Officials hoped to open Interstate 99 on December 2, but a delay in the installation of highway signs pushed that date back to a time between December 12 and 19. When it opens, northbound drivers will be able to seamlessly travel from Bald Eagle to State College Skytop / Port Matilda along new freeway. Southbound drivers however must wait until mid-2008 to fully use the freeway, as crews continue to remove acid rock from the Skytop area north of Port Matilda.

The acid rock removal affects the Interstate 99 interchange with U.S. 322 at Port Matilda, where Interstate 99 north merges with U.S. 322 east. All northbound traffic will be squeezed to one through lane via a temporary configuration until the completion of the acid rock removal process. Interstate 99 south will begin at the High Street diamond interchange west of Port Matilda.

U.S. 220 south & 322 (Eagle Valley Road) west at the Interstate 99 bridge over Bald Eagle Creek and Eagle Valley Road northeast of Port Matilda during construction. Interstate 99 bypasses Port Matilda to the north before crossing over U.S. 220 & 322 onto Eagle Mountain to the east. Photo taken 04/30/05.

Opening of the highway project, despite the acid rock removal, was advocated by State Rep. Rick Geist (R-Altoona) in effort to improve access to State College, its economic development, and safety along the previous two-lane U.S. 220 corridor.

A diamond interchange lies west of Port Matilda, joining Interstate 99 with High Street (U.S. 322). Just north of there is the Laurel Run bridge and merge with the U.S. 322 eastbound freeway. The acid rock removal site lies along the freeway between the U.S. 322 interchange and the Eagle Valley Road under crossing. Photo taken 04/30/05.

The acid rock resulted from an unearthing of sandstone laced with pyrite in 2003. Large amounts of the pyrite-laced sandstone were found at the project site near Port Matilda (Skytop), which when exposed to air and water created sulfuric acid. A now $79-million project began to remove the acid rock from the construction area, causing delays in overall completion and escalation of construction costs.

Interstate 99 turns southward from west of Port Matilda back onto Eagle Mountain. Pictured here are bridge supports for the Interstate 99 span over U.S. 220 (Eagle Valley Road), Bald Eagle Creek, and the Nittany & Bald Eagle Railroad. Photo taken 04/30/05.

More information on Interstate 99 is available at Interstate-Guide.

Sources:

“Interstate 99 opening delayed.” The Altoona Mirror, December 1, 2007.

“Cost of Interstate 99 acid cleanup rises to $50.5 million.) Wilkes Barre Times-Leader, December 5, 2007.