Calculating a facility's greenhouse-gas emissions is one job; actually getting those numbers to the EPA in the right format by the deadline is another. e-GGRT, the Electronic Greenhouse Gas Reporting Tool, is the EPA's online system for that second job. It is the portal through which facilities register, enter or upload their annual emissions data, run it through built-in checks, and certify and submit the report. This guide focuses on the submission mechanics, how you set up an account and facility, how data goes in, and how the tool validates it, rather than on the emission rules themselves.
e-GGRT Reporting Tool in one line: e-GGRT is the EPA's Electronic Greenhouse Gas Reporting Tool, the online portal that facilities use to submit their annual reports under the Greenhouse Gas Reporting Program, including Subpart W for petroleum and natural gas systems. Reporters register accounts, set up their facilities, enter emissions data through web forms or by uploading an XML file, run the tool's built-in verification checks, and then certify and submit the report by the annual deadline of March 31 for the prior calendar year.
Before any data can be entered, e-GGRT requires an account structure to be set up, and the tool is built around distinct user roles. A person registers as an individual user and is then associated with a facility in a role, most importantly as the designated representative who is legally responsible for certifying and submitting the report, with the option of agents who can prepare the report on the representative's behalf. This role separation exists because the submission is a certified legal statement, so the tool tracks who is authorized to enter data versus who is authorized to sign and submit it.
Setting up the facility itself is the next step, where the reporter identifies the facility and selects which subparts of the reporting program apply to it, such as Subpart W for a petroleum and natural gas facility along with any other applicable subparts. This configuration tells e-GGRT which reporting forms and data fields to present, so a facility that reports under several subparts sees the sections for each. Getting the facility registration and subpart selection right up front matters, because it defines the shape of the report the tool will expect to be filled in.
Because the designated representative role carries legal weight, e-GGRT ties submission to an identity-verification and electronic-signature process rather than a simple password. The representative has to be properly registered and authorized before they can certify a report, and agents have to be linked to the facility with the representative's approval. This administrative setup is a one-time-per-facility effort in principle, but it is a real gate: a facility whose representative is not correctly registered and verified cannot submit, no matter how complete the emissions data is, so operators handle this well ahead of the deadline.
e-GGRT offers two main ways to get emissions data into a report. The first is the web-form path, where the reporter works through the tool's on-screen forms subpart by subpart, typing in the required inputs and letting e-GGRT apply the prescribed calculations to produce the emissions results. This path is well suited to smaller reporters or those who prefer to work interactively inside the tool, since it guides the user through the fields the selected subparts require and performs much of the arithmetic internally.
The second path is XML upload, where the reporter prepares the report as an XML file that conforms to the EPA's published schema and uploads it into e-GGRT in one operation rather than typing each field. This suits larger operators and those using third-party or in-house reporting software, because the emissions calculations and data assembly can be done in that external system and the finished report handed to e-GGRT as a structured file. The XML must match the required schema exactly, so the value of this path depends on the preparing software producing a valid file that the tool will accept.
In both cases the underlying inputs are the same activity and emissions data the subpart requires, such as equipment counts, run hours, flow and throughput volumes, gas analyses, and event records, feeding the calculations that yield the methane and carbon-dioxide totals. The choice between web forms and XML is mainly about how a given organization prefers to prepare and manage that data, and larger reporters often lean toward XML precisely because it lets them keep the calculation logic in their own systems and use e-GGRT chiefly as the submission and validation gateway.
Whichever entry path is used, e-GGRT runs the report through built-in verification checks before it can be submitted. These checks look for problems such as missing required fields, values that fall outside expected ranges, and internal inconsistencies, and they flag them so the reporter can review and correct them. The checks are a safeguard rather than a guarantee of accuracy: passing them means the report is complete and internally consistent enough to submit, not that every input is correct, so the reporter still owns the substance of the numbers. Once the report is clean and the designated representative certifies it, the submission is made electronically, with the annual deadline being March 31 for the preceding calendar year.
Much of what the report needs is operating data that already exists in a facility's field systems: compressor run hours, flare and blowdown volumes, meter throughput, tank activity, and pressures and temperatures that feed the calculations. The closer that data is to a continuous, time-stamped record, the easier it is to assemble defensible annual inputs, whether those inputs are typed into e-GGRT's web forms or rolled up into an XML file by a reporting system. Facilities that log the underlying values through SCADA and flow computers spend far less of the reporting season reconstructing numbers from scattered notes.
Merobix contributes to this by giving operators a browser-accessible history of the operating parameters that ultimately drive the calculated methane and carbon-dioxide totals, such as run times, flow volumes, and event logs for blowdowns and flaring. Merobix does not file the report through e-GGRT or perform the emission calculations itself; it supplies the auditable operating record that the person or software preparing the submission draws on to populate the tool. Because e-GGRT reports are retained and increasingly cross-checked, having the field data traceable back to real, continuous records is what turns the annual e-GGRT submission from a scramble into a routine extract from systems that are already running.
Subpart W is the reporting rule that defines what petroleum and natural gas facilities must calculate and report about their greenhouse-gas emissions. e-GGRT is the EPA's electronic tool through which that report is actually submitted, along with reports under other subparts of the program. In short, Subpart W tells you what to report, and e-GGRT is the portal you report it through.
Reports under the Greenhouse Gas Reporting Program are submitted through e-GGRT by March 31 for the preceding calendar year. Because the account, facility registration, and designated-representative verification all have to be in place before a report can be certified and submitted, operators generally complete the administrative setup well ahead of that date rather than leaving it to the final days.
No. e-GGRT supports two data-entry paths: interactive web forms where you type inputs subpart by subpart and let the tool calculate results, and XML upload where you prepare a schema-conformant file in external software and upload it in one step. Smaller reporters often use the web forms, while larger operators frequently use XML so they can keep the calculation logic in their own systems and use e-GGRT mainly for validation and submission.
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Last reviewed: July 27, 2026. Merobix is not affiliated with, endorsed by, or sponsored by these organizations; their names are used only to identify the standards and products discussed.
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