Landfill Risk Assessment Project

Prior to 1972, the City of Red Deer (the City) operated a number of small landfills throughout Red Deer, and in many cases, the city has grown and developed around these former landfill sites. In 2015, the City completed the first stage of a project that involved the testing of former landfill sites that the City owned and/or operated in Red Deer. This testing involved environmental site assessments at each of the former landfill sites and was aimed to help the City better understand the potential impacts of former landfills on the environment and nearby properties.

The second stage of the project included additional testing of the former Montfort landfill site and took place in 2016-2017 after the results from the initial investigations showed potential for some landfill related effects to both the groundwater and soil vapour in the immediate vicinity of the former landfill site.

The next stage of the project involved additional monitoring to confirm the results from the previous testing, account for any seasonal fluctuations and increase understanding of the overall conditions at each of the former landfill sites. Recommendations from the previous stages were reviewed and either implemented or updated based on current testing results. This stage of the project was completed in 2019 and 2020.

In 2021 and 2022, environmental monitoring was completed at each of the sites and additional investigations were completed at select sites based on the recommendations put forward in the 2019-2020 monitoring reports. The investigations completed to date have given the City a good understanding of the conditions and potential impacts at each of the former landfill sites and the City will continue to monitor conditions at these sites for due diligence.

Testing at Former Landfill Sites – Frequently Asked Questions

Why did the City initiate the testing of former landfill sites?

There are several sites in Red Deer that were once used to dump garbage. As the city grows we see more development taking place near these sites; therefore, the City of Red Deer initiated a project to assess former landfill sites in an effort to better understand the impacts and risks associated with development and redevelopment near them. The project was a proactive City driven initiative that will assist the City in making sound and timely decisions about development and redevelopment near former landfills with the best and most current information possible. There were no regulatory requirements to do the project.

Is it common practice to develop near former landfill sites?

Yes. Development near former landfill sites has taken place in Red Deer and communities across Alberta. The Province is responsible for the regulations that dictate where development can occur in relation to landfills and those regulations have changed over time.

Prior to 1978, there were no development regulations that dictated setback distances when homes were constructed around existing landfill sites. In 1978, the province implemented regulations that required a 300 metre setback for homes from operating or active landfill sites. In 1995, the regulations were clarified to include a 300 metre setback from inactive or closed landfill sites as well.

Are there any risks associated with building/developing near a former landfill site?

Potential risks with development in the vicinity of former landfill sites depend on a variety of factors, which include landfilling practices, age of the waste, type of waste, soils surrounding the waste and distance from the landfill.

With improvements in science and technology, we know more about the potential effects of buried waste on the environment and people’s health than we did 50 years ago. Knowledge about the potential risks associated with landfills has evolved over time.

Two potential risks associated with closed landfills include:

Contamination of groundwater by various chemicals present in buried waste

Contaminants from former landfill sites can leach into the groundwater; however, this is generally not a health concern for properties connected to City water. For properties that are not connected to City water, evaluating the potential risk to water well users is specific to the area the property is located in and examines factors like the types of soil in the area surrounding the landfill, the type of waste disposed of, the direction of groundwater flow, and the proximity of the property to the landfill site.

Generation of landfill gas

As landfilled waste decomposes, landfill gas can be generated and may migrate through the soil to collect in confined spaces like utility corridors or basements. Methane gas is one of the primary components of landfill gas and can pose a risk of explosion at certain concentrations. Landfill gas can also contain various other trace gases, which have the potential to cause health effects. The risk assessment process for landfill gas considers things like soil types in the area surrounding the landfill, distance from the landfill, and depth to the groundwater table to determine the potential risk to nearby properties.

What kind of testing did the City conduct on the former landfill sites?

Investigation of the former landfill sites was conducted in a multi-stage approach. The reports summarizing the investigations completed for each site are posted on the City’s website for public view.

Phase I: Environmental Site Assessment
Available information about each of the former landfill sites was reviewed and compiled, including landfilling practices, age of the waste, soils surrounding the waste, and type of developments and distance from the landfill (setbacks).

Phase II: Environmental Site Assessment
A physical investigation of the former landfill sites was conducted to determine the boundaries of waste disposal and collect samples of soil gas and groundwater.

Environmental Risk Management Plan
The data collected during the Phase I and II environmental site assessments was analyzed, and site specific risk management plans were developed. This data was also used to make recommendations on appropriate setback distances from each landfill site.

Additional Environmental Testing
Recommendations from the Phase II Environmental Site Assessments and the Environmental Risk Management Plans included additional monitoring of groundwater and soil gas at each site to evaluate the effects of seasonal conditions and confirm the initial results. Additional testing was conducted at the former Montfort landfill site in 2016 and 2017 and at all sites, including Montfort, in 2019.

Environmental monitoring and additional testing were completed at all sites in 2021, and at the Lindsay Thurber site in 2022, based on the recommendations from the 2019-2020 reports. The City will continue to monitor conditions at these sites for due diligence.

