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Frequently Asked Questions about the Model Aquatic Health Code (MAHC) for Potential Users


What is the MAHC?

The Model Aquatic Health Code (MAHC) is national guidance that can serve as a resource for local and state agencies and others interested in adopting or revising public health laws related to preventing illness and injury associated with treated water recreational swimming venues such as pools, hot tubs/spas, and interactive fountains.

The MAHC provides sample code language and explanatory text covering design, construction, operation, maintenance, and management standards. Most of the guidelines for facility design and construction pertain to new construction and substantial alteration only, not existing aquatic facilities. This guidance language can be used in whole or key components can be used individually. The MAHC Code wording is accompanied by an annex summarizing the scientific evidence base, research, and other materials used to inform the MAHC guidance.

Why is the MAHC needed?

Since 1978, the number of illness outbreaks associated with recreational water has increased significantly. Many of these illnesses can be prevented by proper maintenance and water treatment and by updated disease prevention practices (for example, supplemental treatment of water with ozone or ultraviolet light).

In the United States, there is no federal regulatory agency responsible for aquatic facilities. State and/or local public health or other officials develop, review, and approve all pool codes governing the design, construction, operation, and maintenance of swimming pools and other aquatic facilities. Therefore, requirements for preventing and responding to recreational water illnesses, injuries, and drowning can vary significantly among local and state agencies. In addition, maintaining and updating requirements to reflect the latest science requires a great deal of time and resources.

In 2005, CDC sponsored a workshop—Recreational Water Illness Prevention at Disinfected Swimming Venues—to discuss ways to minimize recreational water illnesses spread through disinfected swimming venues. The workshop brought together experts from different disciplines working in state, local, and federal public health agencies, the aquatics industry, and academia. A key recommendation from the group was to develop a model aquatic health code that local and state agencies could use as a guide for integrating science-and best practices-based language into their individual pool codes to promote healthy swimming. The group suggested the code be open-access, accessible, evidence-based, and updated on a regular basis. The group also suggested that in addition to waterborne diseases, the code should address drowning, chemical injuries, and other public health concerns associated with recreational water use. The following is a summary of key public health issues affected by the design, construction, operation, and maintenance of pools and other aquatic facilities:

What are the anticipated health outcomes?

Use of the MAHC is expected to help reduce the risk of diseases and injuries and promote healthy and safe swimming.

Short-term Outcomes: Use of the MAHC should help reduce the risk of diseases and injuries and promote healthy and safe swimming. We anticipate that the practices promoted in the MAHC will initially lead to the following system improvements:

Long-term Outcomes: By adopting the practices outlined in the MAHC, jurisdictions should also be able to improve the long-term health and safety at aquatic facilities. This should include a reduced risk of the following:

Who wrote the MAHC?

Creating the MAHC was a collaborative effort led by the Centers for Disease Control and Prevention and more than 140 volunteers from across the United States with expertise in aquatic venues, health, or safety. These experts included federal, state and local public health officials; researchers; and representatives of the aquatics industry, certification organizations, and not-for-profit aquatic associations.

To learn more about these experts, see the complete list of MAHC Steering Committee and Technical Committee members.

Was there an opportunity for public comment while the MAHC was created?

Yes. Ensuring multiple opportunities for public comment was a priority from the beginning of the process. The MAHC was developed in a modular fashion with each module developed by the appropriate Technical Committee, approved by the MAHC Steering Committee, and posted for public comment for 60 days from October 2010 through July 2013. After the 60-day public comment period, the Steering Committee and appropriate Technical Committee(s) reviewed the comments and revised the modules as needed. These revised modules were then posted on the website along with the responses to public comment.

After all of the modules were revised, CDC posted in March 2014 the complete MAHC "Knitted" version that combined all the modules for an additional 60-day public comment period to allow stakeholders to review sections across the entire MAHC and check the entire MAHC for completeness. The two public comment periods have allowed interested people, associations, and agencies from across the U.S. to give over 4,400 comments. This process has expanded the number of people having input into the MAHC and greatly improved the document. In addition to the formal public comment periods included in the MAHC development process, there will be additional opportunities for public comment at the state or local level as jurisdictions consider adopting the MAHC.

What is the scientific basis for the MAHC provisions?

The MAHC code language is accompanied by an annex that provides further information about the content of the MAHC and the scientific rationale for the guidance suggested in the MAHC.

