Class I Disposal Scheme


Class I Disposal Scheme

The AER classifies disposal wells based on the type of injection fluid. This classification system is outlined in Directive 051.

Class I fluids (including Class Ia fluids - nonoil field wastes & Class Ib fluids - specific common oilfield wastes or a mixture of oilfield & nonoil field wastes) may be disposed into underground formations or depleted hydrocarbon pools for purposes other than enhanced recovery or gas storage via an approved disposal well, in accordance with the Oil and Gas Conservation Act Section 39(1) (c), (d) and Directives 065 and 051. Additional approvals from the AER or other governmental agencies may also be required to implement a disposal scheme. A proposal to dispose Class I fluids into underground formations must be shown to have no impact on public safety, no adverse effects on the environment or hydrocarbon potential in the surrounding area.

Detailed information regarding Class I disposal application, with some principles applicable to Class I fluids disposal, can be found on the AER’s website (reference to Directives 051, 056, 058 and 065). The following outlines the critical information required by the AER and the process to follow in order to obtain approval for Class I disposal scheme. It contains links to relevant application submission procedures and guidance documents.


The Class I disposal (new or amendment) application and the related Directive 051 application must be submitted using the Digital Data Submission (DDS) system, available through the Systems & Tools on the AER website,

Applications are registered using Integrated Application Registry (IAR), and all material related to an application is stored within this system.

All material related to an application, the applicant acknowledges that all information relating to the application is no longer confidential as of the designation.


All applications are published on the Public Notice of Application (PNoA) page on the AER website ( to encourage public participation in the approval process.

Application is initially reviewed for administrative completeness upon receipt at the AER. Included in this review is the determination whether the proposed disposal well is located within the South Saskatchewan Regional Plan (SSRP) or the Lower Athabasca Regional Plan (LARP) areas. If any portion of the application area occurs within the SSRP or LARP areas, the application must be referred to AER Business Process Management Section for reviewing before moving forward with the application. The application may be closed if significantly deficient of Directive 065 requirements. If declared administratively complete, a technical review will be conducted including the following (supplemental information may be requested during technical review period):

  • Statements of concern (SOC) filed by parties that may be directly and adversely affected by the proposed disposal operations for which approval is sought are evaluated for relevance to the application, and, if relevant, may necessitate a public hearing to address the stated concerns prior to the disposition of the application. The relevance of the SOC is decided at the AER Director level;
  • Notifications were carried out as per Directive 065 requirements, including notification to landowners and occupants within a radius of 0.5 km from the proposed disposal well and notification to the licensees of all wells including abandoned wells within a radius of 1.6 km from the proposed disposal well where the disposal zone is known to be present. The 1.6 km is a minimum requirement and could expand depending on the estimated fluid and pressure plume areas of influence;
  • The applicant is the holder of the mineral rights to the proposed disposal zone in the proposed well, or the requisite disposal consent has been secured from the current mineral rights holder;
  • The Crown has been sent a letter of indemnification as pertains to the proposed disposal activities, if into Freehold lands;
  • Referral to AER Geology to evaluate the proposed disposal zone in the proposed disposal well and in the vicinity of the well. The evaluation includes formation/reservoir suitability for fluid injection, containment, continuity and connection to known hydrocarbon pools;
  • Review the composition of proposed disposal fluids for acid gases and/or H2S content. If acid gases and/or H2S content are confirmed in the proposed disposal fluids, the application is referred to AER Emergency Planning & Assessment Section to confirm Directive 071 compliance of the proposed disposal operations. including the existence of an up-to-date Emergency Response Plan (ERP) to cover the proposed disposal operations;
  • Directive 051 applications for the proposed disposal wells can be submitted with the Directive 065 application or within a prescribed timeframe after the Directive 065 approval of the disposal scheme. The Directive 051 part is referred to AER Wells Operations Section for verification that wellbore integrity of the proposed disposal well is suitable for the proposed operation, in compliance with Directive 051, if applicable. The Directive 051 review includes confirmation that all wells within the area of influence or within 1.6 km of the disposal well, whichever is greater, have been completed, suspended or abandoned in a manner that ensures hydraulic isolation of the proposed disposal zone. Note that disposal operations cannot commence until the AER has confirmed in writing that the well(s) meet Directive 051 requirements;
  • The AER Resevoir Engineering Section assesses the proposed maximum wellhead injection pressure (MWHIP) to determine whether it is appropriate for the proposed operation. This assessment is usually based on the analysis of step-rate injectivity, or equivalent tests, which establish the formation fracture propagation pressure. MWHIP will be assigned based on the safety factor being applied to the formation fracture propagation pressure at bottomhole. MWHIP approvals may also be affected by other factors, such as the casing collapse strength and cement plug integrity of nearby offsets, which should be taken into consideration when requesting MWHIPs.
  • Referred to AER Waste and Storage Section for verification that the receipt and injection of Class I fluids is permitted as per Directive 058. Note that a Directive 058 approval is required before any Class I disposal operation can occur;
  • Technical review will focus on the geological and reservoir engineering aspects of the proposed disposal scheme, or amendment thereof, including the compliance history to approval conditions (amendments) for the potential impact of the proposed disposal activity on public safety, the environment and resource conservation and include;
    • Estimates of the fluid plume and pressure plume areas of influence of the proposed disposal operation, and review verifies that the proposed disposal zone is adequately isolated above and below by seals that confine injected fluids to the proposed zone;
    • If depleted hydrocarbon pools or their associated aquifers are the disposal zone, the reservoir pressure history of the pool should be included in the application and a maximum operating pressure (maximum average reservoir pressure) that does not exceed the initial pressure of the pool will become a condition of the approval;
  • A technical memorandum, with disposition recommendations, and draft approval documents are prepared and presented for supervisory review;
  • The Reservoir Engineering Manager, or his delegate(s) make the final decision on the merits of any application and sign off on the approval;
  • The application is dispositioned as and according to the decision of the panel when a public hearing is required.
  • Application approvals can be appealed after disposition if the SOC is received from eligible parties. Eligibility for SOC is based on the Responsible Energy Development Act (REDA). The filing requirements and process for a request for regulatory appeal, including form, content, and time limits, are set out in section 30 through 33 of the Alberta Energy Regulator Rules of Practice.


The processing time for this application is 140 business days and the AER aims to meet this target 95% of the time. This timeline is made up as follows:

Task Business Days
Administrative Completeness 5
Assignment 5
Referral 30
Supplemental Information 40
Technical Review 40
Decision 20