The Phase I and II Environmental Site Assessments were completed in accordance with the Canadian Standards Association’s standards governing these types of reports. The Environmental Risk Management Plan was completed using Health Canada’s preliminary quantitative risk assessment model, which is a nationally accepted process for risk assessment.

Why was further testing done?

Additional environmental testing was needed so that we could build upon the information we collected during the first stages of the project and ensure there were no changes or upgrades needed to mitigate risk near the former landfill sites.

Conditions in the groundwater and soil can change with the seasons as temperatures go up and down throughout the year; therefore, additional testing was needed to build upon initial results and make decisions about development near former landfill sites today and in the future. This additional testing was necessary to confirm and update the initial assessments and understand any potential impacts to people’s health and safety as well as the environment.

Are Alberta Environment and Alberta Health Services involved?

Yes. The City of Red Deer has been working with both Alberta Health Services and Alberta Environment and Protected Areas (formerly Alberta Environment and Parks) throughout this project to ensure that any risks are properly identified and assessed.

Alberta Environment and Protected Areas is in support of the process the City undertook to assess risk related to former landfill sites, and Alberta Health Services has reviewed the reports and provided input to help the City better understand any potential health impacts. Alberta Environment and Protected Areas and Alberta Health Services will continue to be involved in the project going forward and will be provided the reports summarizing any further investigations completed.

I live close to one of the former landfill sites, is my health at risk?

For most of the former landfill sites, the initial testing concluded low risk to nearby properties.

In the case of the former Montfort landfill site, homes had been built relatively close to the landfill so recommendations from the initial testing included a more detailed evaluation of the risk from landfill gas to the residences near the site.

The initial testing results for the former Montfort Landfill site did not show that adjacent properties were directly impacted by landfill gas. However, because we know that in some cases landfill gases can migrate through soil and collect in confined spaces the City chose to retain a consultant who undertook a more in depth testing process to better understand what impact, if any, chemicals stemming from the former landfill site could have on properties and people living near the former Montfort landfill site.

This testing occurred between December 2016 and September 2017 in an effort to collect information and samples across all seasons. While there are always chemicals that can be found in any groundwater and soil vapour, testing focused on measuring landfill specific chemicals (including volatile organic compounds (VOCs) and methane) at concentrations that could be harmful to people or property.

Testing included the installation of additional probes and wells on the former landfill site itself, and in selected backyards directly adjacent to the site. The testing also included in-home air quality sampling in March 2017 of 10 properties that were selected based on their proximity to the former landfill site.

In all homes where indoor air samples were collected, the chemicals tested for were not detected. This indicated that the former Montfort Landfill is not impacting the indoor air quality of adjacent homes. The groundwater and soil gas test results also showed no chemicals from the former landfill site in a concentration that could be harmful to people or property.

Throughout the process, the City of Red Deer worked closely with Alberta Health Services and Alberta Environment and Protected Areas (formerly Alberta Environment and Parks) to determine where and how best to implement testing in the area. A report compiling the seasonal data, indoor air testing and environmental testing results from 2017 was prepared in 2018. While no further indoor air testing is planned, additional environmental testing was conducted at the former Montfort landfill site in 2019, 2020 and 2021 and the City will continue to monitor conditions and consult with Alberta Health Services and Alberta Environment and Protected Areas for due diligence. The reports summarizing the investigations completed are on the City’s website for public view.

What will the City do if they detect landfill gas or groundwater contamination during the additional testing?

There are a variety of options, some simple and some complex, when it comes to mitigating the impacts and risks associated with landfill gas or groundwater contamination. If we find landfill gas or groundwater impacts in concentrations of concern, there are measures that can be put in place to manage the risks associated with both. If this happens, the City will work directly with residents to facilitate a plan and address the issue. The health and safety of citizens is the City’s first priority.

Will it affect my property value?

There are a number of factors upon which property values are determined including the quality, size, features and age of your home, to name a few. However, the Municipal Government Act dictates how all assessments are legislatively required to be done in the province of Alberta. The valuation standard for residential assessments is market value but must be prepared using mass appraisal principles, which refers to the process of calculating assessed value for an entire group or groups of residential properties as of a specific date based on standardization and statistical testing versus individual appraisals on properties at different times. This project is about protecting property, people and the environment.

How does this affect my ability to redevelop or subdivide my property?

Applications for subdivision or development permits are subject to the current regulations regarding setbacks from landfill sites. Based on the results of testing, recommendations for mitigative measures for development or redevelopment within 300 metres of the former landfill sites were developed for each site. Applications will be addressed on a case by case basis, taking into consideration which former landfill site the application is near and the most current mitigative measure recommendations for that landfill site.

If you are planning to subdivide or apply for a development permit for your property, please contact the City for guidance on the processes that may be required.

Landfill Risk Assessment Project Documents and Resources

Maps and Reports for Former Landfill Sites by Area

For more information:

The City of Red Deer
Environmental Services