The Charter Street Heating Plant is one of two campus heating plants serving the University of Wisconsin in the city of Madison. The environmental impacts of coal-generated energy called for its elimination, which spurred the need to rebuild this coal-fired plant. In addition to transitioning the plant from the use of coal to gas, the rebuild has provided updates to all aspects of the plant with highly advanced equipment and controls.
For this complex, schedule-driven project, the owner, the State of Wisconsin, chose the Engineer-Procure-Construct (EPC) delivery method. This expedited planning, design and construction maximized value and provided the state with a single point of responsibility.
The scope of this project included removing the coal boilers and adding four new 225,000 lb./hr. natural gas/fuel oil package boilers. The facility buildings required an addition of 70,000 sq. ft. to accommodate the new boilers and balance of plant equipment.
The following is a partial list of balance of plant and ancillary equipment included in the project:
- Water treatment equipment
- Feed water system
- Air compressors
- Condensation collection systems
- Upgrade to digital controls for both campus heating/cooling plants
- Electrical system upgrades and additions
- New 920,000 gallon fuel oil tank
- Fire protection for the addition and existing plant
- A new six cell 50,000 GPM cooling tower
- Emission controls
- Piped over 16,000 LF of small bore pipe and over 17,245 LF of large bore pipe
The two heating plants serve approximately 330 buildings on campus, so it was without question that the plant continued to run, and run reliably, during construction. This required careful phasing of the new work and very close coordination when running new utilities for the existing plant.
Construction began when the existing fuel oil tanks were removed to make room for the new addition. After the first two boilers were installed and commissioned successfully, demolition occurred so the Dayton Street building could be finished and the second set of boilers installed. Timing of the boiler delivery became as important as the logistics of these large units, as little space existed for staging on this busy project site.
Demolition work included:
- Rail spurs
- Coal handling equipment and bunkers
- Coordination of removal of four coal boilers
- (2) baghouses, 8- and 12-modules
- 250 ft. tall masonry stack
- Existing balance of plant equipment
In addition to the remaining two boilers, the second part of the new Dayton Street building housed updated water treatment and feed water systems and a new cooling tower was installed. When the cooling season started, the new tower was commissioned and functional and two old towers were demolished.
The existing 3.3 acre site is located in the middle of a 40,000-student college campus as well as a heavily populated residential community. The site has limited lay-down area, an active railroad passing by and thousands of pedestrian, bicycle and vehicular movements through the site on a daily basis. Boldt took a very proactive approach to communication and safety with the owner and its user groups.
Because the project site was nearby an active railroad, the team had to decide how to keep the nearby crane from swinging picks over the tracks. The solution was to program the crane to not allow the radius to extend over the train track. This allowed for no human error to take place during a busy construction project.
Because the crane had to be positioned at a level higher than the stack, the cab was in close proximity to emissions coming from the stack. In this case, the operator was able to perform the crane’s functions via a remote control so as to not be exposed to the stack emissions.
Mill Street is one of the main thoroughfares on campus and all traffic had to be protected. At the same time, Boldt’s only option for a staging area was directly across the street. In order for the crane to make its necessary picks while keeping the community functioning smoothly and out of harm’s way, a protective bridge was built overtop of Mill Street.
Boldt received LEED-NC Gold certification for the project, making it the first campus central utility plant to be LEED certified.
Building Information Modeling
BIM modeling was used on the project. Boldt used software to bring the model into the plant portably via a tablet. The model was most valuable in the field for coordination and tracking of equipment and piping installation.