Greenstone Engineering

10/13/2026

04/08/2026

Dry Cleaners & How Solvent Contaminants Break Down

Dry cleaning operations have historically used chlorinated solvents such as tetrachloroethylene (PCE)—a persistent compound that can impact soil and groundwater. These compounds are classified as dense non-aqueous phase liquids (DNAPLs), meaning they are heavier than water and can migrate downward through the subsurface, accumulating at depth and acting as long-term contaminant sources.

Once released, PCE doesn’t simply disappear. Instead, it undergoes a stepwise breakdown process in the subsurface:

PCE (tetrachloroethylene) → TCE (trichloroethylene) → DCE (dichloroethylene) → VC (vinyl chloride) → ethene

This process, known as reductive dechlorination, typically occurs under anaerobic (low oxygen) conditions and is driven by naturally occurring microorganisms.

Why this matters:
• Breakdown products can be more mobile and, in some cases, more harmful to potential receptors (e.g., vinyl chloride)
• DNAPL behaviour can lead to persistent source zones and complex plume distribution
• Plumes can evolve over time, requiring ongoing monitoring and adaptive site models
• Understanding degradation pathways is critical for risk assessment and remediation design

Effective site characterization goes beyond identifying PCE—it requires evaluating the full suite of daughter products and subsurface conditions influencing degradation and contaminate fate.

03/27/2026

As we continue to evolve and provide our clients with high-impact projects and service options, CE Strategies and Greenstone Engineering have combined forces on select projects. Incorporating GIS and data collection tools with environmental assessment and resources will maximize outcomes to achieve greater project success. Our professionals in Thunder Bay, Sault Ste. Marie, Sudbury, and North Bay will provide the highest quality of services that strengthen the support we provide to our clients.

02/20/2026

Greenstone Engineering is now a member of the Greater Sudbury Chamber of Commerce!

We’re excited to welcome Greenstone Engineering to the Greater Sudbury Chamber of Commerce Community!

Greenstone Engineering is an environmental engineering and consulting firm serving Northern Ontario, with offices in Sault Ste. Marie and North Bay. Backed by a team of experienced environmental consultants and technicians with more than 100 years of combined expertise, they deliver practical and cost-effective solutions to help clients manage complex environmental challenges. Their services include environmental assessments, land use and remediation, waste management, including landfill design and monitoring. Learn more about them at greenstoneengineering.ca

As our network expands, so do the opportunities to connect, collaborate and grow - all at the pace of business.

Looking to join a community that moves with you?
Learn more at sudburychamber.ca

02/20/2026

Did you know?

Drywall joint compound (DJC) historically contained asbestos to improve strength and workability. While not all DJC contains asbestos, it was commonly used in many building types for decades.

Asbestos in DJC was banned in Canada in 1980 by the Hazardous Products Act. It would take another 4-5 years for asbestos-containing DJC to make its way through the supply chain, which is why we will sample all DJC in buildings constructed or renovated prior to 1985.

If you are planning renos/demo, or intrusive work in a building constructed or renovated before 1985, DJC should be properly assessed and sampled.

As always, testing is the only way to confirm!

01/09/2026

We're hiring!

Check out this posting for a full-time Project Assistant at our Head Office in Sault Ste. Marie, ON.

Details and application on our website!

Greenstone Engineering Ltd. is an environmental engineering firm serving clients in Northern Ontario with engineering careers available as listed.

12/12/2025

Discover all that Greenstone Engineering Ltd. has to offer on our website!

Stay informed with the latest updates, explore our wide range of environmental engineering and consulting services, and connect with us for your questions.

Visit us at https://greenstoneengineering.ca today!

Consulting engineering services for due diligence, brownfield redevelopment, RSCs, excess soils, waste management, landfills and contaminated site remediation.

12/10/2025

Greenstone provided environmental consulting support during the removal of three underground storage tanks (USTs) in the Walkerton area recently.

Confirmatory soil sampling and reporting to TSSA is a requirement in Ontario following the removal of a UST, and Greenstone can help!