Nashua battling sinkholes and other infrastructure problems

Telegraph photo by MATHEW PLAMONDON Contractors with Dracut, Massachusetts-based DeFelice Corp. on Tuesday work to update old infrastructure on Nashua’s Pearl Street, as they fill the hole they were working in with dirt and gravel.

NASHUA – The U.S. Department of the Interior defines sinkhole as “a depression in the ground that has no natural external surface drainage. Basically, this means that when it rains, all of the water stays inside the sinkhole and typically drains into the subsurface.”

In Nashua, Division of Public Works officials keep busy by fixing potholes, paving streets and roads, and repairing sidewalks. However, sinkholes continue to be a problem.

“The hole at High Street and Main Street had lot of other utilities in the area, so it took a little longer for us to work around,” DPW spokeswoman Lauren Byers said of last week’s sinkhole.

“The failing infrastructure causes liquids to leak out and then water undermines it, and it erodes enough that we see a hole developing,” Byers said of how a sinkhole forms. “There’s a lot of old infrastructure around Main Street that was built around the 1800s, so it’s pretty old. I’m amazed it’s still working.”

Some of the more notable sinkholes this year include one opening on Manchester Street on April 4, and two opening on Main Street: one at the intersection with Allds Street on March 23, and the most recent, which opened on May 13 at the High Street intersection that left a sizable hole that took multiple days to repair.

During sinkhole repairs, crews work to open up the street where the hole has formed, and then repair the cause of the collapse, be it a sewage or water pipe, among other causes. Once the infrastructure is repaired, crews will fill the hole with either gravel, dirt or a mixture of both. They then pack it down in order to stabilize the structures before patching the fixed area with pavement.

While the cost to repair the aging infrastructure continues to add up, the money that is used for the repairs comes from the DPW’s general operating funds. These funds are used to address issues including potholes, road work and re-paving, along with the sinkholes.

Byers said city officials strive to address safety issues as soon as they are notified of a problem.

“Sewage failures, sinkholes and potholes have to be addressed immediately because they’re major safety issues,” Byers said.

One of the ways the city is working to prevent sinkholes, beyond the planned maintenance and updates of structures that are cannot be repaired, is by installing reinforcements in to the sewage system. By adding liners to the current pipes, Byers said those sewage pipes could potentially last another 40 to 50 years.