How verification of this landfill gas collection & combustion project works
Though created on a continuous basis, carbon offsets are actually delivered in chunks based on the chosen length of a reporting period. These are often one year long, but the Voluntary Carbon Standard allows for longer. In this case, GLRA has a reporting period of a year and a half. For each reporting period, TerraPass compiles the information that allows us to both quantify methane reductions and create an evidence package. At that point, a third-party service is hired for verification of the offsets being claimed.
Most verifications require a site visit in addition to a substantial desk review of the data that the auditor was provided with. The site visit allows the verifier to perform a number of actions required to give them confidence that the emission reductions are real, permanent and additional.
The first thing that takes place on every site visit is an opening meeting. At GLRA last month, we started at 8:00 AM and the attendees were the verifier, myself, and two gentleman from the landfill: the executive director and a staff engineer. During this meeting, the verifier asked a number of questions regarding the regulatory standing of the landfill and the history surrounding GLRA’s ultimate decision to install the gas collection system. She investigated the project’s eligibility, additionality, and quality control systems in place. We at TerraPass strive to work only with projects that are clear of issues of eligibility or additionality by asking these questions as soon as we begin working with a new project!
After getting a better understanding of the project in a big-picture-sense, the verifier went on to take a site tour at about 10:00 AM. This is when we visually followed the gas collection path from the wellheads to the blowers, past the flow meters and into the engines-generator sets. The landfill used to combust all its gas in a huge enclosed flare before it had engine-generator sets installed, so she had to investigate the flare just to be sure it was, in fact, idle.
While on the site tour, the verifier examines the metering devices, checking for proper installation, and jotting down serial numbers to link these back to the project data later on. After spending about an hour outside with the project equipment, driving around the landfill for general context, we regroup back in the main office to get into the details of the verification.
Back in the office after a quick break for Subway sandwiches, the verifier begins to look through the data flow process. How is the information stored? Who pulls the electronic files from the data logger? Who has access to alter this information? What kind of calibration and maintenance procedures are performed on the flow meters? How long are records kept? Then, while viewing a screen loaded with hundreds of data trends, she asks the engineer to display a sample of flow rate data while she checks it against the numbers used for reporting emission reductions.
The end of the site visit is spent typically with the verifier rummaging through various notes and checklists to make sure they covered everything. There’s usually some kind of follow-up for all parties including further data requests or corrections to spreadsheets. All in all, about 5 to 6 hours later, we all shake hands and thank each other for the time spent today. The site visit is complete and the remaining verification activities will be done remotely.