View PDF file for full text

Interim Directive

ID 2001-5

August 14, 2001

To: All Oil and Gas Operators

PUBLIC SAFETY AND SOUR GAS POLICY IMPLEMENTATION
RECOMMENDATIONS 54, 60, AND 61

SITE-SPECIFIC EMERGENCY RESPONSE PLANS FOR SOUR OPERATIONS, EMERGENCY PLANNING ZONES, AND REDUCED PLANNING ZONES

The Provincial Advisory Committee on Public Safety and Sour Gas (Advisory Committee) presented its report of findings and recommendations to the Alberta Energy and Utilities Board (EUB) in December 2000. A number of recommendations deal with EUB practices and requirements related to emergency planning zones (EPZs) and emergency response plans (ERPs) for sour gas operations.

To address these recommendations, the EUB intends to undertake a full review of current emergency preparedness requirements, including the methodology for determining EPZs. This review is dependent on the outcome of actions from other recommendations, including updating information on health effects of hydrogen sulphide (H2S) and sulphur dioxide (SO2) and a review of the current use of dispersion models and probabilistic risk assessment. This work is expected to take 18 to 24 months to complete, after which a comprehensive review of ERP requirements and determination of EPZs, including reduced EPZs, will take place.

However, it is important to reiterate that there are currently emergency response planning and preparedness requirements in place, which are set out in several EUB informational letters (ILs), interim directives (IDs), and guides. These documents are listed in Appendix A. The documents listed in Appendix A all remain in effect until they are replaced or rescinded.

The Advisory Committee requested in Recommendations 54, 60, and 61 that the EUB clarify how it would administer its requirements for determining the size of EPZs, including the use of reduced EPZs, and reviewing ERPs until a comprehensive review of all related issues as identified above is complete. This ID, which is effective immediately, provides further clarification as to how the EUB administers these existing requirements and also introduces some new requirements that will be used in the interim until the comprehensive review is completed. New requirements are underlined.
 
As well, development of a new comprehensive EUB guide on emergency response planning and preparedness, which was already in progress before the Advisory Committee began its work, is continuing. The new EUB guide will compile and clarify existing ERP requirements, including additional enhancements, into a single document and will also address some of the recommendations related to emergency preparedness. The EUB will be seeking stakeholder input on the draft guide in the near future, with its formal release due later in 2001. The guide will be revised as necessary throughout implementation of the Advisory Committee’s recommendations.

1 Approval of ERPs

For all critical sour wells (release rate critical or proximity critical), a site-specific ERP must be submitted as part of a Guide 56: Energy Development Application Guide Category E licence application. The EUB will review the ERP in parallel with the licence application and drilling plan; it will not issue any licence until the ERP is complete and meets all EUB requirements and the EUB’s Operations Group has issued its approval of the ERP in writing.

For noncritical sour wells, pipelines, or facilities that require ERPs under the current requirements, operators must submit a site-specific ERP and receive written approval of the ERP from the EUB prior to commencement of well drilling or prior to receipt of sour gas into a new pipeline or facility.

In cases where the well completion or servicing operations have not been addressed as part of a site-specific drilling ERP, these operations may not commence until the operator has satisfied the ERP requirements and obtained the appropriate approvals as set out in ID 90-1: Completion and Servicing of Sour Wells.

All new wells, pipelines, and other facilities must also be immediately included in existing applicable sour gas facility and gathering system ERPs.

Applicants and licensees should consider the time required for the EUB to complete a detailed assessment of all ERPs submitted and provide for sufficient time within their project plans for this approval process. Inquiries with respect to expected approval process time should be directed to the EUB Operations Group. Operators are reminded that failure to comply with all ERP requirements, including obtaining written approvals, will result in enforcement action, which will escalate for repeated noncompliance. Enforcement actions are based on the EUB’s IL 99-4: Enforcement Process, Generic Enforcement Ladder, and Field Surveillance Enforcement Ladder.

