Dulles South Storage

Dulles South Tanks Elevated Water Storage Tanks and Water Booster Pumping Station

During the summer of 2005, Loudoun Water launched a project to bring much needed water storage to the Dulles South area of Loudoun County. Good water system planning requires a half day's worth of water storage for every connection to the water system. This serves three main purposes: (1) Reliability and consistency of service (2) Emergency supply during major outages, and (3) Fire protection.

We need six million gallons of storage for the communities of South Riding, Stone Ridge and Kirkpatrick Farms, to name a few. Loudoun Water will place two elevated water storage tanks of three million gallons each on a 5-acre site. A preliminary site plan located the tanks based on the required set backs and buffers around the tanks. Some localized pipes around the tank site will need to be increased to distribute the water from the tanks.

Loudoun Water invited members of the community to serve on an advisory group for this project. The group assisted Loudoun Water with identifying site criteria and the weight of the criteria. We performed several soil borings for each tank to determine soil condition. We also conducted a visual assessment of the selected site using test balloons and used the results to prepare a rendering of the tanks.

The Dulles South Elevated Storage Tank site has been selected and is located off Goshen Road south of Route 50. The Dulles South tanks commission permit and special exception tanks were approved in the beginning of 2008 and the design of the tanks was completed in July 2009. The Project went to bid, and our Board awarded the contract to Caldwell Tanks Inc. for the construction of the composite elevated tanks. Each tank will be 165 feet in height and a diameter of 118 feet.

We started working with Caldwell on this project in spring 2010 to first begin pouring the foundation for the tanks. The composite columns were poured in four foot lifts until they reached 112 feet high. The first column was completed in the fall, while the second column was completed at the end of 2011. Construction of the steel bowls began on the ground and then were raised to the top of the column. You can view time lapse photos showing the second steel bowl being raised to the top of one of the columns.