A specialty designation layered on top of geologist licensure in the states that offer it. Where it exists, it is often required for specific groundwater work. Issued by State boards and professional associations, depending on jurisdiction. Intended for geologists specializing in groundwater who practice in states offering the designation.
This is a state-specific specialty, not a national credential. Before you plan for it, confirm your state actually offers it. Candidates regularly spend time preparing for a designation that does not exist where they intend to work.
The essentials
| Credential | Certified Hydrogeologist, also styled as a specialty geologist registration |
|---|---|
| Availability | Varies by state; not offered everywhere |
| Typical prerequisite | Existing Professional Geologist licensure |
| Additional requirements | Specialized hydrogeology experience and, in some states, a further examination |
| Common relevance | Groundwater supply, water rights, and remediation work |
How the specialty designation works
In states that offer it, this is a layer above general geologist licensure rather than a parallel track. You hold the PG first, then demonstrate specialized groundwater experience and in some jurisdictions pass an additional examination.
Where the designation exists, it can be required to take professional responsibility for particular categories of groundwater work. Stacy Choi, who holds both PG and CHG credentials, notes that in those states it is functionally a requirement for senior hydrogeology practice rather than an enhancement.
What this means for you
Check your state board first. The single most useful action here is confirming whether the designation exists in your jurisdiction and what it gates.
If you plan to practice in a state that offers it, structure your early experience so that a meaningful share is groundwater work under an appropriately credentialed supervisor.
Fees, eligibility rules, and examination windows change. Confirm every figure on this page with the issuer before you plan around it.
Frequently asked questions
Is this a national credential?
No. Availability, requirements, and the scope of practice it authorizes vary by state, and some states do not offer it at all.
Do I need a PG first?
In states offering the designation, general geologist licensure is typically a prerequisite.
Other credentials in this field
Professional Geologist Licensure
The single most consequential credential in applied geology. In many states it is not optional if you want to take professional responsibility for your own work.
ASBOG FGASBOG Fundamentals of Geology Exam
A breadth examination across undergraduate geology. The first formal step toward Professional Geologist licensure in most states.
ASBOG PGASBOG Practice of Geology Exam
The applied professional judgment examination, and the final examination step before Professional Geologist licensure.