Oak Glen 6-Month Update
In the early-morning hours of March 17, 2014, an oil spill was reported at Great Parks of Hamilton County’s Oak Glen Nature Preserve in Colerain Township. At a little past the six-month anniversary of the spill, take a tour of the impacted area.
- On March 17, 2014, Great Parks Rangers discovered that the Mid-Valley Pipeline carrying crude oil from Texas to Michigan had ruptured, releasing approximately 21,000 gallons of crude oil directly into Oak Glen Nature Preserve.
- Located in Colerain Township, Oak Glen’s 372 acres of undeveloped high-quality forest, meadow, riparian and wetland habitats serve as home for state-endangered and other species of wildlife.
- Oil from the cracked pipeline flowed down a roughly one-mile long stream and into a one-acre wetland, which can be seen in this aerial photo.
- A temporary dam is installed in the stream to prevent additional oil and contaminated soil from further contaminating the wetland.
- Great Parks Stewardship Manager Bob Mason checks for oil during a stream assessment in April. In the first weeks after the spill, a project team - consisting of Sunoco and its contractors, the US EPA and Great Parks - met twice a day to assess damage and cleanup.
- Oil is cleaned from rescued frogs. Oak Glen will not be considered “clean” until the Ohio EPA determines that biology and wildlife have returned to pre-spill conditions.
- More than 90 salamanders, including state-endangered cave salamanders, were collected from Oak Glen after the spill. The salamanders were given temporary homes at Boonshoft Discovery Museum in Dayton, Ohio, before the majority of them were released into another uncontaminated stream in Oak Glen in May.
- Oil trapped in sediment reveals itself after a rock is flipped during a now weekly inspection in August. During the current “remediation” phase, each rock is removed, cleaned and replaced in the stream bed.
- Oil continues to seep from the strata, or layers of rock, adjacent to the impacted stream. Backed up into the bedrock during the initial spill, the oil emerges when it is pushed out by rain water. The amount of oil trapped in strata is unknown, and could contaminate the stream for years.
- As part of the cleanup, huge quantities of water are flushed through the stream to move residual oil downstream, where it can be collected and removed at the temporary dam.
- The impact of streambank erosion from the flushing water can be clearly seen here, where tree roots are exposed in a stream that is now more than twice its original width. Streambanks are critical habitats for species and also serve to control the amount of water and sediment carried to the wetland below.
- Unfortunately, not all of the impact from cleanup is positive. When native vegetation is trampled by project crews, the space created allows invasive species, like stilt grass and honeysuckle, to quickly move in and take over.
- Seeds from native plants, like this spotted jewelweed, are collected from Oak Glen to use for future replanting in the impacted areas.
- At the six-month mark, a little more than one-third of the stream has been cleaned. Progress is expected to pick up with the entire stream moving from the “remediation” to “monitoring” phase before winter. Restoring the habitat to its previous condition, however, is expected to take years.
To learn more about the oil spill at Oak Glen Nature Preserve, visit greatparks.org.