Oroville, California

California Water Service — Oroville 2025 Consumer Confidence Report. Hardness (total) 144 ppm (138–150) on one 2025 column and 37 ppm on the other. The row is not labeled CaCO3 — this file does not invent grains. Free chlorine 1.3 ppm (0.60–1.8), MRDL 4, 2025. No Measure S-style ban turned up — check the sewer agency on the bill.

Cited chemistry for OrovilleA chart of numbers printed on the utility report, each labeled with its unit. Missing numbers are left off.Free chlorine1.3 ppm (0.60–1.8)WQR
Cited numbers from the utility report. Length follows the printed value against a labeled scale — not a health ranking. If the report has no number, it is not on the chart.
  1. Free chlorine1.3 ppm (0.60–1.8)

Best match for Oroville

Whole-house carbon for chlorine

A single black whole-house carbon tank with a control head, installed in a garage and connected to copper pipe.
Whole-house carbon tank. No brine tank.

That is chlorine. A whole-house carbon filter with an NSF/ANSI 42 chlorine claim is the usual match. A softener will not take chlorine out.

Shop whole-house carbon

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Other options that still fit

On the report

Water utility
California Water Service — Oroville
Hardness
Hardness (total) 144 ppm (138–150) on one 2025 column and 37 ppm on the other. The row is not labeled CaCO3 — this file does not invent grains. — California Water Service Oroville 2025 Water Quality Report
Disinfectant
Free chlorine 1.3 ppm (0.60–1.8), MRDL 4, 2025. — California Water Service Oroville 2025 Water Quality Report
Brine / salt to the sewer
Check the sanitation district before installing. No city or sanitation-district residential self-regenerating softener ban like LACSD Measure S or IEUA Ordinance § 2.6 turned up on the pages we opened. That is not a statewide ban finding. Ask the agency on the sewer bill before you cut a brine drain.

Also around here

Extra context besides the utility report and the chart above — geology, an unregulated table, or a published study. Not a second set of printed tap numbers.

Oroville drinking water on this file is California Water Service — Oroville, PWS CA0410005. No city or sanitation-district residential self-regenerating softener ban like LACSD Measure S or IEUA Ordinance § 2.6 turned up on the pages we opened. That is not a statewide ban finding. Ask the agency on the sewer bill before you cut a brine drain. This is not a legal opinion.

The 2025 report prints Hardness (total) 144 ppm (138–150) on one 2025 column and 37 ppm on the other. The row is not labeled CaCO3 — this file does not invent grains. Free chlorine 1.3 ppm (0.60–1.8), MRDL 4, 2025. Kitchen shopping stays the Cloud RO / Waterdrop path already used on other cities if a listing is why you are looking.

Sources

  1. 2025 Consumer Confidence Report (PWS CA0410005) — California Water Service — Oroville / State Water Resources Control Board. Accessed 2026-09-11.

Updated September 11, 2026. A city file is chemistry we can cite plus the sewer rule. No invented detections.