A successful hydrogeological assessment must consider the physical composition of the ground. At CESI, we analyze the soil and bedrock profiles of each site to determine the nature, depth, and structure of subsurface layers. This includes identifying the presence of materials such as clay, sand, gravel, silt, and various types of bedrock, and evaluating their ability to conduct water.

Site topography is another key element. We map elevations, slopes, and natural depressions to understand how water will flow across and beneath the site. This information is essential for designing efficient drainage systems, planning foundation depths, and preventing unwanted water accumulation that could compromise infrastructure.

We also measure groundwater levels across different seasons to assess seasonal fluctuations. This data helps identify whether the groundwater level may rise above planned sub-grade structures, which could necessitate waterproofing or active drainage systems.

Our hydrogeological studies also include a review of the natural features surrounding a project site. This involves locating and assessing any aquifers, aquitards (low-permeability layers that can restrict water movement), surface water bodies (streams, ponds, rivers), and wetlands that may be sensitive to construction activities.

We also consider areas of natural or ecological significance, including conservation lands and habitats for species at risk. Our assessments ensure that development plans take these features into account, minimizing disruption and aligning with provincial policies such as the Provincial Policy Statement (PPS) and the Clean Water Act.

When de-watering or construction activity may have the potential to impact these sensitive features, we develop mitigation strategies to minimize or eliminate adverse effects, thereby helping our clients maintain both environmental responsibility and public trust.

To fully understand groundwater dynamics at a site, CESI maps the groundwater flow directions and calculates hydraulic gradients — the slope of the water table that drives groundwater movement. This information allows us to predict where water will flow once it is in the subsurface and helps in assessing risks such as erosion, flooding, or off-site migration of potential contaminants.

This analysis is also valuable in the placement of monitoring wells and the design of stormwater infiltration systems. Accurate mapping of hydraulic gradients ensures that engineered solutions function as intended and do not create unintended environmental consequences.

A common requirement in many development projects is the discharge of groundwater, either temporarily during construction or permanently through drainage systems. CESI evaluates the volume and flow rate of groundwater to be discharged and determines whether the receiving system — municipal sewer or surrounding soils — can accommodate it.

We also assess whether the water meets local regulatory requirements. Discharging untreated groundwater can pose environmental and legal risks, especially if it contains elevated levels of metals, sediments, or bacteria. Our assessments help clients avoid fines, delays, or damage to infrastructure by ensuring compliance with sewer use by-laws and environmental standards.

To promote sustainable water use and protect aquifers, CESI conducts Water Balance Studies. These studies estimate how much water enters, exits, and is stored on a property throughout the year. They help determine the capacity of the land to handle stormwater, recharge groundwater, and support local ecosystems.

Our water balance models are essential for developments near sensitive recharge areas or in regions with strict stormwater management regulations. These studies often form part of broader Environmental Impact Assessments and are submitted to approval agencies during the permitting process.