Presumption of Deference and weight To Agency Interpretation

 "The construction of statutes by agencies charged with administration of those statutes is entitled to great weight.23 
A decision of an agency charged by the General Assembly with statewide administration, unless it is clearly wrong, carries great weight and is entitled to deference.24 
The grant of regulatory authority extends only to duties or powers conferred by law. As such, "regulations, promulgated pursuant to definitive statutory authority, have the force and effect of law.
"25 Moreover, those regulations which "clearly and explicitly mirror" statutory authority are likeliest to be sustained.
26 Any regulation of the Department must be reasonably grounded in an identifiable and definitive statutory foundation." 
Op. Va. Att'y Gen. No. 02-074, Sept. (2002). See Also: National Wildlife Federation v. Carol M. Browner, EPA, (D.C. Cir, 1997), 
"Generally, the court accords substantial deference to an agency's interpretations of its own regulations."
[See Auer v. Robbins, 117 S. Ct. 905, 911 (1997); Thomas Jefferson Univ. v. Shalala, 512 U.S. 504, 512 (1994).]
 Provided the interpretation "does not violate the Constitution or a federal statute, it must be given 'controlling weight unless it is plainly erroneous or inconsistent with the regulation.'
[" Stinson v. United States, 508 U.S. 36, 45 (1993) (quoting Bowles v. Seminole Rock & Sand Co., 325 U.S. 410, 414 (1945)).]