Current through Register Vol. 48, No. 9, September 27, 2024
1. Existing
water uses and the level of water quality necessary to protect these existing
uses shall be maintained and protected regardless of the water classification
and consistent with the policies below.
a. A
new activity or expansion of an existing activity shall not be allowed in Class
ONRW, Class ORW, or Shellfish Harvesting Waters if it would exclude, through
establishment of a prohibited area, an existing shellfish harvesting or culture
use. A new activity or expansion of an existing activity which will result in a
prohibited area may be allowed in Class SA or Class SB waters when determined
to be appropriate by the Department and would not remove or impair an existing
use.
b. Existing uses and water
quality necessary to protect these uses are presently affected or may be
affected by instream modifications or water withdrawals. The stream flows
necessary to protect classified and existing uses and the water quality
supporting these uses shall be maintained consistent with riparian rights to
reasonable use of water.
c.
Existing or classified ground water uses and the conditions necessary to
protect those uses shall be maintained and protected.
2. Where surface water quality exceeds levels
necessary to support propagation of fish, shellfish, and wildlife, and
recreation in and on the water, that quality shall be maintained and protected
unless the Department finds, after intergovernmental coordination and public
participation, that allowing lower water quality is necessary to important
economic or social development in the areas where the waters are located. In
allowing such lower water quality, water quality adequate to fully protect
existing and classified uses shall be maintained. The highest statutory and
regulatory requirements for all new and existing point sources shall be
achieved and all cost-effective and reasonable best management practices for
nonpoint source control shall be achieved within the State's statutory
authority and otherwise encouraged. In order to fulfill these goals, the
Department shall consider (a) through (e) below when evaluating any proposed
expansion or new discharge to waters of the State that will lower water quality
to a measurable effect. This includes, but is not limited to, the new or
increased loading of any pollutant or pollutant parameter in the effluent
regardless of whether the discharge flow changes.
a. An alternatives analysis, conducted by the
applicant, must demonstrate to the Department that none of the following
applicable alternatives that would minimize or eliminate the lowering of water
quality are economically and technologically reasonable:
(1) Water recycle or reuse;
(2) Use of other discharge
locations;
(3) Connection to other
wastewater treatment facilities;
(4) Use of land application;
(5) Product or raw material substitution;
and
(6) Any other treatment option
or alternative.
b. If an
evaluation of the alternatives analysis reveals that economically and
technologically reasonable treatment options, combined with any alternatives,
would prevent the need for the lowering of water quality, the Department shall
deny the request.
c. If there are
no economically and technologically reasonable alternatives to a proposed
discharge that will result in the lowering of water quality of a waterbody, the
Department shall evaluate whether the proposed discharge is necessary for
important economic or social development and may deny the request based upon
this evaluation. For purposes of this evaluation, several economic and social
factors may be considered, including, but not limited to, the following:
(1) Employment (increases, maintenance, or
avoidance of reduction);
(2)
Increased industrial production;
(3) Improved community tax base;
(4) Improved housing; and/or
(5) Correction of an environmental or public
health problem.
d.
Conformance of the proposed discharge with the applicable 208 Areawide Water
Quality Management Plans may demonstrate importance to economic and social
development as well as intergovernmental coordination and public
participation.
e. Activities
requiring permits or certification by the Department shall provide for public
participation through the Department's existing public notification
processes.
3. The water
quality of outstanding resource surface waters designated as Class ONRW or
Class ORW shall be maintained and protected through application of the
standards for these classifications as described in Section G.
4. Certain natural conditions may cause a
depression of dissolved oxygen in surface waters while existing and classified
uses are still maintained. The Department shall allow a dissolved oxygen
depression in these naturally low dissolved oxygen waterbodies as prescribed
below pursuant to the Act, S.C. Code Sections
48-1-83, et seq.:
a. For purposes of section D of this
regulation, the term "naturally low dissolved oxygen waterbody" is a waterbody
that, between and including the months of March and October, has naturally low
dissolved oxygen levels at some time and for which limits during those months
shall be set based on a critical condition analysis. The term does not include
the months of November through February unless low dissolved oxygen levels are
known to exist during those months in the waterbody. For a naturally low
dissolved oxygen waterbody, the quality of the surface waters shall not be
cumulatively lowered more than 0.1 mg/L for dissolved oxygen from point sources
and other activities; or
b. Where
natural conditions alone create dissolved oxygen concentrations less than one
hundred ten percent (110%) of the applicable water quality standard established
for that waterbody, the minimum acceptable concentration is ninety percent
(90%) of the natural condition. Under these circumstances, an anthropogenic
dissolved oxygen depression greater than 0.1 mg/L shall not be allowed unless
it is demonstrated that resident aquatic species shall not be adversely
affected pursuant to S.C. Code Section
48-1-83. The Department may modify
permit conditions to require appropriate instream biological monitoring.
c. The dissolved oxygen
concentrations shall not be cumulatively lowered more than the deficit
described above utilizing a daily average unless it can be demonstrated that
resident aquatic species shall not be adversely affected by an alternate
averaging period.
