A. To
permanently close a tank, owners and operators shall empty and clean it by
removing all liquids, accumulated sludges, and vapors. Owners and operators
shall properly dispose of any liquids and sludge removed from a storage tank.
(1) Owners and operators shall either remove
from the ground all USTs closed permanently, fill them with an inert solid
material or close in place in a manner approved by the department.
(2) Owners and operators shall perform the
following closure operations on AST systems:
(a) ASTs being closed in place shall be
rendered vapor free; owners and operators shall make provisions for adequate
ventilation to ensure that the AST remains vapor free;
(b) vent lines shall remain open and shall be
maintained in accordance with the current edition of a standard or code of
practice developed by a nationally recognized association or independent
testing laboratory, or manufacturer's recommendations;
(c) all access openings shall be secured,
normally with spacers, to assist ventilation;
(d) ASTs shall be secured against tampering
and flooding;
(e) the name of the
product last stored, the date of permanent closure and "PERMANENTLY CLOSED"
shall be stenciled in a readily visible location on each AST;
(f) piping shall be removed or closed in
place; if closed in place, piping shall be disconnected from ASTs, rendered
vapor free, and filled with inert material, capped or blind flanged; owners and
operators seeking to close piping in place shall propose a closure plan for the
piping in writing to the department at least 30 days prior to closure; the
department may approve the plan on a case-by-case basis, after considering the
extent and depth of piping, the proximity of the piping to buildings, the
extent of pavement at the facility, and other factors raised by owners and
operators; if the department does not approve a closure plan, owners and
operators shall remove the piping; and
(g) owners and operators shall dismantle or
remove AST systems and secondary containment to the extent needed to conduct
the site assessment required in 20.5.115.1504 NMAC.
(3) For mobile AST systems, owners and
operators shall perform all of the closure requirements in Paragraph (2) of
this subsection, except they need not perform the requirements of Subparagraph
(e) of Paragraph (2) of this subsection. Owners and operators shall remove or
cap piping when permanently closing a mobile AST. Owners and operators shall
perform a site assessment that complies with the requirements of 20.5.115.1504
NMAC before permanent closure of any permanently installed mobile tank is
completed.