Nothing in this chapter shall prohibit the secretary of environment from rescinding a certificate of completion or a covenant not to sue if the department determines that:
A. contamination addressed in the agreement is, with reasonable evidence, an unreasonable threat to human health or the environment;
B. the voluntary remediation agreement was performed in a manner that fails to comply substantially with the terms and conditions of the agreement or voluntary remediation work plan;
C. the voluntary remediation agreement is a result of fraud; or
D. contamination was present at the site at the time the voluntary remediation agreement was signed but the department did not know of the type, extent or magnitude of the contaminants.