Froedtert Hospital is the medical affiliate of the Medical College of Wisconsin, and is a level-one trauma Center serving the Milwaukee area. The hospital was founded in 1980, and is located in Wauwatosa, Wisconsin, just outside of Milwaukee. CannonDesign has been working at Froedtert since 2005, starting with the Clinical Cancer Center which opened in 2008.
CannonDesign recently completed the design of a 9-story mixed-use addition to the campus, known as the Center for Advanced Care (CFAC). The CFAC accommodates the hospital’s significant growth in outpatient services and inpatient care, houses the Heart and Vascular Center and Transplant Center, and creates a single, convenient entrance for surgery and interventional patients.
By moving existing clinical environments to new space aligned with their growth needs, the CFAC permits the consolidation of surgical, cardiac cath, and interventional services on one floor of the facility, as opposed to the multiple locations where these procedures happen presently. The consolidation is known as the Integrated Surgical and Interventional Platform (ISIP). It is a transformational project that will streamline workflows, standardize the patient experience, and enhance staff utilization.
Room challenges and solutions
The CFAC project took the needs of caregivers and patients from the outset. One of the unique design requirements of the caregivers was that all the exam rooms be oriented the same, permitting the caregiver to practice on the right hand side of the patient. This meant that efficient distribution to back-to-back exam room sinks was not possible. In addition, a concern for the needs of bariatric users drove a decision to use only floor mounted water closets. These concepts, amongst others, drove a working design that was accounted for in the layout of all rooms and in the floor structure itself.
Another issue requiring resolution was the location of exam rooms on the second floor in an area located over the main electrical rooms. While far from ideal, this layout was driven by a need to maximize valuable floor space for patient care. The placement of plumbing fixtures in this location created challenges associated with the routing of waste piping, which could not travel through the electrical rooms for code and safety reasons. Floor-mounted, rear outlet water closets with horizontal wall chases proved an effective solution to the issue, allowing sanitary piping to be offset horizontally prior to going vertical.
As is always the case in hospitals, a primary concern was the need for infection control for patients and the public. All public facilities were designed with electronic flush valves and faucets with direct wire connections. All staff fixtures utilize goose neck and wrist blades faucets. Staff water closets feature flush valves, which although manual, have antimicrobial handles. Public men’s restrooms often involve greater sanitary concerns. Therefore, the TOTO UT104EV model urinal was selected based on the angled design of the bowl to control unsanitary results. A sample model was installed in an existing public restroom and tested; and proved to reduce cleanup issues on the floor.
The water supply for the CFAC building, downstream of the water meters, is provided with a chlorine dioxide injection system to protect water from Legionella growth. Active measures for the control of Legionella in health care facilities is mandated by the Wisconsin Plumbing Code. The chlorine dioxide system is one of several approved methods to protect the domestic water supply from Legionella by pulse injection of chlorine dioxide directly into the water stream. Injections are based on flow rates. Chlorine dioxide is highly soluble in water and its half-life ranges from 20 to 180 minutes depending on concentration levels.
In housekeeping closets, mop basins with supplemental soap dispenser connections have been an ongoing concern. In the existing hospital, these dispensers are connected on the outlet of the mop basin faucet. If water supply at the faucet is not turned off or if hoses are not disconnected, a cross connection exists, allowing cold water to pass into the hot water side or vice versa. This creates issues for both hot water circulation and supply to fixtures. The issue was resolved by adding an extra cold water hose bib, with a threaded vacuum breaker at the mop basin, supplemented with an instructional sign for the environmental services staff to use the cold water hose bib only.
Safety was also a paramount concern for two floors of inpatient care located on levels 7 and 8 of the facility. These units, which will house Bone Marrow Transplant (BMT) patients, require dialysis boxes. Existing installations proved problematic due to a chemical interaction between patient medications and the dialyzer solution. As a result, the new unit required boxes that can more effectively flush solids through the waste connection, preventing blockages. After review of available equipment from suppliers, CannonDesign worked with a manufacturer to design a new dialysis boxes were specifically to meet the needs of this patient population. The new models are being installed in the two patient room floors, and include extra fittings to match the various pieces of equipment and flushing water.
As in most projects, cost control measures were front of mind. Since all spaces in the facility employ ducted air return, the team was able to utilize storm, sanitary and clear water systems comprised of PVC without concern for the installation of PVC piping in a plenum space. Domestic water supply utilized copper up to 2-1/2 inches; and welded stainless steel piping over 3 inches. Due to market conditions, stainless proved to be more cost effective at larger diameters. Water supply and HVAC piping were installed along with ductwork and electrical cable trays on the same trapeze support system.
