Washington Gas Light Company (WGL) hired PEER to provide pre- and post-construction closed-circuit television (CCTV) inspection of sanitary sewers and house service connections as part of their gas main replacement program. PEER is providing experienced operators, as well as the necessary inspection equipment, to inspect for gas line intrusions.
PEER’s role is to provide pre-construction and post-construction inspections of sewers and house lateral connections to establish whether any cross-bores/gas line intrusions exist. Lateral inspections are typically completed from the sewer mainline. In the cases where the inspections cannot be completed from the mainline, inspections from cleanouts are conducted using a push camera. During the inspections, the sites of each connection are found using a Sonde locating piece of equipment and the data is then documented.
In an effort to reduce the chance of a gas line intrusion in a sewer lateral, PEER has begun performing “mole shot” inspections. The new gas mains are installed via a direction-ally drilled borehole. PEER is using push cameras to check the borehole for any intrusions into sewer laterals before the gas line is installed. If any intrusions are found, the lateral can be located so it can be repaired and the gas line rerouted prior to installation. In addition, the contractor can use the inspection video to ensure that the hole is clear prior to installing the new gas line.