; (B) the proposed activity will last less than one month and will have limited physical impact on the surface of the historical crossing; (C) the proposed activity has been implemented by the adjacent landowner or other adjacent landowners in the past; or (D) the proposed activity is the subject of a categorical exclusion under the National Environmental Policy Act of 1969 ( 42 U.S.C. 4321 et seq.); and (4) if the Superintendent disapproves the activity, the adjacent landowner may modify the proposed activity and resubmit it for review under paragraph (1). 6. Exotic or invasive species control At the request of an adjacent landowner, within 30 days of such a request, the Superintendent shall authorize the adjacent landowner to participate in the eradication of exotic or invasive species in the Park for a period of up to 10 years, subject to renewal. Such an authorization shall provide— (1) that the exotic or invasive species proposed for eradication is identified as such by the National Park Service; (2) that the method, timing and location of the eradication must be approved by the Superintendent; and (3) appropriate indemnification of the adjacent landowner. 7. Funding clarification No additional funds are authorized to carry out the requirements of this Act. Such requirements shall be carried out using amounts otherwise authorized.