New Finished Water Reservoirs, Baltimore County Bureau of Engineering, Pikesville, MD

Buchart Horn provided design, bidding, and construction phase services for the replacement of a 21-million-gallon uncovered reservoir with two pre-stressed wire-wound concrete storage tanks. A 5 million gallon tank was first constructed adjacent to the existing reservoir and put into service. The existing reservoir was then demolished, and a 15 million gallon tank was constructed in its place.

The 15 million gallon tank was fully buried within the existing reservoir footprint because the stormwater drainage system surrounding the site did not have capacity for the runoff generated from the two new covered storage tanks. Additionally, there was very limited space at the site for the construction of stormwater management ponds.

Both tanks have column-supported flat roofs and mat foundation floor slabs. Soil conditions at the site and the need for a large number of columns to support the soil cover on the large tank resulted in the mat foundation being the most cost-effective design.

The project design also included:

  • More than 2,000 feet of 36-inch pipe
  • 18 large valve and equipment vaults
  • Three 30-inch magnetic flow meters
  • Two 30-inch altitude valves
  • Two 36-inch hydraulically-operated ball valves for reservoir isolation
  • Extensive upgrades to the electrical and instrumentation/controls at the site
  • Upgrade of the Baltimore City SCADA system to incorporate the new facilities
  • Modification of the existing gas chlorination system to accommodate the new equipment
  • Addition of piping to facilitate the future conversion to sodium hypochlorite disinfection
  • Two stormwater management ponds
  • Extensive demolition and earthwork

BH worked closely the Water Analyzer’s Office of Baltimore County to ensure the single tank was adequate during construction of the second tank and both tanks were incorporated into the overall distribution system to the greatest advantage. BH also assisted the County in obtaining Maryland Department of Environment approval for the new storage tanks.