Gas Leak Correction

If not handled correctly, gas can be deadly. If it leaks inside a building people who breathe in the gas may lose consciousness and even die. Explosions are another deadly risk.

It is a known fact that many cities in the U.S. have aging natural gas mains, including New York City (NYC). The oldest systems are made of cast iron, which is no longer permitted for new gas mains in NYC. Some date back to the 1930s, prior to World War II. Prone to leaking, the aging infrastructure is difficult to access and therefore difficult to fix.

Every year thousands of leaks in piped gas systems are reported in Con Edison and National Grid, and scientists have warned that if anyone simply drops a cigarette butt down a manhole, and there is a leak, this could be catastrophic.

The reality is that there are sections underground below cities where the concentration of methane, an odorless gas, is so high, explosions could happen at any time – and they have.

Natural gas has also caused numerous explosions, in spite of the fact that a harmless chemical containing sulfur is added to natural gas to give it a distinctive, recognizable smell. For example:

• In 2015, a gas explosion destroyed a building in East Village, New York killing two people and critically injuring four. An inspection found that a flexible hose had been used illegally to divert gas to upstairs apartments in the building.
• In 2014, a violent explosion ripped two building in East Harlem, New York apart killing eight and injuring many more. More than 100 families were left homeless as a result of the blast. The cause was found to be two incorrectly welded Con Edison gas pipes and a gaping hole in a sewer main the City had known about for more than eight years. Ultimately, gas had been leaking from the gas pipeline system for at least a day before the explosion.
• In 2013, a man in the Bronx suffered second-degree burns after lighting a cigarette which caused a flash of fire. The irony was that shortly before the explosion, his wife had said she could smell gas!
• In 2011, a crack in a gas main that had been installed in Allentown, Pennsylvania in 1928 led to a natural gas explosion that killed five people.
• In 2010, a rupture in a major gas pipeline in San Bruno, California led to an explosion that killed eight people.
• In 2007, a gas leak caused a house in Harlem to explode killing a young mother and injuring her four children critically. They survived but were scarred and disfigured.

There have been numerous explosions in Queens, New York. These are just a few examples:

• In 2011, a small explosion in a basement utility room in Bayside, Queens was found to have been caused by a leak in the steel gas main that had been built in the 1950s.
• In 2009, a house in Queens exploded killing a woman and injuring six others. Investigators found that faulty electric wiring had created in the 1950 gas main, leading to serious leaks and subsequently the deadly explosion.
• In 2008, minutes after a crew from Con Edison had restored the gas service to a building in Queens, a resident tried to light the pilot of his stove and there was an explosion. He and at least 16 other people were injured, and he died a few weeks later.
• In 2007, a house exploded in Queens after residents had detected the sulfurous smell of gas. An elderly woman was critically burned and died a day later. Investigators concluded that wear and tear, as well as corrosion, had led to a crack in the aged gas main that was installed in 1927.

The fatal gas explosions in NYC in 2014 and 2015 eventually prompted the local NYC government to introduce safety legislation in the form of several Local Laws that were signed into law in 2016.

They include:

• Local Law 150 that requires all “gas work” other than that performed, serviced, and maintained by utility companies, to be performed under the supervision of a licensed master plumber (LMP). This comes into effect on January 1, 2020.
• Local Law 151 that relates to final inspections of all permitted gas work. This must be done in the presence of the registered design professional of record, which is a position we hold for our customers, the permit holder, or the superintendent of construction. Any installation defects must be corrected before the Department of Buildings (DOB) will provide the necessary letter of completion. This law came into effect on January 1, 2018.
• Local Law 152 that requires mandatory inspection by an LMP and testing of gas piping systems in most buildings every five years. New buildings must be tested for the first time in the tenth year after the certificate or occupancy or letter of completion.

Gas piping inspections involve all the exposed gas lines from where the pipeline enters the building to each tenant space and includes building service meters. Public spaces in the building, including hallways and corridors, as well as mechanical and boiler rooms must all be included in tests if they contain gas piping or equipment that utilize gas. Specifically, the LMP will be looking for any evidence that piping has deteriorated or is suffering from excessive atmospheric corrosion and, of course, identification of any gas leaks. LMP’s reports must be submitted to the DOB.

Failure to comply with Local Law 152, which came into effect on January 1, 2019, is regarded as “a major violation.”

