under subsection (a) as are necessary to remediate contamination from PFOA and PFOS related to activities at the Air Force base. (c) Funding Funds for the land acquisitions authorized under subsection (a) shall be derived from amounts authorized to be appropriated for fiscal year 2020 for military construction or the unobligated balances of appropriations for military construction that are enacted after the date of the enactment of this Act. (d) Rule of construction The authority under this section constitutes authority to carry out land acquisitions for purposes of section 2802 of title 10, United States Code. 1075. Remediation plan (a) In general Not later than 180 days after the date of the enactment of this Act, the Secretary of Defense shall submit to Congress a remediation plan for cleanup of all water at or adjacent to a military base that is contaminated with PFOA or PFOS. (b) Study In preparing the remediation plan under subsection (a), the Secretary shall conduct a study on the contamination of water at military bases with PFOA or PFOS. (c) Budget amount The Secretary shall ensure that each budget of the President submitted to Congress under section 1105(a) of title 31, United States Code, requests funding in amounts necessary to address remediation efforts under the remediation plan submitted under subsection (a). H Other Matters 1081. Revision to authorities relating to mail service for members of the Armed Forces and Department of Defense civilians overseas (a) Eligibility for free mail Section 3401(a) of title 39, United States Code, is amended to read as follows: (a) (1) First-class letter mail having the character of personal correspondence shall be carried, at no cost to the sender, in the manner provided by this section, when mailed by an eligible individual described in paragraph (2) and addressed to a place within the delivery limits of a United States post office, if— (A) such letter mail is mailed by the eligible individual at an Armed Forces post office established in an overseas area