As PennDOT hurries to rebuild Fern Hollow Bridge, environmentalists worry about waterways below
Pennsylvania and Pittsburgh officials are acting quickly to replace the collapsed Fern Hollow Bridge. While that has some concerned about a rushed idea for the bridge’s aesthetic, others are sounding the alarm about what an accelerated project could mean for Fern Hollow and Frick Park below.
“With the Fern Hollow Bridge seeing more than 14,000 cars daily, we knew it was critical to act quickly to reconstruct,” Gov. Tom Wolf said last week. “This reconstruction will allow commerce to continue without further interruptions to the lives of community members.”
Physical construction work could begin in late April. Design planning, substructure construction and utility work are already underway.
Mike Hiller, executive director of Upstream Pittsburgh, agrees that restoring this traffic artery is important. But he worries bridge wreckage and construction debris in Fern Hollow Creek could mean changing water conditions for Nine Mile Run, which could harm habitats for the birds, fish, beavers and other critters that live there. It would also change the experience for Frick Park visitors.
“For us, it’s just really making sure that the preservation and the restoration of the park underneath the bridge is valued,” he said. “Are we going to be able to consider that… if we’re going to construction next month?”
Upstream Pittsburgh, previously known as the Nine Mile Run Watershed Association, is a group dedicated to protecting Nine Mile Run, a stream that flows through Pittsburgh into the Monongahela River. Fern Hollow Creek, which flows through the ravine under the bridge, is a tributary of Nine Mile Run.
The effort to restore Nine Mile Run took years of work to reroute, plant appropriate flora and build animal habitats. Before the restoration, the stream had been known by locals as “Stink Creek” in the early 2000s. Hiller doesn’t want to see that hard work be affected by construction practices that don’t prioritize the environment.
But there are agencies with authority keeping an eye on these concerns. The Allegheny County Conservation District and Pennsylvania’s Department of Environmental Protection are working with PennDOT to monitor erosion and sediment in the area.
Pennsylvania DEP spokesperson Lauren Fraley said the permit for the construction project has not yet been granted, but when it is, it will be after careful consideration.
“Thoroughness is not diminished when DEP prioritizes or expedites review of an application,” Fraley said. “While DEP plans to expedite its review of the permit application, the application must meet DEP’s regulatory requirements.”
The agency will work with the Allegheny County Conservation District to monitor soil erosion and sedimentation near the construction site, according to PennDOT. Heather Manzo, executive director of the ACCD, said the group has already done inspections in the area and will continue to monitor the ecosystem closely.
“Any sediment loading that happens here will have impact on water quality, quantity and species habitat all the way down into the Gulf of Mexico,” Manzo said. Sediment in Fern Hollow Creek could travel through Nine Mile Run, the Monongahela River, the Ohio River, the Mississippi River into the Gulf.
Maureen Copeland, a senior resource conservationist with ACCD, inspects the site frequently, sometimes more than once a week, to keep track of how sediment moves through the stream.
She said crews have been using limestone, silt socks — which look like long fabric tubes — and straw mulch to trap sediment before it washes into the stream. Crews could plant grass to trap sediment when the weather gets warmer, Copeland said.
Crews have also been using a crane to move materials in and out of the site, which is better than dragging them through the soil, which could lead to compaction, erosion and runoff, Manzano said.
ACCD and the DEP say they’re sharply focused on soil erosion because of the impact it could have downstream.
Due to lack of funding, ACCD isn’t currently able to monitor the water quality up and downstream from Fern Hollow Creek, according to Manzo.
But Hiller said Upstream has noticed a dramatic increase in debris and sediment in their monthly stream testing of Fern Hollow Creek. The group has been testing up and downstream from the collapse site and will continue to monitor how that affects the creek, wetlands and Nine Mile Run.
Pennsylvania’s DEP said it has not yet received notice of any cloudy water.
“While DEP has not observed impacts to aquatic life, visual monitoring for turbidity and siltation up and downstream of the site is a typical component of site inspections,” she said.
In addition to waterway protection, Upstream hopes there is still time to include replanting trees in the design. Some mature trees have already been cut down to make way for construction crews.
The plant life has been “growing in and developing and maturing for about 15 years,” Hiller said. “For us, we’re just hyper-focused on making sure that this place that we’re charged with stewarding maintains its character.”
Design renderings posted online by PennDOT last week do not show trees beneath the bridge.
“That wasn’t the case before the bridge fell,” Hiller said. “We’re trying to elevate that concern and just make sure that it’s being considered in all phases of the plan, design and build of this project.”
Hiller argued that trees should be planted under the bridge and officials should use this moment as an opportunity to restore Fern Hollow to be better than it was before the bridge collapsed.
“There are things that we could do to really enhance that area of Frick Park,” Hiller said. “If you end up depleting the character of this area it will no longer serve the same purpose."
Upstream Pittsburgh has formed a collective with Pittsburghers for Public Transit and BikePGH to develop a list of design recommendations for city and state leaders.
Manzo agreed that the project could bring improvements to the area beneath the bridge, but said conservation work in the area doesn’t need to start or stop with construction on this particular project.
“One of my hopes for this is that we walk away with a park at least as healthy if not healthier than it was before this bridge collapsed,” she said. “So much life lives in this park.”
Manzo believes there will be future opportunities through partnerships with private and public resources to build upon the restoration that happens with the bridge construction.