CWSC Los Altos Suburban
Drinking water quality, contact, and Consumer Confidence Report
Serving 6 cities in CA · PWSID CA4310001
CWSC Los Altos Suburban serves 70,175 people. 3 contaminants currently exceed health-based guidelines — full breakdown below.
- People served
- 70,175
- Last EPA sample
- 2025-09-10
- PFAS
- Not detected above guidelines
- Health-based violations since 2020
- 0
Data sources: EPA SDWIS, CWSC Los Altos Suburban's published Consumer Confidence Report, and compliance monitoring reported to EPA by CA State Water Resources Control Board, Div. of Drinking Water.
This page summarizes publicly available EPA and CCR records. For health decisions about your water, consult your utility or a licensed professional.
Official CWSC Los Altos Suburban Resources
Help Paying Your CWSC Los Altos Suburban Water Bill
- Ask CWSC Los Altos Suburban about payment plans and assistance.
- Call 211 to reach local help with utility bills.Verified from 211.org
- Find your local Community Action Agency.Verified from communityactionpartnership.com
- The federal water-bill program (LIHWAP) ended in March 2024.Verified from acf.govVerified from csd.ca.gov
Programs that may apply to CWSC Los Altos Suburban customers
- Customer Assistance Program (CAP)Bill discount from California Water Service Company.Customers who meet its rules may qualify.Verified from calwater.com
Shutoff protections
- Water Shutoff Protection Act (SB 998), Health & Safety Code §116900 et seq.Shutoff protection from California Legislature (enforced by the State Water Resources Control Board).Verified from leginfo.legislature.ca.gov
Water outage or no water?
Boil water advisories are issued by water systems and state agencies, and they change from day to day. Boil water advisories in California
CWSC Los Altos Suburban Service Area
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This map shows the approximate service area for CWSC Los Altos Suburban. Actual coverage may vary. Contact the utility directly to confirm service availability at your address.
CWSC Los Altos Suburban Water Quality Grade
Not graded: Monitor
CWSC Los Altos Suburban reads Monitor. A letter grade is given only beside a Safe verdict.
Is CWSC Los Altos Suburban Water Safe to Drink?
CWSC Los Altos Suburban has reported 3 contaminants above EPA health-based guidelines (MCLGs) in at least one city served. We recommend reviewing individual city reports below for specific water quality details.
This utility serves 70,175 people across 6 cities in CA. Water quality can vary by location within the service area. Check individual city pages below for detailed contaminant data specific to your area.
Get your water independently tested in California →How does California water quality rank nationally? →
Boil water advisories are issued by water systems and state agencies, and they change from day to day. Boil water advisories in California
Learn more about the contaminants detected in CWSC Los Altos Suburban:
Fluoride in CWSC Los Altos Suburban Water
CWSC Los Altos Suburban
PWSID CA4310001
CWSC Los Altos Suburban reported 0.15 mg/L, below the 0.7 mg/L U.S. Public Health Service recommendation.
CWSC Los Altos Suburban Service Area
Cupertino, CA
Los Altos, CA
Los Altos Hills, CA
Loyola, CA
Mountain View, CA
Sunnyvale, CA
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CWSC Los Altos Suburban Contact & Information
Phone
Mailing Address
B2B Contact Data
B2B Contact Data Available
Contacts for CWSC Los Altos Suburban
| Name | Title | Phone | |
|---|---|---|---|
| J████ S████ | Water Treatment Supervisor | (555) ███-████ | j████@city████.gov |
| M████ J██████ | Utility Director | (555) ███-████ | m████@water████.org |
Water Sources & Treatment
Water Sources
Treatment Methods
Disinfectant Used
chloramines
CWSC Los Altos Suburban Consumer Confidence Report
A Consumer Confidence Report (CCR) is the EPA-mandated annual water-quality report every community water system must publish by July 1 each year (Safe Drinking Water Act §1414(c)(4)). It summarizes contaminants tested, MCL and MCLG comparisons, and any system violations from the prior calendar year.
A current CCR for CWSC Los Altos Suburban has not been published or validated on TapWaterData yet.
Residents: contact the utility directly using the phone number above, or check the EPA’s national CCR portal. Reports are typically distributed by mail or posted on the utility’s official website.
CWSC Los Altos Suburban Annual Water Quality Reports
Historical reports are being compiled. Check back soon for archived water quality data.
What is a CCR? The Consumer Confidence Report (CCR) is an annual water quality report that water utilities are required by the EPA to provide to customers. It contains information about your water source, detected contaminants, and compliance status.
EPA Health-Based Violations Since 2020
CWSC Los Altos Suburban has no health-based EPA violation since 2020 (EPA data as of Q2 2026).
EPA SDWA violation data as of Q2 2026 (downloaded 2026-07-09).
Concerned about what's in your water?
You're viewing 3 contaminants above health-based guidelines here. Your own tap water can differ — upload your test (PDF or a photo) and we'll email a full plain-English reading of every number, free.
Your upload also helps us keep local water data accurate — we only ever share anonymized, area-level summaries.
Upload my testRecommended Water Filters for CWSC Los Altos Suburban
Based on water quality data from cities served by CWSC Los Altos Suburban, we recommend NSF-certified filters that can remove contaminants above health guidelines.
Frequently Asked Questions about CWSC Los Altos Suburban
Is CWSC Los Altos Suburban water safe to drink?
Does CWSC Los Altos Suburban have PFAS in its water?
How do I pay my CWSC Los Altos Suburban water bill?
How many people does CWSC Los Altos Suburban serve?
What cities does CWSC Los Altos Suburban serve?
Does CWSC Los Altos Suburban have any EPA violations?
What is CWSC Los Altos Suburban's phone number?
Where can I find CWSC Los Altos Suburban's Consumer Confidence Report?
Similar water utilities in California
How we built this page
Water-quality and contact data on this page comes from public federal and state records. We update each utility's record whenever its underlying source publishes new data — typically within days of an EPA SDWIS refresh.
- Contaminants & violations: EPA Safe Drinking Water Information System (SDWIS) plus the Unregulated Contaminant Monitoring Rule (UCMR-5) for PFAS and emerging contaminants.
- Annual reports: CWSC Los Altos Suburban's most recent published Consumer Confidence Report (CCR), where available.
- Service area & contact: EPA SDWIS. The compliance records it holds for this system are reported to EPA by CA State Water Resources Control Board, Div. of Drinking Water, the state's drinking-water primacy agency.
Spotted a data issue? Use the Spotted something off? link at the bottom of the page — corrections feed back into the next data refresh. Learn more about TapWaterData.
Are you CWSC Los Altos Suburban? Publish your 2027 CCR
TapWaterData runs a free CCR publishing service for community water systems. Claim this listing to publish your Consumer Confidence Report here — it inherits this page's search authority and reaches every customer who Googles CWSC Los Altos Suburban.
- EPA-compliant distribution. Satisfies the 2027 Revised CCR Rule direct-URL requirement with an auditable archive.
- Publish once a year. Agent-assisted workflow; no login setup for small systems.
- Inherits this page's reach. Your published CCR appears directly on the page customers already find on Google.
Free for operators. No card required. Typical setup: 5 minutes.
Spotted something off on this page?
Residents keep our data honest.
This form corrects our data; it does not reach CWSC Los Altos Suburban. For a problem with your water now (discolored water, no water, low pressure, a leak), contact CWSC Los Altos Suburban directly.
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