Most states have no waterline-specific rule and enforce CDC guidance as the standard of care. A small number have codified testing, and those rules carry specific frequencies and retention periods.
01Washington requires water for nonsurgical procedures to meet the EPA standard of 500 or fewer CFU/mL, with testing per the equipment manufacturer's instructions or quarterly if none exist, and records retained for five years (WAC 246-817-660).
02Georgia requires dental unit waterlines to be tested at least quarterly under Rule 150-8-.05, effective July 20, 2025, with a log of testing and maintenance retained for five years.
03California does not regulate general waterline water quality by rule, but SB 1491 made irrigating exposed dental pulp with water that is neither sterile nor disinfecting unprofessional conduct, effective January 1, 2019.
04Both Washington and Georgia permit pooled sampling, which combines equal volumes from multiple lines in one sample, as an alternative to testing each line individually.
05In states without a waterline-specific rule, CDC guidance still functions as the standard of care and boards can act through their general unprofessional conduct provisions.
How State Regulation Works Here
Is dental waterline testing legally required?
It depends on where you practice. CDC's recommendation applies nationally but is guidance, not law. A small number of states have written waterline testing into administrative rule with a specific frequency and record retention period, and in those states it is legally required. Elsewhere, CDC guidance generally functions as the standard of care and boards act through their general infection control and unprofessional conduct provisions.
A board without a waterline-specific rule can still discipline a licensee over an infection control failure, and a health department can investigate regardless. A specific rule also names a testing frequency and retention period, so a practice needs records to support the claim that it follows CDC guidance.
Scope of This Page
This page lists only states with a provision specific to dental unit water that we have read in the primary source, with the date we last read it. It is not a fifty-state table. A padded list would look more authoritative but would be less trustworthy. State board rules change, so this page is explicit about what it has and has not verified.
States With Dental Water Provisions
Georgia
Testing required by rule
Dental unit waterlines must be tested at least quarterly, with a testing and maintenance log retained for at least five years.
Water quality standard
Water used for nonsurgical procedures must meet the EPA regulatory standard of 500 or fewer CFU/mL.
Testing frequency
At least quarterly.
Sampling method
Lines may be tested individually or as a pooled sample of up to ten lines using an equal volume from each.
Records
A log of testing and maintenance, including dates, the individuals who performed it, and independent testing reports, retained for at least five years.
No general waterline testing rule, but irrigating exposed dental pulp with water that is neither sterile nor disinfecting is unprofessional conduct.
What the statute covers
Procedures performed on exposed dental pulp. SB 1491 made the use of irrigation water that is not sterile, or that does not contain recognized disinfecting or antibacterial properties, unprofessional conduct.
What it does not cover
General dental unit water quality or a waterline testing frequency. The statute addresses irrigants used during specific procedures rather than setting a monitoring program.
Practical effect
Pulpotomies and similar pulp-exposing procedures cannot be irrigated with untreated dental unit water. CDC's 500 CFU/mL recommendation still applies as standard of care for everything else.
What applies in a state with no waterline-specific rule?
CDC's recommendation that dental unit water for nonsurgical procedures meet the EPA drinking water standard of 500 or fewer CFU/mL still applies as the professional standard of care. Many state boards adopt CDC infection control guidelines by reference without specifying a testing frequency, which leaves the frequency to your treatment product's instructions for use.
Defaults where no state rule exists
Water quality
≤500 CFU/mL for nonsurgical procedures, per CDC
Testing frequency
Per your treatment product's instructions for use. The 2018 ADS white paper suggests at least monthly after a new protocol, stepping down to no less than quarterly after two consecutive acceptable results.
Record retention
No federal period. Five years is a reasonable default because it matches what the states with explicit rules require.
Surgical procedures
Sterile solutions through a delivery device that bypasses the dental unit, everywhere, regardless of state rule
Checking Your Own State
Rules change, and they change without announcement to anyone who is not watching for it. Georgia’s rule took effect in 2025. Before relying on any third-party summary, including this one, confirm the current text yourself.
1. Search your state board’s administrative rules for “water” and “infection control” rather than “waterline.” Provisions are often filed under a broader infection control section.
2. Check whether your board adopts the CDC guidelines by reference. If it does, the 2003 guidelines and current CDC best practices become the enforceable content.
3. Check your state’s continuing education requirement for infection control, which is often where waterline content is mandated even when testing is not.
4. Record the date you checked. If your protocol is ever questioned, showing when you last verified the rule is part of showing the program is maintained.
Not Legal Advice
This page is a starting point for your own research, not a compliance determination. Requirements vary by state and by equipment manufacturer, and only your state board can tell you authoritatively what applies to your license.
Practicing somewhere with a rule we have not covered? Send us the citation and we will read the source and add it.
Frequently Asked Questions
Which states require dental waterline testing?+
Washington and Georgia have written waterline testing into administrative rule with a defined frequency and a five-year record retention requirement. Many other states adopt CDC infection control guidelines by reference without specifying a testing frequency. Because board rules change, confirm current requirements directly with your state dental board.
How often does Washington require waterline testing?+
WAC 246-817-660 directs licensed dentists to follow the dental equipment manufacturer's instructions for testing. Where no manufacturer instructions exist, the water delivery system must be tested quarterly. Additional testing is required five to ten days after repairs or changes to the plumbing system, and again twenty-one to twenty-eight days after that.
What does Georgia's Rule 150-8-.05 require?+
Water used for nonsurgical procedures must meet the EPA standard of 500 or fewer CFU/mL, dental unit waterlines must be tested at least quarterly, and a log of testing and maintenance must be retained for at least five years. The log must include dates, the individuals who performed the work, and any independent testing reports. The rule took effect July 20, 2025.
Can I test several waterlines in one sample?+
Both Washington and Georgia permit pooled sampling using an equal volume of water from each line. Georgia's rule allows pooling up to ten lines. Pooling reduces cost but also means a failure identifies the group rather than the individual chair, so per-operatory testing is more useful when troubleshooting.
What applies in a state with no waterline rule?+
CDC's recommendations generally function as the standard of care. A board without a waterline-specific rule can still act on patient harm or on infection control failures through its general unprofessional conduct provisions, and a state or county health department can investigate independently.
Requirements vary by state and by equipment manufacturer. Always follow your dental unit and treatment product instructions for use, and confirm current rules with your state dental board.
Next step
Every rule here assumes a protocol that runs
Quarterly testing and five-year records only help if the daily treatment happens in between. LineTab delivers a consistent dose at every reservoir refill.