OREANDA-NEWS. November 06, 2013. Apache Canada continues to make progress on cleanup and remediation efforts following a produced water release in the area of its Zama operations that was discovered on June 1, 2013.

The containment of the spill site has been maintained and Apache Canada is now moving into a soil remediation phase after an extensive surface water collection and treatment program that commenced in early June.

Apache has been working closely with the Alberta Energy Regulator (AER) throughout its investigation and has submitted an incident report, which will be taken into account by the AER as it compiles its findings.

As a result of Apache's extensive internal investigation in conjunction with third-party experts, the volume of produced water that was released from the pipeline has been revised to approximately 15,400 cubic metres from the original estimate of 9,500 cubic metres. The revised volume has also been submitted to the AER.

The 42-hectare area affected by the release has not increased since the discovery of the incident on June 1, 2013.

The calculation process at the time of the incident was to use the volumes recorded in the production database as the basis for the calculation. These numbers were subsequently reviewed in great detail and Apache has concluded that some of the volumes were incorrectly allocated to another injection well on the pipeline's multi-injection system. A new meter is being installed and new internal procedures and safeguards have been initiated to help prevent future underestimations.

Apache's internal investigation has concluded that the failure of the less than five-year-old pipeline was caused by stress corrosion cracking. Flexsteel pipe is made with an interior plastic liner, which is protected by four layers of steel bands, with an exterior plastic liner. Sulphur gas from the produced water permeated the inner plastic liner and attached to the steel bands. Apache believes a pinhole in the exterior plastic liner allowed water to leak into the pipe, which mixed with the sulphur gas, causing stress corrosion cracking and the sudden failure of the pipe.

We have determined that the failure occurred on May 5, 2013.

To ensure remediation efforts are as comprehensive as possible, more than 110,000 cubic metres of water from the area has been successfully treated and released back to the environment. In addition, 80,000 m3 of affected water originating close to the release site has been safely put downhole into the water injection well, returning the produced water underground to the formation where it originated.

Our environmental contractors continue to conduct soil assessment and sampling at the spill site for hydrocarbon and salinity parameters. Cleanup and remediation efforts are now primarily focused on removing and disposing of affected soil from the spill area prior to winter freeze-up. Affected soil that is removed will be disposed of at a licensed waste facility. Clean soils remaining on the site will meet Alberta Environment soil criteria.

Wildlife, waterfowl, aquatic and plant specialists continue to assess and monitor the area. Specialists are also conducting frog and tadpole catch-and-release programs as part of this effort. To further protect wildlife, fencing and other deterrents have been installed around the site and continue to be monitored. Additional wildlife deterrents have been installed in preparation for the fall migration of waterfowl. Game-monitoring cameras have also been installed at various locations, with recorded footage being reviewed regularly for wildlife activity.