Global emissions from the fossil fuel industry have been a contentious issue for decades, even with methane, also referred to as natural gas. In particular, methane emissions in the United States have been difficult to measure, prompting the EPA to introduce Method 21. And the recent passage of the Inflation Reduction Act, the most significant climate legislation in US history, is bringing new attention to emissions. 

Historically, Method 21 records rely on sparse data, incorrect assumptions, or both. Currently, data is collected through periodic surveys with drones, aircraft, thermal cameras, or other methods. Despite incomplete data, the Environmental Protection Agency has found “widespread noncompliance with Leak Detection and Repair.”

Experts say the current Inflation Reduction Act provisions will dramatically accelerate the decline in US emissions. The goal is to slash emissions in half by 2030 when compared to 2005 levels. 

Given the problem with methane leaks, continuous leak monitoring may be the key to cutting methane emissions and reducing global warming, as well as supporting the goals of the recent legislation.

What is EPA Method 21?

Method 21 was introduced in 1981 by the EPA to require the use of a specialized volatile organic compound (VOC) analyzer to determine whether leaks are present. Method 21 isn’t meant to gauge the emission rate of these powerful greenhouse gases; instead, it is used to detect leaks.

The user may select any analyzer, provided it meets Method 21 requirements, which include:

  •         Portability
  •         Containing a battery-powered sample pump
  •         Certified intrinsically safe
  •         Have a sample probe no larger than 1/4-inch in diameter

While Method 21 tries to identify sources of methane emissions, many factors make this type of leak detection ineffective. In particular, Method 21 programs are prone to significant challenges, including the tedious and expensive manual process required to inspect for leaks, and the lack of constant monitoring.

For example, one case study conducted by the EPA’s National Enforcement Center (NEIC) showed audits and found that the percentage of leaks was, on average, four times higher than the number reported by the facilities. 

Additional case studies and analyses support the idea that the number of methane leaks at oil and gas facilities is far higher than those identified using Method 21 requirements.

Additionally, a 2020 study found more than a half million leaks in local gas distribution systems in the United States, and the leakage from these systems was five times greater than the amount estimated by the EPA.

The Impact of Undetected Methane Leaks

Unfortunately, the failure of Method 21 to correctly identify leaks has contributed to increased atmospheric methane levels that continue to accumulate. These leaks pose an immediate public safety risk if they result in an explosion or fire.

Increasing methane emissions from human activities also contribute to global warming and climate change. Methane traps over eighty times more heat in the atmosphere than carbon dioxide and methane emissions account for approximately a quarter of global warming

Additionally, this warming potential contributes to more intense and frequent extreme weather events, increased food insecurity, greater infectious-disease risk, reduced access to clean water, and deteriorating air quality.

Unfortunately, despite Method 21 regulations, the frequency of significant gas leaks has not declined significantly since 2010 despite the time and money that gas and oil companies have spent attempting to address the problem with methane leaks.

As a result of the grave threat methane emissions pose, many countries have committed to the Global Methane Pledge, which aims to cut methane emissions by 30% by 2030. However, achieving this goal and significantly reducing methane emissions will require better leak detection methods than those provisioned in Method 21.

MPS Extended Range Low Power Methane Gas Sensor

NevadaNano’s Molecular Property Spectrometer™ (MPS™) Extended Range Low Power Methane Gas Sensor is designed for open-air detection of methane and natural gas leaks across various applications. 

It is a low-cost option that allows for continuous monitoring of methane leaks, which goes beyond the requirements of Method 21 and can be a key tool in reducing methane emissions.

This gas detection technology provides many features for the user, including:

  •         Built-in environmental compensation for constant self-testing and fail-safe operation.
  •         Sensor readings are output on a standard digital bus, requiring no additional electronics.
  •         Inherent poison resistance, ensuring users can feel confident in all readings.
  •         No calibration is required, which reduces the total cost of ownership over the lifetime of the sensor.
  •          With a longer life expectancy than most other sensors, the MPS can last and be reliable for five or more years.
  •         Very low power needs of approximately 15 mW, on average.
  •         Intrinsically safe (IS) certification.

The reality is that methane emissions are one of the most significant contributors to global warming. Therefore, cutting these emissions will be imperative in any plan to meet the Global Methane Pledge. 

Method 21 attempts to identify leaks so they can be dealt with quickly, but there are still flaws with many Method 21 monitoring methods. Additionally, the Inflation Reduction Act will require better leak detection and mitigation efforts. The MPS Extended Low Power Methane Gas Sensor provides a better solution. It is a way to continuously monitor methane leaks, effectively reducing methane emissions.