An important part of the Phase I Environmental Site Assessment (ESA) is researching a property's history, particularly how a building was previously heated. This is primarily due to heating oil, which is stored in tanks that can be above or below ground. These tanks typically range in size from 275 to 550 gallons but can be 10,000 gallons or more in large commercial settings. When these tanks leak, they can significantly impact soil and groundwater and often require costly remediation if not properly addressed.
During a recent Phase I ESA in Philadelphia, we reviewed some late 1800s/early 1900s fire insurance maps (AKA Sanborn Maps). These maps showed a roughly 80-foot diameter “gasometer” near the property.
This certainly caught my attention. Normally, I’m on the hunt for gas tanks, petroleum product storage, and the like. So, something literally called GASometer sure made my alarm bells go off.
As it turns out, it was common in the 1800s, and they were used to store natural gas or coal gas, which was then distributed throughout the city for heat and light. Interestingly, the roof was not connected to the walls and would rise and fall with the changing volume.
The earliest reports of gas distribution date back to 500 B.C. China, where bamboo was used as “pipes” to transport natural gas to homes. But it wasn’t until the early 1800s that large-scale distribution was developed. Scottish inventor William Murdoch successfully illuminated his home by piping coal gas over 70 feet through copper lines. Not long after, in 1807, German inventor Frederick Winsor used old musket barrels as pipes to supply a continuous flow of gas to streetlamps, and London’s Pall Mall became the world’s first gas‑lit street. This marked the beginning of public gas infrastructure as we know it today.
With what we learned, the GASometer was not going to be an issue for our property. The above ground structure, used as a holding space, meant that nothing was likely burned at the location. So our Phase I ESA study is complete.
Thankfully, heating technology has come a long way since coal gas, bamboo pipes, and 80‑foot GASometers in your neighborhood. With winter in full swing and temperatures dropping, it’s a good reminder to appreciate reliable heat. Stay warm, everyone, and be thankful for the comfort we have today!
