Environmental Assessment Glossary

The local name for the Dominion Land Survey (DLS) grid as applied in Alberta. The system divides land into townships, sections, and legal subdivisions used for land titles, well licensing, and environmental reporting. The ATS grid covers nearly all of Alberta, and Phaseview overlays the full grid on its interactive map.

The permanent closure of a well by cementing the wellbore to prevent fluid migration. Abandonment is a regulated process overseen by the AER and is a prerequisite for reclamation. An abandoned well is no longer producing but the surface site may not yet be reclaimed.

The provincial agency responsible for regulating Alberta's energy industry, including oil and gas wells, pipelines, and facilities. The AER oversees well licensing, environmental compliance, and site closure. Phaseview sources much of its data from AER public records.

Alberta's framework for evaluating contaminated sites. Tier 1 guidelines are generic numerical standards for soil and groundwater based on conservative assumptions. Tier 2 guidelines allow site-specific modifications considering actual site conditions, exposure pathways, and receptors. Both are published under the EPEA.

An AER program that allows companies to coordinate abandonment and reclamation activities across multiple well sites within a defined geographic area, rather than addressing sites individually. ABC programs aim to increase efficiency and reduce closure costs by consolidating fieldwork, equipment mobilization, and environmental assessments.

The environmental conditions at a site prior to disturbance or contamination. Baseline assessments document existing soil, groundwater, and surface water quality so that future contamination can be distinguished from natural or pre-existing conditions. Formal baseline studies are uncommon at Alberta oil and gas sites, but background data is often referenced during Tier 2 assessments.

The naturally occurring concentration of a substance in local soil or groundwater, unrelated to industrial activity. Background concentrations matter most for metals and salinity, which can be naturally elevated in certain Alberta geological formations. Establishing background levels is central to Tier 2 risk assessments, where site-specific conditions can justify guideline adjustments.

An acronym for benzene, toluene, ethylbenzene, and xylenes, volatile aromatic hydrocarbons found at petroleum-contaminated sites. Benzene is a known carcinogen with strict regulatory limits. BTEX compounds are more mobile and soluble in groundwater than heavier petroleum hydrocarbons.

A chemical substance detected at a site that may pose a risk to human health or the environment. At Alberta oil and gas sites, the most frequent CoCs are petroleum hydrocarbons (PHCs), BTEX compounds, metals, and salinity (chloride/sodium).

An east-west survey line where the ATS grid resets to compensate for the convergence of north-south range lines caused by the curvature of the earth. Correction lines occur at regular intervals (approximately every two townships, or 12 miles) and result in a visible jog or offset in roads and property boundaries. They are a distinctive feature of the prairie survey grid.

The total cost associated with abandoning, remediating, and reclaiming a well site, also referred to as asset retirement obligations (ARO). Closure costs vary widely depending on site contamination, well depth, and land use. Alberta's unfunded liability for well closure is estimated in the tens of billions of dollars.

The process of defining the horizontal and vertical extent of contamination at a site through systematic sampling. Delineation occurs during a Phase II ESA and continues until clean samples are obtained beyond the contamination boundary in all directions.

The AER's registry of wells and facilities that have been inactive beyond regulatory timeframes. DSI sites require licensees to undertake environmental assessment and closure activities on a mandated schedule. Phaseview maps DSI sites as a dedicated layer.

An excavated pit used to contain drilling fluids, cuttings, and other waste generated during well drilling operations. Sumps are a frequent source of soil and groundwater contamination at well sites, mainly from chloride, hydrocarbons, and metals in drilling mud. Sump closure and assessment are part of site reclamation requirements.

The amount of oxygen dissolved in water, important for understanding redox conditions and natural attenuation potential. Low dissolved oxygen in groundwater may indicate ongoing biodegradation of hydrocarbons. It is measured in the field during groundwater sampling.