The annexes:

View the MAHC.

How can the MAHC help prevent disease outbreaks like the cryptosporidiosis ("Crypto") outbreak in Utah in 2007?

Cryptosporidium is a microscopic, chlorine-tolerant parasite that causes the diarrheal disease cryptosporidiosis. Both the parasite and the disease are commonly known as "Crypto." Outbreak investigations routinely show that many people continue to swim despite having a diarrheal illness. This is likely the cause of a massive outbreak of cryptosporidiosis that affected thousands of people and over 450 swimming venues in Utah in 2007. In 2009-2010, Crypto caused at least 27 outbreaks of diarrheal disease associated with recreational water, resulting in over 400 cases of illness. As a chlorine-tolerant parasite, Crypto can survive for days in even a well-chlorinated pool. The MAHC can help prevent Crypto outbreaks by highlighting evidence-based practices that can reduce the risk of disease spread. The MAHC recommends additional secondary disinfection safeguards such as ultraviolet light or ozone, which kills Crypto, particularly for increased-risk aquatic venues like children's wading pools.

How does the MAHC relate to model codes developed by industry?

The MAHC is a free, open-access resource developed to help jurisdictions ensure that their aquatic codes are based on the latest and most scientifically sound data available. The MAHC complements building-specific codes, such as the Uniform Swimming Pool, Spa and Hot Tub Code (USPSHTC) developed by the International Association of Plumbing and Mechanical Officials (IAPMO) and the International Swimming Pool and Spa Code (ISPSC) developed by the International Code Council (ICC).

To ensure that the various pool codes are complementary, CDC has signed agreements with both ICC and IAPMO. CDC has paid careful attention to avoid conflicts between the MAHC and building codes. The MAHC primarily addresses issues for which environmental public health officials have principal regulatory responsibility, including aspects of design and construction that impact public health and all aspects of management and operations. Codes like the USPSHTC and the ISPSC are intended primarily to address issues over which building code officials have principal regulatory responsibility, including most structural, mechanical, and electrical components.

In addition, the MAHC primarily addresses public pools and aquatic venues, whereas other codes may apply to residential pools.

How does the MAHC differ from the Virginia Graeme Baker Pool and Spa Safety Act (VGB)?

The Virginia Graeme Baker Pool and Spa Safety Act (VGB) is a federal law passed in 2008 that requires public pools and spas to use unblockable drain covers or other specified devices or systems designed to prevent suction entrapment. Entrapment can occur when a body part or an object worn by the swimmer, such as jewelry, becomes entangled or stuck in the suction outlet cover, or when a body part forms a seal and suctions the swimmer to the outlet cover. The implementation of VGB is overseen by the Consumer Product Safety Commission.

There are several differences between the MAHC and VGB. While the VGB is a federal law requiring compliance, the MAHC is not a federal law and carries no regulatory authority unless adopted, in whole or part, by a state or locality. Rather, the MAHC is a resource that state and local agencies can use to update their own codes. The MAHC was created through a collaborative effort among public health and the aquatics sector, with opportunities for public review and comments. VGB targeted all pools; the MAHC design and construction elements pertain primarily to new construction or substantial alteration only (and only in those jurisdictions that adopt the MAHC). Finally, VGB only relates to unblockable drain covers. The MAHC covers a broad and complete range of public health concerns, including waterborne disease, drowning and other injuries, and chemical exposure.

What if I have concerns about the MAHC's effect on business?

The MAHC is not a federal law, so it will primarily affect aquatics businesses operating in jurisdictions that choose to adopt all or parts of the MAHC. For larger aquatics corporations operating facilities in multiple localities or states, the MAHC could lead to more consistent design, construction, operation, and maintenance guidance for pools and other aquatic facilities. In addition, expanded MAHC adoption would allow multi-state corporations to have a single, robust risk reduction effort that applies to locations across the United States.

By incorporating the MAHC guidance, aquatics facilities can reduce the risk of outbreaks of waterborne disease, drowning, and chemical and other injuries at their facilities. It is important to note that many MAHC provisions, particularly those related to design and construction, pertain primarily to new construction or substantial alteration only and will not require retrofitting of existing pools.

