I. DETECTING LEAKS
Natural gas is odorless and colorless. Therefore, odorant is intentionally injected in to natural gas so that the average person can perceive it at a concentration well below the explosive range. According to Federal minimum standards for pipeline safety, natural gas in a distribution system is required to be odorized so that, at a concentration of natural gas in air of one-fifth of the lower explosive limit (or about 1% of gas in air), it can be readily detectable by a person with a normal sense of smell. NY regulations require gas in distribution systems to be readily detectible at 1/10 of the lower explosive limit (approximately 0.5% gas in air), making NY’s requirements more stringent than the federal requirements. Odorant is the best means to be able to ensure that leaks inside a building are detectible by people in the building. Any report of gas odor should be investigated immediately. If a presence of natural gas is found, the source of the leak needs to be found and remediated so that the leak can be eliminated.
Under Federal regulation, only those leaks that are immediately hazardous to life or property are required to be repaired. However, in New York, leaks must be classified using a device approved for leak investigation. This classification determines the timeframes for repair. For example, if an immediate hazard is determined to exist, the leak is required to be repaired immediately. Less hazardous leaks can be scheduled for repair, but must be monitored regularly until repaired.
Under certain conditions, the odor added to natural gas may be filtered out or masked, so that odorant cannot completely be relied upon to assure the presence or absence of gas leaks. Therefore, companies that transport natural gas are required to conduct regular leakage surveys of all their piping using an approved device, in addition to investigating reports of leaks from the public. Any leaks found are then classified and repaired as appropriate
II. NEW YORK STATE REQUIREMENTS REGARDING LEAK DETECTION INSTRUMENTS
Federal regulations require leakage surveys to be performed with, “leak detection equipment”. However, New York is more prescriptive and requires leakage surveys to be conducted using only “approved” leak detection equipment.
Specifically, 16 NYCRR Part 255.3(a)(23) states, “Leakage investigation means a survey conducted for the purpose of determining the extent of potential hazard and classifying a leak in accordance with section 255.807 of this Part. For outside leaks, this involves the driving or boring of holes at sufficient depth and testing the atmosphere in these holes and other available openings with a properly calibrated combustible gas indicator (CGI) or approved equivalent device (emphasis added).”; and 16 NYCRR Part 255.3(a)(24) states, “Leakage Survey means a systematic survey made for the purpose of locating leaks in a gas piping system using an approved instrument (emphasis added) which continuously analyzes atmospheric samples near ground level and is capable of detecting the presence of gas in parts per million in air.”
The regulations cited above indicate that both a Leak Investigation or Leak Survey must be performed with approved (emphasis added) instruments. 16 NYCRR Part 255.3(a)(5), states, “approved (emphasis added) means prior approval must be granted by the department, except in emergency situations”. Per 16 NYCRR Part 255.3(a)(11), the “department shall mean the Department of Public Service, Office of Electric, Gas and Water, Pipeline Safety Section, or its successor, Three Empire State Plaza, Albany, NY 12223-1350, (518) 474-5453, Safety@dps.ny.gov.”
The following leak detection instruments/devices are approved to be used in New York (according to the ‘Notes’ that follow the listing):
Instruments used for Leak Survey
Instruments used for Leak Investigation
Note 1: All approved devices must be used within manufacturer recommendations.
Note 2: In case 15-G-0244 Case 15-G-0244 - Proceeding on Motion of the Commission to Develop Implementation Protocols for Complying with Inspection Requirements Pertaining to Gas Service Lines Inside Buildings (issued and effective April 20, 2017)., the Commission approved Combustible Gas Indicators (CGIs) to be used to perform only inside leakage surveys.
III. APPROVAL PROCESS OF LEAK DETECTION DEVICES OTHER THAN THE DEVICES LISTED ABOVE
Operators that wish to request approval to use a specific leak detection instrument or device, other than the devices listed above, should file their request with the Department, at Department of Public Service, Office of Electric, Gas and Water, Pipeline Safety Section, at Three Empire State Plaza, 12th floor, Albany, NY 12223-1350, or via email at Safety@dps.ny.gov. The filing should include the following: a cover letter addressed to the Chief, - Pipeline Safety Section, with an explanation of how the instrument works; a summary of product specifications; reasoning as to why the proposed leak detection device should be approved, and; any literature/ brochure describing the product.