Hourly hydrocarbon and NOx emission inventories were developed for the Marcellus region at multiple spatial scales: the 4 km by 4 km grid cell level and county level for two selected counties, and the county and basin levels for the entire basin.  Depending on the spatial resolution of developed inventories, an aggregation of production and activity data prior to simulation was performed.

Study domain overlapped by 4km-by-4km grid cells, with well sites, midstream sites, and flares; two selected counties are highlighted.

Resources

Marcellus manuscript: Chen, et al. (2025)
Marcellus inventory: Download Inventory Data

Sources for input data
Production data: Enverus
Activity data: EPA Greenhouse Gas Inventory

Sources for simulation

1. Estimating combustion emissions from well sites: EPA Nonpoint Oil and Gas Emissions Estimation Tool

2. Estimating non-combustion emissions from well sites: Methane Emission Estimation Tool (MEET) 

3. Estimating methane emissions from gathering site : Zimmerle, et al. (2020) correlation between site throughput and methane emissions

4. Data source for processing and transmission emissions: EPA Facility Level Greenhouse Gas Emission Data (FLIGHT)

5. Estimating fraction of combustion methane from gathering sites: Vaughn, et al. (2021)

6. Estimating fraction of combustion methane from processing and transmission sites: EPA Greenhouse Gas Inventory

7. Estimating NOx emissions from midstream sites and flares: EPA AP-42 emission factors from stationary sources

8. Reported annual gas flared volume: Annual gas flare volume estimated by Earth Observation Group

9. Raw satellite data for estimating flares: VIIRS satellite detections