• Local Law 153 that requires the owners of buildings to notify their tenants of the correct procedures to follow if they suspect that there is a gas leak. This law came into effect in April 2017.
• Local Law 154 that requires gas utility companies to notify the DOB within 24 hours if gas is shut off and/or not restored after inspection because of safety concerns. This law came into effect in March 2017.
• Local Law 157 relates to carbon monoxide and smoke detecting devices in residential buildings in NYC and specifies whose responsibility it is to provide and install these. It also covers the suitable location of natural gas alarms, as well as the replacement of old devices and alarms. This law took effect between December 2016 and May 1, 2017.

Of course, other legislation, including local codes, provides rules and regulations that have been formulated to prevent gas leaks. For example, the Fuel Gas Code of New York State (NYS) mandates that before any gas piping system can be concealed or put in service it must be tested to make certain it is 100% gas-tight, with no leaks. It also states that when conduit terminates inside a building, any space between it and the gas piping must be sealed to prevent any possible seepage of gas. The way the conduit is installed and sealed is specified in the Code.

The section of the NYS Fuel Gas Code that covers inspection, testing and purging of gas piping installations specifies ways of detecting leaks and other defects. This includes both pressure testing and visual inspections, as well as various other approved leak-detection methods.

When the gas in new piping systems is turned on for the first time the entire system must be inspected to make sure there aren’t any open ends or fittings, and that valves at outlets that are not being used are closed and either capped or plugged. Then the piping system must be checked to make sure there aren’t any leaks. The same applies to gas piping systems that have been altered or extended.

The Code states that equipment and appliances should not be operated until the system has been checked for leaks and purged. All connections to appliances must also be checked for leakages.

If there is any indication that there is a leak in a gas piping system, the affected portion of the gas piping system must be replaced or repaired and then retested. This applies to both new systems and systems that have had service interrupted.

In very old gas piping systems it may be necessary to shut off the entire system, particularly if leaks are an issue. Newer systems are designed with isolation valves that allow specific sections to be shut down. In all instances, design drawings will need to be filed with the DOB by a professional engineering firm like Nearby EngineersNew York Engineers.

The NYC Fuel Gas Code allows leak checks using fuel gas if the piping system has been pressure tested in accordance with the section on inspection, testing, and purging in the chapter on Gas Piping Installations in the Code. These include a visual examination and pressure tests. If gas distribution piping has been welded, radiographic testing is required on all butt welds in the piping and in gas meters.

Distribution pressures for gas distribution piping are specified in the Code. Meter piping, on the other hand, must be pressure tested in accordance with the utility company’s requirements.

Whether the piping is repaired or replaced, this must be carried out in accordance with the manufacturer’s instructions, the approved gas piping design, and with Gas Piping Installations in the NYC Fuel Gas Code. The Code is comprehensive and covers piping:

• In solid partitions and walls, but only if installed in a ventilated casing or chase.
• In concealed locations.
• Through foundations walls, where the piping must be encased in a protective sleeve.
• In solid floors, where the piping must be laid in channels.
• That is installed outdoors above the ground.
• That is installed underground, in which case it must be buried at least 24 inches (610 mm) below the grade. It may not be installed under buildings unless the piping is encased in a steel pipe or wrought iron conduit that is designed to withstand superimposed loads.

Once repairs or replacement has been completed the piping system must be re-checked for leakage.

If repairs don’t pass the test or inspection, additional corrections must be carried out to achieve compliance with the NYC Code and then resubmitted to the DOB for further inspection and testing.

The professional team of engineers at NY Engineers knows exactly how complicated a gas leak correction a gas shut-down can be. We always aim to get our clients’ gas services restored as quickly as possible. Even when we file in accordance with professional certification, which allows plans to be approved within two to three days, the entire correction process can take months. How many months will depend on the extent of the problem and just how much of the gas piping system has to be repaired and/or replaced.

Assuming there hasn’t been an explosion, professional engineers will need to do a survey that identifies the existing gas piping system including valves, gas risers, and meters. Then, what we do is to pressure test sections of the gas piping around fittings and valves to find any leakages that haven’t already been identified.

The next step is to come up with an engineering solution to repair the gas piping and restore the gas service to the building. Plans and working drawings for the repair and/or replacement piping need to be created and then filed with the DOB. It is also necessary to interface with the right department within the relevant utility company. In New York this will either be Con Edison or National Grid, depending on where the building is located.

In very old buildings, chances are that the meters will be locked and shutoff valves will all have to be replaced. An amended system will usually have to be designed to modernize the old system and make it safe.

The necessary inspections and tests are discussed above.

Dealing with this kind of scenario is a specialty of NY Engineers.

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Designing these buildings involves artistic talent and expertise to integrate green building strategies. The idea is to reduce energy consumption while also improving the health of low-income residents. Such initiatives care for the environment to reduce greenhouse gas emissions.