TapMatch

Nitrates

Nitrate (as N) has a 10 mg/L EPA MCL. Point-of-use reverse osmosis can carry an NSF/ANSI 58 nitrate-reduction claim. This page does not diagnose well or farm exposure.

Category
health effects-standard
EPA status
EPA primary MCL 10 mg/L nitrate as nitrogen. Public systems report it on the CCR when they monitor it. Private wells are not on that report.
Typical sources
Fertilizer, septic systems, and some geologic nitrogen. City files only list a number when the opened report printed one.

What actually fits

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Nitrate as N is a regulated contaminant. The MCL is 10 mg/L. We will not add infant-health language beyond pointing at EPA’s table.

A whole-house softener does not remove nitrate. A 42 chlorine carbon tank does not either. NSF/ANSI 58 is the usual drinking-water listing when a shopper wants a nitrate claim — on the exact model.

The list below is only city files that already print a nitrate metric or a printed also-around value. A USGS groundwater-vulnerability map in an also-around note is not treated as a city-tap average.

Cities on file

Only numbers and notes already printed on a city Markdown file. We do not invent a detection to fill this list.

Highest cited numbers on file

Only values already printed on a city file. Sort is the optional numeric field, not a new lab result.

CityCitedOn the file
Upland, California4.7 ppm (range 0.1–6.0)Nitrate
Lodi, California3.7 ppm (range ND–9.2)Nitrate as N
Salinas, California3.3 ppm (range 0.53–7.1)Nitrate as N
Visalia, California2.5 ppm (range 0.43–7.8)Nitrate as N
Chico, California1.7 ppm (range ND–5.6)Nitrate as N
San Juan Bautista, California1.4 mg/L (range <0.1–2.7)Nitrate as N
Pittsburg, California1.2 mg/L (range ND–1.7)Nitrate as N
Antioch, California0.5 mg/L (range ND–0.9)Nitrate as N

All files with a cite

15 city files. Grouped by state.

California 13

  • Upland — 4.7 ppm (range 0.1–6.0)
  • Lodi — 3.7 ppm (range ND–9.2)
  • Salinas — 3.3 ppm (range 0.53–7.1)
  • Visalia — 2.5 ppm (range 0.43–7.8)
  • Chico — 1.7 ppm (range ND–5.6)
  • San Juan Bautista — 1.4 mg/L (range <0.1–2.7)
  • Pittsburg — 1.2 mg/L (range ND–1.7)
  • Antioch — 0.5 mg/L (range ND–0.9)
  • Montclair — 2.5 ppm (range ND–5.9), MCL 10.
  • Newman — 3.65 ppm (range 0.88–5.43), MCL 10, 2024.
  • Salinas — 3.3 ppm (range 0.53–7.1), MCL 10.
  • Santa Paula — 3 mg/L (range 0.4–4.8), MCL 10, 2023–2024.
  • Visalia — 2.5 ppm (range 0.43–7.8), MCL 10.

Iowa 1

  • Des Moines — Fleur Drive 5.90 mg/L (1.05–5.90). McMullen 9.17 mg/L (2.59–9.17).

Texas 1

  • Irving — 1.27–1.75 ppm nitrate as N, 2025.