This opinion will be unpublished and may not be cited except as provided by Minn. Stat. § 480A.08, subd. 3 (1994). STATE OF MINNESOTA IN COURT OF APPEALS C3-96-346 Chad Reding, petitioner, Appellant, vs. Commissioner of Public Safety, Respondent. Filed August 13, 1996 Affirmed Schumacher, Judge Redwood County District Court File No. C395527 J. Brian O'Leary, Post Office Box 76, Springfield, MN 56087 (for Appellant) Hubert H. Humphrey, III, Attorney General, Jeffrey S. Bilcik, William P. Hefner, Assistant Attorneys General, 525 Park Street, Suite 200, St. Paul, MN 55103 (for Respondent) Considered and decided by Short, Presiding Judge, Schumacher, Judge, and Foley, Judge.* U N P U B L I S H E D O P I N I O N SCHUMACHER, Judge Appellant Chad Reding was arrested for driving while under the influence in violation of Minn. Stat. § 169.123 (1994). Reding appeals, arguing that the Intoxilyzer test results were invalid because the tests were administered more than two hours after the accident and because he had consumed alcohol after the accident, but before the tests. We affirm. FACTS On October 8, 1995, around 10:30 p.m., Reding was driving his car and was involved in an accident. Reding left the scene of the accident and testified that he went to his home where he consumed alcohol. Later that night, Reding was contacted by the authorities. State troopers investigating the accident went to Reding's residence and arrested him. Once in custody, Reding was observed by state trooper Cook for a short period of time and was then asked to submit to an Intoxilyzer test at approximately 12:50 a.m. After Reding failed to provide an adequate breath sample for the first test, Cook again observed Reding for a short time, and then asked him to submit to another Intoxilyzer test. This time Reding provided an adequate air sample, and readings of .216 and .217 were obtained. When Cook asked Reding to provide the second required breath sample for the session, however, he refused Cook then met with state trooper Messer to discuss how best to handle Reding's refusal to submit to the second test. At approximately 2:19 a.m., Reding was asked by Messer to submit to testing again. Reding provided an adequate sample and a reading of .18 was obtained. Based on the test results, Reding's driver's license was revoked. Reding petitioned for judicial review of the license revocation. The revocation was sustained. D E C I S I O N Conclusions of law will be overturned only upon a determination that the trial court has erroneously construed and applied the law to the facts of the case. Dehn v. Commissioner of Pub. Safety, 394 N.W.2d 272, 273 (Minn. App. 1986). 1. Reding argues that results of the Intoxilyzer test were invalid and unreliable because the test was administered more than two hours after the accident. He contends that Minn. Stat. § 169.121, subd. 1(e) (1994), requires that the Intoxilyzer test be administered within two hours of the time of driving. Reding also argues that because he testified he consumed alcohol after the accident, and nearly two hours before the test, the results are not valid or reliable to support the trial court's conclusion that he was driving while under the influence of alcohol. Reding contends, therefore, that his license revocation should be rescinded. It is a crime for any person to drive, operate, or be in physical control of any motor vehicle within this state or upon the ice of any boundary water of this state: * * * (e) when the person's alcohol concentration as measured within two hours of the time of driving is 0.10 or more; * * * Minn. Stat. § 169.121, subd. 1(e) (emphasis added); see also Minn. Stat. § 169.123 (1994). Upon the trial of any prosecution arising out of acts alleged to have been committed by any person arrested for driving, operating, or being in physical control of a motor vehicle in violation of subdivision 1, the court may admit evidence of the amount of alcohol or a controlled substance in the person's blood, breath, or urine as shown by an analysis of those items. * * * * The foregoing provisions do not limit the introduction of any other competent evidence bearing upon the question whether or not the person violated this section, including tests obtained more than two hours after the alleged violation and results obtained from partial tests * * *. Minn. Stat. § 169.121, subd. 2 (1994) (emphasis added). The Commissioner has the burden of proof in implied consent cases, and that burden of proof is by preponderance of the evidence. King v. Commissioner of Pub. Safety, 366 N.W.2d 613, 615 (Minn. App. 1985). The Commissioner has the burden of making a prima facie showing that the administration of a chemical test conforms to the procedures necessary to insure reliability. State v. Dille, 258 N.W.2d 565, 567 (Minn. 1977). Once the state has established sufficient foundation to justify admitting the test results, the defendant may then present evidence to impeach the credibility of the test results. Bielejeski v. Commissioner of Pub. Safety, 351 N.W.2d 664, 666 (Minn. App. 1984). The trial court found that Reding had consumed alcohol between the time of driving and the Intoxilyzer test. The trial court also made numerous evidentiary findings that support the conclusion the test results were properly obtained, namely: (1) both state troopers administering the tests were certified Intoxilyzer operators; (2) before administering the tests, Cook observed Reding for any intervening behavior to insure that valid results would be obtained; and (3) both troopers operated the Intoxilyzer machine in the correct manner and recorded the results properly. Concluding that the Intoxilyzer test was properly administered and the results valid, the trial court held that Reding had not presented sufficient evidence to show the test results were attributable to his consumption of alcohol after the accident or that he had an alcohol concentration level of less than .10 at the time of the accident. On review of the record, we believe that the findings of the trial court are supported by substantial evidence. The state troopers were certified Intoxilyzer operators and properly administered the Intoxilyzer test. Although the trial court determined that Reding consumed alcohol after the accident and prior to the Intoxilyzer tests, the court found he failed to any present evidence that would show the test results were attributable to his post-accident drinking. We note that Reding did not testify as to the amount of alcohol he claimed to have consumed after the accident. We conclude, therefore, that Reding has failed to show that the Intoxilyzer test results were invalid. Affirmed. * Retired judge of the Minnesota Court of Appeals, serving by appointment pursuant to Minn. Const. art. VI, § 10.