Good Samaritan Abandoned or Inactive Mine Waste Remediation Act - Amends the Federal Water Pollution Control Act to authorize the Administrator of the Environmental Protection Agency, with the concurrence of the applicable State or Indian tribe, to issue an abandoned or inactive mined land waste remediation permit to a remediating party (the United States, States, Indian tribes, or municipalities) for discharges associated with remediation activity at abandoned or inactive mined land that modifies otherwise applicable requirements under provisions regarding the national effluent discharge elimination system and effluent limitations.

Authorizes remediating parties to apply for such permits at abandoned or inactive mined land from which there is or may be a discharge of pollutants to U.S. waters. Prohibits such a party from applying for a permit if the party owns the land unless the land was purchased for the express purpose of remediating pollutant discharges related to past mining activities to improve water quality.

Sets forth application requirements. Authorizes the Administrator to issue a permit if: (1) relative to the resources available to the remediating party for the proposed activity, such party has made a reasonable effort to identify current land owners, lessees, and claimants and other persons whose activities may have contributed to the discharge of pollutants; (2) no identifiable owner or operator exists; and (3) the applicant's remediation plan demonstrates that it will result in improved water quality to the maximum extent practicable.

Authorizes enforcement actions against parties who fail to comply with permit conditions. Provides for permit termination under certain conditions and absolves parties whose permits are terminated from enforcement liability for any remaining discharges.

Makes remediation plans under permits issued under this Act eligible for certain grants.

Terminates the Administrator's authority to issue permits under this Act ten years after this Act's enactment.