State Highway Administration crews discovered Frederick's third sinkhole in six months on Thursday morning.
Crews monitored the 7-foot-wide, 12-foot-long and 10-foot-deep hole on the shoulder of I-70 throughout the day, which caused the right eastbound lane to be closed, according to SHA spokesman Charlie Gischlar.
Crews closed the sinkhole at about 5:30 p.m. Thursday. Only traffic on eastbound I-70 was affected during the lane closure, Gischlar said. SHA kept one lane open during the repair.
Since the beginning of the year, three sinkholes have been reported, according to the highway administration: one next to Monocacy Boulevard and one on Md. 550 (Sabillasville Road) near Woodsboro, both in April; and Thursday's hole.
Much of the county, as well as western Carroll and eastern Washington counties, has large geological deposits of limestone, or karst, Gischlar wrote in an email.
Sinkholes are caused by changes in the underground water table, which create voids or pockets in the soil. Occasionally, the soil above those voids collapses, and sinkholes form.
SHA does not yet have a cost estimate for the repair work.
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