Because everything is stair-stepped, designing the plumbing system for a sports stadium is a lot different than designing the plumbing for an office building,” Roy West notes. He should know. West, who is senior plumbing designer in the Tampa office of the architectural firm Hellmuth Obata Kassabaum (HOK), designed the plumbing system for the new 65,000-seat Raymond James Stadium. The plumbing contract for the Florida stadium, which is home to the NFL’s Tampa Bay Buccaneers, totaled $3.59 million. An additional $923,000 was spent on the fire protection system.

The stadium’s plumbing includes 800 toilets located in 24 public men’s restrooms, 28 women’s restrooms, 8 unisex/family restrooms and 164 luxury suites (each with its own private bathroom). In addition, there are 48 permanent concession stands, a main kitchen, two 5,700-square-foot locker rooms and 20 drinking fountains.

“Raymond James Stadium is the biggest job I’ve worked on,” West says. “It was challenging at times to get everything to fit in the way it was supposed to. But for me, the greatest satisfaction in working on this project came from getting it done on time and then having everything work the way it was designed to work. It also helped to have a good plumbing contractor to work with.”

Potable water comes into the stadium through a 12-inch main connected to the municipal water supply. The supply main is connected to three variable-speed booster pumps. The smallest pump has a capacity of 500 gpm, which is sufficient to meet the stadium’s water needs on days when only office staff and maintenance personnel occupy the facility. On game days, twin main booster pumps are called into service. Each has a capacity of 1,500 gpm at 173 feet of head. All three of the pumps are sequenced to come on line as water demand increases.

“In actual usage,” says Robert Tintera, P.E., director of engineering for HOK Tampa and the project’s engineer of record, “we have found that one of the main booster pumps is sufficient to handle the water needs on game days. As a result, the second pump is redundant and serves primarily as a stand-by.”

Water leaving the booster pumps enters a 10-inch line that forms a loop that is a half-mile in circumference around the stadium’s interior. Originally designed to be placed in a service tunnel, the loop was actually placed above the ceiling of the service level hallway. “We were ready to install the water line,” Tintera says, “but the service tunnel was scheduled to be completed at a later date. So we decided to move it out of the tunnel.” Four-inch branch lines leave the water loop and go up the stadium’s support columns. To allow for future expansion of services and facilities, designated columns gridded around the stadium had built-in chases to allow for easy access to the plumbing lines.

To test the capacity of the plumbing system, HOK engineers conducted a “superflush” at the end of the project. At Raymond James Stadium, that meant stationing three people in each of the 60 public restrooms. When a signal was given via two-way radio, each person ran down a line of stalls flushing the toilets as quickly as possible.

“The domestic water system worked well,” Tintera says. “The flow meter showed 3,200 gpm of water flowing through the main supply line, while the lowest pressure on the incoming line was 18 psig.”

The stadium’s waste system was designed so that six-inch lines go directly into manholes in the service tunnel. This was done to prevent the backflow problems that could be created by having upper level fixtures tied into lower level lines—a problem that actually occurred during system testing. Due to a design change, waste lines from floor drains in the club area of the stadium were tied into waste lines from the main and upper concourses after the sanitary system in the service tunnel had been completed. During superflush testing, the floor drains overflowed. Ultimately, the lines from the floor drains were rerouted directly to the manholes in the service tunnel, as per the original design intention. A 24-inch waste main exits the facility.

At Raymond James Stadium, PVC pipe was value engineered and used throughout the facility. “But we wouldn’t use it again,” West says. “Every penetration—and there were thousands of them—had to have a firestop, which ate up all the savings.”

All of the hot water for the stadium is provided by electric water heaters. They range from 80-gallon tank-type water heaters for the concession areas and luxury suites to a 1,600-gallon water heater for the main kitchen and a 3,800-gallon unit for the locker rooms. “We prefer to use electric appliances,” West says, “because when they are shut down for lengthy periods, as is often the case in a sports stadium, they don’t deteriorate like gas appliances do.”

The public bathrooms in the stadium are designed to be uni-sex. This meant putting additional stalls in some of the men’s rooms. Why uni-sex restrooms? It was done so that when a largely all-male group—such as Promise Keepers—or a predominantly female group uses the stadium all that needs to be done is for the signs on restrooms to be switched from one gender to the other. Although they probably won’t know why, some men attending an all-male function may wonder why there are no urinals in the “men’s” room, while women attending a mostly female activity may do a double take when they see a line of urinals in the “women’s” room.

“The greatest challenge for me in working on this project,” Tintera says, “was the fast-track scheduling we encountered. Because funding for the stadium depended on passage of a tax referendum, we had to wait until voters approved the project. However, once the stadium tax was approved, we moved ahead on the project like gangbusters.

