Verified license

Petersen – GPM Well Testing and Water Treatment Services LLC

Santa Rosa, CA · Sonoma CountyWell drilling and pump installation

Call (707) 823-4102
WebsiteDirections
License status
Active
checked September 29, 2026
License number
985445
California record
Services
5
Pump Installation and more

About Petersen – GPM Well Testing and Water Treatment Services LLC

Petersen – GPM Well Testing and Water Treatment Services LLC is a well drilling and pump installation contractor based in Santa Rosa, CA (Sonoma County). The California licensing program lists license 985445 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.

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
985445
License type
Well drilling and pump installation
Status
Active
Expires
July 31, 2027
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 985445, limited liability company, first issued 2013, current through 2027-07-31). The C-57 classification covers drilling, casing, cleaning, repairing and destroying water wells and installing and repairing well pumps. Also licensed as: D-21 machinery and pumps. No well completion reports filed with the Department of Water Resources since 2016 under this license number (pump work and repairs are not reported, and reports filed under a driller's individual name may not match).

Services

What the California record says Petersen – GPM Well Testing and Water Treatment Services LLC 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 Sonoma County, California.

Approximate location (Sonoma County)

Well water in Sonoma County

Useful context before you call a contractor here.

15%of households in Sonoma County drink from a private well (est.)
200 to 360 feet; the median of 6,080 domestic wells reported to DWR since 2000 is 260 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 Sonoma County well guide

Typical costs for these services

National ranges to help you read a quote. They are not prices from Petersen – GPM Well Testing and Water Treatment Services LLC; 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.

Brelje and Race Laboratories, Inc.Santa Rosa, CA · 1.7 miSonoma County Public Health LaboratorySanta Rosa, CA · 3.8 miK Prime, LLC.Santa Rosa, CA · 7.7 mi
All labs near here

Before you hire

  1. 1

    Confirm the license

    Look up license 985445 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 Petersen – GPM Well Testing and Water Treatment Services LLC

Is Petersen – GPM Well Testing and Water Treatment Services LLC licensed?

Yes. The California record shows license 985445 (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 Petersen – GPM Well Testing and Water Treatment Services LLC 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 Petersen – GPM Well Testing and Water Treatment Services LLC serve?

The business is based in Sonoma County (Santa Rosa, CA).

How do I contact Petersen – GPM Well Testing and Water Treatment Services LLC?

Call (707) 823-4102 and visit their website. The address on the state record is 5434 Old Redwood Highway, Santa Rosa, CA 95403.

Other licensed contractors near Santa Rosa