2001 Roanoke Sec B Chap 2

Section B: Chapter 2 - Roanoke River Subbasin 03-02-02 97
Chapter 2 -
Roanoke River Subbasin 03-02-02
Includes a portion of the Dan and Mayo Rivers
2.1 Water Quality Overview
This subbasin contains a ten-mile segment of the Dan
River and the Mayo River in Stokes and Rockingham
counties. Mayodan, Madison and Stoneville are the
largest towns. Other streams include Big and Little
Beaver Island Creeks, Hogans Creek and Jacobs Creek.
A map of this subbasin including water quality sampling
locations is presented in Figure B-2.
Bioclassifications for the 1999 sample locations are
presented in Table B-4. Use support ratings for each
applicable category in this subbasin are summarized in
Table B-5. Refer to Appendix III for a complete listing of
monitored waters and further information about use
support ratings.
Most of the land in this portion of the basin is forested (76
percent), but a significant portion is also in use as
cultivated cropland and pasture (22 percent). The
estimated subbasin population, based on the 1990 census, is 19,588. Population is expected to
increase by 28 percent in Stokes County and three percent in Rockingham County over a twenty-
year period (1998 to 2018).
There are nine NPDES permitted dischargers in this subbasin, most of which are small
wastewater treatment plants serving residential areas. One of these small wastewater treatment
plants had problems with elevated BOD and ammonia in its discharge. The largest discharge is
from the Town of Mayodan’s WWTP to the Mayo River. Two facilities in this subbasin are
required to monitor their effluent’s toxicity: Mayodan WWTP and Stoneville WWTP. There
were no indications of toxicity problems during the most recent review period.
Benthic macroinvertebrates in this subbasin were sampled under extreme low flow conditions in
1999. For larger streams affected by nonpoint source pollution, a sharp decline in flow may
result in a higher bioclassification; smaller streams, however, might be adversely affected by
extremely low flow.
Subbasin 03-02-02 at a Glance
Land and Water Area
Total area: 231 mi
2
Land area: 229 mi
2
Water area: 2 mi
2
Population Statistics
1990 Est. Pop.: 19,588 people
Pop. Density: 86 persons/mi
2
Land Cover (%)
Forest/Wetland: 76.1
Surface Water: 0.8
Urban: 1.3
Cultivated Crop: 3.6
Pasture/
Managed Herbaceous: 18.2
Se
c
t
i
o
n

B
:

