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Coastside County Water District

Published drinking-water records and contacts for Coastside County Water District. System CA4110011. Review sources and dates; not a real-time water assessment.

System ID
CA4110011
State or territory
CA
Published population served
18940
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/L2025-04-02Denniston WTP / 4110011802
4:2 FTS< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
6:2 FTS< 0.005 µg/L0.005 µg/L2025-04-02Denniston WTP / 4110011802
8:2 FTS< 0.005 µg/L0.005 µg/L2025-04-02Denniston WTP / 4110011802
9Cl-PF3ONS< 0.002 µg/L0.002 µg/L2025-04-02Denniston WTP / 4110011802
ADONA< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
HFPO-DA< 0.005 µg/L0.005 µg/L2025-04-02Denniston WTP / 4110011802
NEtFOSAA< 0.005 µg/L0.005 µg/L2025-04-02Denniston WTP / 4110011802
NFDHA< 0.02 µg/L0.02 µg/L2025-04-02Denniston WTP / 4110011802
NMeFOSAA< 0.006 µg/L0.006 µg/L2025-04-02Denniston WTP / 4110011802
PFBA< 0.005 µg/L0.005 µg/L2025-04-02Denniston WTP / 4110011802
PFBS< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFDA< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFDoA< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFEESA< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFHpA< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFHpS< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFHxA< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFHxS< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFMBA< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFMPA< 0.004 µg/L0.004 µg/L2025-04-02Denniston WTP / 4110011802
PFNA< 0.004 µg/L0.004 µg/L2025-04-02Denniston WTP / 4110011802
PFOA< 0.004 µg/L0.004 µg/L2025-04-02Denniston WTP / 4110011802
PFOS< 0.004 µg/L0.004 µg/L2025-04-02Denniston WTP / 4110011802
PFPeA< 0.003 µg/L0.003 µg/L2025-04-02Denniston WTP / 4110011802
PFPeS< 0.004 µg/L0.004 µg/L2025-04-02Denniston WTP / 4110011802
PFTA< 0.008 µg/L0.008 µg/L2025-04-02Denniston WTP / 4110011802
PFTrDA< 0.007 µg/L0.007 µg/L2025-04-02Denniston WTP / 4110011802
PFUnA< 0.002 µg/L0.002 µg/L2025-04-02Denniston WTP / 4110011802
lithium< 9 µg/L9 µg/L2025-04-02Denniston WTP / 4110011802

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) 0.0016 mg/L2022-01-01 – 2024-12-312026Q3
Lead (PB90) 0.0027 mg/L2019-01-01 – 2021-12-312026Q3
Lead (PB90) 0 mg/L2016-01-01 – 2018-12-312026Q3
Lead (PB90) 0.007 mg/L2014-01-01 – 2016-12-312026Q3
Lead (PB90) 0.005 mg/L2011-01-01 – 2013-12-312026Q3
Lead (PB90) 0.0054 mg/L2006-01-01 – 2008-12-312026Q3
Lead (PB90) 0.0112 mg/L2003-01-01 – 2005-12-312026Q3
Lead (PB90) 0.0112 mg/L2005-01-01 – 2005-12-312026Q3
Twelve most recent imported state laboratory records
SubstancePublished resultSample dateLocation / source
NITROGEN-AMMONIA AS (N)< 0.150000000 MG/L2026-06-24DENNISTON RESERVOIR - RAW / California DDW laboratory results
MAGNESIUM5.1 MG/L2026-06-24SAN VINCENTE RESERVOIR - RAW - PROPOSED / California DDW laboratory results
ORTHOPHOSPHATE< 0.100000000 MG/L2026-06-24SAN VINCENTE RESERVOIR - RAW - PROPOSED / California DDW laboratory results
PH7.3 PH2026-06-24SAN VINCENTE RESERVOIR - RAW - PROPOSED / California DDW laboratory results
TURBIDITY2.2 NTU2026-06-24DENNISTON RESERVOIR - RAW / California DDW laboratory results
CALCIUM22 MG/L2026-06-24DENNISTON RESERVOIR - RAW / California DDW laboratory results
NITRATE< 0.100000000 MG/L2026-06-24SAN VINCENTE RESERVOIR - RAW - PROPOSED / California DDW laboratory results
HARDNESS, TOTAL (AS CACO3)83 MG/L2026-06-24DENNISTON RESERVOIR - RAW / California DDW laboratory results
CARBON, DISSOLVED ORGANIC (DOC)1.75 MG/L2026-06-24SAN VINCENTE RESERVOIR - RAW - PROPOSED / California DDW laboratory results
NITROGEN-AMMONIA AS (N)< 0.150000000 MG/L2026-06-24SAN VINCENTE RESERVOIR - RAW - PROPOSED / California DDW laboratory results
MAGNESIUM7.0 MG/L2026-06-24DENNISTON RESERVOIR - RAW / California DDW laboratory results
CARBON, TOTAL2.33 MG/L2026-06-24DENNISTON RESERVOIR - RAW / 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)

Rogren, Mary: 650-276-0889

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