An AER directive covering Licensee Life-Cycle Management, including the liability management framework, licence eligibility requirements, and mandatory closure spending targets. Directive 088 establishes the regulatory structure that ensures licensees address their abandonment, remediation, and reclamation obligations on an ongoing basis.

A field measurement of water's ability to conduct electricity, which correlates with dissolved ion concentration. Elevated conductivity in groundwater often indicates salinity impacts. It is a quick screening tool used alongside TDS analysis.

Alberta's primary environmental legislation governing pollution prevention, contaminated site management, and reclamation. EPEA provides the legal framework for environmental assessment requirements, soil and groundwater guidelines, and reclamation standards.

Light Non-Aqueous Phase Liquid (LNAPL), a separate phase of petroleum product such as gasoline, diesel, or condensate that floats on the water table. Free product in a monitoring well indicates serious contamination and usually requires active recovery before other remediation methods can work. Thickness is measured during routine groundwater monitoring.

When a contaminant concentration in soil or groundwater exceeds the applicable regulatory guideline value. In Alberta, exceedances of Tier 1 guidelines do not automatically require remediation, but trigger further assessment or risk evaluation under the Tier 2 framework.

A well installed to collect groundwater samples and measure water levels. Monitoring wells are constructed with screened intervals at target depths and are used during Phase II ESAs, remediation programs, and long-term monitoring. Their locations and construction details are documented in environmental reports.

The measured height of the water table or potentiometric surface at a monitoring well, reported in metres above sea level (masl). Groundwater elevations determine flow direction and hydraulic gradient, which control how contamination migrates. Elevation data from multiple wells is used to construct groundwater contour maps in Phase II and remediation reports.

The formal system for identifying parcels of land in Alberta using the Alberta Township System. An LLD has four components: Legal Subdivision (LSD), Section, Township, and Range, referenced to a meridian. For example, "14-23-045-12 W4M" identifies LSD 14, Section 23, Township 045, Range 12, West of the 4th Meridian. Quarter-section notation (NW, NE, SW, SE) also appears in older records and land titles.

The smallest unit in the Alberta Township System, representing 1/16 of a section -- approximately 40 acres (16 hectares). Each section is divided into 16 LSDs numbered 1-16 in a serpentine (boustrophedon) pattern. LSDs are the primary unit used to locate well sites and environmental assessments.

The company or individual holding the AER licence for a well, pipeline, or facility. The licensee is legally responsible for all environmental obligations including assessment, remediation, and reclamation of the site.

The AER's regulatory framework for managing the financial risk that licensees will not meet their environmental closure obligations. The LMF assesses each licensee's ability to pay for abandonment, remediation, and reclamation relative to their total liability. It replaced the earlier Licensee Liability Rating (LLR) system and is a core component of Directive 088.

The former AER metric that compared a licensee's deemed assets to their deemed liabilities to assess financial risk. A ratio below 1.0 indicated the licensee's liabilities exceeded their assets. The LLR system has been replaced by the broader Liability Management Framework (LMF), but the term remains widely used in industry discussions about well liability.

A remediation approach that relies on natural processes (biodegradation, dilution, dispersion, and chemical reactions) to reduce contaminant concentrations over time. MNA requires ongoing monitoring to confirm that natural processes are working and that contamination is not migrating. Often applied to petroleum hydrocarbon plumes in Alberta groundwater.

A north-south reference line used as the starting point for measuring ranges. Alberta primarily uses the Fourth, Fifth, and Sixth meridians of the Dominion Land Survey. The Fourth Meridian (W4M) forms the Alberta-Saskatchewan border, while the Fifth Meridian (W5M, near 114 degrees west) runs through central Alberta near Calgary, and the Sixth Meridian (W6M, near 118 degrees west) runs through western Alberta near Grande Prairie.

Inorganic elements that may be present naturally or from industrial contamination. Common metals of concern in Alberta include arsenic, barium, cadmium, chromium, lead, mercury, and zinc. Some metals are naturally elevated in certain geological formations, requiring careful baseline comparison.

