Columbia Gas of Maryland Inc. has filed a request with the state’s Public Service Commission (PSC) to approve an annual revenue increase of about $6.5 million to replace and upgrade underground natural gas distribution pipelines.

The NiSource Inc. subsidiary, which services western Maryland, has invested more than $170 million in the state for infrastructure replacement and development over the last decade. From 2007-2019, $120 million was invested to replace more than 90 miles of its 658 mile-long system.

Columbia Gas of Maryland’s 30,000 residential customers using, on average, 70 therms of gas/month would see their monthly bill rise 15.17%, to $89.43 from $77.65 .

As for the 3,500 commercial customers that purchase on average 250 therms of gas/month, bills would rise 11.26%, to $285.09 from $256.23. The monthly bill of the 10 small industrial customers that purchases on average 3,980 therms/month would see a rate increase of 4.65%, or to $2,652.35 from $2,534.42.

If the current request is approved by the PSC, more than 33,000 Maryland customers would not see rate adjustments until December. Columbia Gas last filed for a rate adjustment in May 2019, and were implemented on December 18, 2019.