Yet another sinkhole repair on Route 422 in Palmyra.
Users of Route 422 who want to travel through Palmyra on the way to points east and west should get ready for a four to five week detour around the borough starting on Tuesday, July 9.
A slight depression in the sinkhole-prone section of highway surfaced in late May, and was temporarily patched by PennDOT. Now, a more durable repair requiring the installation of a 130 foot long by 38 foot wide concrete slab is about to get underway near the Sinkhole Saloon, according to PennDOT spokespersons Fritzi Schreffler and Tony Travis.
The through traffic detour will use use Route 934 in Annville at the east end and the combination of Lingle Avenue and Palmyra Roads at the west end. They will route through traffic south onto Route 322, completely bypassing Palmyra.
It seems that even the detour has been detoured by newer sinkholes.
Original plans called for using Route 117, also known as South Forge Road, at the western end. But a sinkhole on South Forge appeared on Thursday, June 20, forcing PennDOT to push the west end even further west to Lingle Avenue at Route 422.
Later on June 20, there were reports of a sinkhole opening on Lingle Avenue, but LebTown was unable to confirm them at publication time, and will update this story if there are further developments.
Local traffic will be unaffected
PennDOT wants the public to know that the detour will only re-route through traffic away from Route 422, and that it has taken steps to minimize disruption to businesses and local traffic.
For all intents and purposes, it will be like a bridge being out. “Signs at each end of the detour will clearly show that Route 422 remains open to Palmyra businesses and residential areas up to both sides of the repair,” said Travis.
PennDOT’s detour will not use or directly impact any residential street or any local road other than Route 422, Travis added. “Any other detours within the borough or North Londonderry Township will be determined by local officials, not PennDOT.”
Sinkhole repairs in past years have led to inventive drivers creating “unofficial” detours through residential areas such as Maple Street, risking damage to borough and township streets and upsetting residents. GPS and real time traffic navigation apps like Waze can aggravate the problem by suggesting possible unofficial detour routes.
PennDOT is strongly urging motorists not to do this. “We hope to avoid overuse of Maple Street this time,” said Schreffler, “and we will work with the borough and the township to accomplish that.”
North Londonderry Township Police Chief Kevin Snyder said he is aware of the upcoming sinkhole closure and the problems on Maple Street the last time Route 422 was closed. He is resigned to some of the same this time.
“We hope they don’t, but unless they violate a weight restriction, which we will be enforcing, disobey a traffic control, or break some other law, we can’t stop motorists from using Maple Street.”
Chief Snyder said that PennDOT paid the township for increased use of township resources the last time there was a prolonged Route 422 closing. He was waiting to learn whether the same would happen this time.
Why do we have sinkholes? Water dissolves limestone
The upcoming sinkhole repairs are the latest in a seemingly endless series of costly disruptions of commerce and transportation that have plagued Palmyra for at least seventy years.
Almost one third of the total acreage of Lebanon County sits atop limestone and dolomite carbonate rock formations. These minerals dissolve in water, unlike more water resistant minerals such as quartz. Underground water, over thousands of years, eats away at limestone and dolomite.
As a result, empty spaces form under the surface. If they are big enough, close to the surface, and if enough water flows into them, the surface can sag or completely collapse and eventually become an open sinkhole.
Heavy rainfall raises the underground water table and increases surface water flow, which can accelerate the process.
So can human activity. Broken drains and water mains, sewer pipes, and changes to surface water runoff can make the problem worse.
No permanent solution. Water always wins.
People close to the situation wonder if a solution is any nearer today than on June 7, 1949, when the Lebanon Daily News reported that “[o]n the recommendation of the highway committee . . . [Palmyra Borough] council ordered a dangerous sinkhole at South Prince and Main Streets be filled.”
Reports of sinkholes threatening highways and swallowing large objects throughout the county, and especially in the western part, go back almost 100 years, maybe longer.
On March 22, 1920, a Daily News story headlined “Sinkholes on the Horseshoe Pike” declared “Several terrible sink holes have been reported on the Horseshoe Pike,” and reported that “. . . while the highway is not yet effected by the sinkholes, there is no telling when the surface may cave in . . . “
Unfortunately, other than moving Palmyra or Route 422, Schreffler said there is no permanent solution to sinkholes, just an assortment of temporary fixes, some better than others. And, there is no guarantee that water flow patterns wouldn’t change and undermine a re-located roadway.
According to Travis, some recent fixes like installation of underground bridge decking in 2014 have held up, but a 2017 repair using a fabric mesh sagged in May, making the upcoming repairs necessary.
They aren’t likely to be the last.