Leakage Into Tributary Abated

Restoration of an additional 2,200 feet of Harrisburg’s Spring Creek was completed in June 2005, utilizing natural channel design (Rosgen) methodology to improve stream flow and provide additional habitat for the stream’s wild brown trout population. This work was completed under a $150,000 Growing Greener Grant received from DEP in 2004. All told, approximately 3,000 feet of stream corridor has now been restored, beginning just below Paxton Street and extending down through the 5 Senses Garden to S.R. 441.

During the early stages of our restoration work, residents living approximately a mile upstream from the start of the project site reported smelling noxious fuel odors emanating from an unnamed tributary of Spring Creek. DEP’s Emergency Response team was called in to investigate, and after drilling a number of test borings determined that the source of the groundwater contamination was one or more leaking fuel storage tanks at the Mobil service station on 29th Street. DEP said tests confirmed that up to 9,000 gallons of unleaded fuel had found its way into the groundwater, but prompt action by their cleanup contractor resulted in recapturing more than 5,000 gallons of the leaking fuel. When the storage tanks were unearthed, it was determined that the bottom of one or more of the tanks had been penetrated by the metering stick used by the service station operator to measure fuel levels.

Subsequent stream testing by a DEP biologist showed a general lack of macroinvertebrate life in the tributary immediately below the fuel leakage site, but the overall prognosis was that quick response from their agency averted any serious long-term damage to aquatic life downstream in the main stem. It was further stated that natural reproduction combined with normal drift (repopulation from upstream) should repopulate this section within a relatively short time frame. During the following weeks when our restoration contractor was on site, no fish kills or oil slicks were observed in the project area downstream. DEP has also installed several monitoring wells in the area of the tributary to sample and extract any residual fuel from the groundwater.

The stream restoration work by Aquatic Resource Restoration Company included about a dozen cross vane and J-hook in-stream structures constructed of either massive rock or rock/log combinations. Some of the individual limestone rocks used in building these structures weighed as much as 4 or 5 tons. These structures serve the dual purpose of channeling the stream flow for improved sediment transport and better erosion control, as well as creating additional habitat for the aquatic life of the stream. Other work on the project included placement of additional rock and/or log fish habitat structures, and grading of high stream banks to disperse stream flows to the adjoining floodplain during high water events. Approximately 200 trees of several species were planted along the newly created riparian borders to retain soil, and ultimately provide increased shading of the stream corridor.

Only time will tell if our stream improvement efforts will pay off in terms of increasing a wild trout population which appears to be sustaining itself in spite of encroaching development and the extreme runoff conditions experienced during high water events. It was encouraging to see that trout had already moved into several of the new structures even before the construction project was completed, including a couple of stream sections where trout had not been previously observed. With nearly 3,000 feet of stream restoration completed, our sights are now set on an additional 2,000 feet of corridor to be restored below S.R. 441 during 2006 by Aquatic Resource Restoration Company. Funding for this additional work has already been approved under a $110, 000 Growing Greener Grant from DEP.

Anyone wishing to tour the project area should contact Bob Pennell at (717) 236-1360 for additional information.