A well, pipeline, or facility whose licensee is defunct or financially unable to meet environmental obligations. Orphan sites are managed by the Orphan Well Association (OWA), which funds assessment and reclamation through an industry levy.

A not-for-profit organization funded by an industry levy that manages the assessment, abandonment, remediation, and reclamation of orphan wells and facilities in Alberta. As of 2025, the OWA manages thousands of orphan sites across the province.

The AER's online portal where licensees submit regulatory applications, reclamation certificate applications, tiered environmental assessments, and other compliance documents. OneStop is the primary digital interface between industry and the regulator. Phaseview sources environmental report data from OneStop public records.

A desktop and site reconnaissance study that identifies potential or actual contamination on a property through historical records review, site inspection, and interviews. Phase I ESAs do not involve sampling or laboratory analysis. In Alberta, they are required before property transfers, well site reclamation, or development.

A field investigation that follows a Phase I ESA when potential contamination is identified. Phase II ESAs involve soil and groundwater sampling, laboratory analysis, and comparison of results to regulatory guidelines. They confirm whether contamination exists and delineate its extent.

The route by which a contaminant travels from its source to a receptor. Examples include groundwater migration, soil vapour intrusion, surface water runoff, and direct contact with contaminated soil.

A remediation-focused investigation conducted after contamination has been confirmed in a Phase II ESA. Phase III ESAs involve additional delineation drilling, remediation system design, pilot testing, and implementation of cleanup strategies. Scope depends on the nature and extent of contamination identified.

A group of organic compounds with multiple fused benzene rings, produced during incomplete combustion of organic materials. PAHs are found at sites with coal, creosote, or heavy petroleum contamination. Some PAHs are carcinogenic and persist in soil.

Petroleum hydrocarbons classified into four fractions by carbon chain length: F1 (C6-C10, gasoline-range, excludes BTEX to avoid double-counting), F2 (C10-C16, diesel-range), F3 (C16-C34, lubricant-range), and F4 (C34-C50+, heavy oil). This fractionation system is defined in the Canada-Wide Standard for Petroleum Hydrocarbons in Soil (CCME) and is used across Canadian jurisdictions for soil and groundwater guidelines.

A measure of acidity or alkalinity on a scale of 0-14, with 7 being neutral. Natural Alberta groundwater usually falls between pH 6.5 and 8.5. Extreme pH values can mobilize metals and affect contaminant transport in soil and groundwater.

Saline water brought to the surface during oil and gas production that may contain dissolved salts, hydrocarbons, trace metals, and naturally occurring radioactive materials. Produced water spills are a leading cause of soil and groundwater salinity impacts at Alberta well sites. Volume and chemistry vary widely between formations and production methods.

A division of a section into four quarters (NE, NW, SE, SW), each approximately 160 acres (65 hectares). Quarter sections are used to describe surface lease locations and land ownership before narrowing to the LSD level. Many older environmental reports and land titles reference quarter sections rather than individual LSDs.

The process of removing, treating, or containing contamination in soil, groundwater, or sediment to meet regulatory standards. Methods used in Alberta include excavation, bioremediation, soil vapour extraction, and groundwater pump-and-treat systems.

An evaluation of potential harm to human health or the environment from site contamination. Alberta uses a tiered approach: Tier 1 compares results to generic guidelines, while Tier 2 allows site-specific risk-based criteria considering exposure pathways, receptors, and site conditions.

Restoring land disturbed by industrial activity to an equivalent capability for its prior or intended use. In Alberta, well sites must be reclaimed after abandonment, including removing infrastructure, recontouring the surface, replacing topsoil, and re-establishing vegetation. A Reclamation Certificate (RecCert) is issued upon successful completion.

Any person, organism, or environmental feature that could be exposed to contamination. Receptors include residents, workers, wildlife, surface water bodies, and groundwater aquifers. Identifying receptors is a key step in risk assessment.