2 Determination of Calculated EPZs

Section 3.2 of ID 97-6: Sour Well Licensing and Drilling Requirements sets out the accepted methodology for determining the size of the calculated EPZ based on the maximum anticipated sour gas release rate for wells. Accepted methodology for determining EPZs for pipelines and facilities are included in the Canadian Petroleum Association’s CPA Guidelines for Preparation of Sour Gas Emergency Response Plans for Sour Gas and Oil Facilities, April 1987. EPZ calculations are also reflected in the EPZ curves shown in Figures 1 to 4. This methodology must be used as the basis for all initial EPZ determinations. The actual shape of the EPZ should also reflect site-specific topographical features, population distribution, and access/egress considerations to determine the most effective EPZ for emergency planning purposes. All other sour well licensing and drilling requirements set out in ID 97-6 also remain in effect.

3 Use of Reduced EPZs

The use of reduced EPZs was a key issue raised by the Advisory Committee, which recommended that the entire issue be reviewed once other recommendations, such as health effects and dispersion modelling, have been addressed. The Advisory Committee was concerned that currently many of the ERPs with reduced EPZs do not adequately address public safety when the ignition of the well changes the public safety hazard from H2S to SO2. It was also concerned that ERPs with reduced EPZs do not clearly define who is responsible for public safety beyond the reduced EPZ. Therefore, the Advisory Committee recommended that if the EUB is to continue to approve reduced EPZs, develop an interim policy that clearly sets out the conditions by which a reduced EPZ will be considered until further work is completed.

The EUB agreed to move forward with development of an interim policy, since the detailed work will take some time to complete. This section of the ID clarifies the conditions under which a reduced EPZ will be considered, including what is meant by immediate ignition.

The EUB has set out the following policy for the use of reduced EPZs until comprehensive reviews (ERPs, EPZs, health effects, dispersion modelling, and risk assessment, etc.) are completed. The EUB emphasizes that this is an interim policy.

The EUB will continue to approve the use of an EPZ that is reduced in size from that calculated using the approach outlined in Section 2 above. The use of a reduced EPZ will only be considered when the calculated EPZ is very large and involves many people and when the implementation of typical emergency response procedures, such as evacuation, would be impractical. In such cases, the public protective measures used in conjunction with a reduced EPZ must provide the same or greater level of public safety as would an unreduced EPZ. Therefore, approval of a reduced EPZ is always contingent upon immediate ignition of any release of H2S. “Immediate ignition” is defined in Section 3.4.

Immediate ignition of a sour gas release does not remove the need to develop plans to protect the public from a hazard. However, the hazard is changed from an immediate hazard of exposure to H2S of the public in the immediate vicinity of the release to a hazard of exposure to SO2, which due to the plume rise of the release would disperse higher into the atmosphere. The area potentially affected on the ground and the calculated SO2 EPZ would likely be much different in extent from that for H2S. However, until the work required to address some of the issues around dispersion modelling, health effects, and EPZ determinations is completed, the EUB will continue to accept the use of a reduced EPZ to a minimum of 4 kilometres, within which a full plan for early evacuation at the first indication of a well control problem prior to any release must be developed. In addition, a plan to address a distance equal to twice (2 x) the size of the
 
reduced EPZ or to the distance of the calculated H2S zone, whichever is less, must be developed to address the hazard of exposure to SO2. Details of minimum requirements, including those associated with this SO2 plan, are included in the following sections.

3.1 Request for Reduced EPZ

Applicants and licensees must assess the practicality of typical emergency response procedures such as evacuation within a calculated EPZ, prior to developing the ERP. This evaluation should examine the public safety protective measures available versus the EPZ’s size, including, but not limited to, population density, topography, access/egress routes, and other identifiable factors that may affect timely implementation of emergency response measures. If this evaluation determines that timely evacuation within the EPZ would be impractical, the applicant or licensee may request that the EUB approve a reduced EPZ. The EUB will only consider a reduced EPZ for wells with H2S release rates at or above 3 cubic metres per second, as stated in ID 97-6. The request must be submitted in writing for preapproval to the EUB’s Operations Group before the applicant or licensee completes detailed preparation of the ERP and before it conducts the detailed full public consultation program required with each resident prior to filing an application. However, the applicant should consider conducting a broad consultative process, possibly open houses or public meetings within the community, in advance of submitting a request for a reduced EPZ to the EUB.

