Portola Valley, California

California Water Service — Bear Gulch 2025 Consumer Confidence Report. Hardness (total) 62 ppm (8.1–112), 2025. The row is not labeled CaCO3. Same official booklet as Woodside. Chloramine 2.5 ppm (0.24–3.5), MRDL 4, 2025. No Measure S-style ban turned up — check the sewer agency on the bill.

Cited chemistry for Portola ValleyA chart of numbers printed on the utility report, each labeled with its unit. Missing numbers are left off.Chloramine2.5 ppm (0.24–3.5)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. Chloramine2.5 ppm (0.24–3.5)

Best match for Portola Valley

Whole-house catalytic carbon for chloramine

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.

Catalytic carbon with a chloramine claim (NSF/ANSI 42 for chloramine). Regular chlorine carbon is the wrong box.

Shop catalytic carbon for chloramine

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Other options that still fit

On the report

Water utility
California Water Service — Bear Gulch
Hardness
Hardness (total) 62 ppm (8.1–112), 2025. The row is not labeled CaCO3. Same official booklet as Woodside. — California Water Service Bear Gulch 2025 Water Quality Report
Disinfectant
Chloramine 2.5 ppm (0.24–3.5), MRDL 4, 2025. — California Water Service Bear Gulch 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.

Portola Valley drinking water on this file is California Water Service — Bear Gulch, PWS CA4110006. 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) 62 ppm (8.1–112), 2025. The row is not labeled CaCO3. Same official booklet as Woodside. Chloramine 2.5 ppm (0.24–3.5), 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 CA4110006) — California Water Service — Bear Gulch / 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.