PG&E will begin hydrostatic testing of a portion of their natural gas lines in San Carlos today, according to San Carlos officials.

The first step in the testing will be venting gas near the intersection of Interstate Highway 280 and Edgewood Road today and on Thursday. Residents may hear the venting or smell natural gas, city officials said.

Affected residents were notified by letter and by telephone by PG&E, city officials said.

“The natural gas will quickly dissipate into the atmosphere and will not be harmful,” PG&E said in its letter to local residents and businesses.

Service to PG&E customers will not be interrupted during this work, the letter also said.