Geothermal Driller: Job, Salary, License, and How to Get In

"Geothermal driller" is two different jobs. One drills shallow boreholes, commonly 75 to 500 feet deep, and installs the sealed loop pipe that feeds a ground-source heat pump. The other drills geothermal power wells, which at The Geysers in California run 8,000 to 12,000 feet, using rigs, casing programs and well-control practices that came out of oil and gas. Pay, equipment, crew size and hazards differ between the two. Local 150's apprenticeship and the federally registered Geothermal and Well Drilling Operator apprenticeship occupation both apply to shallow loop and water-well drilling, not to deep geothermal power drilling.

Shallow loop drilling is the better-documented of the two. It has a federal occupation code with its own 2025 wage series, a named union apprenticeship at IUOE Local 150 with a published wage progression, a federally registered apprenticeship occupation, a geothermal-specific national certification, and state licenses that spell out who may drill a heat-exchange borehole. Deep-well drilling differs materially in equipment, credentials, working conditions and hazards.

The federal wage figures on this subject come from O*NET, the US Department of Labor's occupational database, as displayed on September 15, 2026. It carries a trap: for some geothermal occupations it displays a parent occupation's wage and says so in small print. Most "geothermal driller salary" pages repeat that number without the caveat.

Two Trades Under One Name

The shallow trade is closed-loop geothermal drilling. The driller advances a borehole, commonly to 75 to 500 feet, inserts sealed heat-transfer pipe, and grouts the hole. The bore is not meant to produce groundwater. In the US Department of Energy's Building America guidance this is the standard vertical ground-source heat pump installation, and it is the work that IUOE Local 150 describes when it says its geothermal drillers "drill deep wells and install header and loop systems."

Water-well drilling is a neighbor to this trade rather than the same thing. A water-well driller is looking for an aquifer that produces, and the job typically adds production casing, screens, well development and pumps. An open-loop heat pump system, which pumps groundwater through the heat exchanger and returns it, sits closer to water-well work than to closed-loop work. Most state licensing schemes are built around this water-well/closed-loop boundary.

Deep geothermal power drilling is a different occupation. DOE's subsurface-accessibility material describes technology derived from oil and gas drilling applied to hotter and often harder or fractured rock, with lost circulation, larger well diameters and high-temperature well-control problems. DOE's description of drilling at The Geysers covers 8,000 to 12,000-foot directional wells, mud and air circulation, steel casing, cement, and repeated drill-string trips. Crews are sized accordingly: a 2024 Bureau of Land Management environmental assessment for a Utah geothermal production project described a 24-hour drilling operation with up to 23 people on site, including an always-present drilling supervisor. That is a deep-well number and does not describe a loop crew. No national standard establishes a typical shallow loop crew size. Staffing varies with rig automation, drilling method, site logistics, borefield size, and whether loop insertion and grouting run as separate operations.

Federal occupational data mirrors the split. Shallow loop and water-well drilling is classified under O*NET 47-5023.00, Earth Drillers, Except Oil and Gas. Deep power-well jobs may be classified under oil-and-gas codes such as 47-5012.00, Rotary Drill Operators, Oil and Gas, depending on the employer and duties, and those codes are defined expressly around hydrocarbon extraction. If the design side of the industry is what you are after, that is a separate route entirely, covered in our geothermal engineer career guide.

What a Geothermal Driller Does

O*NET's definition of 47-5023.00 covers operating drilling equipment, pumps and compressors; installing and maintaining drilling equipment; drilling earth or rock; collecting geological samples; and recording operational and environmental data. O*NET lists "Geothermal and Welldrilling Operator," "Horizontal Directional Drill Operator" and "Well Drill Operator (Const)" as approved apprenticeship titles under this occupation.

The US Department of Labor's apprenticeship bulletin for the occupation lists the drilling methods a driller is expected to learn: auger, mud rotary, air rotary, down-the-hole hammer, coring, and sonic percussion. The same bulletin lists casing, grouting, drilling logs, samples, environmental protection and public safety as parts of the trade.

