exceeded
 Apr 1, 2014 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 Apr 1, 2014 Resolved
Combined Uranium
Contaminant limit exceeded
 Jan 1, 2014 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.011 mg/L, federal limit 0.01 mg/L (1.1 times the limit)
 Jan 1, 2014 Resolved
Combined Uranium
Contaminant limit exceeded
 Oct 1, 2013 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.01185 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
 Oct 1, 2013 Resolved
Combined Uranium
Contaminant limit exceeded
 Jul 1, 2013 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.01343 mg/L, federal limit 0.01 mg/L (1.3 times the limit)
 Jul 1, 2013 Resolved
Combined Uranium
Contaminant limit exceeded
 Apr 1, 2013 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.01425 mg/L, federal limit 0.01 mg/L (1.4 times the limit)
 Apr 1, 2013 Resolved
Combined Uranium
Contaminant limit exceeded
 Jan 1, 2013 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.013 mg/L, federal limit 0.01 mg/L (1.3 times the limit)
 Jan 1, 2013 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.01275 mg/L, federal limit 0.01 mg/L (1.3 times the limit)
 Oct 1, 2012 Resolved
Combined Uranium
Contaminant limit exceeded
 Jul 1, 2012 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.01175 mg/L, federal limit 0.01 mg/L (1.2 times the limit)
 Jul 1, 2012 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.0187 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
 Apr 1, 2012 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.01875 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
 Jan 1, 2012 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.0187 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
 Oct 1, 2011 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.0186 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
 Jul 1, 2011 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.0186 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
 Apr 1, 2011 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.018 mg/L, federal limit 0.01 mg/L (1.8 times the limit)
 Jan 1, 2011 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.019 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
 Oct 1, 2010 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.018 mg/L, federal limit 0.01 mg/L (1.8 times the limit)
 Jul 1, 2010 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.018 mg/L, federal limit 0.01 mg/L (1.8 times the limit)
 Apr 1, 2010 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.0185 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
 Jan 1, 2010 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.0179 mg/L, federal limit 0.01 mg/L (1.8 times the limit)
 Oct 1, 2009 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.0187 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
 Jul 1, 2009 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.0187 mg/L, federal limit 0.01 mg/L (1.9 times the limit)
 Apr 1, 2009 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Jan 1, 2009 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Oct 1, 2008 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Jul 1, 2008 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Apr 1, 2008 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Jan 1, 2008 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Oct 1, 2007 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Jul 1, 2007 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Apr 1, 2007 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Jan 1, 2007 Resolved
Arsenic
Contaminant limit exceeded
Measured 0.021 mg/L, federal limit 0.01 mg/L (2.1 times the limit)
 Oct 1, 2006 Resolved
Total Coliform
Contaminant limit exceeded
 Jun 1, 1996 Resolved
Total Coliform
Contaminant limit exceeded
 Apr 1, 1996 Resolved
Total Coliform
Contaminant limit exceeded
 Mar 1, 1996 Resolved
Total Coliform
Contaminant limit exceeded
 Sep 1, 1993 Resolved

Enforcement actions

California regulators took 5 formal enforcement actions against City of Lathrop between 1996 and 2018. The most recent was a compliance order (no penalty) in October 2018.

Date By Action Violations covered
Oct 15, 2018 California Compliance order (no penalty) 2 violations: Haloacetic Acids (HAA5), Total Trihalomethanes (TTHMs)
Oct 24, 2012 California Compliance order (no penalty) 15 violations (15 health-based): Combined Uranium, Arsenic
Dec 26, 2008 California Compliance order (no penalty) 23 violations (23 health-based): Arsenic
Mar 3, 2006 California Compliance order (no penalty) 1 violation: Lead and Copper Rule
Jul 17, 1996 California Compliance order (no penalty) 1 violation (1 health-based): Total Coliform

Where the water comes from

City of Lathrop draws water from 4 wells. It also buys water from South San Joaquin Irrigation District.

Buys water from

Annual water quality report

City of Lathrop must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.

Systems serving 10,000 or more people must mail or deliver the report to every customer, and from 2027 they must send it twice a year.

Find a posted report with EPA's Consumer Confidence Report search

Testing your own water

To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by California.

Certified drinking water labs by state EPA guidance for private wells