Wyo. Stat. § 35-11-1610 (2026)

covenants not to sue, certificates of completion or no further
action determinations; conditions; recording.

     (a) The department may reopen a remedy agreement, covenant
not to sue or certificate of completion at any time if:

          (i) The current owner fails substantially to comply
with the terms and conditions of the remedy agreement, covenant
not to sue or certificate of completion;

          (ii) An imminent and substantial endangerment to
human health or the environment is discovered;

          (iii) Contamination is discovered that was present on
the site but was not known to the owner or the department on the
date of the remedy agreement or when the department issued a
covenant not to sue or certificate of completion; or

          (iv) The remedy fails to meet the remediation
objectives that are contained in the remedy agreement or
certificate of completion.

     (b) The department may reopen a no further action
determination at any time if:
          (i) An imminent and substantial endangerment to human
health or the environment is discovered; or

          (ii) The department determines that the monitored
natural attenuation remedy under W.S. 35-11-1608(b) is not
effective in meeting the standards for a no further action
letter under this section.

     (c) The department may terminate a remedy agreement,
covenant not to sue, certificate of completion or no further
action letter if it is discovered that any of these instruments
were based on fraud, material misrepresentation or failure to
disclose material information, or if an owner's willful
violation of any use restriction results in harmful exposures of
any toxic contaminant to any user or occupant of the site.

     (d) If a remedy agreement, covenant not to sue,
certificate of completion or no further action letter is
reopened or terminated, the department shall record a notice of
such action in the office of the county clerk with the deed for
the site and shall file the notice in the office of the county
clerk no later than ten (10) business days after the date of the
remedy agreement, covenant not to sue, certificate of completion
or no further action letter is reopened or terminated.