ADP-ribose glycohydrolase that hydrolyzes ADP-ribose and acts on different substrates, such as proteins ADP-ribosylated on glutamate and O-acetyl-ADP-D-ribose. Specifically acts as a glutamate mono-ADP-ribosylhydrolase by mediating the removal of mono-ADP-ribose attached to glutamate residues on proteins. Does not act on poly-ADP-ribosylated proteins: the poly-ADP-ribose chain of poly-ADP-ribosylated glutamate residues must by hydrolyzed into mono-ADP-ribosylated glutamate by PARG to become a substrate for OARD1. Deacetylates O-acetyl-ADP ribose, a signaling molecule generated by the deacetylation of acetylated lysine residues in histones and other proteins. Catalyzes the deacylation of O-acetyl-ADP-ribose, O-propionyl-ADP-ribose and O-butyryl-ADP-ribose, yielding ADP-ribose plus acetate, propionate and butyrate, respectively. 2''-O-acetyl-ADP-D-ribose + H2O = acetate + ADP-D-ribose + H(+) 5-O-(ADP-D-ribosyl)-L-glutamyl-[protein] + H2O = ADP-D-ribose + H(+) + L-glutamyl-[protein] alpha-NAD(+) + H2O = ADP-D-ribose + H(+) + nicotinamide Subject to competitive inhibition by the product ADP-ribose. Localizes both in the nucleoplasm and in the nucleolus. Relocalizes to the nucleoplasm in response to DNA damage. Recruited to DNA lesion regions following DNA damage.