Sonoma, California
Valley of the Moon Water District 2025 CCR, PWS 4910013. Total hardness two labeled columns — 109.83 ppm (106–125) and 95.861 ppm (43–160). Narrative: Sonoma County Water Agency treats with chlorine. A numeric residual was not printed. No Measure S-style ban turned up — check the sewer agency on the bill.
- Hardness (column 1)109.83 ppm (106–125)
- Hardness (column 2)95.9 ppm (43–160)
- Chlorineused; residual not printed
Best match for Sonoma
Salt-based water softener — confirm the district first
Check the sanitation district before installing a salt system.
Ask the agency on the sewer side of the bill before you cut a brine drain. California lets districts restrict self-regenerating units. A “banned in California” blog is not your district.
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Other options that still fit
Salt-free conditioner
A salt-free conditioner changes how scale sticks. It does not soften. Soap and spots stay closer to untreated. No brine line.
Whole-house carbon for chlorine
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.
Under-sink reverse osmosis
The under-sink RO we actually run is Cloud RO — NSF/ANSI 58, kitchen tap, not a whole-house tank. Check the exact listing if PFAS is why you are shopping. Shop Amazon first for under-sink RO, or buy Cloud direct. Waterdrop is a tankless option if you want that path. A certifier-listed pitcher is the cheap first step. Nobody is paying for a medical claim.
Shop under-sink reverse osmosisBuy Cloud RO directShop Waterdrop reverse osmosisShop PFAS-listed pitchers
Test the tap first
A homeowner kit is a start. It is not a state-certified lab. Use a certified lab when the decision is expensive.
On the report
- Water utility
- Valley of the Moon Water District
- Hardness
- Total Hardness (ppm) 2025: 109.83 (106–125) and 95.861 (43–160) on two printed columns. Calcium and magnesium concentration. Labeled columns, not a blend. Footnote: second-column range includes 2023 samples. — Valley of the Moon Water District 2025 Annual Water Quality Report
- Disinfectant
- Narrative: Sonoma County Water Agency treats the water with chlorine for bacterial disinfection. A numeric distribution residual was not printed on the hardness page — this file does not invent one. — Valley of the Moon Water District 2025 Annual 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.
- MicroplasticsWHO’s 2019 review examined studies that found microplastic particles in treated tap and bottled water in many places. That is a published-occurrence finding, not a number from this city’s water-quality report, and we do not invent a particles-per-liter count for the tap.Microplastics in drinking-water — World Health Organization
- PFASEPA’s Fifth Unregulated Contaminant Monitoring Rule required community systems this size to test 29 PFAS and lithium in 2023–2025. Open the UCMR 5 Data Finder for this PWS. This file does not invent a detection.Fifth Unregulated Contaminant Monitoring Rule — U.S. Environmental Protection Agency
Sonoma drinking water on this file is Valley of the Moon Water District, PWS CA4910013, for the addresses that district serves. City of Sonoma municipal water can be a different bill — check the utility name. 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 total hardness as two labeled columns — 109.83 ppm (106–125) and 95.861 ppm (43–160). Narrative: chlorine disinfection. Kitchen shopping stays the Cloud RO / Waterdrop path already used on other cities if a listing is why you are looking.
Sources
- 2025 Annual Water Quality Report (PWS CA4910013) — Valley of the Moon Water District / 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.