Rio Vista, California

City of Rio Vista 2025 Consumer Confidence Report. Hardness 66.7 mg/L (31.4–88.4), 2022–2024, described as magnesium and calcium cations usually naturally occurring. The row is not labeled CaCO3 — this file does not convert it to grains. Chlorine, Free 1.94 mg/L (0.21–1.94), MRDL 4.0. Chlorine, Total 0.00 mg/L on that 2024 row. No Measure S-style ban turned up — check the sewer agency on the bill.

Cited chemistry for Rio VistaA chart of numbers printed on the utility report, each labeled with its unit. Missing numbers are left off.Free chlorine1.94 mg/L (0.21–1.94)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 chlorine1.94 mg/L (0.21–1.94)

Best match for Rio Vista

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
City of Rio Vista
Hardness
Hardness 66.7 mg/L (31.4–88.4), 2022–2024, described as magnesium and calcium cations usually naturally occurring. The row is not labeled CaCO3 — this file does not convert it to grains. — City of Rio Vista 2025 Consumer Confidence Report
Disinfectant
Chlorine, Free 1.94 mg/L (0.21–1.94), MRDL 4.0. Chlorine, Total 0.00 mg/L on that 2024 row. — City of Rio Vista 2025 Consumer Confidence 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.

Rio Vista drinking water on this file is City of Rio Vista, PWS CA4810004. 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 66.7 mg/L (31.4–88.4), 2022–2024, described as magnesium and calcium cations usually naturally occurring. The row is not labeled CaCO3 — this file does not convert it to grains. Chlorine, Free 1.94 mg/L (0.21–1.94), MRDL 4.0. Chlorine, Total 0.00 mg/L on that 2024 row. 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 CA4810004) — City of Rio Vista / 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.