Dear Suncor Energy stakeholder

A Community Update by Suncor related to the remediation work of Sand Creek and surrounding areas...

We wanted to provide you with a brief update on our progress and efforts related to Sand Creek. We believe it's important that we continue to communicate with all of you when we have significant milestones to report. Our outreach efforts continue to be critical in ensuring you are kept apprised of the facts relating to our work to protect Sand Creek, the South Platte River, and our surrounding environment. We value your questions and communication with us, so please let us know if you need additional information. Thanks, Lisha Burnett. 303-570-2540 lburnett@suncor.com

Sand Creek
Sand Creek remediation work continues. Our current efforts are focused on protecting the waterways by installing trench systems designed to contain contaminated material that could migrate underground off Suncor Energy property or into Sand Creek. Part of our efforts also includes mitigating the trace levels of benzene entering Sand Creek through the groundwater. We've completed the trench on neighboring Metro Wastewater Reclamation District property that will protect both Sand Creek and the nearby South Platte River. At approximately 1,000 feet long and 30 feet deep, this trenching system consists of a slurry wall (a trench backfilled with clay-like material) designed to block migrating material and a parallel collection trench to recover material. We've also completed more than 90% of a 2,100-foot trench and slurry wall on Suncor’s property.

In regards to water quality standards in Sand Creek and the South Platte River (which are different), we aim to meet any and all regulatory standards. We are sensitive to the fact there are downstream water users; although we understand there are no drinking water intakes directly in the South Platte River between Sand Creek and the fully mixed point downstream (where the river is now meeting drinking water standards on a regular basis).

We are continually testing the water quality at Sand Creek and in the South Platte River to monitor for contaminants and to better understand what is happening. Suncor remains concerned about any level of benzene entering Sand Creek. We are working closely with CDPHE and continue to monitor the water quality/water sample results in both the creek and the river.

To further reduce the amount of benzene reaching Sand Creek and the South Platte River, we had installed an air sparging system in Sand Creek some time ago. This system injects air into the water to vaporize trace levels of benzene. While initial results in terms of reducing contaminant levels were not what we were hoping to see, we continue to optimize this system by adding more sparging and a larger compressor, as well as changing locations so that we place the systems just before the water enters the South Platte. We've also been working closely with CDPHE on additional ideas to address the benzene levels in Sand Creek. More recently, we have installed a water spray system to assess the benefits of its use with respect to trace benzene reduction.

 It should be understood that the air sparging and air spray systems we're using in Sand Creek to address the benzene levels are not the final solution. In parallel, we are working on permanent systems to fully address the issue. This will include the removal of and/or the depletion of benzene underground through soil vapor extraction systems and air sparge systems. One new air sparge system has been started up. It is currently injecting air through the groundwater to treat dissolved hydrocarbons. This system is designed to reduce and eventually eliminate any benzene in the groundwater. It does this by stimulating the growth of natural bacteria that feed on hydrocarbon molecules.

 Our goal, overall, is to minimize the impact of our operations. We are confident we will achieve this with permanent solutions, including the collection trenches and soil vapor extraction systems and the air sparge systems. We continue to show improving results on the waterways with respect to trace levels of dissolved benzene and would expect that our permanent solutions will bring us into compliance. We've had great success delivering on very tough CDPHE orders with tight deadlines. Suncor is following directions from--and collaborating for a positive outcome--with regulators to achieve the best result for the environment. We are a responsible operator and will continue to manage the situation as best we can. We are seeing dramatic reduction in levels of material at the original interceptor trench at Sand Creek; we believe this indicates that the larger trenches on Metro property and Suncor property are working. From day one, our focus has been on protecting the environment and making sure the right response is being carried out.