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The Bubble

South Middleton Township is working to make improvements at the park where the Bubble is located in Boiling Springs.

The agreed-upon theory among the villagers of Boiling Springs was that water from the local side of South Mountain fed into the Bubble near Children’s Lake.

“People for years told me the water comes off of the South Mountain chain,” South Middleton Township Supervisor Tom Faley said.

He was, therefore, stunned when other news reached his ears. A recent study from Franklin & Marshall College in Lancaster County indicated that this wasn’t the whole story.

This is something hydrogeologists had suspected for decades but had been unable to prove, according to recent F&M graduate and researcher Jake Longenecker.

While some of the water at the Bubble located behind the Boiling Springs Tavern could be traced to this area of South Mountain, most of the water didn’t share the same characteristics, he said. Scientists believed for decades that there was another source of the water.

That was where scientists in the past left it.

Longenecker himself may have very well ended up joining those ranks.

In 2015, he was an undergraduate who was already doing graduate-level work in his chosen career path. He worked with mapping and did a project at Indian Echo Caverns. Another student was leaving behind the project to find the Bubble’s water source, and Longenecker received approval from geoscience adjunct professor Tim Bechtel to take on the task that others couldn’t solve.

It was clear that the usual methods of locating the water source wouldn’t be useful. Longenecker understood why so many had abandoned the search.

“That’s where I would have left it,” he said.

What scientists didn’t have then that Longenecker did, however, was access to a NASA satellite.

“NASA had just launched a satellite to make data available to the public,” he said.

Where precipitation data could be patchy and sparsely available through local channels, the NASA satellite could collect the data for all areas in a uniform fashion. The satellite could tell Longenecker where and when it was raining, which could help determine the source of the water when comparing it to fluctuations in the Bubble’s water levels.

Understanding the potentially ground-breaking data, however, was another matter.

Longenecker, with the help of an F&M alumnus, had to create something to make sense of the raw data they collected. Longenecker created the algorithm to find water sources, and his friend coded it to use the data.

The result was so astounding that he thought their ECHO computer program must be incorrect.


While about 20 percent of the Bubble’s water in fact comes from the local part of South Mountain, the source of the other 80 percent was narrowed down to the area of Pigeon Hills in York County near the Maryland border — on the other side of the mountain chain.

But it wasn’t just that the source was more than 50 miles away than previously thought. The way the water moved through multiple rock formations and got to this area — where it was thought a type of volcanic rock made it impenetrable to outside water sources — was what concerned Longenecker. What geologists believed for years to be true of the area’s geology didn’t seem to support ECHO’s results.

“The geology didn’t seem to allow for the water to be coming out of there,” he said.

Using ECHO with data for other sites with established water sources — Big Spring in Missouri, Areuse in Switzerland and Sägebach in Austria — it became apparent that the program was functioning fine.

And that means what was thought to be the geology of South Mountain is in question. Longenecker said that, generally, there are a lot of questions now.

“It raised more questions than it provided answers,” he said with a laugh.

That’s not to say he and his professors — Bechtel and geoscience associate professor Robert Walter — don’t already see the usefulness of the program he created. Sourcing a water supply correctly could help with isolating contaminant pathways and pollutant source-identification. The data could also help governments know where not to approve a pig farm based on proximity to an important water source.

Better knowing the source of water could also help establish more accurate flood warning systems for residents.

Though the data hasn’t yet been used in such a manner, the study that was published in May has garnered worldwide attention. Longenecker, who finished his undergraduate degree this year, will speak at World Water Week in Sweden at the end of the month.

Even with this breakthrough, there is more work to be done. Longenecker is talking with those at Shippensburg University who are interested in continuing research on the Bubble, which may involve using dye to track the water flow. Longenecker said the dye they use is often colorless and not harmful, but detectable with their equipment.

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