C
h
a
p
t
e
r

2

-

R
o
a
n
o
k
e

R
i
v
e
r

S
u
b
b
a
s
i
n

0
3
-
0
2
-
0
2
98
Fi
g
u
r
e

B
-
2

S
a
m
p
l
i
n
g

L
o
c
a
t
i
o
n
s

w
i
t
h
i
n

S
u
b
b
a
s
i
n

0
3
-
0
2
-
0
2
Section B: Chapter 2 - Roanoke River Subbasin 03-02-02 99
Table B-4 DWQ Monitoring Locations and Benthic Macroinvertebrate Bioclassifications
(1999) for Roanoke River Subbasin 03-02-02
Site Stream County Road Bioclassification
Benthic Macroinvertebrates
B-1* Mayo River Rockingham SR 1358 Good
B-5* Mayo River Rockingham SR 2177 Good-Fair
Ambient Monitoring
N1400000 Mayo River Rockingham SR 1358 N/A
* Historical data are available; refer to Appendix II.
Benthic macroinvertebrates were collected from two locations on the Mayo River in 1999. The
most upstream location (near the NC/VA state line) has consistently received Good
bioclassifications over five collections since 1986. The most downstream location (near the
confluence with the Dan River), however, received a Good-Fair bioclassification in 1999,
indicating a decline in water quality as the river flows through North Carolina. Water quality in
the Mayo River is discussed further in Part 2.5 of this chapter.
Water chemistry samples are collected monthly from the Mayo River near the North
Carolina/Virginia state line. These data have indicated good water quality with few violations of
water quality standards. Although the geometric mean of fecal coliform bacteria samples was
below the 200 colonies/100ml reference level, this station had elevated levels of fecal coliform
compared to other monitoring locations in the Roanoke River basin. Turbidity was also slightly
elevated.
For more detailed information on sampling and assessment of streams in this subbasin, refer to
the Basinwide Assessment Report - Roanoke River Basin (DENR-DWQ, May 2000), available
from DWQ Environmental Sciences Branch at http://www.esb.enr.state.nc.us/bar.html or by calling
[phone].
Section B: Chapter 2 - Roanoke River Subbasin 03-02-02 100
Table B-5 Use Support Ratings Summary (1999) for Monitored and Evaluated
1 Freshwater
Streams (miles) in Roanoke River Subbasin 03-02-02
Use Support
Category
FS PS NS NR Total
2
Aquatic Life/
Secondary Recreation
85.5 0 0 45.8 131.3
Fish Consumption3 09.30 09.3
Primary Recreation 0 0 0 11.3 11.3
Water Supply 00000
1 For the fish consumption use support category, only monitored stream miles are presented.
2 Total stream miles assigned to each use support category in this subbasin. Column is not additive
because some stream miles are assigned to more than one category.
3 These waters are impaired because of a statewide fish consumption advisory for bowfin. Refer to
Section A, Part 4.8.4 for further information. Fish tissue monitoring in the Dan River is discussed
in Chapter 3 of this section.
2.2 Status and Recommendations for Previously Impaired Waters
This section reviews use support and recommendations detailed in the 1996 basinwide plan,
reports status of progress, gives recommendations for the next five-year cycle, and outlines
current projects aimed at improving water quality for each waterbody. The 1996 Roanoke River
Basinwide Plan did not identify any impaired stream segments in this subbasin.
2.3 Status and Recommendations for Newly Impaired Waters
The Dan River, from the confluence with Jacobs Creek to a point just downstream of Matrimony
Creek in subbasin 03-02-03, is rated partially supporting based on recent DWQ monitoring
(1995-1999). This section outlines the potential causes and sources of impairment and provides
recommendations for improving water quality.
2.3.1 Dan River (14.2 miles from Jacobs Creek to Matrimony Creek)
Current Status
The turbidity standard (50 NTU) was exceeded at the Dan River near Wentworth (N2300000)
ambient monitoring station in 18 percent of 55 samples collected from 1995 to 1999. Results of
data collected from this station are discussed more thoroughly in Section A, Chapter 3. All
particles in the water that may scatter or absorb light, including suspended sediment, aquatic
organisms and organic particles such as pieces of leaves, contribute to turbidity. Therefore, all
types of nonpoint source pollution have the potential to increase turbidity concentrations.
Construction in the Madison/Mayodan area, agricultural activities, suspended sediment loading
from upstream in both the Dan and the Mayo Rivers, as well as permitted instream mining
operations are all potential sources.
Section B: Chapter 2 - Roanoke River Subbasin 03-02-02 101
2001 Recommendations
DWQ will work with the Division of Land Resources to evaluate and reduce turbidity from
permitted instream mining operations in the Dan River. As permits are renewed, monitoring
upstream and downstream of mining operations and instream BMPs (such as those used by the
NC Department of Transportation during bridge construction) could be required. Refer to
Section A, Chapter 4 for further discussion and recommendations about instream mining
operations and other potential sources of nonpoint source pollution in the watershed. In addition,
DWQ will notify local agencies of water quality concerns regarding these waters and work with
them to conduct further monitoring and to locate sources of water quality protection funding.
2.4 Section 303(d) Listed Waters
Currently in this subbasin, no waterbodies are listed on the state’s year 2000 §303(d) list. A
portion of the Dan River, discussed above, will likely be added to the list in 2002. Refer to
Appendix IV for more information on the state’s §303(d) list and listing requirements.
2.5 Other Issues and Recommendations
The surface waters discussed in this section are fully supporting designated uses (or not rated)
based on recent DWQ monitoring; however, data revealed some impacts to water quality.
Although no action is required for these streams, voluntary implementation of BMPs is
encouraged and continued monitoring is recommended. DWQ will notify local agencies of water
quality concerns regarding these waters and work with them to conduct further monitoring and to
locate sources of water quality protection funding. Additionally, education on local water quality
issues is always a useful tool to prevent water quality problems and to promote restoration
efforts. Nonpoint source program agency contacts are listed in Appendix VI.
2.5.1 Mayo River
As was noted in the overview of monitoring data, a decline in biological integrity was observed
in the Mayo River between the upper sampling station near the NC/VA state line and the lower
sampling station near the confluence with the Dan River at Mayodan. The lower site declined to
Good-Fair under low flow conditions in 1999. Two of the most common pollutants in runoff
associated with livestock grazing in riparian areas (with direct access to streams) are bacteria and
sediment. Failing septic systems and problems with wastewater treatment plants can also cause
high levels of fecal coliform bacteria.
There are several discharges between the two Mayo River monitoring stations; however, records
did not indicate significant compliance or toxicity problems with these discharges over the past
five years. There is one permitted instream mining operation in this section of the Mayo River.
Urban/construction and agricultural runoff are likely contributing to this decline in water quality
as well. DWQ will continue to monitor water quality in the Mayo River. Section A, Chapter 4
contains general recommendations for development, construction, stormwater and agricultural
best management practices, as well as instream mining activities.
Section B: Chapter 2 - Roanoke River Subbasin 03-02-02 102
2.5.2 Projected Population Growth
Stokes County is projected to receive the largest population increase of the sixteen counties in
the NC portion of the Roanoke River basin. From 1998 to 2018, the estimated population
growth for Stokes County is 28 percent and Rockingham County is three percent. Growth
management within the next five years will be imperative, especially in and around urbanizing
areas, in order to maintain good water quality in this subbasin. Growth management can be
defined as the application of strategies and practices that help achieve sustainable development in
harmony with the conservation of environmental qualities and features of an area. On a local
level, growth management often involves planning and development review requirements that
are designed to maintain or improve water quality. Refer to Section A, Chapter 4 for more
information about urbanization and development and recommendations to minimize impacts to
water quality.
2.5.3 NPDES Discharges
As was mentioned in this chapter’s overview, one facility experienced problems complying with
NPDES permit limits over the most recent two-year review period: Bethany Elementary School.
Rockingham County upgraded the WWTP at Bethany Elementary in 1998 to a recirculating sand
filter system with ultraviolet disinfection. This facility is currently in full compliance (Russell,
June 7, 2001).
Section B: Chapter 2 - Roanoke River Subbasin 03-02-02 103