The following information must be submitted with the request for a reduced EPZ:

• maximum anticipated cumulative H2S release rate of the proposed well;
• size of the calculated H2S EPZ and size of the proposed reduced EPZ;
• reasons for proposing a reduced EPZ, along with a written summary of the evaluation undertaken to determine the practicality of evacuation within the calculated H2S EPZ; this would address all the factors relevant to the request for a reduced EPZ, including, but not limited to, population density, number of residences, details about any publicly used facilities or businesses, terrain and topographical features, access and egress issues, communication/notification issues, and general land use;
• a detailed map of the reduced EPZ and the area out to twice (2 x) the reduced EPZ or to the distance of the calculated H2S zone, whichever is less, which shows
  - surface location of the proposed well,
  - locations of all residences, including those bordering the EPZ or on roads outside the EPZ where people would be required to egress through the EPZ,
  - corporate boundaries of urban centres,
  - locations of places of business, including industrial operations,
  - locations of publicly used facilities (e.g., parks, campgrounds, schools, churches, community centres),
  - primary, secondary, and access roads, and
  - topographical features, including lakes, rivers, streams, and any significant elevation feature that could affect either dispersion of a sour gas release or ability to evacuate;
• a description of the discussions, interactions, and agreements made with the relevant public and municipal emergency services regarding emergency response roles and responsibilities;
• an indication or substantiation that no concerns have been received regarding the approval of a reduced EPZ; and
• a commitment that the minimum emergency response measures set out in Sections 3.2 to 3.7 of this ID will be included in the ERP if a reduced EPZ is approved.

3.2 Notification Expectations for Area Beyond the Reduced EPZ

The EUB will accept the following forms of public notification prior to filing an application for the area beyond the reduced EPZ to twice (2 x) the size of the reduced EPZ or to the distance of the calculated zone, whichever is less:

• direct contact with all residents and businesses, or\
• such methods as notices in local newspapers, a general mail-out within the area, open houses, or public meetings.

Regardless of the process chosen, the public must be given a reasonable opportunity to become informed of the proposed well and emergency response measures and to have questions and concerns addressed.

All other notification and consultation requirements for the EPZ as specified in Guide 56 remain in effect.

3.3 Mandatory ERP Components for a Reduced EPZ

If the EUB has approved a reduced EPZ, any ERP submitted to the EUB must include the following:

• concise and detailed plan that deals with the reduced EPZ (the H2S zone); this plan must outline the actions that will take place up to and including the immediate ignition of the well;
• immediate ignition based on the criteria detailed in 3.4 below;
• a concise and detailed plan that recognizes the potential flow rates and dispersion of SO2 after the well has been ignited; this plan must detail the actions to be taken once the well has been ignited to ensure the protection of the public and address Sections 3.4 to 3.7 below;
• a detailed communication plan that will be used in the event of an emergency for each hazard situation (H2S and SO2) to keep the potentially affected public informed.

3.4 Immediate Ignition

There must be immediate ignition of an uncontrolled or partially controlled flow as soon as all personnel working at the site have been cleared to a safe distance. The EUB requires the operator to take immediate steps to prepare for ignition at the earliest signs of a well control problem to ensure that there will be no delay. Ignition must occur within 15 minutes of the beginning of the uncontrolled sour gas release under the following conditions, unless specific approvals specify otherwise:

• the well is experiencing an uncontrolled flow and well effluent has reached the surface; the EUB defines an uncontrolled flow as an unrestricted well flow at surface that cannot be shut off at the licensee’s discretion, or
• the well is flowing small volumes of sour gas to surface and is partially controlled, but safety of the public cannot be assured because
  - evacuation of the public within the reduced EPZ has not been accomplished, or
  - monitoring results indicated H2S levels that exceed 20 parts per million (ppm) (3 minute average) in any unevacuated area, or
  - monitoring is not taking place due to unforeseen circumstances, such as weather, or
  - monitoring results indicate H2S concentrations of 1 ppm (1-hour average) or greater at the boundary of any urban centre.

The EUB defines a partially controlled flow as a restricted flow at surface that cannot be shut off at the operator’s discretion with equipment on site.

Operators are reminded of the mandatory requirement for dual-well ignition systems at critical sour wells, as set out in IL 88-17: Ignition Equipment for Drilling Critical Sour Wells.

