Verified license

Sierra Exploration Drilling Co Inc

Paso Robles, CA · San Luis Obispo CountyWell drilling and pump installation

Call (805) 238-3396
License status
Active
checked September 29, 2026
License number
327073
California record
Services
5
Pump Installation and more
Counties served
3
on the state record

About Sierra Exploration Drilling Co Inc

Sierra Exploration Drilling Co Inc is a well drilling and pump installation contractor based in Paso Robles, CA (San Luis Obispo County). The California licensing program lists license 327073 as active, and we last checked the record on September 29, 2026.

The state record covers pump installation, pump repair, well abandonment, well drilling and well repair. It lists 3 counties where the business works, including Ventura County, Santa Barbara County and Los Angeles County.

This profile is built from public state license records checked on September 29, 2026. Well Water Insider does not rate or endorse contractors. Own this business? Claim the profile to add photos, hours and a description.

License record

Verified against state records
License number
327073
License type
Well drilling and pump installation
Status
Active
Expires
January 31, 2028
Last verified
September 29, 2026

Check this license yourself on the official California lookup.

What the state record says

Holds an active California C-57 Well Drilling contractor license (CSLB license 327073, corporation, first issued 1976, current through 2028-01-31). The C-57 classification covers drilling, casing, cleaning, repairing and destroying water wells and installing and repairing well pumps. Filed 69 well completion reports with the Department of Water Resources since 2016 (60 new wells, 27 of them domestic supply; 6 well destructions), most recently in June 2026, mostly in Ventura, Santa Barbara and Los Angeles counties.

Services

What the California record says Sierra Exploration Drilling Co Inc is licensed or registered to do.

Pump Installation

Setting a new submersible or jet pump with the pressure tank, switch and controls.

Pump Repair

Tracking down low pressure, short cycling or no water, then repairing or replacing parts of the pump system.

Well Abandonment

Sealing an unused well to state standards so it cannot carry surface water down into the aquifer.

Well Drilling

Drilling a new private well, setting the casing and grouting it the way state rules require.

Well Repair

Fixing casings, caps, pitless adapters and other parts of an existing well.

Service area

Based in San Luis Obispo County, California. The state record lists 3 counties.

Approximate location (San Luis Obispo County)Counties on the state record

  • Ventura County
  • Santa Barbara County
  • Los Angeles County

Well water in San Luis Obispo County

Useful context before you call a contractor here.

15%of households in San Luis Obispo County drink from a private well (est.)
300 to 600 feet; the median of 1,878 domestic wells reported to DWR since 2000 is 440 feettypical private well depth
Not statewidewater test when a home with a well is sold: no statewide rule in California, but some local areas require one
Open the San Luis Obispo County well guide

Typical costs for these services

National ranges to help you read a quote. They are not prices from Sierra Exploration Drilling Co Inc; ask for a written estimate.

Submersible pump replacement$1,000 to $2,500installed; deep wells cost more
Pressure tank replacement$800 to $1,500installed
New well, complete$6,000 to $16,000typical 200 ft well with pump; drilling alone about $20 to $30 per foot; deeper wells cost more
Shock chlorination$80 to $200by a contractor; under $30 to do yourself

National 2026 ranges. Sources, checked September 2026: HomeGuide cost guides, Angi.

Certified labs nearby

Test your water before and after any work on the well.

San Luis Obispo County Water Quality LaboratorySan Luis Obispo, CA · 3.3 miCounty of San Luis Obispo Public Health LaboratorySan Luis Obispo, CA · 4.8 miFruit Growers Laboratory, Inc.San Luis Obispo, CA · 6.1 mi
All labs near here

Before you hire

  1. 1

    Confirm the license

    Look up license 327073 on the California state lookup and make sure it is active for the work you need. Open the California lookup.

  2. 2

    Get a written estimate

    Ask for the scope, parts, depth or pump size, permit fees and warranty in writing. Compare two or three quotes for big jobs.

  3. 3

    Ask about permits and the well log

    New wells and many repairs are reported to the state. Ask who files the paperwork and for a copy of the well log.

  4. 4

    Test the water after the work

    Any work on a well can disturb bacteria. Test for coliform bacteria once the job is done.

Questions about Sierra Exploration Drilling Co Inc

Is Sierra Exploration Drilling Co Inc licensed?

Yes. The California record shows license 327073 (well drilling and pump installation) with the status "active", last checked on September 29, 2026. You can confirm it on the state lookup.

What services does Sierra Exploration Drilling Co Inc offer?

The state record lists pump installation, pump repair, well abandonment, well drilling and well repair. Call to confirm they take on your type of job.

What areas does Sierra Exploration Drilling Co Inc serve?

The business is based in San Luis Obispo County (Paso Robles, CA). The state record lists 3 counties, including Ventura County, Santa Barbara County and Los Angeles County.

How do I contact Sierra Exploration Drilling Co Inc?

Call (805) 238-3396. The address on the state record is PO BOX 1167, Paso Robles, CA 93447.

Other licensed contractors near Paso Robles