Is WGS84 (EPSG:4326), with subsequent transformation to GDA94 or GDA2020 outside of GXLab, confirmed with the Regulator as compliant with the ACCU Soil Carbon method?

GXLab retains spatial layers in their original coordinate reference system, including WGS84 (EPSG:4326), because many base datasets used for stratification such as NDVI, elevation and TWI are supplied in WGS84 or mixed CRS formats. Within the platform, data are displayed in WGS84 for consistency at the interface level.

From an ACCU Soil Carbon Method perspective, the CRS only becomes relevant if project boundaries are defined inaccurately at the outset. If cadastral or legally defined project boundaries are imported in their correct projected CRS (for example GDA94 or GDA2020), then subsequent transformation between WGS84 and GDA94 or GDA2020 does not in itself create a compliance issue.

The main risk arises where project boundaries are manually digitised on a web map background (for example using a Leaflet base map in WGS84) rather than imported from authoritative cadastral data. For that reason, we do not recommend manually drawing project boundaries in the interface for ACCU projects. Importing survey-grade or cadastral boundary files in the correct projected CRS avoids this issue. Minor exclusions are generally lower risk, as small positional shifts are unlikely to materially affect sampling locations.