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Higuera Apartments

What EPA’s and California’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves
30 people
Connections
25
Water source
Groundwater
Based in
San Luis Obispo, CA
County
San Luis Obispo
Owner
Private
Hardness
Very hard
The ZIP code it serves

93401

The short answer

1 result is above EPA’s legal limit, and 1 more is above the health goal. The worst: Nitrate, above the legal limit. 23 health-based violations since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2017 to 2021.

Nitrate, haloacetic acids (HAA5), chromium (total), total trihalomethanes (TTHM), fluoride and arsenic: California’s own results, samples taken from Feb. 16, 2021 to Dec. 10, 2025, with EPA’s 2012 to 2019 file for earlier years.

Above the legal limit1

Nitrate

Comes from the source

Above the legal limit

14.4ppm

Highest sample; found in 6 of 6

2025, one sample: 8.6 ppm

From 2021 to 2023, four samples were above EPA’s legal limit of 10 ppm, the highest 14.4 ppm in 2021. Four have no follow-up sample on file within 30 days. In 2025, the latest year on file, its one sample was 8.6 ppm. EPA recorded violations for nitrate at this utility in 2021, 2022, 2023, 2024, 2025 and 2026. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 13 ppm, in 2017, and EPA recorded a violation in 2017.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

Above the health goal1

Lead

Comes from pipes, often your own

Above the health goal

11ppb

90th percentile, 2021

In the latest period, 9 in 10 homes sampled were at or below 11 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027, and this result is at or above that. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits4

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

22ppb

Highest yearly average, 2021

Averaged by year, the highest was 22 ppb, in 2021, below EPA’s legal limit of 60 ppb. That is the only year on file.

What handles it

No certification claim covers this compound yet.

Chromium (total)

Comes from the source

Below EPA’s limits

15ppb

Highest yearly average, 2021

Averaged by year, the highest was 15 ppb, in 2021, below EPA’s legal limit of 100 ppb. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 11 ppb, in 2012.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

5.8ppb

Highest yearly average, 2021

Averaged by year, the highest was 5.8 ppb, in 2021, below EPA’s legal limit of 80 ppb. Its highest single sample was 7.2 ppb. That is the only year on file.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.2ppm

Highest yearly average, 2021

Averaged by year, the highest was 0.2 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.2 ppm, in 2012.

What handles it

One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

  • NSF/ANSI 53

    Claims: Nitrate/Nitrite (30 ppm challenge), Lead Reduction

    For: Nitrate, Lead

  • NSF/ANSI 58

    Claims: Nitrate/Nitrite Reduction, Lead Reduction

    For: Nitrate, Lead

    Other certifiers’ wording: Nitrate

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. How whole-house systems compare.

Filters with those claims on a certifier’s listing

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Compare five-year costs

The best reverse osmosis systems, ranked

The best water filters for lead, ranked

Hardness

Very hard, 710 mg/L (41.5 grains per gallon), at its one sampling point, in 2021.

Hardness is calcium and magnesium. EPA sets no limit for it: it shows up as scale on fixtures and in water heaters, and as soap that won’t lather. USGS calls water above 60 mg/L moderately hard, above 120 hard and above 180 very hard.

Softeners compared at 41.5 grains per gallon, salt includedSoftener or salt-free conditioner?California water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleApril 1, 2026 to June 30, 202611 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJan. 1, 2026 to March 31, 202611 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleOct. 1, 2025 to Dec. 31, 202511 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJuly 1, 2025 to Sept. 30, 202511 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleApril 1, 2025 to June 30, 202511 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJan. 1, 2025 to March 31, 202511 MG/LArchived
Lead and Copper Rule RevisionsThe required inventory of lead service lines was not completed or submitted on time.EPA: LSL InventoryOct. 17, 2024—Unaddressed
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleOct. 1, 2024 to Dec. 31, 202411 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJuly 1, 2024 to Sept. 30, 202411 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleApril 1, 2024 to June 30, 202411 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJan. 1, 2024 to March 31, 202411 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleOct. 1, 2023 to Dec. 31, 202311 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJuly 1, 2023 to Sept. 30, 202311 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleApril 1, 2023 to June 30, 202311 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJan. 1, 2023 to March 31, 202314.4 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleOct. 1, 2022 to Dec. 31, 202214.4 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJuly 1, 2022 to Sept. 30, 202214 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleApril 1, 2022 to June 30, 202214 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJan. 1, 2022 to March 31, 202212 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleOct. 1, 2021 to Dec. 31, 202112 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJuly 1, 2021 to Sept. 30, 202112 MG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleApril 5, 2021 to July 4, 202112 UG/LArchived
NitrateA sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single SampleJan. 1, 2017 to Dec. 31, 201713 UG/LResolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 8 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Nitrate, haloacetic acids (HAA5), chromium (total), total trihalomethanes (TTHM), fluoride and arsenic results here are California’s own from 2021 on, with EPA’s national file for 2012 to 2019. Higuera Apartments’s own annual report, which it must send you every year, has the contaminants this page does not show.

  • Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.

  • What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.

  • Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; California’s results run from Feb. 16, 2021 to Dec. 10, 2025.

Testing your own tap

Higuera Apartments’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab California certifies.

The 3 labs California certifies closest to the area Higuera Apartments serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Fruit Growers Laboratory, Inc.

    San Luis Obispo, CA · about 3 miles

    Certified for bacteria

    (805) 783-2940

  • County of San Luis Obispo Public Health Laboratory

    San Luis Obispo, CA · about 3 miles

    Certified for bacteria

    (805) 781-5507

  • Abalone Coast Analytical, Inc.

    San Luis Obispo, CA · about 3 miles

    Certified for bacteria

    (805) 595-1080

All 145 certified labs for California

Sources

PWSID CA4000563. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in San Luis Obispo County

All California utilities

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