Rockland County Sewer District No. 1 – Odor Control System Replacements & Miscellaneous Heating and Ventilation System Improvements
The Rockland County Sewer District No. 1 (RCSD) Wastewater Treatment Plant (WWTP) provides sewage treatment for the Towns of Ramapo and Clarkstown and was originally constructed in 1967 to treat 10 million gallons per day (MGD). The WWTP was later expanded in the 1980s to treat 28.9 MGD and also received 12 odor control systems to collect and treat potential odorous air from various unit operations throughout the plant.
RCSD retained a design-build team lead by Jett Industries, Inc., to provide design and construction services for the replacement of the existing odor control systems as well as improvements to the related heating and ventilation systems.
The existing odor control systems are over 35 years old have exceeded their expected useful life cycle and many components of each system are not functional. Based on the age and condition of existing systems, RCSD has commissioned this project is to replace 11 odor control systems and add two new odor control systems, resulting in a total of 13 odor control systems. Each system will be a carbon adsorber type. Each new system will consist of odor source supply ductwork, demister, blower, instrumentation and controls, blower discharge ductwork, carbon containing vessel, and vessel discharge ductwork.
D&B Project Responsibilities
D&B’s responsibilities on the design-build team include electrical and heating and ventilation design and design services during construction.
D&B’s electrical design responsibilities include design and design services during construction for the electrical system upgrades necessary for the replacement of the odor control systems, including the new odor control blowers, control panels, local control stations, conduit and wiring. The existing blowers are served at 480 volts from branch circuits originating in motor control centers, located throughout the plant in vicinity of the odor control systems. The compartments in the motor control centers for the blowers include the motor starters (constant speed), as well as interconnecting control wiring for starting and stopping the blowers. The motor starters, conduit, and wiring for the odor control systems are 35 to 40 years old and are considered to have met their useful life. In addition to the age of the existing conduit and wiring, it is not practical to attempt to reuse the conduit and wire for the new blowers for the following reasons: 1) the increased horsepower of the proposed blowers in some cases; 2) the locations of the proposed blowers is different than the existing blower locations; and 3) new blowers will be powered from the odor control panels versus the existing blowers which were powered from the motor control centers. In addition, the existing motor starters are for constant speed operation and would not support the proposed blowers which are variable speed.
D&B’s heating and ventilation design responsibilities include design and design services during construction for the replacement of air handling units, exhaust fans, odor control bypass fans, and electric heating systems in multiple locations throughout the Plant. The heating and ventilation systems in multiple areas of the Plant have exceeded their expected useful life and many of the existing components are not functional. These systems need to be upgraded and/or replaced to provide proper heating and ventilation in accordance with applicable codes and rules and regulations, to provide a safe and suitable environment for the staff working in these areas, and to protect the integrity of the equipment and operations within these areas. Additionally, since the air ventilated from several areas of the Plant have occasionally been odorous, the air ventilated from these areas is to be connected to new odor control systems to prevent the emission of odorous airs to the atmosphere and surrounding community.
D&B’s electrical design responsibilities also include design and design services during construction for all electrical upgrades related to the heating and ventilation system upgrades.