Put together, a typical day on a loop job runs in this order:

1. Inspect and set up the rig.
2. Operate the drilling equipment and its pumps or compressors.
3. Advance the bore, adding drill pipe as the hole deepens and pulling it back out.
4. Manage cuttings and drilling fluid or air.
5. Install the loop (or casing, on a water well) and grout.
6. Collect samples, maintain the equipment, and complete the drilling log.

O*NET's work-context survey of Earth Drillers puts numbers on the conditions. Of respondents, 84% use common protective or safety equipment every day. 53% normally work more than 40 hours a week. 42% experience whole-body vibration every day. 45% are exposed to hazardous conditions every day. If you want the homeowner-facing version of what happens on site, our guide to geothermal drilling and wells covers the process from the customer's side.

Geothermal Driller Salary: What the Federal Data Shows

O*NET, as displayed on September 15, 2026, publishes no wage series under the title "geothermal well driller." The defensible proxy for the shallow loop trade is Earth Drillers, Except Oil and Gas, 47-5023.00, and its numbers are the occupation's own:

• 2025 median wage: $28.94 per hour, $60,190 per year. O*NET labels the source "Bureau of Labor Statistics 2025 wage data." This is 47-5023.00's own series, not a figure borrowed from a broader occupation.
• Employment: 18,300 in 2024.
• Projected growth: 3% to 4% for 2024 through 2034.
• Projected openings: about 1,700 per year, on average, across 2024 through 2034. That is an annual-average figure, not a ten-year total. O*NET still displays the 2024–2034 projection; BLS has since published a 2025–2035 projection of about 1,400 annual openings for the same occupation.

Those employment and openings figures cover all non-oil earth drillers, so they include water-well, environmental and construction drilling as well as geothermal loop work. They are not a count of geothermal drillers.

The parent-occupation trap

The other O*NET occupation with "geothermal" in the title is 49-9099.01, Geothermal Technicians, which covers power-plant operation and maintenance and heat-pump installation and service. It does not describe drill-rig operators, and its wage row is not its own. O*NET displays $23.67 per hour and $49,230 per year for 2025, but the page carries this label in O*NET's own words: "Median wage data for Installation, Maintenance, and Repair Workers, All Other." The employment and industry data shown on that page belong to the same parent occupation. Any article that presents $49,230 as the geothermal technician or geothermal driller wage is reporting a catch-all repair-worker figure without the caveat that O*NET itself prints.

The deep-well comparison

Deep power-well drilling has no geothermal-specific wage series either. The oil-and-gas codes that such jobs may fall under each carry their own 2025 medians on O*NET, and each is an oil-and-gas figure rather than a geothermal one:

• 47-5012.00, Rotary Drill Operators, Oil and Gas: $32.64 per hour, $67,890 per year. O*NET defines this occupation around oil and gas extraction and exploration.
• 47-5013.00, Service Unit Operators, Oil and Gas: $27.96 per hour, $58,160 per year. This covers service rigs, stuck pipe and casing, and improving producing wells, not initial loop drilling.
• 47-5071.00, Roustabouts, Oil and Gas: $22.58 per hour, $46,960 per year. This is rig-hand and support work, handling pipe and guiding loads, and it is not a geothermal-driller classification.

Where a deep geothermal job lands among those codes depends on how the employer classifies it.

Local 150's Geothermal Well Driller Apprenticeship and Wages

The International Union of Operating Engineers Local 150 runs a named Geothermal/Water Well Driller apprenticeship, separate from its general heavy-equipment operator program. Local 150's program page says its geothermal drillers drill deep wells and install header and loop systems, and that training covers drilling methods, safety, and operation of different kinds of drilling equipment.

Program length and requirements

Per Local 150's apprenticeship FAQ, the program requires:

• 6,000 or more hours of on-the-job learning
• 240 or more classroom hours
• 192 or more field-instruction hours
• Approximately four or more years to complete

Entry minimums listed on the same page: age 18, a high-school diploma or GED, residency within Local 150's jurisdiction, a valid driver's license that matches, English proficiency, a physical-capacity statement after indenture, and drug testing. Geothermal-well-driller applications are accepted year-round and remain active for two years after scoring.

