Local officials in many parts of Connecticut are not waiting for the national data center boom to come to them.

Earlier this month, for example, the East Lyme Zoning Commission voted unanimously to adopt an indefinite ban on all data center development, one of the first such blanket prohibitions in Connecticut. The ban, which went into effect on Saturday, came before anyone had announced even the faintest plan to construct a data center in the coastal town.

“It seems like all over the country, they’re trying to figure out the effects of pollution, energy consumption, chemical runoffs,” Anne Thurlow, the chairwoman of East Lyme’s Zoning Commission, said during an August meeting.

“I think it’s a good thing to ban them until we know more about them,” Thurlow added.…