California Private Well Guide

When You Need a Private Well

Private wells are generally installed when a property is not served by a public (municipal or community) water system – for example in rural or unincorporated areas beyond water district service.

About two million California wells tap groundwater, compared to tens of thousands of public systems. A domestic well typically serves only one home (up to 4 taps); public systems serve 5+ connections. In practice, if no water line access exists, or installation of a meter is infeasible, a private well is required.

Local health or water agencies issue permits and require Bulletin 74 standards for well siting, design, and construction.

Well Drilling Costs in California

Well drilling costs vary widely with depth, geology, and locality. Industry estimates show total new domestic well projects in California often cost on the order of $15,000 to $45,000 (much higher for very deep wells or difficult rock).

Timeline: From Decision to Drinking Water

The project can take a few weeks to several months. Expect 2–4 months overall, with permits often dominating the schedule.

By statute, the driller must submit a Well Completion Report to CA DWR within 60 days of finishing the well. Note that local conditions (e.g. heavy permit workloads) can lengthen approval time.

Permits & Process

Step-by-Step Process

1. Hire a licensed well driller (C-57) or licensed pump contractor (C-61/D-21) and arrange a site survey.
2. Submit a well permit application to your county Environmental Health Department (or local water district if applicable). The application usually includes site maps (showing septic tanks, property lines, etc.), geologic info, and a driller's work plan.
3. Local agency reviews compliance with safe separation distances (septic, contaminants) per Bulletin 74 standards and issues or conditions the permit.
4. Schedule drilling; contractor installs casing, grout seals, develops the well (pumps or surging), and disinfects as needed.
5. Install pump, pressure tank and service lines (by licensed contractor).
6. Collect water samples for lab tests (often required for permit compliance).
7. Local health or building officials may inspect major components (e.g. sanitary seal, connections) as required by jurisdiction.
8. Once testing is passed and inspection (if any) completed, the well is activated.
9. Driller files the Well Completion Report with DWR (Water Code §13751) within 60 days.

Who Does What?

Required Inspections/Approvals

Procedures vary by county. Commonly, plan review is performed prior to drilling. Some agencies may inspect on-site at stages (e.g. verify the sanitary seal depth or pitless adapter installation). Counties typically require submission of the driller's log and test results for final approval.

For example, Placer County requires an initial bacteriological sample before issuing building permits. In all cases the enforcing agency (usually county health or a municipal water dept.) must clear the well before it can be legally used for drinking water.

Water Quality

Recommended Testing

• At minimum (annually): The EPA advises annual testing for coliform bacteria, nitrates, and total dissolved solids (plus pH)
• Regional contaminants: Test for arsenic, uranium, fluoride, lead, VOCs, pesticides, etc. based on local geology or land use
• After any event: Flooding, well repairs, taste/odor changes

The homeowner pays for testing (typically $100–$400 per standard analysis), although programs under AB 2454 can supply free testing for rental wells or disadvantaged areas.

Common California Water Quality Issues

Treatment Options

Treatment must match the contaminant. The SWRCB notes multiple options: filtration (sediment/carbon filters), reverse osmosis (RO), distillation, and ultraviolet (UV) or chemical disinfection, among others.

• UV lamps or chlorination eliminate bacteria
• Activated-carbon filters remove many organic chemicals and improve taste/odor
• Reverse-osmosis units remove most heavy metals, nitrates and salts
• For iron and manganese, oxidizing media filters or water softeners are effective

The SWRCB's Division of Drinking Water publishes a list of certified arsenic- and nitrate-removal devices. Always test after installation to verify effectiveness.

Maintenance & Problems

Ongoing Maintenance

Regular upkeep is essential. The EPA advises well owners to test annually for coliform, nitrates and other key parameters. Change filter cartridges (in any sediment or carbon filters) and UV bulbs per manufacturer schedules.

• Test water annually for bacteria, nitrates, and key contaminants
• Inspect the wellhead: ensure the well cap/seal is intact and dirt-free
• Check pressure tank air charge annually
• Replace filter cartridges and UV bulbs per schedule
• Keep records of maintenance, disinfection, and repairs

Warning Signs of Problems

Call a Professional vs DIY

Owners can do routine tasks: periodic water testing, changing simple filter cartridges, and sanitizing small tanks. However, major work must be by professionals.

By California law, any drilling or alteration of the well (including pump installation) requires a licensed C-57 or C-61/D-21 contractor. If your pump fails, or the well runs dry, call a certified well company. Always consult professionals for treatment system sizing or contamination remediation.

Find a Licensed Driller

California law requires a licensed contractor for all well work. Search for C-57 (well drilling) or C-61/D-21 (pumps) licensed contractors.

How to Verify a Driller

1. Ask for their CSLB license number
2. Verify at CSLB Check-A-License
3. Check for appropriate classification (C-57 or C-61/D-21)
4. Get 2-3 written quotes
5. Ask for references from recent jobs

You can also call (800) 321-2752 to verify license status and complaints.

Resources & Contacts

Certified Testing Labs

Water samples must be analyzed by a state-certified (ELAP-accredited) laboratory. The CA State Water Board maintains an online GIS map of accredited labs. Always verify current status via the SWRCB ELAP directory.

Key Regulatory References

• DWR Bulletin 74 – "CA Well Standards" for legal well construction requirements
• CA Water Code §13751 – Mandates filing of well completion reports
• CA Health & Safety Code and Title 17 CCR – Govern public drinking water (domestic wells use guidance from these on standards)

Frequently Asked Questions