Section 258.16 - Closure of existing municipal solid waste landfill units(a) Existing MSWLF units that cannot make the demonstration specified in § 258.10(a) , pertaining to airports, § 258.11(a) , pertaining to floodplains, or § 258.15(a) , pertaining to unstable areas, must close by October 9, 1996, in accordance with § 258.60 of this part and conduct post-closure activities in accordance with § 258.61 of this part.(b) The deadline for closure required by paragraph (a) of this section may be extended up to two years if the owner or operator demonstrates to the Director of an approved State that: (1) There is no available alternative disposal capacity;(2) There is no immediate threat to human health and the environment. Note to subpart B: Owners or operators of MSWLFs should be aware that a State in which their landfill is located or is to be located, may have adopted a state wellhead protection program in accordance with section 1428 of the Safe Drinking Water Act. Such state wellhead protection programs may impose additional requirements on owners or operators of MSWLFs than those set forth in this part.