Among early adopters of wastewater monitoring for SARS-CoV-2 have been colleges and universities throughout North America, many of whom are using this approach to monitor congregate living facilities for early evidence of COVID-19 infection as an integral component of campus screening programs. Yet, while there have been numerous examples where wastewater monitoring on a university campus has detected evidence for infection among community members, there are few examples where this monitoring triggered a public health response that may have averted an actual outbreak.

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A wastewater surveillance program targeting a university residence hall was implemented during the spring semester 2021 as a proactive measure to avoid an outbreak of COVID-19 on campus. Over a period of 7 weeks from early February through late March 2021, wastewater originating from the residence hall was collected as grab samples 3 times per week. During this time, there was no detection of SARS-CoV-2 by RT-qPCR in the residence hall wastewater stream. Aiming to obtain a sample more representative of the residence hall community, a decision was made to use passive samplers beginning in late March onwards. Adopting a Moore Swab approach, SARS-CoV-2 was detected in wastewater samples on just two days after passive samplers were activated. These samples were also positive for the B.1.1.7 (Alpha) Variant of Concern (VOC) by RT-qPCR. The positive result triggered a public health case finding response including a mobile testing unit deployed to the residence hall the following day with testing of nearly 200 students and staff, which identified two laboratory-confirmed cases of B.1.1.7 variant COVID-19. These individuals were re-located to a separate quarantine facility averting an outbreak on campus. Aggregating wastewater and clinical data, the campus wastewater surveillance program has yielded the first estimates of fecal shedding rates of the B.1.1.7 VOC of SARS-CoV-2 in individuals from a non-clinical setting.

Aeration is a major part of the operating cost in biological aerated filtration (BAF) systems for wastewater treatment. This study investigated the effect of reducing aeration at the City of Windsor’s Lou Romano Water Reclamation Plant to find the lowest possible airflow rate while maintaining a satisfactory ammonia and biological oxygen demand (BOD) in the BAF effluent. Profiles of temperature, dissolved oxygen, pH, BOD, ammonia and nitrate concentration were measured along the height of cell No. 7 at the plant, at different time intervals during filtration, at airflow rates varying from 1300 to 1700 m3/h per cell. This study found that the BOD and ammonium removal were satisfactory at the lowest airflow rate.

Abstract:A phase doppler anemometer (PDA) was used to determine the effects of evaporation on water spray for three rotary bell atomizer operational variable parameters: shaping air, bell speed and liquid flow. Shaping air was set at either 200 standard liters per minute (L/min) or 300 L/min, bell speed was set to 30, 40 or 50 thousand rotations per minute (krpm) and water flow rate was varied between 100, 200 or 300 cubic centimeters per minute (cm 3 /min). The total evaporation between 22.5 and 37.5 cm from the atomizer (cm 3 /s) was calculated for all the combinations of those variables. Evaporation rate increased with higher flow rate and bell speed but no statistically significant effects were obtained for variable shaping air on interactions between parameters.