Current through Register Vol. 48, No. 9, September 27, 2024
(a)
During the closure period the owner or operator must:
(1) Continue all operations (including pH
control) necessary to maximize degradation, transformation, or immobilization
of hazardous constituents within the treatment zone as required under
Section264.273(a)(a), except to the extent such measures are inconsistent with
paragraph (a)(8) of this section.
(2) Continue all operations in the treatment
zone to minimize run-off of hazardous constituents as required under
Section264.273(b)(b);
(3) Maintain
the run-on control system required under Section264.273(c)(c);
(4) Maintain the run-off management system
required under Section264.273(d)(d);
(5) Control wind dispersal of hazardous waste
if required under Section264.273(f)(f);
(6) Continue to comply with any prohibitions
or conditions concerning growth of food-chain crops under
Section264.276;
(7) Continue
unsaturated zone monitoring in compliance with Section264.278, except that
soil-pore liquid monitoring may be terminated 90 days after the last
application of waste to the treatment zone; and,
(8) Establish a vegetative cover on the
portion of the facility being closed at such time that the cover will not
substantially impede degradation, transformation, or immobilization of
hazardous constituents in the treatment zone. The vegetative cover must be
capable of maintaining growth without extensive maintenance.
(b) For the purpose of complying
with 264.115, when closure is completed the owner or operator may submit to the
Department certification by an independent, qualified soil scientist, in lieu
of a qualified Professional Engineer, that the facility has been closed in
accordance with the specifications in the approved closure plan.
(c) During the post-closure care period the
owner or operator must:
(1) Continue all
operations (including pH control) necessary to enhance degradation and
transformation and sustain immobilization of hazardous constituents in the
treatment zone to the extent that such measures are consistent with other
post-closure care activities;
(2)
Maintain a vegetative cover over closed portions of the facility;
(3) Maintain the run-on control system
required under Section264.273(c)(c);
(4) Maintain the run-off management system
required under Section264.273(d)(d);
(5) Control wind dispersal of hazardous waste
if required under Section264.273(f)(f);
(6) Continue to comply with any prohibitions
or conditions concerning growth of food-chain crops under Section264.276;
and,
(7) Continue unsaturated zone
monitoring in compliance with Section264.278, except that soil-pore liquid
monitoring may be terminated 90 days after the last application of waste to the
treatment zone.
(d) The
owner or operator is not subject to regulation under paragraphs (a)(8) and (c)
of this section if the Department finds that the level of hazardous
constituents in the treatment zone soil does not exceed the background value of
those constituents by an amount that is statistically significant when using
the test specified in paragraph (d)(3) of this section. The owner or operator
may submit such a demonstration to the Department at any time during the
closure or postclosure care periods. For the purposes of this paragraph:
(1) The owner or operator must establish
background soil values and determine whether there is a statistically
significant increase over those values for all hazardous constituents specified
in the facility permit under Section264.271(b)(b).
(i) Background soil values may be based on a
one-time sampling of a background plot having characteristics similar to those
to the treatment zone.
(ii) The
owner or operator must express background values and values for hazardous
constituents in the treatment zone in a form necessary for the determination of
statistically significant increases under paragraph (d)(3) of this
section.
(2) In taking
samples used in the determination of background and treatment zone values, the
owner or operator must take samples at a sufficient number of sampling points
and at appropriate locations and depths to yield samples that represent the
chemical make-up of soil that has not been affected by leakage from the
treatment zone and the soil within the treatment zone, respectively.
(3) In determining whether a statistically
significant increase has occurred, the owner or operator must compare the value
of each constituent in the treatment zone to the background value for that
constituent using a statistical procedure that provides reasonable confidence
that constituent presence in the treatment zone will be identified. The owner
or operator must use a statistical procedure that:
(i) Is appropriate for the distribution of
the data used to establish background values; and,
(ii) Provides a reasonable balance between
the probability of falsely identifying hazardous constituent presence in the
treatment zone and the probability of failing to identify real presence in the
treatment zone.
(e) The owner or operator is not subject to
regulation under Subpart F of this regulation if the Department finds that the
owner or operator satisfies paragraph (d) of this section and if unsaturated
zone monitoring under Section264.278 indicates that hazardous constituents have
not migrated beyond the treatment zone during the active life of the land
treatment unit.
