The Science Of Safety In Aquatic Play Features

The tremendous popularity of parks with unique aquatic play features has changed the landscape of recreational waters. More families than ever are attracted to these venues as a way to spend time together.

Today, these features include everything from water slides, lazy rivers and activity pools to mushroom sprays, splash pads and wave pools.

These innovative recreational features decrease the fear of swimming for young bathers--the shallow water, bubbling actions and sprays offer comfort and reassurance, and create fun and fond memories for the entire family.

For aquatic directors, these exciting play features can present new challenges and risk factors, including additional water-quality concerns.

Water Quality

The risk of contamination increases dramatically at these facilities because there is a much higher bather load and instance of fecal contamination. Thus, it is critical for operators to have a complete understanding of the complexities surrounding recreational water illness (RWI).

Because of the sheer size of the facilities, and the high user rate, there is a constant need for adequate disinfection, which must be continually monitored; therefore, local and state health regulators are updating their guidelines to call attention to higher contamination probabilities.

One important addition to the health codes is the implementation of supplemental sanitation. The recommended level for disinfectants--such as free available chlorine--is 2.0 to 4.0 parts per million. With the higher bather loads, free chlorine combines rapidly; therefore, oxidation must take place at a faster rate. For this reason, a supplemental sanitizer is now recommended.

Ozone and Ultraviolet (UV) systems have gained acceptance as an additional means of eliminating chloramines and fighting RWIs. Controllers and automatic chemical-feed systems, in conjunction with Oxidation Reduction Potential (ORP) metering, have proven to be a safeguard in fighting contamination.

ORP probes are installed on the return side of the filtration system to measure chlorine activity; expressed in millivolts, the ORP probes measure the ratio of oxidation/reduction. ORP is influenced by the pH reading. Operators must take precautions to ensure that the probes are calibrated and cleaned during routine maintenance. It is also advisable to take manual readings throughout the day to effectively monitor free available chlorine and pH.

Most aquatic play features are installed in shallow water or even in zero-depth entry pools. Shallow water and splashing typically cause an increased demand for replacement water. It is important for operators to test the local water supply, as make-up water directly influences the sanitization and water-balance parameters.

Water chemistry for aquatic play features also requires testing the five factors of water balance:

• pH

• Alkalinity

• Calcium hardness

• Temperature

• Total dissolved solids.

When these factors are calculated under the saturation index parameters of -.03 to +.03 on the Langelier Saturation Index Scale, the disinfection process is optimized. These balancing factors are influenced by bather waste, disinfection, source water, airborne debris, aeration and evaporation.

A low saturation index can cause corrosion of the pool surfaces, eye burn, and equipment damage. If the saturation index is high, scale forms on the pool surfaces and within the circulation piping. It is vital that pool operators understand the parameters of water balance to reduce the need for premature interior resurfacing and equipment replacement.

Risk Factors

Ensuring bather safety is always a priority at aquatic venues, and particularly where play features are present. A regular examination of the main drains is mandatory. The Virginia Graeme Baker Act, signed into law in December 2007, mandates that all main drains and other suction ports be inspected and retrofitted to meet the new guidelines enforced by the Consumer Product Safety Commission. (Reference: ASME/ANSI A112.19.8-2007 or successor standard.)

Slips and falls around and in shallow water may be reduced by careful inspection of all decking around the feature areas to eliminate puddles. Depth markings on the deck and within the pools must be installed, and risk-warning signage must be posted.

When retrofitting an existing venue with new feature designs, make sure that the lifeguards’ lines of sight are carefully considered. It is vital that children playing in and around these activity pools are able to be seen at all times. It is also recommended that children who cannot swim wear life jackets and remain under parental supervision.


Water-feature training should be required for all operators and staff. This is especially needed at those amenities that include rides and slides. An attendant who monitors the dispatching of patrons onto the rafts, slides and rides should always be on duty. An established set of rules for entry should be posted, learned, and enforced by all operators.

Maintenance staff must also be thoroughly trained on all the structures, in addition to knowing water-quality requirements. Water slides need regular maintenance, and some need to be waxed on a scheduled basis to protect the surfaces. Pumps and motors require examination to be sure the circulation is flowing at the right flow rate in order to optimize performance of the slides and rides. Keeping regular inspection lists and repair logs can help minimize liability.


A risk-management and emergency-response action plan should be put into place for each of these amenity parks to guide staff in identifying, analyzing, and taking steps to reduce exposure to accidents. The hiring and training of operators includes in-service sessions related to chemical hazards, chemical treatments, water-quality management, equipment repair and maintenance, as well as accident-related injuries.

The training should be ongoing and conducted on a regular, scheduled basis to ensure the education includes up-to-date technologies and recent changes in health codes. The National Swimming Pool Foundation offers a series of online training programs that address the critical aspects of aquatic management. .

Checklist for Aquatic Play-Feature Operators

• Keep a maintenance-equipment file and chemical log on each water feature

• Manually test each water feature, and calibrate with automatic controls

• Determine water balance by using the Langelier Saturation Index

• Maintain a file on all chemical treatments (MSDS sheets)

• Develop a chemical safety-handling program

• Implement an emergency-response action plan.

There is much intrinsic value to adding aquatic play features at pool facilities. Interactive water invites the community to experience an entirely new attraction--a love for water fun. Investments in water play features can add to the bottom line; however, knowing how to manage the risks is paramount to providing a safe, fun and profitable facility. Proactively engaging in education and training to protect the bathers should be a lifetime activity for aquatic operators.

Connie Sue Centrella is a professor and Program Director for the online Aquatic Engineering Program at Keiser University eCampus. She is a five-time recipient of the Evelyn C. Keiser Teaching Excellence Award “Instructor of Distinction.” Centrella is an industry veteran with over 40 years experience in the pool and spa industry. She is a former pool builder with extensive knowledge in pool construction and equipment installation as well as manufacturing.


Online Course

The Aquatic Play Feature online course provides professional training for any facility that has an aquatic play feature, large or small. People who operate and manage these innovative recreational features will appreciate this training course. The course is just $50, and includes the Aquatic Play Feature Handbook. Or purchase the handbook alone for $19.95 plus shipping. Visit or call (719) 540-9119.