Chapter 3

Chapter 3
North Carolina Water Quality Classifications and Standards

3.1 Description of Surface Water Classifications and Standards

North Carolina’s Water Quality Standards Program adopted classifications and water quality
standards for all the state’s river basins by 1963. The program remains consistent with the
Federal Clean Water Act and its amendments. Water quality classifications and standards have
also been modified to promote protection of surface water supply watersheds, high quality
waters, and the protection of unique and special pristine waters with outstanding resource values.

3.1.1 Statewide Classifications

All surface waters in the state are assigned a primary classification that is appropriate to the best
uses of that water. In addition to primary classifications, surface waters may be assigned a
supplemental classification. Most supplemental classifications have been developed to provide
special protection to sensitive or highly valued resource waters. Table 9 briefly describes the
best uses of each classification. A full description is available in the document titled:
Classifications and Water Quality Standards Applicable to Surface Waters of North Carolina.
Information on this subject is also available at DWQ’s website:
http://h2o.enr.state.nc.us/wqhome.html.

3.1.2 Statewide Water Quality Standards

Each primary and supplemental classification is assigned a set of water quality standards that
establish the level of water quality that must be maintained in the waterbody to support the uses
associated with each classification. Some of the standards, particularly for HQW and ORW
waters, outline protective management strategies aimed at controlling point and nonpoint source
pollution. These strategies are discussed briefly below. The standards for C and SC waters
establish the basic protection level for all state surface waters. The other primary and
supplemental classifications have more stringent standards than for C and SC, and therefore,
require higher levels of protection.

Some of North Carolina’s surface waters are relatively unaffected by pollution sources and have
water quality higher than the standards that are applied to the majority of the waters of the state.
In addition, some waters provide habitat for sensitive biota such as trout, juvenile fish, or rare
and endangered aquatic species.

High Quality Waters (Class HQW)
There are 15.5 stream miles HQW waters in the Savannah River basin (Figure 7). Special HQW
protection management strategies are intended to prevent degradation of water quality below
present levels from both point and nonpoint sources. HQW requirements for new wastewater
discharge facilities, and facilities which expand beyond their currently permitted loadings,
address oxygen-consuming wastes, total suspended solids, disinfection, emergency requirements,
volume, nutrients (in nutrient sensitive waters) and toxic substances.

Chapter 3 – North Carolina Water Quality Classifications and Standards 33
Table 9 Primary and Supplemental Surface Water Classifications

PRIMARY FRESHWATER AND SALTWATER CLASSIFICATIONS
Class* Best Uses
C and SC Aquatic life propagation/protection and secondary recreation.
B and SB Primary recreation and Class C and SC uses.
SA Suitable for commercial shellfish harvesting and SB and SC uses.
WS Water Supply (WS): Assigned to watersheds based on land use characteristics. The WS classifications have
management strategies to protect the surface water supply. For WS-I through WS-IV, these include limits on
point source discharges and local programs to control nonpoint source and stormwater runoff. A WS Critical
Area (CA) has more stringent protection measures and is designated within one-half mile from a WS intake
or WS reservoir. All WS classifications are suitable for Class C uses.
WS-I Generally located in natural and undeveloped watersheds.
WS-II Generally located in predominantly undeveloped watersheds.
WS-III Generally located in low to moderately developed watersheds.
WS-IV Generally located in moderately to highly developed watersheds.
WS-V Generally upstream of and draining to Class WS-IV waters. No categorical restrictions on watershed
development or treated wastewater discharges.
SUPPLEMENTAL CLASSIFICATIONS
Class Best Uses
Sw Swamp Waters: Waters that have low velocities and other natural characteristics that are different from
adjacent streams (i.e., lower pH, lower levels of dissolved oxygen).
Tr Trout Waters: Provides protection to freshwaters for natural trout propagation and survival of stocked trout.
HQW High Quality Waters: Waters that have excellent water quality, primary nursery areas and other functional
nursery areas, WS-I and WS-II or SA waters.
ORW Outstanding Resource Waters: Unique and special waters of exceptional state or national recreational or
ecological significance which require special protection.
NSW Nutrient Sensitive Waters: Waters subject to excessive plant growth and requiring limitations on nutrient
inputs.
* Primary classifications beginning with "S" are assigned to saltwaters.

For nonpoint source pollution, development
activities which require a Sedimentation and
Erosion Control Plan in accordance with rules
established by the NC Sedimentation Control
Commission or an approved local erosion and
sedimentation control program, and which drain to
and are within 1 mile of HQWs, are required to
control runoff from the development using either a
low density or high density option. The low-density
option requires a 30-foot vegetated buffer between
development activities and the stream; whereas, the
high-density option requires structural stormwater
controls. In addition, the Division of Land
Resources (DLR) requires more stringent erosion
controls for land-disturbing projects within 1 mile of and draining to HQWs.

Criteria for HQW Classification
• Waters rated as Excellent based on
DWQ’s chemical and biological
sampling.
• Streams designated as native or special
native trout waters by the Wildlife
Resources Commission (WRC).
• Waters designated as primary nursery
areas or other functional nursery areas
by the Division of Marine Fisheries.
• Waters classified by DWQ as WS-I,
WS-II or SA.

