Fairfax County Government Norman Cole Pollution Control Plant
The Noman Cole facility is the largest advanced wastewater treatment plant in Virginia. Nearly half of the 100 million gallons per day of wastewater generated in the county are treated at the plant. It operates 24 hours a day, seven days a week, and is designed to treat 67 million gallons of wastewater per day. The on-site laboratory for monitoring water quality consists of 18 laboratories with a total of 14 fume hoods and 31 dedicated work-bench and snorkel exhausts. Brinjac commissioned the laboratory and adjacent administration building HVAC systems when originally constructed in 2000.
In 2012 & 2013 Brinjac re-commissioned the entire HVAC system in the laboratory and administration buildings. The laboratory and administration buildings were up-graded with an additional RTU, new humidifiers, and a complete building management control system replacement. The phoenix air valves serving the laboratories and fume hoods were re-integrated with the new Siemens TALON BACnet based control system.
Early on in the project numerous control integration issues with the fume hoods and laboratory air valves were discovered along with many latent maintenance deficiencies with the existing equipment. These items were found during the commissioning and subsequently addressed by the facility management team. This required additional effort in identifying problems and troubleshooting.
Rebalancing of the systems was performed and verified as maintaining the required pressure relationships between the laboratories and corridors.
The 100% outdoor air laboratory air handling unit includes a runaround energy recovery coil, steam humidifiers, dehumidification sequences, and supply/exhaust air tracking. The chiller plant consists of two primary variable flow chillers with heat recovery. The boiler plant operates on a primary/secondary system with two fire tube boilers and integration with the chiller heat recovery. VAV air handling units and RTUs serve the administration building. Induction VAV air terminal units with hot water reheat are utilized throughout these spaces.