1. Cleaning
  2. Hand Sanitizer
  3. Ventilation
    1. Ventilation (HVAC) Strategy for the Return to Campus
  4. Water Treatment Program and Legionella Testing
  5. Tunnels
  6. Questions

Facilities Management and Planning (FMP) has completed preparing Carleton’s buildings and grounds for the return of faculty, staff and students.


FMP has cleaning protocols in place for buildings, classrooms, common spaces and study spaces. Additional resources are being secured as required to ensure compliance with public health cleaning guidelines.

Hand Sanitizer

Hand sanitizer stations have been deployed at building entrances for students, faculty, staff and community members to use while on campus. These stations are monitored regularly to determine the frequency of use. Depending on the traffic volume, additional stations will be deployed as needed. Should a hand sanitizer station require servicing, individuals are encouraged to notify the FMP Service Desk. Additional hand sanitizing mitigation measures are outlined in each unit’s approved return to campus plan.


Carleton University is adhering to the core recommendations of the American Society of Heating Refrigerating, and Air-Conditioning Engineers (ASHRAE) Epidemic Task Force guidelines (PDF, 258 KB). This was confirmed by a third-party consultant who was engaged to verify and recommission the ventilation systems.

Across campus, the main air handling systems in all buildings have been fitted with high-efficiency (MERV 13) filters as recommended by ASHRAE.

All main air handling systems are providing pre- and post-occupancy flushes of ventilation air at least two hours before occupancy and two hours after occupancy. The systems are continuously monitored throughout the day by Facilities Management and Planning (FMP) Building Operations staff.

Ventilation (HVAC) Strategy for the Return to Campus

March 2022

In order to support and maintain a safe indoor building environment, the role of ventilation and heating, ventilation, and air conditioning (HVAC) systems is important to ensure the continued health and safety of the campus community. Carleton University is adhering to the core recommendations of the American Society of Heating Refrigerating, and Air-Conditioning Engineers (ASHRAE) Epidemic Task Force guidelines (PDF, 258 KB). These outline five major priorities that should be followed to reduce the risk of airborne infectious aerosols. In brief, they are as follows:

  1. Public Health Guidance – follow all regulatory and statutory requirements
  2. Ventilation, Filtration, Air Cleaning – provide required outdoor airflow rates; use MERV 13 or better filters; use air cleaners as required (MERV – Minimum Efficiency Reporting Value and is used to evaluate the efficiency of an air filter based on how effective it is at capturing particles, ASHRAE Filtration and Disinfection FAQ)
  3. Air Distribution – promote air mixing without causing strong air currents
  4. HVAC System Operation – maintain proper temperature and humidity; maintain clean air supply as designed for occupancy; when necessary operate systems for a time to achieve three air changes; limit re-entry of contaminated air.
  5. System Commissioning – verify that HVAC systems are functioning as required. Carleton has engaged with a third party to conduct a thorough review of all HVAC systems to ensure we are compliant with the above. Any areas not functioning as required were identified and remediated. This was confirmed by the third party.

In addition to meeting the ASHRAE recommendations, Carleton is piloting additional ventilation strategies to help keep all members of our community safe. UVC Air Disinfection lights are being installed in all AHUs across campus. This will provide for in-duct air disinfection in classrooms and high congregation areas. In addition to these strategic actions, Carleton continues to monitor all HVAC operations in real time to immediately identify and address any concerns.

The university has also ensured that the tunnels are properly ventilated to current building code and all previously mentioned ASHRAE Core Recommendations. This project was completed at the end of June 2022, and general access to the famous Carleton Tunnel system resumed July 1, 2022.

If you have any concerns regarding the above, please contact ehs@carleton.ca.

Water Treatment Program and Legionella Testing

March 2022

In March 2020 and the beginning of the pandemic, most of the buildings on the Carleton University campus were closed and/or had limited usage. As a result of this closure, the buildings had limited water flow which could create conditions for Legionella bacterial growth.

Two distinct illnesses, Legionnaires’ disease and Pontiac fever, have been associated with Legionella bacteria. The milder form is Pontiac fever, an influenza-like illness that is rarely fatal. Legionnaires’ disease is a much more serious form, with severe pneumonia-like symptoms, and is fatal in 10–15% of the cases.

Legionella is potentially a serious health concern in many public buildings. The only effective way of preventing such outbreaks is the proper design, operation, and maintenance of components in mechanical systems that are susceptible to bacterial growth and dissemination. Testing is useful for determining the effectiveness of the operation and maintenance program.

Legionella growth is most favourable when water conditions are between 25-42 °C, pH is between 6-8 and if you have stagnation of your water supply.  Legionella is primarily spread through the formation of aerosols.  Cooling towers and open water sources such as fountains are the most possible sources.  Legionella bacteria does not survive at temperatures above 49 °C and domestic hot water systems are not as great as a concern for growth.

Carleton University has been flushing the water in our buildings as well as testing for the presence of any Legionella bacteria regularly since March 2020 to ensure the safety of all members of our campus community. Carleton University has also been following the testing protocols as outlined in the Public Works and Government Services Canada Standard, MD15161 -2013 Control of Legionella in Mechanical Systems (PDF, 516 KB).

Carleton University tests for Legionella as per below.

System Type Frequency Test Type
Cooling Towers Weekly Microbial activity
Monthly Legionella
Start-Up Rapid Pathogens Analysis
Humidifiers – Steam Every 3 months (if stagnant water present) Microbial activity
When indicated by testing Rapid Pathogens Analysis
Humidifiers – Non-Steam Monthly Microbial activity
Every 3 months (if stagnant water present) Legionella
When indicated by testing Rapid Pathogens Analysis
Open Water System Weekly Microbial activity
Every 2 months Legionella
24 hours after start-up, cleaning and disinfection Rapid Pathogens Analysis
Domestic Hot Water Systems Monthly – showers with tank storage at < 50 deg. C Microbial activity
Every 6 months (most remote shower) Legionella
When indicated by testing Rapid Pathogens Analysis

In addition to Legionella testing, Carleton conducts regular testing of our cold water systems to ensure our drinking water remains healthy and safe. All samples and testing is completed by a third party and adheres to the Ontario Drinking Water Standards, Objectives and Guidelines, ODWSOG.


Following the installation of new exhaust fans and air handling units throughout the entire tunnel system, access to the tunnels has resumed.


If you have any questions, please contact ehs@carleton.ca.