Water, Water, Everywhere
A look at a Bloomington pool, splash pad
Aquatic recreation is a very large part of our American society. We swim, we boat, we fish and we are captivated and energized by water in many ways.
One way we enjoy our connection with water is through warm weather swimming pools, and recently, splash pads. Millions of people country wide, young and old, enjoy the benefits of aquatic activities. Operating and maintaining these aquatic facilities is challenging and time-consuming and requires large amounts of funding to build and operate them safely and properly.
Public safety is certainly foremost in the minds of aquatic facility operators. We must be constantly vigilant maintaining public safety and trust. We also want to make sure our customers always have positive and enjoyable experiences when they visit and use our aquatic facilities. We walk that tightrope of providing quality service, at the same time working to make the best use of the budget dollars we have available.
How do we make all of these things happen? If we are in a position to be considering a new aquatic facility then we can design everything we need into this new facility. We can make sure we have what we need to meet the safety and operational goals for our facility. It is important to remember, though, if we have an existing aquatic facility all is not lost in trying to make it function better and more efficiently. We know the mechanical equipment in our facilities does not last forever. What that means is when replacements are needed this is our opportunity to look at some new concepts and equipment. Choices must be made but like most industries, equipment and products related to aquatics are being worked on and improved every day.
I would like to take you on a short journey through the large outdoor pool and splash pad that are in operation in the park system in Bloomington, MN, a suburb of Minneapolis and St. Paul.
Aquatics Very Popular
Even though our summer swimming season is relatively short, outdoor aquatic activities are a very important part of park programs. To serve our customers in this city of approximately 88,000 people, we have a large outdoor pool and also a splash pad for use by toddler age children. Our large outdoor pool is located at one of our large playfields that encompasses five baseball fields, 11 softball fields, two basketball courts, 24 horseshoe courts, two playgrounds, a small skateboard area and six lighted tennis courts.
Our 580,000-gallon outdoor pool is one of the summer focal points of activity at this site. This pool is accessed through our bathhouse which includes a registration/ entry lobby and locker room/restrooms for both male and female patrons. Once our customers have entered through the bathhouse, they move out onto the large concrete deck area that surrounds the entire pool. There is plenty of area for sunbathing and also various areas around the pool where shade is provided. Through the use of a number of large umbrellas and two picnic gazebos, patrons who do not want to spend all of their time in the sun have an alternative. We also have 75-80 reclining lounging chairs that are generally all in use shortly after we open each day.
The pool itself has the water surface level at the same level as the deck. This provides safe and easy access at any point and also is much more aesthetically pleasing than our old pool where the water was below the perimeter.
The pool consists of three distinct areas. There is a zero depth area that goes from zero to approximately three feet in water depth. This is where all of the “little ones” hang out. Also included in this zero depth we have a number of water toys in the shallow depth that the children can use and interact with. The second area is the 50-meter, 8-lane competition area. This large area of the pool goes from 3 feet in depth to 5 feet deep.
This pool, because of its 50-meter length and being one of only a handful of 50-meter outdoor pools in Minnesota, is very popular for swim teams to practice and hold swim meets. Off one corner of this competition area is the exit area where users of our two large flume water slides enter the pool. These slides are 30 feet above the pool surface so the users get a great ride down from the top to the water. These large flumes are very popular and there is generally a line waiting for this experience. The third area is an 11-foot-deep diving well. There are two one-meter springboards and a small water tube slide that use this area of the pool.
Challenges
With all of these unique areas of different sizes, depths and uses, maintaining proper and safe water conditions can be a challenge. When designing this new pool in some ways we over built our mechanical systems. We have a fair amount of “redundancy” built into systems. Each of these three areas of the pool has its own pump, chlorinator and pH control system. When we chose pumps we chose lower rpm, larger pumps that could be serviced locally. The pumps are sized to meet the different requirements for water change-over that each of the use areas of the pool needs.
Our chlorination system includes three pellet chlorinators. Although this type of system is generally more costly to operate than, for example, gas chlorine, it is much safer and easier to operate. We have a redundant pH regulating system. The primary way pH is controlled is with a CO2 system. One concern with this system is that although it is relatively inexpensive to operate it increases the alkalinity which must be maintained between 50-120 ppm. To help control the alkalinity we also have a hydrochloric acid system that can be used to help regulate the alkalinity. We have multiple pumps that feed CO2 into the three distinct pool areas and also three other pumps that, when needed, feed hydrochloric acid into the three pool areas. To both monitor and also control the water chemistry, we have three separate electronic controllers that read, display and control water chemistry.
We also have two large 3.5 million-BTU heaters to keep the water at the proper temperature. Although one of these heaters alone could do the job of maintaining the water temperature, spring warm-up of the water would take more time with only one heater. It must be understood that other influences such as the material the pool vessel is made from and the chemical makeup of the water used in the pool, just to name a couple, are things that can affect water chemistry and what is required to maintain the proper and safe water chemistry.
Having redundant duplicate systems also helps ensure that we can continue to operate safely if we have some mechanical challenges. Interestingly, we did have one heater go down this spring but had no problems opening and operating. The value of this duplication I believe is the main reason that we have not had one minute of downtime in six years of pool operation related to mechanical issues. It is also very important that all local and state requirements are understood and followed when it comes to designing, constructing, and operating pools and splash pads.
Installing A Splash Pad
A few years ago, as part of our capital improvement program, we installed at one of our smaller parks a splash pad. This aquatic area consists of a large concrete pad that is sloped to a drain in the center of the pad. Spaced throughout the pad are a number of aquatic features that challenge and entertain the users as they play. Because this aquatic facility is at an unsupervised park we have done a few things related specifically to that unsupervised nature.
The operation of the entire system is controlled by time clocks. The system will only operate during set times pre-determined by the time clock settings. Also, once the time clocks activate power to the splash pad, the water features will not turn on and operate until someone touches the activation pedestal that is located on the pad. Then the water features turn off after a pre-set amount of time and can be activated again by someone touching the activation pedestal. This eliminates any operation of the system if no one is there to use it.
Another feature of this splash pad related to the unsupervised nature is the type of water delivery system we chose to use. We had two choices. We could have gone with a more traditional pool filter, heated recirculation system that would operate much like a pool mechanical system. Or we could go with a system that is generally called “pump and dump.” This type of system does not heat or treat the water but uses city water. When the splash pad is activated, the water used goes down the drain and is not reused. We chose the pump and dump system because of no supervision at this site and the fact that we did not want to have to build a structure to hold all of the mechanical equipment needed for a more standard pool filtration system.
At our splash pad location the water that goes down the drain does not go into the storm sewer system but goes into a rain garden on the site and then percolates into the ground.
Even though we do not heat the water we have had no complaints about water temperature. I guess Minnesota kids must be tough.
In the end we believe we are providing our customers with safe, enjoyable aquatic opportunities and at the same time we are able to maximize our operational resources with systems that continually function and have allowed us to provide uninterrupted service for many years.
Public perception can be reality and with that in mind, we all hope to be able to continue to provide quality service to our customers and make sure that we are looked on positively as the professionals we are.
This brief journey to the Bloomington, MN, aquatic facilities is by no means meant to demonstrate the only way aquatic facilities should be built and operated. Rather, it is one way we have found that has worked very well for our operation.
Remember what Ralph Waldo Emerson said, “An ounce of action is worth a ton of theory.”