Waterline FAQ

You can find our complete BiofilmAlert price list here.  

You can expect to receive results in 4 business days. Your test kit includes overnight return shipping. All tests are processed the same day they are received, followed by a 72 hour laboratory test.  We always report your results the same day they are ready.


Water samples are collected and shipped by your office on Thursday.  They will arrive to our laboratory and begin testing on Friday.  Test results will be delivered to your office via email on Monday.

Heterotrophic Plate Count Enzyme Substrate Method.

This method uses Multiple Enzyme Technology (MET) to detect heterotrophic bacteria in water. The most common enzymes of waterborne bacteria are all targeted for detection.

Standard method 9215E is U.S. EPA approved and included in Standard Methods for Examination of Water and Wastewater. This method correlates with U.S. EPA-approved, pour-plate method using plate count agar and 48-hour, 35°C incubation. Internal comparisons to Standard Methods (9215B) pour-plate method show a correlation coefficient (r) of 0.97.

Biofilms are microorganisms that can grow on many different surfaces. Microorganisms that form biofilms include bacteria and fungi. Biofilms thrive in wet environments.

Over the course of regular use, waterlines and connected devices such AW syringes can build up biofilms which contaminate the water which flows through them. A few disease-causing microorganisms found in untreated dental unit water include Legionella, Pseudomonas aeruginosa, and nontuberculous Mycobacterium. Dental health care personnel and patients could be placed at risk of adverse health effects if water is not appropriately treated.

The ADA states "The only way to ensure effectiveness of a dental unit waterline cleaning regimen is to actually test the water coming out of the unit."- ADA

Microbial counts can reach <200,000 colony-forming units (CFU)/mL within 5 days after installation of new dental unit waterlines. These counts can occur because dental unit waterline factors (e.g., system design, flow rates, and materials) promote both bacterial growth. - CDC 

Some dental unit manufacturers provide a schedule for monitoring your equipment. Check with your manufacturer to see if they have a recommended waterline maintenance schedule. 


Dentists in Washington State:

Effective December 1, 2021, WAC 246-817-660 requires dental offices to follow their dental unit manufacturer's instructions for testing frequency. If the manufacturer's instructions are unavailable, then quarterly testing is required.

Dentists are also required test the water delivery system five to ten days after repair or changes in the plumbing system and again at twenty-one to twenty-eight days later.

Sterile bottle systems and self-contained units must also be tested.

The ADA recommends that the number of bacteria in water used as a coolant/irrigant for nonsurgical dental procedures should be no greater than 500 CFU/mL, which is the regulatory standard for safe drinking water established by EPA, the American Public Health Association (APHA), and the American Water Works Association (AWWA).

There are several methods for improving dental unit water quality, including:

  • Filtration;
  • Chemical treatments;
  • Anti-retraction valves;
  • Use of water sources separate from the public water system

It is important to remember that these methods will not completely eliminate biofilms, and that it is important to continue regular monitoring.

-ADA Oral Health Topics

If a line is between 200 CFU/mL and 500 CFU/mL, shock your waterlines within 7 days and then continue regular treatment and testing. If a line is at 501 CFU/mL or more, treat your lines immediately and retest to verify that lines are operating below the CDC guideline limit of 500 CFU/mL.


Various products exist to treat and prevent biofilm in waterlines. The easiest and most cost effective treatment is to shock your lines with diluted bleach.  Consult your device manufacturer for maintenance recommendations.

  1. Use water that meets EPA regulatory standards for drinking water (i.e., ≤ 500 CFU/mL of heterotrophic water bacteria) for routine dental treatment output water.
  2. Consult with the dental unit manufacturer for appropriate methods and equipment to maintain the quality of dental water.
  3. Follow recommendations for monitoring water quality provided by the manufacturer of the unit or waterline treatment product.
  4. Use sterile saline or sterile water as a coolant/irrigant when performing surgical procedures.