The City of Calgary (The City) recently implemented a mixed liquor vacuum degassing (MLVD) system at Bonnybrook Wastewater Treatment Plant (WWTP) that uses rapid bubble desorption to lower the dissolved gas concentration in the mixed liquor, allowing for denitrification in the secondary clarifiers to occur while delaying microbubble formation. Total dissolved gas pressure (TDGP) sensors were constructed and deployed at site for a four-month test campaign to monitor TDGP in the wastewater before and after degasification. The MLVD system typically reduced the TDGP by 16 percent but the technology performance was inconsistent with the reduction in TDGP ranging from 10 to 26 percent. Vacuum pump off gas samples were analyzed to determine that nitrogen accounted for over 90 percent of the gas pressure reduction. As a result, the available capacity (in terms of concentration) for nitrogen to dissolve into solution prior to forming microbubbles in the secondary settling tanks (SSTs) (5 m deep tank with a 1 m deep sludge blanket) increased by 2 to 5 mg/L depending on MLVD performance (non-degassed mixed liquor available capacity of 7.4 mg/L increased to 9.5 to 12.5 mg/L after degasification). With inconsistent MLVD performance, an operational review was completed suggesting vacuum pump design improvements and operational optimization is required. Overall, the research provides an understanding and means to monitoring dissolved gas, specifically nitrogen, in biological nutrient removal facilities. Monitoring such parameters will become increasingly important as more stringent effluent requirements are enforced, wastewater becomes more concentrated through water conservation efforts, and processes are intensified within existing tankage.