In K.S.A. 8-1020, the legislature limits the issues that can be addressed during an administrative hearing. Essentially, the administrative hearing is limited to the statements the officer certified on the DC-27 form. These limited issues differ depending on the situation (refused test (h)(1), failed breath test (h)(2), and failed blood test (h)(3)).

In all three situations, administrative hearing can consider whether the person “was operating or attempting to operate a vehicle.” When discussing this in the context of a refused test (h)(1), the standard of proof is clear—“A law enforcement officer had reasonable grounds to believe the person was operating or attempting to operate a vehicle while under the influence of alcohol or drugs, or both.” However, in the failed breath test (h)(2) and the failed blood test (h)(3), the standard is not clear. Both state that the administrative hearing may consider whether “the person was operating or attempting to operate a vehicle” but do not give any definitive standard of proof.

Nevertheless, if you look at the DC-27 form, it states that the officer certify why he or she believes there is reasonable grounds that the person was operating or attempting to operate a vehicle.

Overall, it seems likely that the standard of proof for “a person operating or attempting to operate a vehicle” is reasonable grounds.

How Does The Court Define Reasonable Grounds? 
Kent v. Kan. Dept. of Revenue, 2011 WL 3276227 (Kan. Ct. App. 2011).
In prior cases, this court has equated “reasonable grounds” with “probable cause.” Probable cause to arrest refers to sufficient knowledge of facts, circumstances, and inferences therefrom which would lead a prudent, reasonable, person to believe a suspect is committing, is about to commit, or has committed an offense.

Angle v. Kan. Dept. of Revenue, 758 P.2d 226 (Kan. Ct. App. 1988).
“Reasonable grounds” is not defined in K.S.A.1985 Supp. 8–1001(b). It has been suggested that reasonable grounds must be defined as “probable cause.” Gottlieb & Zinn, An Analysis of Recent Changes in Drunk Driving Laws, 3 Kansas Criminal Procedure Review 59, 60 n. 10 (1986). The conclusion is based on two grounds: (1) “reasonable grounds” is synonymous with definitions of probable cause given in Kansas decisions and is synonymous with the common-law definition of probable cause, which the United States Supreme Court equates with the Fourth Amendment requirement; and (2) blood tests under the statute would be unconstitutional if not based on probable cause. Schmerber v. California, 384 U.S. 757 (1966).

Huelsman v. Kan. Dept. of Revenue, 980 P.2d 1022 (Kan. 1999).
While “reasonable grounds,” within meaning of informed consent law allowing officer to request breath test if officer has reasonable grounds to believe motorist was operating or attempting to operate a vehicle while under the influence of drugs or alcohol, is synonymous in meaning with probable cause, one may have reasonable grounds to believe that a person was operating a vehicle under the influence but not have the probable cause required to arrest. K.S.A. 8-1001(b)(1).