Lake DeForest Water Treatment Plant Upgrade and PFAS Removal Design

Veolia Water New York’s Lake DeForest Water Treatment Plant serves approximately 300,000 customers in Rockland County. Originally constructed in the 1960s, the facility serves a growing population and increasingly stringent water quality regulations. Over time, contaminants such as road salt, fertilizers, and per- and polyfluoroalkyl substances (PFAS) have compromised the quality of the raw water, creating significant challenges in meeting modern regulatory standards. While temporary measures, like copper-based treatments, have provided some relief, a more comprehensive and permanent solution was necessary to ensure the water supply’s long-term reliability. 

The current plant, with a treatment capacity of 20 million gallons per day (MGD), has undergone several expansions and updates since its inception. However, as new regulations were adopted, particularly those targeting emerging contaminants like PFAS, the plant’s infrastructure required significant modernization. The client sought a partner to design and implement these upgrades while maintaining continuous operations and meeting public health and environmental standards. 

Our team provided design, permitting, and construction engineering for Phase I of the Lake DeForest Water Treatment Plant upgrade, which focused on critical infrastructure improvements to enhance water treatment processes while minimizing operational disruptions.  

New rapid mixers optimize the blending of chemicals with raw water, improving contaminant removal efficiency and easing the load on downstream processes. A powdered activated carbon silo and control building now better address taste, odor, and organic pollutants. 

The pre-oxidation treatment facility and contact basins apply ozone to neutralize contaminants like iron, manganese, and organic matter, leading to more effective filtration and compliance with stricter regulations. Replacement of the aging raw water pumps increases energy efficiency and water flow reliability, supporting overall plant performance. Gravity filter upgrades further strengthen the plant’s ability to remove fine particles, pathogens, and harmful substances. 

In Phase II, we are providing design, permitting, bid, and construction engineering services for a state-of-the-art PFAS treatment facility, incorporating advanced filtration technology to remove these contaminants. The facility includes two 1.1-million-gallon storage tanks with interior baffling to improve disinfection of the finished water supply while providing essential water storage and a steady supply during peak demand. 

A new transfer pump station and 20 MGD high service pump station guarantee the efficient distribution of treated water. These facilities, integrated with electrical and control rooms for real-time monitoring, allow for precise management of plant operations and rapid response to issues. 

Chemical storage and feed systems for sodium hypochlorite, sodium hydroxide, and corrosion inhibitors enhance water safety, prevent contamination, and prolong infrastructure lifespan. Hydraulic modeling and transient surge protection establish reliable pump operation and safeguard against pressure fluctuations, protecting the system and improving longevity. 

The execution of both phases includes a strong commitment to resilience and minimal operational disruption, ensuring that Veolia Water New York can continue delivering safe, reliable water to Rockland County for decades.