Destroying an Unused Water Well in California: Permit, Procedure and Cost
Plenty of California properties have one: a steel pipe in the weeds behind the barn, or a hole someone once dropped a rock into and never heard land. The instinct is to leave it alone — or, if it's in the way, to push some dirt in and level the ground. Both are wrong, and in California the second is also illegal. Permanently retiring a well is a regulated procedure with its own name: well destruction.
An unused well is an open pipe into your drinking water
A properly built well is sealed along its upper length so surface water can't run down the outside of the casing into the aquifer. An old one usually isn't — the seal has failed, the casing has corroded, or it predates any seal requirement. What's left is a shortcut from the surface, past every foot of soil that would normally filter a contaminant, straight into the water-bearing zone. Irrigation runoff, fertilizer, a leaking fuel can: any of it reaches the aquifer in hours instead of decades. A neglected well also drains poor-quality shallow water into the deeper zone neighboring wells pump from.
This isn't theoretical. A 1992 study in the Journal of Hydrology by C.B. Avcı modeled flow between confined aquifers through improperly plugged boreholes and showed a single badly sealed hole is enough to establish sustained cross-aquifer flow (DOI 10.1016/0022-1694(92)90197-4). Jiménez-Martínez, Aravena and Candela made the same point at regional scale in Water, Air, & Soil Pollution in 2011, tracing the contamination of a deep confined aquifer under a farmed Spanish region back to leaky, never-properly-sealed boreholes (DOI 10.1007/s11270-010-0480-3). Where nitrate pressure already exists — much of the Central Valley and Inland Empire — an open well is part of that problem; our guide to nitrate in California well water, testing and treatment cost covers the receiving end.
There's a blunter hazard too: large-diameter hand-dug and bored wells under a rotted plywood cover are a fall risk for children and livestock, and the owner carries that liability as long as the hole exists.
"Destruction" is a legal procedure, not filling the hole
California's well standards live in Department of Water Resources Bulletin 74-81, the revised statewide Water Well Standards, together with Bulletin 74-90 — which DWR itself calls an informal compilation of 74-81 plus supplemental material. The state doesn't enforce them directly: local environmental health agencies implement standards that meet or exceed them, and 74-90 has been adopted into county ordinances statewide. The rules feel state-level, but the permit counter is local.
Two Water Code sections do the heavy lifting. Section 13750.5 says no person may dig, bore, drill, deepen, reperforate — or abandon or destroy — a water well unless the person responsible holds a C-57 Water Well Contractor's license. Section 13751 requires whoever destroys a well to file a report of completion with DWR within 60 days of finishing. Under 74-81 a well counts as abandoned or permanently inactive once it has gone a year without use, unless the owner shows intent to use it again and keeps it properly maintained meanwhile.
Only a C-57 contractor can legally do it
A general "B" license does not cover this, and neither does a C-36 plumbing license. C-57 Well Drilling is its own classification, and well rehabilitation and destruction is a listed subject on its state exam. Before signing anything, look the contractor up on the CSLB license-check tool and confirm the C-57 classification appears on the license, that it's active, and that bond and workers' comp are current — our guide to California plumbing contractor license classifications explains how to read a CSLB record. Counties add local requirements on top: San Luis Obispo, for one, requires drillers to carry a surety bond registered with the county.
What actually happens on site
A legitimate destruction follows a sequence, and every step exists for a reason:
- Clearing the well. Pump, drop pipe, wiring and years of fallen junk come out. Debris left in the hole leaves voids the grout can't fill.
- Dealing with the casing. Where the seal must reach the formation outside the pipe — always the case for gravel-packed wells — the casing is perforated or punctured opposite the zone being sealed, or removed entirely, so grout fills the annular space and not just the inside of a tube.
- Sealing the full depth from the bottom up. Neat cement or an approved bentonite grout is placed through a tremie pipe run to the bottom, or pressure-grouted, so the column fills upward and displaces water instead of falling through it and separating. Dirt, gravel and concrete rubble cannot substitute for this step.
- Cutting the casing below grade. The casing top is cut off below ground surface — counties specify the depth, commonly a few feet, typically on the order of three to five — the seal is brought up to that point, and the ground restored.
- Inspection and paperwork. The permitting agency inspects, usually while grout is being placed, and the Well Completion Report goes to DWR.
Which office do you actually call?
In most California counties it's the county environmental health department's well program. San Joaquin County, for instance, issues a well destruction permit application that requires a C-57, names acceptable sealing materials, mandates inspection, and cites Bulletins 74-81 and 74-90 by number.
But not everywhere. In Santa Clara County the permitting agency is Valley Water, the water district — not county environmental health. Its permits are valid one year, an authorized district inspector must be on site for the grouting, and it wants 24 hours' notice to schedule plus a second call about two hours before grouting starts. Same job, different phone number. Search your county's name plus "well destruction permit" before assuming, and ask for the current fee schedule.
When destruction stops being optional
Common triggers: connecting the house to municipal water and retiring the well (see what a well-to-city-water conversion costs in California — destruction is a separate line item people forget to budget); subdividing or building, where the county requires unused wells destroyed before sign-off; a sale where the lender or county flags an inactive well; and a well that has simply failed. If yours is struggling rather than dead, read what to do when a private well runs dry first — drilling a replacement well costs far more than restoring one.
What drives the price, and what a real bid includes
There's no statewide rate. Cost tracks four things: depth (grout volume scales with it), casing diameter (a 36-inch bored well swallows far more sealing material than a 6-inch drilled one), obstructions (a seized pump or collapsed casing turns a one-day job into a fishing operation), and access for the rig. County permit and inspection fees sit on top, published in each agency's fee schedule. Broadly, a shallow, clean, small-diameter well on accessible ground lands in the low four figures; a deep, large-diameter or obstructed one moves into the mid four figures and up. Treat that as orientation and price yours from real bids.
A bid worth accepting states, in writing: that the contractor pulls the permit and pays the fees (or itemizes them); the sealing material and how it will be placed; how obstructions are handled and at what rate; that the inspection is scheduled and attended; that the Well Completion Report is filed with DWR and a copy given to you; and that the site is restored. Keep that report — it proves the well is gone when you sell, and it's the one thing a dirt-filled hole can never produce.
Two loose ends while the equipment is out: the old buried line from wellhead to house usually stays in the ground and can quietly leak, so have it cut and capped (leak detection pricing if you suspect it's still live), and well-fed gear — softener, filters, pressure tank — becomes surplus on municipal water (water softener cost). Still on the well and undecided? Private well water testing in California covers what to test.
If you have an unused well and want licensed contractors to price the destruction properly, request a free quote and describe the well's depth, diameter and condition as best you know them.
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