People in the small eastern New Brunswick village of Dorchester are trying to understand how they were hit with a boil order four years after a $1.8-million upgrade to the water system.

Residents in the community were told on Monday that they would have to boil their water after a test sample found a higher than acceptable bacteria count in the latest water test.

Dorchester Mayor Melvin Goodland said he can remember standing next to federal and provincial politicians in 2005 on the day the water upgrades were finished and announcing that the days of boil orders in the village were over.

At the time, the village had just gone through a string of boil orders, some lasting up to a year.

Now Goodland said he was surprised to find out this week the village was subject to another boil order.

"I wonder because of the fact that we have a new plan, how this could happen," Goodland said.

"That's our main question that we're trying to answer is: how it can happen since we have a new system in place."

The village provides water to about 2,000 people, including the community, the Fort Folly First Nation, and two prisons.

The water system's upgrades that were announced in 2003 saw improvements to the village's water supply and distribution system, upgrading of the Woodlawn Road well, construction of a water treatment plant and the installation of an 800-metre water main.

Goodland said the suspect sample came from section of pipe that was not replaced during the recent upgrade.

"It wasn't at the plant; it had nothing to do with the wells," he said.

Goodland said the village has flushed the water pipes and now he's waiting for new test results.

Calls to the Department of Health to explain the test results were referred to back to the mayor.