What apprentices are paid

Local 150's general rule, in its own words: "First year apprentices typically start off at 50% of the current Journeyperson scale for the contract they are working under." Pay therefore depends on the contract the apprentice is dispatched under, not on a single union-wide geothermal rate.

The published scale appears in the wage allocation for Local 150's Districts 1–3 Building/Heavy Highway/Underground agreement, effective June 1, 2026. Apprentice hourly wages in that document:

• First year: $34.85
• Second year: $43.55
• Third year, by half: $50.25 and $53.60
• Fourth year, by half: $56.95 and $61.65

Two caveats travel with those numbers. The document does not label them as a geothermal-driller scale; they are the apprentice rates in that building and heavy-highway agreement. And whether that agreement governs every Local 150 geothermal assignment could not be established from Local 150's published material. Read the scale as the best available published Local 150 apprentice progression, with the 50%-of-journeyperson rule as the operative principle for whatever contract you are actually working under.

The Federally Recognized Apprenticeship

Apprenticeship.gov Bulletin 2011-11 recognized "Geothermal and Well Drilling Operator," RAPIDS code 2006HY, as a hybrid apprenticeable occupation with a 4,000 to 6,000-hour term. The bulletin's work-process outline covers auger, mud rotary, air rotary, down-the-hole hammer, coring and sonic percussion, along with casing, grouting, logs, samples, environmental protection and public safety.

The 2011 bulletin classifies the occupation under the now-retired O*NET-SOC code 47-5021.00. That code has since been retired, and current O*NET redirects 47-5021.00 to 47-5023.00, Earth Drillers, Except Oil and Gas. The bulletin is still the governing federal recognition of the occupation, but the wage and outlook data that go with it live under 47-5023.00, not the code printed on the bulletin.

What License You Need Starts With Which State

Loop-drilling licensure is set state by state, and Indiana, Wisconsin, Minnesota and Illinois use four different models. The required credential depends on the state where the drilling happens.

Indiana: the water-well license covers it

Indiana's Department of Natural Resources, Division of Water, requires a valid Indiana Water Well Drilling License for drilling "water wells, water test wells, water monitoring wells, or geothermal heat pump wells." Closed-loop geothermal drilling is folded into the ordinary water-well license. Indiana licenses individuals rather than companies, and the licensed individual must perform or actively supervise the covered work on site.

Wisconsin: a separate Heat Exchange Driller License

Wisconsin's Department of Natural Resources issues a Heat Exchange Driller License that is distinct from its water-well-driller license. Under Wisconsin's geothermal rules, a geothermal drillhole extending more than 25 feet must be constructed by a licensed heat-exchange driller or by a registered heat-exchange rig operator working for one. Below 25 feet the rule does not apply; above it, a water-well license alone is not the credential the state names.

Minnesota: full well license or a limited geothermal license

Minnesota's Department of Health, Well Management Section, requires that a bored geothermal heat exchanger be constructed by either a fully licensed well contractor or a Limited Bored Geothermal Heat Exchanger Contractor. The limited license covers constructing, repairing and sealing bored geothermal heat exchangers and nothing else; the full well-contractor license covers geothermal heat exchangers plus water wells and other regulated borings. Minnesota excludes closed-loop piping installed in a boring 15 feet or less below grade from its bored-geothermal permit definition, so a shallow horizontal loop sits outside the bored-exchanger scheme.

Illinois: closed-loop certification on top of registration

The Illinois Department of Public Health licenses water-well contractors and separately administers closed-loop-well certification, registration, permits and construction rules. A current Illinois-licensed water-well contractor may obtain closed-loop-well contractor certification without examination or fee, but the certification does not remove the annual registration requirement. An applicant who does not hold an Illinois water-well license must document 180 days of work as a geothermal well driller and take the examination route. Illinois therefore does not treat a standard water-well license alone as the complete closed-loop credential.

The comparison

• Indiana: geothermal heat-pump wells are inside the water-well license.
• Wisconsin: a separate heat-exchange license, triggered above 25 feet.
• Minnesota: either a full well-contractor license or a geothermal-limited license; 15 feet or less is excluded.
• Illinois: closed-loop certification plus annual registration; 180 days' geothermal drilling experience for non-water-well applicants.

