How much nitrate is in Hollister water?

The maximum detected level of nitrate in Hollister water is 28 ppb. The EPA limit is 10 mg/L (as nitrogen). See the ZIP code table above for area-specific levels.

Detected Nitrate

Nitrate in Hollister, CA Drinking Water

Q: Is nitrate in Hollister water safe?

Nitrate was detected in Hollister water at 28 ppb, below the EPA limit of 10 mg/L (as nitrogen). Check ZIP-level data on this page for your specific area.

Nitrate data for Hollister, California · 58,374 residents · 2 ZIP codes

ZipCheckup's reading of Nitrate in Hollister, California: the highest detected level is 28 ppb; the EPA limit is 10 mg/L (as nitrogen). Nitrate carries a high health-risk designation.

Water quality records for Hollister, California show Nitrate detections on file - a finding that places it among the contaminants worth tracking for this area.

28 ppb

Max Level Detected

28 ppb

Average Level

10 mg/L (as nitrogen)

EPA MCL

High

Health Risk

Reverse Osmosis or Ion Exchange

Best Filter Method

Data: EPA SDWIS, CCR Reports, ECHO Last verified: 2026-07-13

Nitrate in Hollister Tap Water

Nitrate has been detected in Hollister, California drinking water at a maximum level of 28 ppm — 2.8x the EPA MCL.

This analysis covers 58,374 residents across 2 ZIP codes in Hollister.

Hollister's overall water quality grade is C (64/100).

Is Nitrate in Hollister Water Safe?

Nitrate was detected in Hollister water but currently falls within EPA limits. However, some health organizations argue the EPA MCL may not be protective enough.

If you are concerned, a reverse osmosis or ion exchange filter can reduce nitrate levels further.

Nitrate Levels by ZIP Code

ZIP Code	Nitrate Level	EPA Limit	Status
95023	28 ppm	10 mg/L (as nitrogen)	Exceeds limit
95024	28 ppm	10 mg/L (as nitrogen)	Exceeds limit

Average nitrate level across Hollister: 28 ppb

Health Effects of Nitrate

Methemoglobinemia ("blue baby syndrome") in infants under 6 months
Increased risk of colorectal and bladder cancer (long-term)
Thyroid disease from chronic exposure
Possible reproductive effects

Health risk severity: High. Governed by the National Primary Drinking Water Regulations.

How Nitrate Gets Into Drinking Water

Agricultural fertilizer runoff
Animal feedlot operations and manure
Septic system leachate
Urban stormwater and wastewater discharge

What to Do About Nitrate in Hollister Water

Reverse osmosis is the most effective method for nitrate removal
Ion exchange systems designed for nitrate can also work
Standard carbon filters do NOT remove nitrate
Boiling water increases nitrate concentration — never boil for nitrate

Look for filters certified under NSF 53 / NSF 58 for nitrate removal.

Home → Contaminants → Nitrate → California → Hollister

How to cite this page

APA ZipCheckup. (2026). Nitrate in Hollister, CA Drinking Water. https://zipcheckup.com/contaminants/nitrates/hollister-ca/

BibTeX

@misc{zipcheckup-contaminants-nitrates-hollister-ca,
  author = {{ZipCheckup}},
  title  = {{Nitrate in Hollister, CA Drinking Water}},
  year   = {2026},
  url    = {https://zipcheckup.com/contaminants/nitrates/hollister-ca/}
}

Data as of July 2026.