34 Chapter 3 – North Carolina Water Quality Classifications and Standards

Outstanding Resource Waters (Class ORW)
There are 36.9 stream miles and 23.7 lake acres of ORW waters in the Savannah River basin
(Figure 7). These waters have excellent water quality (rated based on biological and chemical
sampling as with HQWs) and an associated outstanding resource.

The requirements for ORW waters are
more stringent than those for HQWs.
Special protection measures that apply to
North Carolina ORWs are set forth in 15A
NCAC 2B .0225. At a minimum, no new
discharges or expansions are permitted,
and a 30-foot vegetated buffer or
stormwater controls for new developments
are required. In some circumstances, the
unique characteristics of the waters and
resources that are to be protected require that a specialized (or customized) ORW management
strategy be developed. This strategy is described in Section 1.5.2. A total of 21.7 stream miles
and 17.0 lake acres fall under the modified ORW strategy.
The ORW rule defines outstanding resource values
as including one or more of the following:

• an outstanding fisheries resource;
• a high level of water-based recreation;
• a special designation such as National Wild and
Scenic River or a National Wildlife Refuge;
• within a state or national park or forest; or
• a special ecological or scientific significance.

Primary Recreation (Class B)
There are 33.0 stream miles and 637.8 lake acres classified for primary recreation in the
Savannah River basin. Waters classified as Class B are protected for primary recreation, include
frequent and/or organized swimming, and must meet water quality standards for fecal coliform
bacteria. Sewage and all discharged wastes into Class B waters much be treated to avoid
potential impacts to the existing water quality.

Trout Waters (Class Tr)
There are 162.8 stream miles and 619.0 lake acres classified as trout (Tr) waters in the Savannah
River basin. Different water quality standards for some parameters, such as dissolved oxygen,
temperature and turbidity, have been developed to protect freshwaters for natural trout
propagation and survival of stocked trout. These water quality standards result in more
restrictive limits for wastewater discharges to trout waters.

There are no watershed development restrictions associated with the Tr classification; however,
the NC Division of Land Resources (DLR), under the NC Sedimentation and Pollution Control
Act (SPCA), has requirements to protect Tr streams from land disturbing activities. Under G.S.
113A-57(1), “waters that have been classified as Tr waters by the Environmental Management
Commission (EMC) shall have an undisturbed buffer zone 25 feet wide or of sufficient width to
confine visible siltation within the twenty-five percent of the buffer zone nearest the land-
disturbing activity, whichever is greater.” The Sedimentation Control Commission, however,
can approve land-disturbing activities along Tr waters when the duration of the disturbance is
temporary and the extent of the disturbance is minimal. This rule applies to unnamed tributaries
flowing to the affected Tr water stream. Further clarification on classifications of unnamed
tributaries can be found under Administration Code 15A NCAC 02B .0301(i)(1). For more
information regarding land-disturbing activities along designated Tr streams, see the DLR
website at http://www.dlr.enr.state.nc.us/.
Chapter 3 – North Carolina Water Quality Classifications and Standards 35
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* There are no ORWs or HQWs in the western portion on the Savannah River Basin.
0 2 4 6 81
MilesPlanning Section
Basinwide Planning Unit
August 11, 2006
Figure 7 ORWs and HQWs in the Savannah River Basin
Legend
Hydrography
HQW
ORW
Municipality
County Boundary
Subbasin Boundary

The NC WRC administers a state fishery management classification, Designated Public
Mountain Trout Water. It provides for public access to streams for fishing and regulates fishing
activities (seasons, size limits, creel limits, and bait and lure restrictions). Although many of
these waters are also classified Tr by DWQ, this is not the same classification.

Water Supply Watersheds (Class WS)
The Savannah River basin currently does not contain any water supply classified streams. The
purpose of the Water Supply Watershed Protection Program is to provide a proactive drinking
water supply protection program for communities. Local governments administer the program
based on state minimum requirements. There are restrictions on wastewater discharges,
development, landfills and residual application sites to control the impacts of point and nonpoint
sources of pollution to water supplies.

There are five water supply classifications (WS-I to WS-V) that are defined according to the land
use characteristics of the watershed. The WS-I classification carries the greatest protection for
water supplies. No development is allowed in these watersheds. Generally, WS-I lands are
publicly owned. WS-V watersheds have the least amount of protection and do not require
development restrictions. These are either former water supply sources or sources used by
industry. WS-I and WS-II classifications are also HQW by definition because requirements for
these levels of water supply protection are at least as stringent as those for HQWs. Those
watersheds classified as WS-II through WS-IV require local governments having jurisdiction
within the watersheds to adopt and implement land use ordinances for development that are at
least as stringent as the state’s minimum requirements. A 30-foot vegetated setback is required
on perennial streams in these watersheds.

3.1.3 Reclassification of Surface Waters

A surface water classification may be changed after a request is submitted to the Classifications
and Standards Unit. DWQ reviews each request for reclassification and conducts an assessment
of the surface water to determine if the reclassification is appropriate. If it is determined that a
reclassification is justified, the request must proceed through the state rule-making process. To
initiate a reclassification, the “Application to Request Reclassification of NC Surface Waters”
must be completed and submitted to DWQ’s Classifications and Standards Unit. For more
information on requests for reclassification and contact information, visit
http://h2o.enr.state.nc.us/csu/.
Chapter 3 – North Carolina Water Quality Classifications and Standards 37

38 Chapter 3 – North Carolina Water Quality Classifications and Standards