A driller moving across a state line should assume the credential does not travel until the receiving state's well program says it does.

NGWA Certification: CVCLD and the Contractor Designations

The National Ground Water Association runs a voluntary national certification program. It certifies individuals, not companies, and it is not a substitute for state licensing. What it adds is a portable, geothermal-specific credential in a licensing landscape that is otherwise state by state.

The geothermal designation is the Certified Vertical Closed Loop Driller (CVCLD). NGWA describes it as an independent designation requiring relevant experience and passage of the Vertical Closed Loop exam. It stands alongside NGWA's general contractor designations, Certified Well Driller (CWD) and Certified Pump Installer (CPI), for which eligibility generally requires age 20, 24 consecutive months of full-time experience, two qualifying exams and professional references. The advanced designation is Master Groundwater Contractor (MGWC).

NGWA's state-licensing page says 14 states and two counties use its exams to some extent in their own licensing, and that Maine uses the CVCLD exam as an endorsement. In those jurisdictions the NGWA exam is part of the state process rather than a parallel credential; which states, and how far, is a question for each state well program. For the parallel credential on the installation side of the heat-pump trade, the IGSHPA installer track is covered in our geothermal installer certification guide.

Hazards, Hours, and the Seasonal Downside

OSHA's oil-and-gas well drilling eTool gives a detailed account of rig hazards, though some are specific to oil and gas operations. OSHA says drilling processes vary but many hazards are similar across rigs: moving tubulars, suspended loads, slips, trips and falls, lifting-equipment failure, and caught-between incidents. OSHA identifies struck-by, caught-in and caught-between events as the leading category of well-site fatality, involving vehicles, falling equipment and high-pressure lines. Other documented exposures include noise, diesel exhaust, temperature extremes, overexertion, fatigue and pinch points.

Some of those hazards occur on a shallow loop rig too; others belong to deep oil, gas and geothermal-power drilling.

• Shallow loop rigs share the mechanical-handling hazards. Drill pipe is still a moving tubular. Loads are still suspended. The deck is still wet and the rig is still loud. Diesel exhaust, heat, cold, vibration and fatigue occur on shallow loop work too, though their intensity and frequency vary with the rig, the site and the operation. Across the broader Earth Drillers occupation O*NET reports 45% exposed to hazardous conditions daily and 42% to whole-body vibration daily; it publishes no geothermal-loop-specific breakdown.
• Deep drilling adds hazards shallow loop work does not have: blowout, hydrocarbon fire and high-pressure reservoir releases. The distinction is between pressure created by the drilling equipment and pressure released from the formation. A grouted closed-loop borehole does not produce high-pressure reservoir fluid, though shallow drilling and grouting equipment still involves pressurized lines.

The other downside is the calendar. Local 150 says plainly in its apprenticeship FAQ that construction work is seasonal, employment is not guaranteed, and layoffs occur. An hourly rate is not an annual salary if the rig is parked for part of the winter, and the federal number does not correct for that: the $60,190 annual median is the $28.94 hourly median annualized at 2,080 hours, a full-time year-round assumption; it does not account for seasonal layoffs or for workers who get fewer hours. Neither figure is a promise of annual earnings.

Demand for Geothermal Drillers

The strongest federal statement on driller demand is DOE's January 2025 report, Pathways to Commercial Liftoff: Geothermal Heating and Cooling. It says a deficit of drilling labor and expertise can significantly increase project costs. It reports high demand in the Northeast and describes at least one case of a project sourcing drillers from Alabama and Oklahoma to meet it. It also says that among the core ground-source heat pump occupations, drillers have the longest training duration and the highest equipment-capital barrier, which is the report's explanation for why driller supply lags the rest of the trade.

A 2024 Connecticut DEEP/NEEP workforce assessment reached a similar regional conclusion, identifying an uneven supply of workers relative to project demand.

On September 8, 2026, DOE's Hydrocarbons and Geothermal Energy Office awarded $1.2 million to eight teams through the GHP PATHs Prize, specifically to strengthen the workforce for geothermal heat-exchange systems and shallow drilling. That funding covers workforce development for shallow drilling and the wider geothermal heat-exchange industry, not drillers alone.