“Opening day made everything worthwhile,” Tintera adds. “After working on this physically huge monster for nearly three years, it was tremendously exciting on opening day to see the stadium packed with noisy, cheering fans.”

Tennessee's New Stadium

A few states further north, another new stadium is nearing completion. Located in Nashville, the 67,000-seat Tennessee Stadium will be home to the NFL’s Tennessee Titans (formerly the Oilers). Robert Coss, chief plumbing engineer with IC Thomason Engineers, Inc., was in charge of the plumbing design for the stadium. The stadium, which is responsible for the largest plumbing contract ever issued in Nashville, is expected to be completed this month.

“Because the city of Nashville has a booster station a few blocks from the stadium and supplies us with water that is already properly pressured,” Coss says, “we didn’t need to install booster pumps.” A 12-inch line enters the stadium and is reduced down to four 8-inch risers, one in each quadrant of the stadium, that supply water to the upper deck areas. Additional 8-inch lateral lines serve the lower level areas.

Providing hot water for the stadium are 126 light commercial point-of-use electric units, which range in size from 2 to 82 gallons in capacity, and two, larger, gas-fired package systems. All of the water heaters were supplied by Lochinvar Corp.

Each of the package systems consists of two commercial gas water heaters, each with an output of 2,650,000 BTUs, and one 3,500-gallon, glass-lined, jacketed and insulated storage tank. To save space inside the stadium, the systems were stacked, which allowed them to occupy the footprint normally required for a single unit.

What do you do with 7,000 gallons of hot water? In the Tennessee Stadium it will be used in the players’ locker rooms, laundry rooms, coaches’ rooms, referees’ rooms and for therapy applications. After all, it takes a lot of hot water to clean up two professional football teams and their towels and uniforms after they’ve been fighting it out in the mud and the blood on a sweaty Sunday afternoon.

The stadium’s waste system is also divided in quadrants. Each quadrant has a 10-inch line that ultimately feeds into the 12-inch line that exits the facility. Although cast iron pipe was originally specified, it was later value engineered to PVC pipe.

“We switched to PVC to help keep the project on schedule,” Coss says. “By the time the plumbing subcontractor was able to begin work, the schedule had become very tight. Changing to PVC allowed the subcontractor to work faster and ultimately catch up to the schedule’s completion dates. “The most challenging aspect of working on the stadium,” Coss says, “was accumulating a real domestic water usage total. It’s a difficult task when you consider that you have 67,000 fans who are all tensely waiting for intermission and the chance to use the restrooms. But it was satisfying to see everything come together as it should and to get the test results we were looking for.”

Cleveland's Reincarnated Browns

The demand for hot water in skyboxes can fluctuate dramatically, from thousands of gallons being used in a four-hour period during a Sunday afternoon football game, to not a single drop being used for periods of two weeks or longer. For that reason, and others, plumbing designers working on sports stadiums look for practical and efficient ways to fulfill this erratic demand for hot water.

Due to the increasing number of luxury skyboxes in just about every stadium nationwide, one method being increasingly specified is individual, on-demand water heaters. One of the National Football league’s oldest and newest franchises is an example.

When the reincarnated Cleveland Browns kick off their football season this September, more than 150 on-demand electric water heaters will be used to supply the stadium’s luxury boxes in the Loge and Club sections. The heaters, supplied by Controlled Energy Corporation, were specified for several reasons. First, because each of the luxury boxes has its own private bathroom and bar area, the need for separate hot and cold water lines running to each skybox was eliminated. Instead, water is supplied to each skybox using a single cold water supply line.

The on-demand water heaters also helped eliminate patrons having to wait for hot water to come out of the faucet (Figure 1); a problem they might have encountered if remote water heaters, each supplying several suites simultaneously, had been specified. Because patrons pay premium prices for the luxury skyboxes, providing an amenity like “it’s there when you need it” hot water was important to Cleveland Browns’ management.

Another advantage offered by the water heaters was their compact size (Figure 2 shows a typical installation). The units specified for the Cleveland Browns stadium measure 12.75 x 6.5 x 3 inches. In addition, installation was made easier due to the fact that the water heaters did not have to be mounted “right side up”—they can be mounted in any position. This allowed plumbing designers to make the most efficient use of available space. Because of the stadium’s sporadic use, the on-demand water heaters also helped eliminate potential problems of water stagnating in tank-type heaters. In addition, the water heaters eliminated standby heat loss because they use electricity only when water flow is detected, triggered by someone opening the water faucet.