Confidence: I'm as sure as I can be.
Notes: Fertile (anthers dehiscing). Glumes obtuse. Upper surface of leaf-blades scabrous-ribbed.
The glaucus/pruinose leaf-sheaths and spikelets, although qualitative characters here, are indicative. The habitat, surrounded by what looks to be intensive arable cropping, is coastal and is probably (?definately) reclaimed saltmarsh, which is a typical habitat for E. atherica.