Coastside County Water District

The District sources water from pristine and carefully protected watersheds in the Sierra Nevada Mountain Range and San Mateo County's Coastal Mountain Range. The District manages the Denniston Project (combining surface and groundwater) and operates the Pilarcitos Creek Infiltration Well Field, both capturing water from the local coastal range.

Raw water is also purchased from the San Francisco Public Utilities Commission (SFPUC). This water comes from Pilarcitos Reservoir (fed by local coastal runoff) and Upper Crystal Springs Reservoir (supplied by SFPUC's Regional Water System, including the Hetch-Hetchy watershed).

All water undergoes complete treatment at our two facilities in compliance with federal and state standards. The Nunes Water Treatment Plant processes up to 4.5 million gallons daily from Pilarcitos Lake, Pilarcitos Creek Canyon infiltration wells, and Upper Crystal Springs Reservoir. The Denniston Water Treatment Plant handles up to 1.4 million gallons daily from Denniston Creek and Well Field.

Please note that Coastside County Water District does not add fluoride to its water supply. For fluoridation information, visit waterboards.California.gov/drinking_water/certlic/drinkingwater/Fluoridation.shtml.

Frequently Asked Questions

1. How do I pay my water/sanitation bill?

   IN OFFICE: Cash, check, or money order payments accepted in person or by mail. After hours, use our Payment Drop Box located outside the Water and Sanitation Division office.

   ELECTRONIC PAYMENTS: Set up electronic checks through your personal online banking. Contact your bank for details about this process.

   CREDIT/DEBIT CARDS: Accepted in office with no convenience fees (except American Express). Payments by phone or online through "Official Payments Corporation" include a $2.95 convenience fee per transaction.

2. Is my water safe to drink?

   To ensure County Service Area (CSA) water systems meet strict EPA and California Water Resources Control Board standards, water samples are regularly collected and tested by an independent state-certified laboratory.

3. What should I do if I encounter a snake while hiking?

   DON'T PANIC. Snake encounters are common on trails, especially when they're sunning themselves to regulate body temperature. Rattlesnakes and other species inhabit the Preserve but aren't typically aggressive unless threatened.

   If you encounter a snake: Don't approach, disturb, or try to move it. Back away slowly to avoid startling it. All preserve animals are protected as essential parts of the ecosystem.

   If bitten: Remain calm to slow venom spread. Keep the wound below heart level. Apply direct pressure and a loose bandage if bleeding occurs. Don't clean the wound, apply ice, cut the wound, or attempt to suck out venom. Transport to San Antonio Community Hospital (999 San Bernardino Rd, Upland) as quickly as possible.

4. I think my meter is reading incorrectly. Can I get it tested?

   The Division installs Sensus IPERL water meters compliant with ANSI/AWWA standards C700. Our certified testers use equipment verified by the Department of Weights and Measures. Contact our office to schedule a calibration test if you believe your meter is inaccurate.

5. When is the Preserve open and when are there closures?

   The North Etiwanda Preserve habitat conservation site is open from dawn to sunset for hiking only. Nighttime closure allows wildlife recovery and ensures visitor safety. Violators may be cited.