Questions and Answers: Soil vapour testing in proximity to 17 Sydenham Street

Why does indoor testing have to be done in homes near the site now?
The most current groundwater and soil vapour data at the property boundary on 17 Sydenham St. suggests that contaminant from historical on-site industrial operations may extend off-site towards some neighbouring residential properties. In close consultation with the Ministry of the Environment, Conservation and Parks (MOECP) the City and MOECP have concluded that additional monitoring is required at certain locations adjacent to 17 Sydenham Street, due to the potential for off-site migration of TCE. It is important to note that it is not known for certain at this point if any off-site migration of TCE has actually occurred. 
Are current TCE levels a risk to homes in proximity to the site or to the public at large?
The most recent soil samples show levels of TCE that are above the current provincial standard at the property line of 17 Sydenham. At this stage it’s important to note that we do not know for certain if any off-site migration of TCE has actually occurred. That is why the MOECP and City feel the need to conduct additional testing. Based on consultation with the Brant County Health Unit, it is important to note that this issue does not present a public health threat to the community at large. 
Why didn’t the City do this additional testing sooner?
The City acted to put an action plan in place in the most timely manner possible within the framework of the remediation process. Once the remediation process was complete, a Record of Site Condition (RSC) was successfully obtained from the Ministry of the Environment, Conservation and Parks (MOECP), for the Site in March 2018, which allows the site to be redevelopment for residential purposes in the future. As part of the RSC process, a Certificate of Property Use (CPU) was issued by the MOECP, which included conducting post-remediation environmental monitoring on Site for a minimum of two (2) years, completed in the Fall of 2019. Following the completion of the two-year monitoring program, an additional one year of monitoring was completed to further assess the concentration of Trichloroethylene (TCE) on Site which was completed at the end of 2020. 
What is trichloroethylene (TCE)?
TCE is a clear colourless liquid used mainly for degreasing metal parts in the automotive and metal industries. It can also be found in some household products, such as glues, adhesives, paint removers, spot removers, rug cleaning fluids, paints, metal cleaners and typewriter correction fluid.
How does TCE get into the environment?
The largest source of TCE in the environment is typically through air emissions from factories that use it to remove grease from metals. TCE can also enter air and groundwater if it is improperly disposed of or leaks into the ground. It evaporates easily but can stay in the soil and in groundwater for an extended period of time. The source of the TCE on the brownfield site located at 17 Sydenham St. was believed to be an equipment pit located in the southwest portion of the historical industrial facility.
How can I be exposed to TCE?
Aside from workers with occupational exposure, the most common sources of exposure to TCE for the general population are through air and drinking water. The potential route of exposure to TCE in the study area is not through outdoor air, but possibly through indoor air. Low levels of TCE in the groundwater underneath homes can evaporate and migrate through building foundations into the building’s indoor air. This process is called “soil vapour intrusion.” Based on soil vapour testing results in the study area, if TCE has migrated into indoor air, it is expected levels would be extremely low. 
What are the health risks associated with TCE exposure?

As with exposure to any chemical, a person’s health risk depends on a number of factors, including:

  • • How much TCE an individual was exposed to (the dose);
  • • How long the exposure lasted (the duration);
  • • How the person was exposed (breathing, drinking, eating or skin contact);
  • • Other factors associated with the individual (such as age, health, lifestyle choices, family traits, and other chemicals the person is exposed to).

Health risks can be categorized into acute effects and chronic / sub-chronic effects. Acute effects are those that occur after short-term exposure (e.g. minutes, a few days) to very high concentrations of TCE (e.g. concentrations in the hundreds of thousands of micrograms per cubic meters (μg/m3) or greater).

Symptoms of acute exposure can include drowsiness, decreased memory and perception, visual effects and anesthesia. If TCE is present in indoor air in the study area, it is expected that concentrations would be significantly lower than levels that give rise to acute effects.

Chronic effects are those that occur after long-term exposure, dependent on the levels of TCE (e.g. several years). Sub-chronic effects are those that occur after intermediate-term exposure, dependent on the levels (e.g. several months). These potential exposures combined with above factors may include cancer (from chronic exposure) and non-cancer effects (from sub-chronic or chronic exposure). The main concern with TCE exposure is the risk of cancer. Overall, studies in humans and animals are highly suggestive of an increased risk for cancer in people who are exposed to elevated levels of TCE over long periods of time (e.g. workers exposed to levels 20,000 μg/m3). Cancers that have been associated with TCE include kidney, liver and lymphoid tissue cancers.

The risks of cancer associated with chronic exposures to low levels of TCE are as follows: An air level of TCE at 0.5 μg/m3 corresponds to a one in one million risk of cancer over a lifetime (70-year exposure). An air level of TCE at 5 μg/m3 corresponds to a one in one hundred thousand risk of cancer over a lifetime (70-year exposure). An air level of TCE at 50 μg/m3 corresponds to a one in ten thousand risk of cancer over a lifetime (70-year exposure).
Chronic and sub-chronic effects, other than cancer, are less understood and research is ongoing. Potential effects include those to the central nervous system, kidney, liver, respiratory, developmental and reproductive systems. However, it is generally recognized that cancer is the most sensitive health outcome.

What is the level of risk to residents in the study area?
Although there are many health effects described for TCE, especially for acute exposures to high concentrations, the levels of TCE in the area are not expected to result in the acute effects described for TCE. While health risks associated with sub-chronic and chronic TCE exposure, in particular cancer, are possible, the potential risk is very low given the low concentrations of soil vapour TCE.
What are the recommended action levels?

Recommended action levels are many times lower than the levels that have caused health effects in human and animal studies that have been used to set action levels or standards. The recommended action levels are based on the assumption that people are continuously exposed to TCE in air all day, every day for as long as a lifetime (70 years). This is rarely true for most people who, if exposed, are likely to be exposed for only part of the day and part of their lifetime. If time spent in the basement of the house is limited, this would further limit the risk of exposure. These action levels are for the general population, including infants, children, the elderly and those with pre-existing health conditions.

Where needed, remediation measures in homes are usually very successful at reducing the levels of TCE in indoor air.

Results from initial soil vapour testing showed that TCE could affect air quality in some houses in the study area. Based on direction from the Ministry of the Environment, Conservation and Parks (MOECP), the City of Brantford together with Consultant Jacobs Engineering intends to conduct indoor air testing in homes adjacent to the brownfield property.

How much TCE is present on the site right now?
The most recent soil samples show levels of TCE that are above the current provincial standard at the property line of 17 Sydenham which backs onto some abutting residential properties.
What are the future development plans for the Site?
There are no redevelopment plans at this time. The properties at 17 and 22 Sydenham Street have been remediated to a standard that supports the future redevelopment of these lands for parkland and residential purposes, and a rezoning of the lands will be required though a public process before redevelopment can occur.
Will the City be hosting public meetings about this issue?

Yes, the City will be providing more information to impacted residents and the community at large regarding upcoming virtual and/or in person opportunities to ask questions of the project team. In the meantime, questions can be emailed to or residents can call the City’s Customer Contact Centre at 519-759-4150. 

Who can I contact now if I have more questions?

If you have any questions about the proposed residential indoor air quality monitoring program, please call 51-759-4150 or email and a member of the project team will get back to you as soon as possible.

If you have any questions of the Ministry of the Environment, Conservation and Parks, please call 226-820-6536 or email

If you have any questions related to your personal health, please reach out to your general practitioner (GP) or personal health care provider. If required, your health care provider can contact the Brant County Health Unit for additional technical information regarding potential health impacts of TCE at 519-753-4937 ext. 470 or email: