If you're on a private well in Sonoma, Marin or Napa County, you already know the deal — nobody's coming to fix this but you and whoever you call. There's no utility to report an outage to. When the pressure goes, it's your equipment and your bill.
The good news is that well systems fail in a fairly small number of ways, and most of them announce themselves clearly if you know what to listen for. The most expensive mistake homeowners make is replacing a perfectly good pump because a $250 pressure switch failed. Five minutes of checking first is worth real money.
The 10-second version: if your pump switches on and off every few seconds while water is running, the problem is almost certainly your pressure tank — typically a $600 to $1,400 fix. If the pump runs constantly without building pressure, or doesn't run at all, you're looking at the pump, pressure switch or wiring, and the range widens considerably.
Five Checks to Run Before You Call Anyone
All of these are safe for a homeowner. None require opening electrical equipment.
Confirm it's whole-house
Run a tub spout — not a sink, tubs have the fewest restrictions — and an outdoor hose bibb. Weak everywhere means the well system. Weak at one or two fixtures means a clogged aerator, a failing cartridge, or a partly closed valve, and your well is fine.
Check the breaker
Find the well pump breaker and confirm it hasn't tripped. If you reset it and it trips again immediately, stop. A repeatedly tripping pump breaker means a short in the pump or the wiring down the well, and repeated resets can destroy a motor that might otherwise have been salvageable.
Watch the pressure gauge through a full cycle
Your pressure tank has a gauge on it. Run water and watch. Healthy systems cycle between about 40 and 60 psi, or 30 and 50 — a 20 psi spread. Note where the pump kicks on and where it shuts off. If it never reaches cut-off pressure, or the spread is tiny, you've learned something useful.
Knock on the pressure tank
Rap on the side of the tank from top to bottom with your knuckles. The top should sound hollow, the bottom solid — that's air above, water below, exactly as designed. If it sounds solid all the way up, the tank is waterlogged and the bladder has failed. This is the most common well problem in the North Bay, and this test finds it in ten seconds.
Count the cycles
With one fixture running steadily, count how many times the pump kicks on. Every few seconds is short cycling — a pressure tank problem, not a pump problem. It's also actively destroying your pump, because starting is the hardest thing a motor ever does.
If you take one thing from this page
Short cycling is urgent even though the water still works. Every day you run a short-cycling system, you're spending pump life to avoid a tank bill. A short-cycling system can burn through a pump's entire service life in a season or two — and the tank costs a fraction of what the pump does.
What Each Symptom Usually Means
| What You're Seeing | Most Likely Cause | Typical Cost |
|---|---|---|
| Pump clicks on/off every few seconds | Waterlogged pressure tank — failed bladder | $600 – $1,400 |
| No water at all, pump silent, breaker fine | Pressure switch or control box | $200 – $600 |
| Pump runs constantly, never builds pressure | Worn pump, leak in drop pipe, or dropping water level | $400 – $5,500 |
| Fine in the morning, fades by evening, recovers overnight | Low-yield well — recovery rate, not a broken part | $800 – $15,000+ |
| Air spitting from faucets, cloudy water, sediment | Pump drawing near water level, or waterlogged tank | Diagnose first |
| Gradual decline over months | Clogged sediment filter or fouled well screen | $75 – $2,000 |
| Breaker trips repeatedly | Short in pump or downhole wiring | $1,500 – $5,500 |
These are typical installed ranges for Sonoma, Marin and Napa County, and they vary with well depth, access, and what's found once the system is opened up. A 400-foot well in the Mayacamas is a different job than a 90-foot well in the Santa Rosa Plain.
The North Bay Problem Nobody Warns You About
Here's a failure mode that isn't a failure at all, and it gets misdiagnosed constantly.
Your pump is fine. Your tank is fine. But your well can't refill as fast as your household empties it. Pressure is great at 7am, fades by dinner after laundry and irrigation, and is back to normal the next morning. Homeowners describe this as "my pump is dying," and sometimes get sold a pump that doesn't fix anything.
This is common in western Sonoma County, the hillsides around Napa and Sonoma valleys, and rural Marin — areas drawing from fractured rock rather than a productive alluvial aquifer. It gets worse in dry years, and Sonoma County has been through enough of those that dry-weather well testing is now part of the county's permitting process for new wells.
