GROTON — Continuing dry weather conditions are keeping the town on extreme alert even as a second ground fire breaks out.

The blaze struck the same area as another fire that burned as much as 40 acres of remote woodland before hundreds of firefighters from surrounding communities managed to get it under control.

“The first fire was off Indian Hill Road and was about 8 acres in area when we reached it,” said fire Chief Joseph Bosselait. “By the time we got it under control, it had grown to cover almost 40 acres. Although we’ve managed to put it out on the surface, it’s still burning underground.”

According to Bosselait, his department thought they had the first fire in a nearly inaccessible forest about a mile off Indian Hill Road under control early last week when a report came in a couple of days later that it had flared up again.

The Fire Department first responded to reports of a fire on the morning of July 5 and after determining the extent of the problem, called in crews who were on the job by dark. The blaze grew to cover 15 acres during the day but within 24 hours the chief had predicted that it would be under control by the end of that day.

The magnitude of the fire was such that men and equipment were rushed from surrounding towns including a pair of brush fire task forces from the North Shore. The blaze also caught the attention of the State Fire Marshall’s Office, which supplied vehicles and communications as well as a state police helicopter needed for aerial surveillance.

Steep and rocky terrain far from any roadway made combating the fire difficult necessitating the use of ATVs and physically hauling water from Long Pond to the site of the blaze.

But no sooner had the first fire been contained than a second was spotted close by on July 8. Located between Robin Hill and Sandy Pond Road, Bosselait said it was easier to deal with than the first due to its being close to a subdivision construction site where roadways had already been laid out. So in addition to response time being cut down from 3 to 1 hour, the presence of hydrants installed in the development made water immediately available helping to keep the fire from spreading beyond 15 acres.

Bosselait said that although both fires are still under investigation, the remnants of a camp site were found in the vicinity of the second with evidence that flames “jumped outside the fire pit and took off from there.”

But the abnormally dry conditions in town have prevented firefighters from completely extinguishing the flames at either site. Though fires had been put out above ground, they continued to eat away at buried root systems and peat moss deposits resulting in sudden breakouts above the surface. Which was exactly what happened on July 8, the same day the second burn was discovered at Robin Hill, when a National Grid helicopter spotted smoke and flames and called them in.

“The same day as the Robin Hill fire, the first fire we fought kicked back up again,” said Bosselait. ” A helicopter flying overhead checking power lines spotted a hot spot from the first fire so we sent the forestry guys over there and they confirmed that flames covered a 3-5 acre area with a headwall flame that must have come up overnight.

“Basically,” he said, “we brought in three bulldozers and cut fire lines around the blaze to stop it and then to contain it. Since then, we’ve been going up every day looking for hotspots on the perimeter. That first fire continues to burn root systems 6-8 inches down.

“These combined fires have been the biggest, most resourced fires I’ve ever had to deal with,” said Bosselait. “This is like something that they have out in the Midwest that burns for months.

“For now, all we’re trying to do is to contain them so that no structures are involved,” said the chief. “After that, we’ll let mother nature try to put them out. We intend to keep watch every day to make sure all the hot spots are out.

“What we really need is a long, soaking rain that will penetrate down and put those hot spots out. Until that happens, all we can do is to maintain a perimeter around the fires and hope that mother nature puts them out for us. That’s the driving factor right now.”

As of early this week, the fires in Groton were under control.