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Golden State Water Company - Nipomo

Published drinking-water records and contacts for Golden State Water Company - Nipomo. System CA4010018. Review sources and dates; not a real-time water assessment.

System ID
CA4010018
State or territory
CA
Published population served
4506
System type (source code)
CWS

Published records and dates

Missing records here do not mean the provider did not test. Published records are not a real-time assessment of your tap water.

Published testing results

Selected recent records are shown below. Different sampling locations and dates are not interchangeable. These excerpts are not a complete testing history.

“<” means below the stated reporting limit, not zero. A reported measurement alone is not a safety verdict. Read an example

EPA UCMR 5 — most recent imported sample per substance
SubstancePublished resultReporting limitSample dateSampling location
11Cl-PF3OUdS< 0.005 µg/L0.005 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
4:2 FTS< 0.003 µg/L0.003 µg/L2025-07-23Osage Filters Effluent / 4010018017
6:2 FTS< 0.005 µg/L0.005 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
8:2 FTS< 0.005 µg/L0.005 µg/L2025-07-23Alta Mesa IX / 4010018025
9Cl-PF3ONS< 0.002 µg/L0.002 µg/L2025-07-23Alta Mesa IX / 4010018025
ADONA< 0.003 µg/L0.003 µg/L2025-07-23Osage Filters Effluent / 4010018017
HFPO-DA< 0.005 µg/L0.005 µg/L2025-07-23Alta Mesa IX / 4010018025
NEtFOSAA< 0.005 µg/L0.005 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
NFDHA< 0.02 µg/L0.02 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
NMeFOSAA< 0.006 µg/L0.006 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
PFBA< 0.005 µg/L0.005 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
PFBS< 0.003 µg/L0.003 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
PFDA< 0.003 µg/L0.003 µg/L2025-07-23Osage Filters Effluent / 4010018017
PFDoA< 0.003 µg/L0.003 µg/L2025-07-23Osage Filters Effluent / 4010018017
PFEESA< 0.003 µg/L0.003 µg/L2025-07-23Osage Filters Effluent / 4010018017
PFHpA< 0.003 µg/L0.003 µg/L2025-07-23Osage Filters Effluent / 4010018017
PFHpS< 0.003 µg/L0.003 µg/L2025-07-23Osage Filters Effluent / 4010018017
PFHxA< 0.003 µg/L0.003 µg/L2025-07-23Osage Filters Effluent / 4010018017
PFHxS< 0.003 µg/L0.003 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
PFMBA< 0.003 µg/L0.003 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
PFMPA< 0.004 µg/L0.004 µg/L2025-07-23Osage Filters Effluent / 4010018017
PFNA< 0.004 µg/L0.004 µg/L2025-07-23Alta Mesa IX / 4010018025
PFOA< 0.004 µg/L0.004 µg/L2025-07-23Osage Filters Effluent / 4010018017
PFOS< 0.004 µg/L0.004 µg/L2025-07-23Alta Mesa IX / 4010018025
PFPeA0.0032 µg/L0.003 µg/L2025-07-23Alta Mesa IX / 4010018025
PFPeS< 0.004 µg/L0.004 µg/L2025-07-23Alta Mesa IX / 4010018025
PFTA< 0.008 µg/L0.008 µg/L2025-07-23Alta Mesa IX / 4010018025
PFTrDA< 0.007 µg/L0.007 µg/L2025-07-23Osage Filters Effluent / 4010018017
PFUnA< 0.002 µg/L0.002 µg/L2025-07-23La Serena Reservoirs combined / 4010018014
lithium< 9 µg/L9 µg/L2025-07-23Osage Filters Effluent / 4010018017

Download all EPA UCMR 5 records (CSV)

Lead and copper: 90th-percentile summaries

These describe a monitoring period across sampled locations, not the result at your home. How to read the 90th percentile

Eight most recent imported monitoring summaries
SubstancePublished 90th percentileMonitoring periodSource quarter
Lead (PB90) 0.0052 mg/L2021-01-01 – 2023-12-312026Q3
Lead (PB90) 0.0028 mg/L2018-01-01 – 2020-12-312026Q3
Lead (PB90) 0 mg/L2015-01-01 – 2017-12-312026Q3
Lead (PB90) 0.0031 mg/L2012-01-01 – 2014-12-312026Q3
Lead (PB90) 0.0029 mg/L2009-01-01 – 2011-12-312026Q3
Lead (PB90) 0.004 mg/L2006-01-01 – 2008-12-312026Q3
Lead (PB90) 0.0041 mg/L2006-01-01 – 2006-12-312026Q3
Lead (PB90) 0.0041 mg/L2005-01-01 – 2005-12-312026Q3
Twelve most recent imported state laboratory records
SubstancePublished resultSample dateLocation / source
NITRATE5.5 MG/L2026-07-14LA SERENA WELL / California DDW laboratory results
NITRATE5.5 MG/L2026-07-14ALTA MESA GAC TP LAG VESSEL EFFLUENT / California DDW laboratory results
NITRATE0.96 MG/L2026-07-14ALTA MESA IX NITRATE TP EFFLUENT / California DDW laboratory results
NITRATE3.2 MG/L2026-07-14LA SERENA RESV 1 NO3 BLENDED EFFLUENT / California DDW laboratory results
NITRATE3.2 MG/L2026-07-14LA SERENA RESV 2 NO3 BLENDED EFFLUENT / California DDW laboratory results
NITRATE2.2 MG/L2026-07-14EUCALYPTUS 02 / California DDW laboratory results
IRON< 50.000000000 UG/L2026-07-08OSAGE WELL (1988) / California DDW laboratory results
IRON< 50.000000000 UG/L2026-07-08OSAGE TP (FE/MN FILTER) EFFLUENT / California DDW laboratory results
MANGANESE< 10.000000000 UG/L2026-07-08OSAGE TP (FE/MN FILTER) EFFLUENT / California DDW laboratory results
MANGANESE41 UG/L2026-07-08OSAGE WELL (1988) / California DDW laboratory results
NITRATE11 MG/L2026-07-07ALTA MESA 02 / California DDW laboratory results
IRON160 UG/L2026-07-07LA SERENA TP - COMBINED INFLUENT / California DDW laboratory results

State sampling points can include untreated water. Publisher qualifiers and units are retained; consult the full source notes before interpreting a record.

Download state records with source notes (CSV)

Published compliance history

0 imported records. Status is as recorded in the source; historical records are not current advisories. Missing records do not establish that no violations occurred.

Source dates and refresh checks

A refresh check is not a sample date. Publication periods, sample dates and checks are shown separately.

Administrative contact (EPA filing)

White, Dawn: 916-853-3615

An administrative filing contact may not be a customer-service line. Confirm current contact details with the provider.

Official state resources · How to read these records