Category Archives: Research

Revised MAHC Modules Posted: Disinfection & Water Quality, Regulatory

Centers for Disease Control and Prevention (CDC) sent this bulletin on 1/24/2014

Model Aquatic Health Code

Thank you for your interest in the Model Aquatic Health Code (MAHC), a collaborative effort of public health, academia, and industry working to protect individuals, families, and communities from preventable waterborne diseases and injuries through evidence-based guidance. Read below for the latest information.


The Disinfection and Water Quality Module and the Regulatory Module have been revised and re-posted after the first public comment period. View the revised modules and the response to comments documents.


The first full version of the MAHC is coming soon, and we want your feedback! We plan to release the first full version of the MAHC—a combination of all revised modules and supplemental information—in spring 2014 for a 60-day public comment period.

Get a head start!

Because the MAHC will be a long document, we encourage you to get a head start and begin compiling your comments now on the modules that have been revised after the first public comment period so that you have plenty of time to submit your feedback. The content of these modules will not change substantially, but we will have to reorganize information that may be duplicated in multiple modules and resolve conflicts where duplicate items make different recommendations. We will announce when the full version is posted and we are accepting public comments for 60 days.

Each module has a short synopsis or abstract highlighting the most critical recommendations.

You can monitor the status of all modules on the MAHC website.

All Stories


I ThinkImagine that during a triathlon, a cyclist wrecked in the middle of the road, and everyone just stood around saying, “Poor guy.  Dude must have had a heart attack.  Or maybe he wasn’t all that good on a bike.  Nothing we can do now.” 

Sound ridiculous?  Most people understand that just because a person knows how to ride a bike, that’s not a guarantee that s/he will never fall off of it, nor get seriously hurt, nor even die.  Accidents happen.  And when they do, people notice.  And help.

With many a triathlon swim course, however, there is often a foregone conclusion that nothing can be done for accidents that occur in the water.  Recently a race director remarked about distress cases in the swim, “It’s not like you can drive an ambulance up to the athlete.”

For the cycling portion, USA Triathlon has helmet requirements and other rules to minimize life-threatening injuries on the bike course.  Many of those measures have come from experts in the field of cycling.  Yet, too often missing from the swim course are experts from the field of aquatic safety, the people trained to notice, as well as to advise on other swim precautions. 

Lifeguards discern the subtle changes in body position and behavior that indicate distress, or a more serious medical event in progress or imminent.  In pre-incident radio chatter, water rescuers say things like “head-up breaststroker coming your way, lifeguard six” and “pink cap on her back trying to unzip her wetsuit” and “yellow cap, number 1277, holding a kayak for the second time”, just a few of the precursors to and signs of swimming distress that lifeguards not only notice, but monitor closely to anticipate where the need to respond quickly may arise. 

As early as childhood, we learn that no one is ever drown-proof.  (Until recently, drowning was defined as any death that occurs within 24 hours of a submersion event.)  We are told to swim near a lifeguard, and that water safety requires different “layers” of protection.  Like riding a bike, just knowing how to swim is not a guarantee against in-water distress.  Even the most qualified swimmers, taking every precaution, are not exempt.  Yet, increasingly pervading triathlon culture is the disturbing concept that triathletes are tough, and shouldn’t NEED a lifeguard.0714Reef540

Yet unlike the land under a bike path, water is a different element.  It is big.  It can be quiet or deafening.  It resists, or rushes.  It can lift up, or swallow up.  It hides.  A swim path isn’t lined with spectators.  Even if it were, it’s not likely that any one of those cheering fans would detect something wrong, or be able to render the kind of aid that may be necessary.  Constant skilled supervision is required to spot the often vague and hazy signs of concern.  And a specific competence is demanded for rescue in that environment.

Insist on certified lifeguards at triathlons and open-water swim events. 

Because it’s not like riding a bike.


Revised MAHC Module Posted: Facility Design and Construction

Centers for Disease Control and Prevention (CDC) sent this bulletin at 12/16/2013 04:05 PM EST

Model Aquatic Health Code

December 16, 2013

Thank you for your interest in the Model Aquatic Health Code (MAHC), a collaborative effort of public health, academia, and industry working to protect individuals, families, and communities from preventable waterborne diseases and injuries through evidence-based guidance. Read below for the latest information.


The Facility Design and Construction Module has been revised and re-posted after the first public comment period. View the revised module and the response to comments document.


Each module has a short synopsis or abstract highlighting the most critical recommendations.

You can monitor the status of all modules on the MAHC website.

2014 Pool & Spa Operator™ Handbook Released

The 2014 edition of the Pool & Spa OperatorHandbook, published by non-profit National Swimming Pool Foundation® (NSPF®), is now available and includes important updates and a new look. Offered in English and Spanish with both U.S. and Metric units, this fundamental training and reference manual is including operators, health officials, service who help keep pools safer, and open. Important updates to the 2014 version are found in Chapters 2, 6, 16, and Appendix C-3.

  • Chapter 2: Updated Material Safety Data Sheet section with information about transition to SDS (Safety Data Sheets) terminology and the Globally Harmonized System (GHS).
  • Chapter 6: A short section about the Ryznar Stability Index (RSI), another saturation index used by some industry professionals, has been added.
  • Chapter 16: Now includes a brief section, which describes the new Swimming Pool & Spa Routine Maintenance online course from NSPF.
  • Appendix C-3: A summary on two new Module Aquatic Health Code (MAHC) modules has been added: Fecal/Blood/Vomit Contamination Response module; and Preface/User Guide/Glossary modules are now included.

“NSPF has once again updated the Pool & Spa Operator handbook to be the most current reference manual in the industry. This will ensure that NSPF Instructors and professionals who focus on keeping pools and spas safer, and open, are educating to the most current industry standards,” said Alex Antoniou, Ph.D., NSPF Director of Educational Programs. The Pool & Spa Operator Handbook is also wearing a new cover with a copy of original artwork in pastel, titled “Swimmer” created in 1997, by acclaimed artist Mela Lyman, whose passion for swimming is often reflected in her artwork. Lyman has been on the faculty of The School of the Museum of Fine Arts Boston and the combined degree program at Tufts University for over 20 years. To see more of Mela Lyman’s art, visit www.MelaLyman.

MAHC Recirculation Systems and Filtration (CH Comments)

CDC posts the Model Aquatic Health Code’s module for Recirculation Systems and Filtration for public comment with a closing date of October 9, 2013. Hydrologicblog posted this announcement with the supporting documents.

Recirculation Systems and Filtration

The Counsilman – Hunsaker team posted a group response in support of the public comment requirements. This response can be viewed at the below link.

MAHC Recirculation Systems Filtration comments