Water supply and grid design
The water supply distribution for the facility presented unique considerations specific to the hospital’s concerns for long term maintainability. Shutting down water systems for maintenance or remodeling can be a major problem for hospitals. Shut downs and draining of the water system takes time and is usually required to be done at premium time (nights and weekend). This is costly and often requires either a temporary tie-in to provide water or a new main placed around the remodeled area to fulfill basic water supply requirements. Accommodating the realities of future remodeling was incorporated into the CFAC water distribution system by using a “grid” system.
The grid system concept utilizes multiple domestic hot and cold risers, parallel mains, and branches interconnecting the mains in a grid pattern. Hot and cold main lines traverse the building’s east and west sides on each floor, and are connected to risers. Running north and south between these building mains are intermediate supply lines, forming a grid. Individual lines feed off each grid line connected to the individual fixtures. The CFAC project was an ideal candidate for this type of distribution because it has a relatively square footprint.
Sizing of the grid system proved challenging because the piping must be sized for both for current fixture layouts and potential future reconfigurations. The concept assumes that the mains and cross-connecting branches stay in place permanently, and only the run outs to individual fixtures are modified in the future, The main headers and risers also needed to be sized for redundancy to support the entire distribution on the floor in the event that one of the risers or main headers was shut down for any reason. The design provided 2 inch domestic cold water and 1-1/4 inch domestic hot water pipe grid lines spaced approximately every 30 feet. The lines are consistent in size across the entire footprint of all floors through the clinics, and pre- and post-operative care areas. These sizes were derived based on the worst-case scenario for the building occupancy. The domestic hot water flows in one direction through the grid and is collected along the west side’s floor plate where it becomes return pipe. Grid lines at the hot water return pipe are set to a one gallon per minute (gpm) return flow rate set by using a balancing valve. The domestic cold water is fed from both directions, and separated by a midpoint shut off valve to prevent water stagnation.
The grid line spacing is based upon the distance and time required to provide hot water at the individual fixtures. Un-recirculated horizontal fixture branches were held to a 15-foot maximum run length, including the vertical drop of a maximum of 10 feet, to the fixture to reduce time needed to deliver hot water at each faucet. For future remodeling, the shutdown procedure is simple. Each grid line has a shut off valve at each end where it connects to the main. Therefore, water lines to the entire floor would not need to be shut off, only the renovation area.
The zoning of water distribution for the multi-story, high rise facility also needed to accommodate phasing. The building started as a 3-level below grade parking facility with 5 levels above grade. During construction, four additional floors were added. Four more floors can also be added in the future. The initial five-story, above-grade building required a booster pump system for levels 4 and 5. When levels 6 to 9 (nine is known as “M”) were added, this created opportunities to examine the booster pump system based on the phase increments to minimize rework and first cost of installation.
The final design was resolved as follows. The 9th floor (designated as the “M” level) and all floors above are designated as future high zones, and up fed from the ninth floor with a PRV station with a water pressure set to 80 pounds. Levels 4 to “M” are mid-zones and are down fed from the ninth floor with the water pressure set by a pressure reducing valve at 40 psi on the “M” level; the final pressure on level 4 is at 76 PSI. The remaining low zone serves the parking through the third levels utilizing street pressure.
Water heating system(s) were placed within each of the three pressure zones. Hot water is generated by steam-to-water heat exchangers, with heat recovery for pre-heat using steam condensate. Froedtert is served by a district steam system, and they are allowed to extract heat out of the steam and condensate without concern for the temperature of the condensate returns. A plate and frame heat exchanger was installed with 160 degree condensate on one side and 50 degree incoming cold water on the other, which preheated water prior to water heaters.
The below-grade parking facility presented another challenge to the project team. Due to the parking area’s depth with three level below grade, legitimate concerns for water infiltration at the basement levels was raised. Ground water was measured at a constant flow of 4 GPM per the Geotechnical Report. Underslab drainage is provided, sized to accommodate the maximum flow rate. Both a duplex sewage ejector and storm water pumping system were required, and were designed with 100 percent redundancy, and further connected to standby generators. All pumping systems are monitored by the Building Automation System (BAS). In addition, backflow prevention was addressed via10 reduced principle backflow preventers, including sets on each of the two incoming water services.
This project demonstrated a logical solution to a complex array of design challenges. By working closely with the hospital’s plant operations team, CannonDesign was able to develop a solution that meets the present and long-term facility needs.
Brian Tym, P.E., GPD, has 30 years of experience evolving projects from inception to final closeout with owners. He has successfully set the standards for the design quality of plumbing systems including medical gas, solar, water distribution, fire protection, industrial gases, sanitary, storm and clear water systems, as well as site utilities and flex fuel system design. Brian is also responsible for engineering procedures for specification writing, project cost analysis, bid negotiation and construction management. He is certified in Green Plumbing Design, and earned his architectural engineering degree from the Milwaukee School of Engineering.