A column of townships running north-south, numbered westward from each meridian. The maximum range number varies by meridian -- up to 30 west of the 4th Meridian, about 27 west of the 5th, and about 12 west of the 6th. For example, Range 12 W4M means the 12th column west of the Fourth Meridian.

Strips of land reserved for roads within the survey grid, typically 20 metres (66 feet) wide along section lines and 30 metres (99 feet) wide along township and range lines. Road allowances affect precise coordinate calculations and are accounted for in Phaseview's LLD-to-coordinate conversion.

An official certificate issued by the Alberta Energy Regulator (AER) confirming that a well site has been successfully reclaimed to meet regulatory standards. Obtaining a RecCert requires completing environmental assessment, remediation (if needed), and land restoration. It is the final step in the well lifecycle and ends surface lease payment obligations to the landowner, which makes it a major financial motivator for licensees.

A document outlining the strategy for addressing contamination at a site, including remediation objectives, selected methods, timelines, and monitoring requirements. A RAP is prepared after a Phase II ESA confirms contamination and is submitted to the AER or landowner for approval before remediation begins.

A regulatory document that formally records the environmental condition of a site at a point in time. In Alberta, a RoSC may document that a site meets applicable guidelines after remediation, or that contamination remains but is managed through a risk management plan.

The migration of volatile contaminants from contaminated soil or groundwater into overlying buildings through cracks in foundations, utility penetrations, and other openings. Soil vapour intrusion is a key exposure pathway for VOCs and BTEX, assessed through sub-slab soil vapour sampling. It becomes a concern when contamination exists near occupied structures.

A square parcel of land approximately 1 mile by 1 mile (259 hectares). Each township contains 36 sections, numbered 1-36 in a serpentine pattern starting from the southeast corner. Sections are subdivided into 16 Legal Subdivisions (LSDs).

A legal agreement granting an oil and gas company the right to use a specific area of a landowner's property for a well site, pipeline, or facility. Surface leases are smaller than an LSD and require ongoing rental payments to the landowner until a Reclamation Certificate is obtained. The lease area defines the boundary for environmental assessment and reclamation obligations.

The date on which drilling of a well begins. The spud date marks the start of the well's lifecycle and is recorded by the Alberta Energy Regulator. It is used to track the age of wells and calculate liability timelines.

A temporary shutdown of a well that is not currently producing but has not been permanently abandoned. Suspended wells must meet AER requirements for wellbore integrity and are monitored as part of the Dormant Site Inventory if inactive beyond specified timeframes.

Elevated concentrations of dissolved salts, primarily chloride and sodium, in soil or groundwater. Salinity is one of the most common contaminants at Alberta oil and gas sites, usually originating from produced water (brine) spills or drilling waste. Salinity impacts can persist for decades because natural attenuation is limited, and they affect vegetation, soil structure, and drinking water quality.

A grid unit approximately 6 miles by 6 miles, containing 36 sections. Townships are numbered sequentially from 1 (at the US border) to 126 (in northern Alberta). Combined with range and meridian, townships provide the framework for Alberta's land survey system.

The total concentration of dissolved minerals, salts, and organic matter in water, measured in mg/L. High TDS in groundwater can indicate salinity impacts from oilfield brine spills or natural geological conditions. Alberta's groundwater TDS varies widely across the province.

A measure of water clarity, indicating the amount of suspended particles. High turbidity in groundwater samples can affect analytical accuracy and may indicate well development issues or disturbed conditions during sampling.

Organic chemicals that easily evaporate at room temperature. VOCs include BTEX compounds, chlorinated solvents, and other petroleum derivatives. Their volatility means they can migrate through soil vapour and potentially enter buildings through vapour intrusion.

A unique identifier assigned by the AER to each licensed well in Alberta. The well licence number is used to track a well through its entire lifecycle, from drilling approval through abandonment and reclamation. Phaseview uses well licence numbers to link environmental reports to specific well sites.