How UV can help
In simple terms, UV technology works by targeting the nucleic acids of micro-organisms. Exposure to UVC light prevents the DNA/RNA from replicating, preventing the micro-organisms from reproducing and thus rendering them harmless.
While traditional pools can be maintained using chemical parameters based on bather load, water volume and usage time, the dosage and sizing requirements for UV systems are calculated on flow rate (gpm) and the type of micro-organisms to be inactivated. UV technology is a one-pass system; it should be sized large enough for the entire pool volume to be exposed to UV light within a 24-hour time period.
This proven treatment is now mandated for use on all interactive water features located on cruise ships through the Vessel Sanitation Program (VSP). The growing popularity of children’s activity pools and aquatic environments aboard cruise ships has required an increase in disinfection controls. The final draft of the new VSP is currently under review, but as it stands, UV disinfection will be required on specific types of aquatic play features where children are present. The latest draft can be found at www.cdc.gov/nceh/vsp/.
Stay informed

Ongoing education and study is a must, as these technologies play a vital role in the elimination of Crypto and other RWIs. The Aquatic Play Feature™ Handbook, published by the NSPF, describes different types of features and the unique requirements needed to operate them and maintain water quality. The book focuses on risk reduction to the users, employees and the facility itself and emphasizes the importance of increased disinfection and an understanding of SDSs.
With the growing popularity of these water environments, it is important that pool contractors, engineers and service technicians know how to design and retrofit these supplemental systems for new and existing water environments. All pool industry professionals must unite to help combat the waterborne pathogens that cause RWIs.
Get involved
Over the past four years, this column has focused on providing busy pool professionals an education experience and a venue to express their ideas with other pool and spa professionals by interacting online with a Keiser University eCampus Aquatic Engineering instructor. Readers participate in the same way as students who are enrolled in the two-year online college degree program. The instructor presents a learning topic to which the reader may respond with research and discussion. The topic for this column: What are the benefits of providing UV systems on aquatic play features? E-mail responses to ccentrella@keiseruniversity.edu; a communication thread will share responses and present a forum for ideas and further discussion.
Resources
World Aquatic Health Conference Seminars 2007; 2009; 2010 (http://www.nspf.org)
Dr. Ernest Blatchley presentations
Aquatic Play Feature Handbook (http://www.nspf.org)
Model Aquatic Health Code (http://www.cdc.gov/healthywater/swimming/pools/mahc/)
Vessel Sanitation Program (www.cdc.gov/nceh/vsp/)
Connie Gibson Centrella, MBA, is program chair and professor for the online Aquatic Engineering Program at Keiser University eCampus. She was recently honoured for the fourth time with the Evelyn C. Keiser Teaching Excellence Award as an ‘Instructor of Distinction.’ An industry veteran with more than 40 years experience, Centrella is a former pool builder with extensive knowledge in pool construction, equipment installation and manufacturing.