Manufactured Gas

May 2010

On any given evening a flick of a switch fills my room with light. Electricity and the evening light it provides are so ingrained in our culture that it is easy to take for granted. Even before we had electricity we had evening lighting, and we are still paying the consequences of the technology that brought that light to preceding generations. 

Electricity began to replace its predecessor, manufactured gas, in the early 1900s. Manufactured gas was first made in the 1790s in England. It was produced by heating combustible materials, usually coal, but sometimes wood or oil, in enclosed ovens. In the absence of oxygen to ignite the materials, gases were volatilized and then recaptured for use as fuel. The gases were much easier to transport and produced less soot upon burning than did the original fuel sources. 

At first, manufactured gas was used principally for street lighting. Over time production increased, the cost of the fuel decreased, and people began using it in their homes for cooking and lighting. Towns throughout the country had manufactured gas plants to provide the fuel to the growing market. Manufactured gas offered a lucrative business for approximately 100 years. Eventually rural electrification, which began in earnest in the 1930s, and the increasing availability of natural gas made manufactured gas obsolete. Manufactured gas use lingered on until the last gas plant ceased operation in 1972. However, the legacy of gas manufacturing is still with us.

Waste management during the heyday of manufactured gas plants was not sophisticated, and by-products of gas production were quite nasty. The worst of the lot were the thick oily tars that would condense from the gasified coal at various stages. The tars would not mix with or dissolve in water. Densities of the tars differed so that some floated while others sank. They contained a mix of toxic chemicals including benzene, toluene, ethyl-benzene, xylenes, and various polycyclic aromatic hydrocarbons (PAHs). Frequently the coal tars were simply buried in a pit on site. From there they sometimes reached groundwater or surface water.  

According to the New York State DEC, there were roughly 300 manufactured gas sites in the state. For two-thirds of these, remediation has begun or is scheduled. The use of manufactured gas in Vermont was less extensive. However, the plant at Burlington’s Pine Street Canal site was the last in the United States to supply straight manufactured gas (up until 1966) and was one of the first to be scheduled for remediation under the national Superfund program. The Lake Champlain Committee was heavily involved in the Barge Canal clean up effort drafting the citizen involvement process (which has served as a national model for public engagement) and helping create the remediation plan. Work is still ongoing there to ensure that contaminants don’t migrate to Lake Champlain.  

Currently, major remediation efforts are planned for the Saranac St. manufactured gas plant in Plattsburgh. The New York State Electric and Gas Company (NYSEG) is responsible for the clean-up. They have already excavated and incinerated the coal tars on land at the old site, but over time much of the material has escaped to the Saranac River and migrated downstream to Lake Champlain.  

This summer they will begin what is an anticipated three-year effort to remove the coal tars from the bed of the Saranac River, excavating to a depth of up to six feet. This will require confining the river to half its normal width while heavy equipment removes the tars and sediments from the other half of the river. The coal tars are actually under the river bottom so the clean sediment on top needs to be removed before the pollutants can be reached. NYSEG anticipates removing about 40,000 tons of sediments from the river bed; of that, 15,000 tons will be transported off-site and incinerated.  

Each generation creates a mess for which subsequent generations must pay. NYSEG has taken responsibility for the manufactured gas plants they now own, but certainly the cost of clean-up will be reflected in customers’ bills, even though few of today’s employees or customers benefitted from the use of the facility. As infuriating as this may be our own generation is not blameless. Our present economy depends on oil and gasoline for moving freight and people; much of the country generates their electricity from coal combustion. Our economy continues to depend upon pumping carbon dioxide into the atmosphere as if there were no consequences of our activities, despite increasing evidence of resultant climate change. Just as our predecessors did, we shamelessly pass on costs to the next generation. A glimpse at our history of contamination should provide motivation for proactively addressing today’s environmental problems.

Lake Look is a monthly natural history column produced by the Lake Champlain Committee (LCC). Formed in 1963, LCC is the only bi-state organization solely dedicated to protecting Lake Champlain’s health and accessibility. LCC uses science-based advocacy, education, and collaborative action to protect and restore water quality, safeguard natural habitats, foster stewardship, and ensure recreational access.

Get involved by joining LCC using our website secure form (at, or mail your contribution (Lake Champlain Committee, 208 Flynn Avenue - BLDG 3 - STUDIO 3-F, Burlington, VT 05401), or contact us at (802) 658-1414, or lcc@ for more information.