Current through Register Vol. 39, No. 6, September 16, 2024
The Department shall classify the risk of each known
discharge or release as high, intermediate, or low risk, unless the discharge
or release has been classified under Rule .0504 of this Section. For purposes
of this Section:
(1) "High risk" means
that:
(a) a water supply well, including one
used for non-drinking purposes, has been contaminated by a release or
discharge;
(b) a water supply well
used for drinking water is located within 1000 feet of the source area of a
confirmed discharge or release;
(c)
a water supply well not used for drinking water is located within 250 feet of
the source area of a confirmed discharge or release;
(d) the groundwater within 500 feet of the
source area of a confirmed discharge or release has the potential for future
use in that there is no source of water supply other than the
groundwater;
(e) the vapors from a
discharge or release pose a serious threat of explosion due to accumulation of
the vapors in a confined space or pose a risk to public health from exposure;
or
(f) a discharge or release poses
an imminent danger to public health, public safety, or the
environment.
(2)
"Intermediate risk" means that:
(a) surface
water is located within 500 feet of the source area of a confirmed discharge or
release and the maximum groundwater contaminant concentration exceeds the
applicable surface water quality standards and criteria found in
15A NCAC
02B .0200 by a factor of 10;
(b) in the Coastal Plain physiographic region
as designated on a map entitled "Geology of North Carolina" published by the
Department in 1985, the source area of a confirmed discharge or release is
located in an area in which there is recharge to an unconfined or semi-confined
deeper aquifer that the Department determines is being used or may be used as a
source of drinking water;
(c) the
source area of a confirmed discharge or release is within a designated wellhead
protection area, as defined in
42 U.S.C.
300h-7(e);
(d) the levels of groundwater contamination
for any contaminant except ethylene dibromide, benzene, and alkane and aromatic
carbon fraction classes exceed 50 percent of the solubility of the contaminant
at 25 degrees Celsius or 1,000 times the groundwater standard or interim
standard established in Rule .0202 of this Subchapter, whichever is lower;
or
(e) the levels of groundwater
contamination for ethylene dibromide and benzene exceed 1,000 times the federal
drinking water standard as referenced in
15A NCAC
18C .1518, incorporated by reference
including subsequent amendments and editions and is available free of charge at
http://reports.oah.state.nc.us/ncac/title 15a - environmental quality/chapter
18 - environmental health/subchapter c/15a ncac 18c
.1518.pdf.
(3) "Low risk" means that:
(a) the risk posed does not fall within the
high or intermediate risk categories; or
(b) based on review of site-specific
information, limited assessment, or interim corrective actions, the discharge
or release poses no significant risk to human health or the environment.
If the criteria for more than one risk category applies,
the discharge or release shall be classified at the highest risk level
identified in Rule .0507 of this Section.
Authority
G.S.
143-215.3(a)(1);
143-215.84;
143-215.104AA;
143B-282;
Eff. March
1, 2016;
Readopted Eff. June 1,
2019.