Unable to add soil or ecoregion layers

NRCS has wfs and wms. The wfs URL doesn't retrieve anything, the wms is recognized as NRCS data mart but CalTopo has "Error encountered" across the screen. URLs are here: https://sdmdataaccess.sc.egov.usda.gov/WebServiceHelp.aspx#SDM

EPA ecoregions data may be here but I don't know what or how to import. 

https://services.arcgis.com/U7I2hMhPtOeGx0fs/ArcGIS/rest/services/EPA_Ecoregions_for_Terrestrial_Levels_1234/FeatureServer/3

https://www.epa.gov/eco-research/ecoregion-download-files-region#pane-04

I would greatly appreciate help, thank you.