Authority to ignite a sour gas release must reside on the well site with a fully qualified person whose authority and responsibility does not require consultation with any other person. Operators must ensure that source ignition can be maintained throughout the duration of an uncontrolled sour gas flow.

Operators are reminded that the requirement to ignite a sour gas release applies to all releases where the public cannot be protected through evacuation or other measures, as set out in EUB IL 89-15: Evacuation and Ignition for Sour Wells.

3.5 Monitoring

As detailed in Section 3.4(4) of EUB ID 97-6: Sour Well Licensing and Drilling Requirements, for all critical sour wells where the EPZ includes all or a portion of an urban centre, the EUB requires continuous mobile monitoring equipment to be on lease during the drilling, servicing, or completion of the potential sour zones. The EUB will review the need for continuous mobile monitoring equipment to be on site for other sour wells on a site-specific basis. The mobile monitoring equipment must be deployed from the lease immediately in the event of a well control problem to determine H2S concentrations at locations where there are people and at any urban boundary within a reduced EPZ. When a well has been ignited, air quality monitoring equipment must be deployed to locations where there are people to determine SO2 and residual H2S concentrations.

3.6 Evacuation

When a reduced EPZ is in effect, at the first indication of an escalating well control problem (a level-1 emergency), notification must commence immediately and voluntary evacuation of people may begin within the reduced EPZ. Full mandatory evacuation of the reduced EPZ must occur at a level-2 emergency.

If there is a situation that requires immediate ignition, as outlined above, the following evacuation procedures must be implemented in addition to those above:

• notification to all individuals beyond the reduced EPZ to a distance twice (2 x) the reduced EPZ or the distance to the calculated H2S EPZ, whichever is less, so that action may be taken voluntarily, such as leaving the area until the release is controlled to avoid any exposure to SO2;
• mandatory evacuation of all the public wherever necessary if monitored SO2 levels reach or exceed 5 ppm (15-minute average), 1 ppm (3-hour average), or 0.3 ppm (24-hour average). This includes areas that extend beyond twice (2 x) the reduced EPZ.

The ERP must detail methods that will be used for notification and evacuation.

The operator is reminded that it will also be responsible for compensation, as outlined in EUB IL 89-20: Compensation in Case of Well Blowout.

3.7 Coordination with Other Emergency Response Agencies

Finally, the EUB reminds all applicants and licensees that the use of a reduced EPZ does not eliminate the responsibility for the protection of public beyond the reduced EPZ or twice the reduced EPZ. The applicant or licensee is still responsible beyond the EPZ to whatever distance is necessary to ensure protection of the public. This responsibility beyond the EPZ is not automatically turned over to other emergency response agencies; it is a shared responsibility. The EUB requires the licensee, during plan development, to coordinate its ERP with any affected agency that would need to respond during a sour gas release. The ERP must include a concise description of the roles and responsibilities that each agency and any other key response organization has agreed to undertake in cooperation with the licensee.

Any questions concerning these matters should be directed to the EUB Operations Group at (403) 297-2625 or (403) 297-8288. 

<original signed by>

Neil McCrank
Chairman

Attachments
 
 
APPENDIX A—ILs, IDs, and Guides Respecting Emergency Preparedness

IL 87-8: Emergency Response Plans for Sour Gas Facilities
IL 88-17: Ignition Equipment for Drilling Critical Sour Wells
IL 89-15: Evacuation and Ignition for Sour Wells
IL 90-17: Emergency Procedure Plans for Sour Gas Facilities – Biennial Meetings
IL 96-11: Government of Alberta Emergency Response Support Plan for an Upstream Petroleum Industry Incident
ID 90-1: Completion and Servicing of Sour Wells
ID 91-2: Corporate-Level Emergency Response Plans
ID 94-3: Underbalanced Drilling
ID 97-6: Sour Well Licensing and Drilling Requirements
CPA-IPAC Guidelines for the Preparation of Public Safety Emergency Response Plans for Sour Gas Drilling, Completion and Servicing
CPA Guidelines for Preparation of Sour Gas Emergency Response Plans for Sour Oil Facilities

View PDF file for full text including all attachments