The Croton Lake Gatehouse (CLGH), an integral component of the New York City Department of Environmental Protection’s (NYC DEP) Croton Water Supply System, is located near the Croton Reservoir in Westchester County, New York. As a historic structure, CLGH plays a critical role in managing the flow of water from the Croton Reservoir to New York City’s extensive water supply network. In order to maintain the reliability and safety of this vital infrastructure, the DEP initiated a series of upgrades and renovations between 2022 and 2023, with Volmar serving as the general contractor for the project. The primary motivation for these upgrades stemmed from conditions within the Gatehouse Tunnel, where algae growth began compromising water quality and producing unpleasant odors downstream. These issues highlighted the need for immediate intervention to preserve the integrity of the water supply system and ensure compliance with health and safety standards. Volmar was contracted to design and install a complex chemical delivery system, which would mix and deliver a safe solution of sulfuric acid and peroxide to combat the algae and maintain water quality. The scope of the chemical delivery system included: Three sulfuric acid tanks and three peroxide tanks. Two generators to mix and control the solution. Automated controls to monitor the levels of chemicals in the water. A series of CPVC piping to deliver the mixture to the reservoir. As with all NYC DEP water delivery facilities, CLGH is a secure facility, requiring all tradespeople to obtain security clearances prior to commencing work.