Chapter 8 Classifications

Chapter 8
North Carolina Water Quality Standards and Classifications

8.1 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.

8.1.1 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 18 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
(NCDENR-DWQ, August 2004). Information on this subject is also available at DWQ’s website
http://h2o.enr.state.nc.us/csu.

Table 18 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 uses.
SA Waters classified for commercial shellfish harvesting.
WS Water Supply watershed. There are five WS classes ranging from WS-I through WS-V. WS classifications
are assigned to watersheds based on land use characteristics of the area. Each water supply classification has
a set of management strategies to protect the surface water supply. WS-I provides the highest level of
protection and WS-V provides the least protection. A Critical Area (CA) designation is also listed for
watershed areas within a half-mile and draining to the water supply intake or reservoir where an intake is
located.
SUPPLEMENTAL CLASSIFICATIONS
Class Best Uses
Sw Swamp Waters: Recognizes waters that will naturally be more acidic (have lower pH values) and have 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 possessing special qualities including excellent water quality, Native or Special
Native Trout Waters, Critical Habitat areas, or WS-I and WS-II water supplies.
ORW Outstanding Resource Waters: Unique and special surface waters which are unimpacted by pollution and
have some outstanding resource values.
NSW Nutrient Sensitive Waters: Areas with water quality problems associated with excessive plant growth
resulting from nutrient enrichment.
* Primary classifications beginning with a "S" are assigned to saltwaters.
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8.1.2 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 273.6 stream miles of HQW waters in the
French Broad River basin (Figure 12). 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.

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 one 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 setback 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 one 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.
• 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.

Outstanding Resource Waters (Class ORW)
There are 263.0 stream miles of ORW waters in the French Broad River basin (Figure 12).
These waters have excellent water quality (rated based on biological and chemical sampling as
with HQWs) and an associated outstanding resource.

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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 setback 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.
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 294.7 freshwater acres and 185.0 stream miles classified for primary recreation in the
French Broad 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
There are 272.2 freshwater acres and 2,132.5 stream miles classified as Trout (Tr) waters in the
French Broad 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 water streams. 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 for protecting trout streams from land-disturbing activities. The SPCA states that
“waters that have been classified as trout waters by the Environmental Management Commission
(EMC) shall have an undisturbed zone either 25 feet wide or of sufficient width to confine
visible siltation within the twenty-five percent (25%) of buffer zone nearest the land-disturbing
activity, whichever is greater” [G.S. 113A-57(1)]. This rule applies to all named and unnamed
tributaries flowing to the affected trout water stream. For more information regarding land-
disturbing activities along designated trout streams, refer to the DLR website at
www.dlr.enr.state.nc.us/.

The NC Wildlife Resources Commission (WRC) administers a state fishery management
classification known as the Designated Public Mountain Trout Waters. 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)
There are 710.9 freshwater stream miles and 566.4 freshwater acres currently classified for water
supply in the French Broad River basin (Figure 13). 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
Chapter 8 – North Carolina Water Quality Standards and Classifications Introduction 93

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 minimum 30-foot setback is required
on perennial streams in those watersheds in low density areas; a minimum 100 feet setback is
required in high density areas. The French Broad River basin currently contains WS-I, WS-II,
WS-III and WS-IV water supply watersheds.

8.2 Reclassification of Surface Waters

The classification of a surface water may be changed if a request is submitted by a local
government, watershed group, or a local citizen. 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
Classification and Standards Unit. For more information on requests for reclassification and
contact information, visit http://h2o.enr.state.nc.us/csu/.

8.2.1 Pending and Recent Reclassifications in the French Broad River Basin

In Chapters 1 through 7, DWQ identified those surface waters as having Excellent
bioclassification, and therefore, may be eligible for reclassification. There may also be many
other surface waters eligible for reclassification that were not identified with the subbasin
chapters. Both private and public stakeholders play an important role in the reclassification
process and are responsible for filing formal requests with DWQ for reclass consideration. The
following waters have been reclassified or have been identified by the NC Wildlife Resources
Commission (WRC) as potential areas for reclassification.

Richland Creek [AU# 5-16-(1)] and several of the tributaries in the upper watershed were
reclassified and given the supplemental classification of Tr. Rules associated with the Tr
classification became effective September 1, 2004. Refer to Section 5.3.3 for more information
related to Richland Creek in the Pigeon River watershed.

Although the biological indices may not support reclassification at this time, the WRC believes
that portions of the Little River (AU# 6-38) will be eligible for reclassification to HQW in the
future. Little River supports listed and otherwise rare and sensitive aquatic species.

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