The aquatics sector has been heavily involved in the creation of the MAHC alongside public health experts. This helps ensure that the guidance proposed by the MAHC drives meaningful change while reflecting practical realities. CDC hopes that the design, maintenance, and operation of aquatic facilities become increasingly science-based through gradual changes that allow all parties to prepare. CDC shares the aquatics industry’s goal of making swimming healthy and safe.

How will the MAHC affect the construction and operation of pools in my area?

The MAHC is intended to provide optional and voluntary language to make the design, construction, and operation of pools safer and healthier. States and localities that choose to adopt the MAHC will likely affect pool operations by incorporating science-based practices into pool operation and maintenance.

MAHC provisions relating to design and construction will pertain primarily to the construction of new or substantially altered aquatic facilities and will not require retrofitting of existing aquatic facilities. Over time, adoption of the MAHC guidance could drive greater consistency in aquatic facility construction and operation requirements.

What are the roles for federal, state, and local government agencies with regard to aquatic health?

In the United States, there is no federal regulatory authority responsible for design, construction, operation, and maintenance of aquatic facilities. State and/or local legislatures or agencies develop, review, and approve all pool codes. These codes are implemented by state and/or local public health officials and, in some cases, building code officials. Sixty-eight percent of local health departments have a pool inspection program.

As a federal agency, CDC tracks illnesses and injuries associated with recreational water nationally through reports it receives from state and local partners. When state and local public health agencies detect an outbreak associated with treated recreational water, they might ask CDC to investigate or help control the outbreaks. Data collected during outbreak investigations and through research are then used to inform CDC recommendations and policy decisions taken by state and local regulators. As part of the response to prevent future outbreaks, drowning, and injuries, CDC has been committed to aquatic health since the 1950s when it issued its first of a series of aquatic health and safety guidance documents to public health agencies and the aquatics industry. CDC has continued to issue assistance and guidance since that time culminating in the creation of CDC's Healthy Swimming Program in 2001 that currently leads the MAHC effort.

What are the gaps in current state aquatic health codes?

Each jurisdiction's aquatic health code is different and will have to be evaluated by stakeholders in that jurisdiction. The MAHC has attempted to identify keys areas for improvement based on scientific data and current best practices, learning lessons from outbreaks, and other data sources.

For example, hygiene is an important issue that is linked to the spread of disease at aquatic facilities. The MAHC is intended to help improve swimmer hygiene to reduce the risk of spreading illness at aquatic facilities that are associated with poor swimmer hygiene. Thus, the MAHC contains sample requirements for new or substantially altered construction that include the following:

What if my jurisdiction’s regulations are stricter than the MAHC?

The MAHC is a guidance document and not a federal law and is only enforceable once adopted by a particular state or locality. The MAHC provides guidance on minimum standards for the design, construction, operation, maintenance, and management of aquatic facilities needed to protect public health and safety.

State or local stakeholders should evaluate the current laws and practical considerations in their jurisdictions to determine the most appropriate use of the MAHC in their communities. Jurisdictions may choose not to adopt the MAHC at all or may choose to adopt or revise all or parts of it to meet their needs.

Does my jurisdiction need to use all the code language in the MAHC?

No. The MAHC addresses a wide variety of aspects of aquatic health and safety. These aspects include operator training, risk management, ventilation and air quality, recirculation and filtration, facility design, and others.

Stakeholders should evaluate current laws and practical considerations in their jurisdictions to determine the most appropriate use of the MAHC in their community. Jurisdictions may choose not to adopt the MAHC at all, or may choose to adopt or revise key parts of the MAHC to meet their needs before adopting as regulation.

If facilities in my jurisdiction don’t have a high incidence of illness or injury, do we still need to review and update our aquatic health code?

Low incidence of recreational water illness and injury in a jurisdiction does not mean that aquatic facilities in that jurisdiction are optimally preventing and controlling the risk of recreational water illness and injury. Jurisdictions should also consider the recent increase in outbreaks of Cryptosporidium, which is not effectively controlled by traditional chlorination practices, as they review their aquatic health codes.

The MAHC is based on the best scientific data available for protection of public health. These guidelines are based on the principle of reasonable risk reduction, meaning that they are intended to minimize opportunities for recreational water illness and injury. As is the case with many public health prevention efforts, the value is often more easily understood after a tragedy occurs, such as a drowning, chemical poisoning, or outbreak. By incorporating evidence-based practices based on the science, jurisdictions reduce the likelihood of these events occurring in their communities.

What other resources are available?

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