The February 2022 inspection of the repaired concrete structures of the Third High Reservoir in Washington, D.C. confirmed the success of the Penetron System to permanently waterproof the water reservoir’s concrete floor and walls.
The Washington Aqueduct provides potable water to approximately one million people in the District of Columbia and Northern Virginia. As part of the water treatment and supply system, the Washington Aqueduct maintains and operates the Dalecarlia and McMillan water treatment plants. Potable water from these plants is pumped to the 20-million-gallon Third High Reservoir.
Also known as the Fort Reno Reservoir, the Third High Reservoir is adjacent to Fort Reno Park in northwest Washington, D.C. Constructed in the mid-1950s, the reservoir is a sub-surface concrete structure measuring approximately 380 feet x 300 feet and 26 feet deep.
Upgrading a Key Water Source for the Nation’s Capital
“Due to the rapid aging and deterioration of the city’s water supply infrastructure, a comprehensive repair project for the drinking water reservoirs was recently completed,” explains Christopher Chen, Director of The Penetron Group. “The upgrades and repairs to the Third High Reservoir will ensure improved water quality and more efficient operation within the Washington Aqueduct distribution system.”
In addition to replacing outdated infrastructure in the water storage structure with new architectural, mechanical, and electrical improvements, a program of extensive concrete repairs was completed, including the sealing of joints and cracks in the concrete floor of the reservoir tank.
“Do It Well, Do It Quickly”
“Because the reservoir is a critical component of the Washington Aqueduct distribution system, the time allotted for upgrades and repair work was restricted,” adds Christopher Chen. “The project engineers required an experienced contractor with the necessary resources and expertise to handle the repairs quickly and successfully.”
After researching the challenges of concrete repair, the project engineers at Nova Consulting and Hazen & Sawyer asked SGS, the project contractor, to contact Penetron. The local Penetron specialist was dispatched to the site and a detailed repair plan was submitted.
In the initial step, PENEPLUG, a rapid-setting, crystalline compound, was applied to stop all active leaks in the floor of the reservoir tank. SGS then routed out all leaking construction joints, visible cracks and leaks, and cut back any exposed rebar stubs and damaged concrete. PENECRETE MORTAR, a crystalline repair grout, was applied to the prepared areas. In addition, to protect the reinforced concrete structures from further water penetration due to the reservoir’s high hydrostatic pressure, PENETRON, a topical crystalline material, was applied as a slurry to permanently waterproof the concrete surfaces.
Streamlining the Repair Work
“We were originally asked to provide a repair plan for just the active leaks in the concrete floor of the reservoir,” notes Christopher Chen. “But after evaluating the site we informed them we could also repair the leaks in the walls without the use of expensive injection systems, which made the job much quicker, more economical – and just as effective.”
Once applied to a prepared concrete surface, the proprietary chemicals in Penetron’s crystalline products react in a catalytic reaction with moisture to generate a non-soluble crystalline formation throughout the pores and capillary tracts of the concrete. The resulting formation seals pores and micro-cracks, and becomes an integral part of the matrix, making the concrete impermeable.
“An important aspect for water storage applications like the Third High Reservoir is that all Penetron crystalline products are completely non-toxic and contain no VOCs," explains Christopher Chen. “Our crystalline materials are nationally certified (NSF-61) and completely safe for use in potable water applications.”