Current through Register Vol. 50, No. 9, September 20, 2024
A. A groundwater monitoring system must be
capable of yielding groundwater samples for analysis and must consist of:
1. monitoring wells (at least one) installed
hydraulically upgradient (i.e., in the direction of increasing static head)
from the limit of the waste management area. Their number, locations, and
depths must be sufficient to yield groundwater samples that are:
a. representative of background groundwater
quality in the uppermost aquifer near the facility; and
b. not affected by the facility;
and
2. monitoring wells
(at least three) installed hydraulically downgradient (i.e., in the direction
of decreasing static head) at the limit of the waste management area. Their
number, locations, and depths must ensure that they immediately detect any
statistically significant amounts of hazardous waste or hazardous waste
constituents that migrate from the waste management area to the uppermost
aquifer;
3. the facility owner or
operator may demonstrate that an alternate hydraulically downgradient
monitoring well location will meet the criteria outlined below. The
demonstration must be in writing and kept at the facility. The demonstration
must be certified by a qualified groundwater scientist and establish that:
a. an existing physical obstacle prevents
monitoring well installation at the hydraulically downgradient limit of the
waste management area;
b. the
selected alternate downgradient location is as close to the limit of the waste
management area as practical; and
c. the location ensures detection that, given
the alternate location, is as early as possible of any statistically
significant amounts of hazardous waste or hazardous waste constituents that
migrate from the waste management area to the uppermost aquifer;
d. lateral expansion, new, or replacement
units are not eligible for an alternate downgradient location under this
Paragraph.
B.
Separate monitoring systems for each waste management component of a facility
are not required provided that provisions for sampling upgradient and
downgradient water quality will detect any discharge from the waste management
area.
1. In the case of a facility consisting
of only one surface impoundment, landfill, or land treatment area, the waste
management area is described by the waste boundary (perimeter).
2. In the case of a facility consisting of
more than one surface impoundment, landfill, or land treatment area, the waste
management area is described by an imaginary boundary line which circumscribes
the several waste management components.
C. All monitoring wells must be cased in a
manner that maintains the integrity of the monitoring well bore hole. This
casing must be screened or perforated, and packed with gravel or sand where
necessary, to enable sample collection at depths where appropriate aquifer flow
zones exist. The annular space (i.e., the space between the bore hole and well
casing) above the sampling depth must be sealed with a suitable material (e.g.,
cement grout or bentonite slurry) to prevent contamination of samples and the
groundwater.
AUTHORITY NOTE:
Promulgated in accordance with
R.S.
30:2180 et
seq.
