Petitioner Volpe Vito, Inc. appeals a decision by the Secretary of the United States Department of Agriculture ("Secretary"), under the Animal Welfare Act ("AWA"), 7 U.S.C. §§ 2131-59. The Secretary imposed against Volpe Vito a $26,000 civil penalty, issued a cease and desist order, and revoked Volpe Vito's license to operate an animal park. For the reasons that follow, we affirm the decision of the Secretary.
I.
Volpe Vito operates the Four Bears Water Park and Recreation Area ("park"), *86 a 125-acre park in Utica, Michigan, displaying animals such as zebras, elephants, goats, camels, and chimpanzees. Since 1983, Volpe Vito has been licensed to exhibit animals in compliance with AWA regulations concerning the transportation, housing, handling, treatment, and inspection of its animals. Sites such as Volpe Vito are inspected at least once annually by the Animal and Plant Health Inspection Service ("APHIS"), an agency within the Department of Agriculture, to ensure compliance with the AWA.
Dr. Lisa Dellar, an APHIS veterinarian, inspected the park in 1988 after it was first licensed. Dr. Dellar observed several AWA violations. Despite her discussions with park employees regarding compliance with the act, she noted both recurring and new violations on each of her subsequent visits. Following her ninth visit in February 1994, APHIS filed an administrative complaint against Volpe Vito. The Administrative Law Judge ("ALJ") issued an Initial Decision and Order ("Initial Decision") finding that Volpe Vito had violated five provisions of the AWA. The ALJ dismissed several of the allegations in the complaint, however, finding that Dr. Dellar was biased in her written comments regarding animal care and husbandry. The ALJ issued a cease and desist order and revoked Volpe Vito's license.
**2 Volpe Vito appealed the Initial Decision to a Judicial Officer ("JO"), the final deciding officer in administrative proceedings. APHIS filed a cross-appeal. The JO affirmed in part and reversed in part. The JO upheld the ALJ's finding of five violations and the ALJ's dismissal of twenty-three of the other allegations. The JO failed to find bias on the part of Dr. Dellar, however, and reversed the ALJ's dismissal of the remaining allegations. Pursuant to the JO's decision, the Secretary issued a cease and desist order, revoked Volpe Vito's license, and also imposed a $26,000 fine. Volpe Vito filed a petition for reconsideration, which the JO denied. Volpe Vito subsequently filed a timely notice of appeal.
II.
Our review of an administrative decision is narrow; we set aside an agency's action only if it is not supported by substantial evidence. See Citizens to Preserve Overton Park, Inc. v. Volpe, 401 U.S. 402, 414, 416 (1971). Substantial evidence is "such relevant evidence as a reasonable mind might accept as adequate to support a conclusion." Moon v. Transport Drivers, Inc., 836 F.2d 226, 229 (6th Cir. 1987).
Volpe Vito first argues that the JO erred in overturning the ALJ's finding that Dr. Dellar was biased. We find this argument unpersuasive. The JO is not required to accept the ALJ's findings of fact, even when those findings are based on *87 credibility determinations, see Mattes v. United States, 721 F.2d 1125, 1129 (7th Cir. 1983) (citing 5 U.S.C. § 557(b)), and the JO is authorized by statute to substitute his or her judgment for that of the ALJ. See Parchman v. United States Dept. of Agriculture, 852 F.2d 858, 860 (6th Cir. 1988) (citing Mattes, 721 F.2d at 1129). Moreover, given an established presumption that policymakers with decision-making power exercise their power with honesty and integrity, see Navistar Int'l Transp. Corp. v. United States Envtl. Protection Agency, 941 F.2d 1339, 1360 (6th Cir. 1991) (internal cites omitted), the burden of overcoming the presumption of impartiality rests on the party making the assertion of bias. See id. (internal cites omitted). In the present case, the park was unable to convince the JO of bias on the part of Dr. Dellar, and the evidence proffered by APHIS clearly supports his findings.
The park next contends that the complaint should be dismissed in its entirety because the ALJ found Dr. Dellar to be biased. This argument lacks merit. The JO rejected the ALJ's finding on this matter. The park mischaracterizes Dr. Dellar's inspection reports, which were promptly prepared after all inspections, regardless whether violations were found or litigation was anticipated. Therefore, Volpe Vito is misguided in its reliance on Young v. United States Dep't of Agric., 53 F.3d 728, 730-31 (5th Cir. 1995) (disallowing documents after determining that they were prepared solely for administrative proceedings).
Volpe Vito further contends that the Secretary acted inappropriately by imposing a $26,000 sanction and argues that its actions were neither willful nor intentional. According to Volpe Vito, the Secretary also failed to consider mitigating circumstances in Volpe Vito's favor: no prior convictions of state or local regulatory violations involving the treatment of animals; the city water main break that flooded the entire park moments prior to Dr. Dellar's arrival; Volpe Vito's decision to fire a park manager for contributing to the violations; its compliance with the AWA following the complaint; and the ailing health of Mr. Stramaglia, Volpe Vito's president. The park further contends that because the $26,000 penalty was harsher than that imposed on other parties who committed more egregious violations under the AWA, the Secretary's motive was punitive, not remedial, and contrary to the purpose of the AWA.
**3 A sanction under the AWA, if within the bounds of the agency's lawful authority, is subject to very limited judicial review. We determine only whether the agency properly applied the regulations, and whether the sanction is warranted in law and justified in fact. See Woodward v. United States,725 F.2d 1072, 1077 (6th Cir. 1984) (internal cites omitted). Provided that violations are willful, the Secretary is empowered under the AWA to impose a civil penalty up to $2,500 for each violation. See 7 U.S.C. § 2149(a), (b). ""Willful" means action knowingly *88 taken by one subject to the statutory provisions in disregard of the action's legality; no showing of malicious intent is necessary. See Donovan v. Capital City Excavating Co., Inc., 712 F.2d 1008, 1010 (6th Cir. 1983) (internal cites omitted). In imposing a penalty, the Secretary "shall give due consideration to the appropriateness of the penalty with respect to the size of the business of the person involved, the gravity of the violation, the person's good faith, and the history of previous violations." 7 U.S.C. § 2149(b).
We are unpersuaded by Volpe Vito's arguments. Dr. Dellar's nine inspections clearly revealed that Volpe Vito committed violations willfully: notwithstanding Dr. Dellar's efforts to improve the park's compliance with AWA regulations following each inspection, the park allowed 51 recurring and new violations. The mitigating circumstances proffered by the park do not make its actions less deliberate, intentional, or reckless. Furthermore, this court will not consider the severity of a sanction in a particular AWA case relative to sanctions imposed in other cases, provided that the sanction is "permitted by the authorizing statute and the departmental regulation, and the statute and regulation themselves are not challenged." Garver v. United States, 846 F.2d 1029, 1030 (6th Cir. 1988). "This court does not review administrative agency sanctions for reasonableness, or for whether they comport with our ideas of justice." Id. In this case, we find that the license revocation was justified by the reported violations, and the $26,000 fine was permitted under the AWA and were substantially lower than the statutory maximum.
Volpe Vito's final claim, that its compliance with the AWA following the filing of the administrative complaint constitutes a mitigating factor, is without merit. Subsequent compliance, while laudable, does not absolve 51 prior violations.
III.
For the reasons stated above, we affirm the decision of the Secretary of the Department of Agriculture.