Contaminated Stream Restoration – Swift Run Creek

Streamside was contracted by GAI Consultants, Inc. for the removal of bentonite that spilled into the creek during a drilling project near Elkton, Virginia. Bentonite is used as a lubricant in the drilling process and also helps to provide a seal around the pipeline. The depth of the creek varied from six to thirty inches. In the shallow areas, temporary sand bag dams were utilized along with the two-inch Sand Wand System. The three-inch Sand Wand was used in areas with a greater depth and when obstacles such as rocks were not present. The Sand Wand process consistently removed all of the bentonite and sand from the interstitial areas, while at the same time controlling the turbidity or re-suspension of the bentonite.

The details

The project began in early January in subfreezing conditions, starting at the uppermost section of the affected area, closest to the spot of initial contamination. This was evident by severe deposits of bentonite up to 16” in depth. The property owners limited the access to the stream, so all transport of equipment and piping to the site was through the creek bed. The project did not cause any bank disturbance, environmental footprint or evidence of the effort. The discharge consisted of bentonite and water slurry and was pumped some 700 feet using two booster pumps to a 7000-gallon tanker truck supplied by GAI. The trucks were typically filled in approximately 30 to 40 minutes, at that time the truck would leave the site to dispose of the bentonite in a local farm pond, which helped to seal any possible leaks. Two trucks running per crew was the ideal allowing each crew time to move their system to the next affected downstream reach and commence cleaning, with minimal downtime waiting on a truck.

In conclusion

Nearly five thousand feet of Swift Run Creek had been affected by the spill, and was successfully restored and completely free of any bentonite at the end of the project. The Sand Wand technology was effective at selectively removing the bentonite clay from surface deposits, and also selectively flushed and removed harmful subsurface clay deposits, leaving a cleanwashed native cobble and gravel substrate. The Virginia Department of Fish and Game gave the final OK on the cleanup, and our crews withdrew from the project site in mid-March.