Current through Register Vol. 39, No. 6, September 16, 2024
The following water quality standards shall apply to
surface waters within water supply watersheds classified as WS-IV. Water
quality standards applicable to Class C waters as described in Rule .0211 of
this Section shall also apply to Class WS-IV waters.
(1) The best usage of waters classified as
WS-IV shall be as a source of water supply for drinking, culinary, or
food-processing purposes for those users where a more protective WS-I, WS-II or
WS-III classification is not feasible as determined by the Commission in
accordance with Rules .0212 through .0215 of this Section and any other best
usage specified for Class C waters.
(2) The best usage of waters classified as
WS-IV shall be maintained as follows:
(a)
Water quality standards in a WS-IV watershed shall meet the requirements as
specified in Item (3) of this Rule.
(b) Wastewater and stormwater point source
discharges in a WS-IV watershed shall meet the requirements as specified in
Item (4) of this Rule.
(c) Nonpoint
source pollution in a WS-IV watershed shall meet the requirements as specified
in Item (5) of this Rule.
(d)
Following approved treatment, as defined in Rule .0202 of this Section, the
waters shall meet the Maximum Contaminant Level concentrations considered safe
for drinking, culinary, or food-processing purposes that are specified in 40
CFR Part 141 National Primary Drinking Water Regulations and in the North
Carolina Rules Governing Public Water Supplies,
15A NCAC
18C .1500.
(e) Sources of water pollution that preclude
any of the best uses on either a short-term or long-term basis shall be deemed
to violate a water quality standard.
(f) The Class WS-II or WS-III classifications
may be used to protect portions of Class WS-IV water supplies. For
reclassifications of these portions of WS-IV water supplies occurring after the
July 1, 1992 statewide reclassification, a WS-IV classification that is
requested by local governments shall be considered by the Commission if all
local governments having jurisdiction in the affected areas have adopted a
resolution and the appropriate ordinances as required by
G.S.
143-214.5(d) to protect the
watershed or if the Commission acts to protect a watershed when one or more
local governments has failed to adopt protective measures as required by this
Sub-Item.
(3) Water
quality standards applicable to Class WS-IV Waters shall be as follows:
(a) MBAS (Methylene-Blue Active Substances):
not greater than 0.5 mg/l to protect the aesthetic qualities of water supplies
and to prevent foaming;
(b) Odor
producing substances contained in sewage, industrial wastes, or other wastes:
only such amounts, whether alone or in combination with other substances or
waste, as will not cause organoleptic effects in water supplies that cannot be
corrected by treatment, impair the palatability of fish, or have an adverse
impact, as defined in
15A NCAC
02H .1002, on any best usage established for
waters of this class;
(c)
Chlorinated phenolic compounds: not greater than 1.0 ug/l to protect water
supplies from taste and odor problems due to chlorinated phenols shall be
allowed. Specific phenolic compounds may be given a different limit if it is
demonstrated not to cause taste and odor problems and not to be detrimental to
other best usage;
(d) Total
hardness: not greater than 100 mg/l as calcium carbonate (CaCO3
or Ca + Mg);
(e)
Solids, total dissolved: not greater than 500 mg/l;
(f) Toxic and other deleterious substances
that are non-carcinogens:
(i) Barium: 1.0
mg/l;
(ii) Chloride: 250
mg/l;
(iii) Nickel: 25
ug/l;
(iv) Nitrate nitrogen: 10.0
mg/l;
(v) 2,4-D: 70 ug/l;
(vi) 2,4,5-TP (Silvex): 10 ug/l;
and
(vii) Sulfates: 250
mg/l;
(g) Toxic and
other deleterious substances that are carcinogens:
(i) Aldrin: 0.05 ng/1;
(ii) Arsenic: 10 ug/l;
(iii) Benzene: 1.19 ug/1;
(iv) Carbon tetrachloride: 0.254
ug/l;
(v) Chlordane: 0.8
ng/1;
(vi) Chlorinated benzenes:
488 ug/l;
(vii) DDT: 0.2
ng/1;
(viii) Dieldrin: 0.05
ng/1;
(ix) Dioxin: 0.000005
ng/l;
(x) Heptachlor: 0.08
ng/1;
(xi) Hexachlorobutadiene:
0.44 ug/l;
(xii) Polynuclear
aromatic hydrocarbons (total of all PAHs): 2.8 ng/l;
(xiii) Tetrachloroethane (1,1,2,2): 0.17
ug/l;
(xiv) Tetrachloroethylene:
0.7 ug/l;
(xv) Trichloroethylene:
2.5 ug/l; and
(xvi) Vinyl Chloride:
0.025 ug/l.
(4) Wastewater and stormwater point source
discharges in a WS-IV watershed shall meet the following requirements:
(a) Discharges that qualify for a General
NPDES Permit pursuant to
15A NCAC
02H .0127 shall be allowed in the entire
watershed.
(b) Discharges from
domestic facilities, industrial facilities and trout farms that are subject to
Individual NPDES Permits shall be allowed in the entire watershed.
(c) Stormwater discharges that qualify for an
Individual NPDES Permit pursuant to
15A NCAC
02H .0126 shall be allowed in the entire
watershed.
(d) No discharge of
sewage, industrial wastes, or other wastes shall be allowed in the entire
watershed except for those allowed by Sub-Items (a) through (c) of this Item or
Rule .0104 of this Subchapter, and none shall be allowed that have an adverse
effect on human health or that are not treated in accordance with the permit or
other requirements established by the Division pursuant to
G.S.
143-215.1. Upon request by the Commission,
dischargers or industrial users subject to pretreatment standards shall
disclose all chemical constituents present or potentially present in their
wastes and chemicals that could be spilled or be present in runoff from their
facility which may have an adverse impact on downstream water supplies. These
facilities may be required to have spill and treatment failure control plans as
well as perform special monitoring for toxic substances.
(e) New industrial discharges of treated
wastewater in the critical area shall meet the provisions of Rule
.0224(c)(2)(D), (E), and (G) of this Section and Rule .0203 of this
Section.
(f) New industrial
connections and expansions to existing municipal discharges with a pretreatment
program pursuant to
15A NCAC
02H .0904 shall be allowed in the entire
watershed.
(g) No new landfills
shall be allowed in the Critical Area.
(h) No new permitted sites for land
application residuals or petroleum contaminated soils shall be allowed in the
Critical Area.
(5)
Nonpoint source pollution in a WS-IV watershed shall meet the following
requirements:
(a) Nonpoint source pollution
shall not have an adverse impact on waters for use as a water supply or any
other designated use.
(b) Class
WS-IV waters shall be protected as water supplies that are located in
watersheds that meet average watershed development density levels specified for
Class WS-IV waters in Rule .0624 of this Subchapter.
Authority
G.S.
143-214.1;
143-215.3(a)(1);
Eff. February 1, 1986;
Amended Eff. January 1, 2015; May 1, 2007;
April 1, 2003; June 1, 1996; October 1, 1995; August 1, 1995; June 1,
1994;
Readopted Eff. November 1,
2019.