The City of Evanston says a century-old tunnel under the North Shore Channel may be a source of methane gas found around James Park.
The tunnel was part of the distribution system for the Skokie Manufacturered Gas Plant, which operated on the southwest corner of McCormick Boulevard and Oakton Street until the 1950s, and the tunnel provided part of the distribution system from the gas plant.
In its response to a federal court request from Nicor Gas for a declaratory judgment that it’s not responsible for the gas found around the park, the city this week countersued Nicor and Commonwealth Edison, which at different times owned the Skokie gas plant site.
In its court filing, the city says that methane at an average concentration of 85.25 percent and a pressure of about 12 pounds per square inch has been found “immediately in front of” Dawes Elementary School at the edge of the park.
A 1950 photo of the Skokie gas plant from SkokieSite.com
Methane is potentially explosive at concentrations as low at 5 percent. However, the city says its ongoing tests have not found any instances of methane at explosive levels inside the school or any of the other buildings around the park.
The city also claims that the utilities are responsible for contamination of the soil and groundwater in the James Park area with Lowe Process waste oil — a substance used in the production of gas at the plant and stored in large above-ground tanks on the gas plant property.
The city alleges that the tunnel and a gas pipeline running down Oakton Street that replaced it leaked, releasing methane and the waste oil into the ground. And it further claims that the waste oil eventually degrades into methane.
A large gas distribution system pipeline also runs down Dodge Avenue past the park, and city says that it has found “a black crust coating” on a nearby water line that is consistent in its chemical make-up wth the compounds known to be present in the waste oil.
The Skokie gas plant site, now owned by the Metropolitan Water Reclamation District, has been undergoing an extensive environmental cleanup project for more than two years.