Water Storage Facility Reaches End of Useful Life
The community of West Burlington in the southeast corner of Iowa relies on two water storage facilities to meet the town’s water needs. While the city sources its water supply from the neighboring town of Burlington, they independently maintain and control its own storage and distribution system. When their 500,000-gallon ground storage tank (which accounts for half of the city’s water storage) began leaking, it was evident significant updates were necessary.
The city partnered with the Snyder & Associates team to examine the entire water storage and distribution system while simultaneously investigating the requirements for replacing the failing storage tank. Our team was also tasked with determining the required storage volume, water level elevations, potential locations, and opinions of probable costs for various water tower styles to give city leaders multiple options.
Inspection Determines Aging Infrastructure Requires Replacement
Constructed in 1961, the leaking ground storage tank generally served the northern portion of the city. During inspections, our team found thinning walls and significant corrosion with at least one ½-inch-diameter hole on the side of the tank. Because of this hole, the operating level was roughly half of the tank’s maximum capacity. Additionally, the booster station associated with the tank had only one operable pump. Due to a lack of available parts, two other nonfunctioning pumps were deemed unsalvageable.
With the compromised system, the water pressure could rapidly drop in the event of a booster station failure. After bringing our findings to the attention of city leaders, it was clear a total system upgrade was necessary.
Switching from Ground to Elevated Storage
During our planning stages, continuing with a ground storage tank was quickly ruled out due to the lack of energy efficiency associated with those units. Water towers, by contrast, utilize gravity and only require energy to pump and refill the tower basin instead of requiring constant pumping during high-demand hours like a ground storage tank. This difference drastically reduces wear and tear on the pumps, as well.
Location & Design Considerations for New Water Tower
Determining the ideal storage location, type, size, and pumping equipment for a community’s water needs is an extremely customized process. Our experts are well-versed in determining the optimal water storage solution for communities and were able to guide West Burlington’s decision-makers through this complex process.
Because the city already has an existing storage tower on the south side of town, the north side of town was the obvious choice for the new tower. Several possible locations were presented to the city for consideration, with the two preferred sites being on the north side of the existing public works facility or at an existing well site to the south, near Highway 34.
Since the site near the public works building did not require land acquisition, it was ultimately selected for construction. Additionally, this tower location would not only be convenient but would also reduce response time in the event of an emergency.
With a proper location selected, it was time for the community to decide on the type of new water tower. Four styles of elevated towers were considered for this project: Multi-leg Tower, Pedesphere Tower, Composite Tower, and Fluted Column Tower. Each style option could provide the necessary storage volume and pressures and could be adequately staffed by qualified technicians already employed by the city.
A composite tank was selected as the best option. This style features a single concrete pedestal that supports a welded steel container and allows for easy and safe access to the tank in the event of inclement weather. Additionally, since the column is composed of concrete it’s not painted, which eliminates the costs associated with periodic repainting.
Booster System Upgrade Complements Storage Tower
At our team’s recommendation, the city also decided to construct a new booster system situated within the tower’s base. This station was designed to include a chemical dosing system like the community’s previous system so that technicians can continue to independently boost chlorine levels during the yearly three-week period when the City of Burlington is shocking the supply system.
Design for redundancy, this new system can pump a total of 1,400 GPM even with one pump out of service. This capacity, combined with the 1,400-GPM capacity of the W. Agency Road booster station, can provide sufficient flows for fighting large fires across the city if needed.
Bringing New Water Tower Online
With the new tower situated nearly half a mile from the previous water storage facility, an additional water main pipe was needed to connect the new structure to the city’s water system. While geographically this was a straight shot, the corridor already housed numerous utilities, including gas, communications, sewer, and distribution service pipes. To navigate this busy corridor, our experts worked closely with several city departments and strategically timed construction efforts to minimize disruptions to existing systems and roadway traffic.
With the new composite water tower in place, West Burlington businesses and residents will continue to receive safe and reliable drinking water for many decades to come.