Vacuum Excavation

Hallen Construction is the exclusive provider of vacuum excavation for Con Edison in the New York City boroughs of Queens, Bronx, Manhattan and Westchester.

Vacuum excavation is primarily used in areas where the subsurface utilities are highly congested. The advantage of vacuum excavation is that existing subsurface utilities aren’t damaged, the excavation size is smaller than that of conventional excavation, and there is the ability to remove soil that is between the highly congested utilities. The applications where vacuum excavation is used are test holes, leak repair, service cut and cap, and cathodic protection.

Hallen’s primary use for vacuum excavation is repairing low pressure and medium pressure leaks on Con Edison’s distribution pipelines which range in pipe sizes from 2” through 36”. The repairs are performed on bell joints, couplings, drip pots and end caps.

The repair consists of installing an epoxy encapsulation kit that is installed over the leak once the pipe has been sandblasted. Much of this work is for clearing leaks that are a hazard to the public. The advantage of vacuum excavation is that a two-man vacuum crew will excavate, repair and backfill a leak within a few hours. The impact to the community and traffic flow is minimized and is for a short duration.

Hallen vacuum crews are regularly called to respond to emergency leaks. These leaks occur when gas enters a building or subsurface structure, which could lead to a potential explosion. The crew’s responsibility would be to clear the hazard, locate the leak, repair the leak, and backfill.

Hallen also utilizes vacuum excavation for cathodic protection. Our crew will excavate a small opening over the pipeline, install test wires and anodes, test the station, and backfill.

In an effort to minimize excavation size and expedite the excavation process, Hallen uses a two-man vacuum excavation crew to cut and cap gas services which range in size from ½” to 4”. Cut and cap of a service is performed by excavating over the service connection at the main. Once the service is exposed, it is disconnected from the main. The excavation is then backfilled and restoration follows. This process is far more efficient than a hand excavation crew which requires a larger excavation and more time to perform.

Hallen has also supported many utilities, engineering firms and environmental firms by providing test pitting. The vacuum excavation is perfectly suited for providing subsurface information. The information provided to engineering firms includes the type of utility, size, quantity, location and depth. All this information is gathered in a small excavation with minimal impact to traffic and the community.

Utility customers have asked Hallen to test pit new installations to provide a means of random inspection as a part of ongoing quality control.

Environmental firms have used vacuum excavation to locate the limits of subsurface contamination prior to designing a remediation plan.