How to tell it's yield and not the pump
What actually fixes it
| Fix | What It Does | Rough Cost |
|---|---|---|
| Low-water cutoff / pump protection | Doesn't add water — stops the pump from destroying itself running dry. Cheapest insurance available. | $300 – $800 |
| Storage tank + booster | Well trickles into a holding tank all day; booster pump serves the house. The standard answer for a genuinely low-yield well. | $4,000 – $12,000 |
| Lower the pump in the casing | Sometimes buys real capacity if there's usable depth below the current setting. | $1,200 – $3,500 |
| Deepen or drill new | Last resort. Permitted work through your county, with no guarantee of a better result. | $15,000 – $60,000+ |
| Reduce demand | Unglamorous and genuinely effective — irrigation timing, flow rates, leak repair. | Low |
Before you spend anything big on a low-yield well, find your leaks. A running toilet flapper wastes hundreds of gallons a day. On city water that's an annoying bill; on a marginal well it's the difference between adequate and inadequate.
We've seen households convinced they needed a $10,000 storage system who needed a $12 flapper and an irrigation timer adjustment.
Your Well Water Quality Is Entirely Your Responsibility
Worth stating plainly, because a surprising number of well owners don't realize it: no agency tests your well water. Public systems are regulated and monitored constantly. A private well is tested when the owner pays to test it, and not otherwise.
Standard guidance is annual testing for coliform bacteria and nitrate. Test additionally after:
- Any work on the well, pump or plumbing that opened the system
- Flooding or heavy runoff near the wellhead
- Wildfire in the area — a real concern across Sonoma and Napa
- Any change in taste, smell, color or clarity
- A new pregnancy or infant in the house — nitrate matters most for infants under six months
What the common complaints mean
Rotten egg smell
Usually hydrogen sulfide or sulfate-reducing bacteria. Typically handled with shock chlorination, then filtration or aeration.
Orange or brown staining on fixtures and laundry
Iron, sometimes accompanied by manganese. An oxidizing filter is the usual fix.
Scale on fixtures, soap won't lather, short water heater life
Hardness — extremely common in this region. See our guide to hard water in Sonoma, Marin and Napa County.
Cloudy water that clears from the bottom up
That's air — often a waterlogged tank or a pump drawing near the water level. Fix the mechanical cause, not the water.
Cloudy water that stays cloudy
Sediment or turbidity. Sediment filtration helps, but the well itself is worth investigating.
Metallic or bitter taste
Metals, or corrosion caused by acidic low-pH water. Test before treating — a neutralizer and a filter solve different problems.
Well water in this region is frequently hard, which is why well households tend to replace water heaters sooner than they expect. Scale buildup is the quiet expense.
Permits: Check Before, Not After
Sonoma County requires permits through Permit Sonoma for well construction, deepening, modification and destruction, and new wells can carry additional requirements around metering and dry-weather yield testing. Marin and Napa County run their own processes.
Straightforward like-for-like pump or pressure tank replacement is generally handled differently from work on the well itself — but "generally" isn't a good enough basis for a five-figure decision, and requirements change. Unpermitted well work has a way of surfacing at the worst possible moment, which is during escrow.
Any legitimate contractor will tell you what's required before starting. Anyone who waves off the question is telling you something about how they operate.
How Long Your Equipment Should Last
| Component | Expected Life | What Shortens It |
|---|---|---|
| Submersible pump | 8 – 15 years | Short cycling, running dry, sediment, undersizing |
| Jet pump (shallow well) | 6 – 12 years | Loss of prime, cavitation |
| Pressure tank | 5 – 15 years | Wrong precharge, waterlogging |
| Pressure switch | 5 – 10 years | Contact pitting from frequent cycling |
| Well casing | 30 – 50+ years | Corrosion, ground movement |
Notice how many of these say "cycling." A properly sized, properly precharged pressure tank protects everything downstream of it. It's the cheapest component in the system and the one most responsible for the lifespan of the expensive ones.
Signs You Should Call Us About Your Well
- The pump cycles on and off rapidly while water is running
- Pressure fades through the day and returns overnight
- Air spitting from faucets, or sand and grit in the water
- The pump runs constantly and never reaches shut-off pressure
- The pump breaker trips more than once
- Any sudden change in taste, smell, color or clarity
- You've never had the water tested and don't know what's in it
Frequently Asked Questions
Common questions Sonoma, Marin and Napa County well owners ask about pressure and pump problems.
Sources & further reading
- Permit Sonoma — Water Wells, well permitting information, and dry weather well testing requirements
- Sonoma County Emergency & Preparedness Information — guidance for residential well water users
- Regional well service cost data, cross-referenced against local job pricing
Cost ranges are typical for Sonoma, Marin and Napa County as of August 2026 and vary with well depth, access and site conditions. Permit requirements change — confirm current rules with your county before work begins.