The Northeast has a documented shortage of shallow-drilling labor, experience and rig capacity. No national count exists: neither a vacancy figure nor a shortage estimate specific to geothermal drillers is available from DOE, O*NET or the state programs. O*NET's projection of about 1,700 annual openings for 2024 through 2034 covers all Earth Drillers, Except Oil and Gas — water-well, environmental, mineral-exploration and construction drilling included — and reflects ordinary replacement and growth demand rather than a geothermal-specific shortage.

How to Become a Geothermal Driller

Most people enter the trade by one of these routes.

1. Check your state's well program first. Find out whether your state folds geothermal wells into the water-well license (Indiana), issues a separate heat-exchange license (Wisconsin), offers a limited geothermal license (Minnesota), or layers closed-loop certification on registration (Illinois). Whether the state also uses an NGWA exam, as 14 states and two counties do to some extent, changes what you study for.
2. If you are in Local 150's jurisdiction, apply to the Geothermal/Water Well Driller apprenticeship. Applications are accepted year-round and stay active for two years after scoring. Minimums are age 18, a diploma or GED, residency, a matching driver's license, English proficiency, a physical-capacity statement after indenture, and drug testing. Plan on roughly four-plus years, starting at about half the journeyperson rate for the contract you are dispatched under.
3. Elsewhere, look for a registered apprenticeship under RAPIDS 2006HY, Geothermal and Well Drilling Operator, or hire on with a licensed contractor and log hours. Illinois' 180-day requirement for closed-loop applicants without a water-well license is an example of how documented time on a rig converts into a credential.
4. Add the NGWA CVCLD once you have the experience. It is a voluntary national credential named for vertical closed-loop drilling and it does not replace a state license. Maine uses its exam as an endorsement.
5. Compare any offer against the 2025 federal median of $28.94 an hour, or $60,190 a year. That figure is 47-5023.00's own series, not the $49,230 parent-occupation number shown on the Geothermal Technicians page.

Frequently Asked Questions

How much does a geothermal driller make?

O*NET's 2025 median for Earth Drillers, Except Oil and Gas (47-5023.00), the occupation that covers geothermal loop and water-well drilling, is $28.94 per hour and $60,190 per year, from the occupation's own wage series. O*NET publishes no wage series titled "geothermal well driller" as of September 15, 2026.

What is the Local 150 geothermal well driller salary?

Local 150 does not publish a single geothermal-driller wage; its rule is that first-year apprentices typically start at 50% of the journeyperson scale for the contract they work under. The published apprentice progression in the Districts 1–3 Building/Heavy Highway agreement effective June 1, 2026 is $34.85 in the first year, $43.55 in the second, $50.25 and $53.60 in the two halves of the third year, and $56.95 and $61.65 in the two halves of the fourth. Whether that agreement covers every Local 150 geothermal assignment could not be established.

Do I need a license to drill geothermal wells?

Indiana, Wisconsin, Minnesota and Illinois all require a license or certification for regulated vertical or bored geothermal systems — but the credential differs and so do the depth thresholds. Indiana uses its water-well license (which expressly includes geothermal heat pump wells); Wisconsin has a separate Heat Exchange Driller License, required above 25 feet; Minnesota accepts a full well-contractor license or the limited geothermal one, and excludes closed-loop piping in a boring 15 feet or less; Illinois requires closed-loop certification plus annual registration. Shallow work can fall below a state's threshold entirely. Requirements vary elsewhere; consult the relevant state well program directly.

Is the NGWA CVCLD a license?

No. NGWA's Certified Vertical Closed Loop Driller is a voluntary national certification of an individual, requiring relevant experience and the Vertical Closed Loop exam. It does not substitute for a state license. NGWA says 14 states and two counties use its exams to some extent, and Maine uses the CVCLD exam as an endorsement.

Is there a shortage of geothermal drillers?

Regionally, yes, on DOE's evidence: the January 2025 Liftoff report cites a drilling-labor deficit, high Northeastern demand, and drillers sourced from Alabama and Oklahoma. No national vacancy count or geothermal-driller-specific shortage estimate is available.