The fourth stage of the Lehigh River and Pohopoco Creek Bridge Replacement Project by the Pa. Turnpike Commission is well under way.

This is the last phase of the project, and the most obvious aspect of it is the demolition of the old turnpike bridges, which were replaced by four new bridges two over the Lehigh River and two over the Pohocopo Creek that opened last year.

The project cost was $102 million.

Individuals traveling on Route 248 in Parryville, which runs beneath the new bridges, notice a lot of activity during both the day and night. Workers are on the scene around the clock tearing down the old bridges.

Presently the Lehigh River Bridge is being disassembled.

The bridge is being town down piece-by-piece, which is unlike typical bridge demolition, where dynamite just brings a span down. The dynamite method of demolition isn't practical with the old turnpike bridges because of busy Route 248 beneath the span, and because of stringent state and federal regulations pertaining to the Lehigh River, Lehigh Canal, and Pohopoco Creek, all which flow beneath the bridges.

The complete construction activities which comprise Stage 4 of the project includes:

Ÿ Constructing hiking trails.

Ÿ Constructing a wetland mitigation site.

Ÿ Constructing causeways for bridge demolition.

Ÿ Demolishing existing Pohopoco and Lehigh bridges.

Ÿ Remove temporary pavement and grade for future widening.

The final phase is expected to be completed by November, although the bridge demolition could be finished by summer.

The first stage of the project began in January 2009 and included construction of the foundations for the new bridges, installing temporary rock causeways in the Pohopoco Creek and Lehigh River, and temporarily widening the northbound turnpike at both the south end and north end of the work zone.

In the fall of 2009, the second phase began which included the continued foundation and substructure construction of the new bridges and constructing a retaining wall adjacent to the southbound turnpike at the north end of the project.

The third phase was the completion of the superstructures.

The general contractor is Walsh Construction.