Oradell Reservoir Aeration Assessment and Design

Oradell Reservoir is a 720-acre waterbody owned and operated by Veolia, providing over 750,000 people with potable water. While it is a run-of-the-river reservoir with a flushing rate of approximately 2 weeks, blooms of cyanobacteria that produce gas vacuoles, such as Aphanizomenon, impact its water quality from spring to late fall. These gas vacuole-cyanobacteria migrate through the water column on a daily basis, entering the multiple intakes and directly impacting the quality of the raw water entering the treatment plant. To minimize these impacts on the raw water quality, a destratification system has been in operation for over 17 years to disrupt these concentrated blooms. The destratification system also provides additional water quality benefits and Princeton Hydro was the organization who originally proposed the installation of the destratification system as part of an earlier Management Plan.

Veolia recognized that the existing and aging destratification system was requiring more maintenance and repair. Additionally, aeration technology has substantially improved over the last 17 years in both operation and energy efficiency. Thus, Veolia contracted with Princeton Hydro to assess various aeration technologies, design a new system, submit for any required permits and oversee the installation of the new system.

In 2020 Princeton Hydro conducted an analysis of various water quality parameters prior to (1999 to 2004) and after (2016-2020) the destratification system was installed. It quantified and confirmed that the system provides a number of benefits including increasing filter run times due to lower algal densities, a reduction in taste and odor compounds such as manganese, and limiting the amount of hypolimnetic phosphorus. This analysis also included an assessment of various aeration technologies.

It was decided to remove the old existing aeration system and replace it with a HydroLogic Airlift aeration system. Princeton Hydro worked with the selected sub-contractor to design the CAD specifications and have them reviewed / approved by a certified professional engineer. Princeton Hydro then submitted for all of the necessary permits, which are currently being reviewed by NJDEP and other required agencies. Once the permits are approved, Princeton Hydro will oversee and work with the sub-contractor in the installation of the Airlift system, which is tentatively scheduled to be installed in the first half of 2023.