NC0024406_2009 Dan River Summary Report_20101227

PDuke CORPORATE EHS SERVICES
wEnergy@Duke Energy Carolinas, LLC
Carolinas 526 SOUTH CHURCH STREET
CHARLOTTE, • NC 28202
Mailing Address:
EC13K / P. 0. BOX 1006
CHARLOTTE, NC 28201-1006
December 27, 2010
Mr. Jay Sauber OF impa�.V 6 -am
Environmental Sciences Section — �� 1�, p• yr ret, a.- IL
North Carolina Department of Environment
and Natural Resources
1621 Mail Service Center ilp
Raleigh, NC 27699-1621
Subject: Belews Creek Steam Station NPDES Permito. NCO024406
2009 Dan River Summary Report
Dear Mr. Overton:
Enclosed are three copies of the 2009 Dan River summary report, as required by Part I.A.(4.) of NPDES permit No.
NCO024406 for Belews Creek Steam Station in Stokes County, North Carolina. The selenium concentration in fish
muscle tissue remained well below the 10 pg/g concentration considered by the North Carolina Department of
Health and Human Services as the maximum safe concentration for human consumption. This annual update
continues to indicate no detrimental impact to the aquatic .biota in the Dan River from the discharge of Belews Creek
Steam Station ash basin that was initiated in November, 1985.
Based on historical monitoring data, per your approval the following monitoring program changes recommended in
the report will be initiated in 2011:
• With no apparent spatial trend and consistent low concentrations of zinc in fish muscle tissue since 1984,
the discontinuation of zinc concentration analyses in fish tissue is recommended.
• With no consistent differences of bioaccumulation of zinc in macroinvertebrates between upstream and
downstream locations, discontinuation of zinc macroinvertebrate sampling is recommended.
• Additional sampling at the reference site (Anderson Creek) is recommended to get elemental data for all
appropriate macro invertebrate taxa including Plecoptera and Trichoptera to compare with historical -data
collected from the Dan River.
Since I will be retiring at the end of 2010, if you have any questions concerning this report and monitoring program
changes requested, please contact Allen Stowe at (704)-382-4309 or allen.stowep_duke-energy.com .
Sincerely,
0Pp$
9 � y
Etl DEC 2 8 2010
Dtll'.J¢$-ids°,k',e `,�'� �ft�La.
Ron Lewis PC, EI SGt1; E �,(AL.1)' G�1
Water Management
Attachments
xc w/att: Mr. Tom Belnick, NCDENR-DWQ, 1617 Mail Service Center, Raleigh, NC 27699-1617
www.duke-energy.com

BELEWS CREEK STEAM STATION
2009 DAN RIVER SUMMARY
Principal Investigators:
i
T Michael A. Abney
John E. Derwort
Keith A. Finley
DUKE ENERGY
Corporate EHS Services
McGuire Environmental Center
13339 Hagers Ferry Road
Huntersville, NC 28078
December 2010

ACKNOWLEDGMENTS
The, authors wish to express their gratitude to a number of individuals who made significant
contributions to this report. First, we are much indebted to the EHS Scientific Services field
staff in carrying out a complex, multiple -discipline sampling effort that provides the
underpinning of this report. We would like to thank Glenn Long and Chase Fulk for support
in water quality and sediment sample collections. Kim Baker and Bob Doby were vital
contributors in completing fisheries collections and sample processing. James Hall, Aileen
Lockhart, Shannon McCorkle, and Jan Williams contributed in macroinvertebrate sampling,
sorting and taxonomic processing.
We would also like to acknowledge the valuable contributions of Sherry Reid. The benefit of
her diligent efforts and patience in assembling and editing several drafts of the report can
hardly be overstated. Finally, we are indebted to multiple reviewers; including Penny
Franklin, Duane Harrell, Ron Lewis, and John Velte. The insightful commentary and
suggestions from these individuals and also between co-authors have benefited the report in
myriad ways.
ii

TABLE OF CONTENTS
EXECUTIVE SUMMARY.................................................................................................. iv
LIST OF TABLES"
............................................................................................................. viii
LISTOF FIGURES............................................................................................................... ix
CHAPTER 1- INTRODUCTION......................................................................1-1
BACKGROUND INFORMATION................................................................................1-1
DAN RIVER FLOW CHARACTERIZATION.............................................................1-2
CHAPTER2- FISH............................................................................................. 2-1
MATERIALS AND METHODS.................................................................................... 2-1
RESULTS AND DISCUSSION.....................................................................................2-1
RECOMMENDATIONS................................................................................................ 2-3
CHAPTER 3- MACROINVERTEBRATES....................................................
3-1
MATERIALS AND METHODS....................................................................................
3-1
RESULTS AND DISCUSSION.....................................................................................
3-2
Habitat..........................................................................................................................
3-2
Bioclassification...........................................................................................................
3-3
Elemental Concentrations in Organisms......................................................................3-3
Selenium...................................................................................................................
3-4
Zinc...........................................................................................................................
3-5
Arsenic......................................................................................................................
3-6
SUMMARY....................................................................................................................
3-7
RECOMMENDATIONS................................................................................................
3-7
CHAPTER 4- WATER AND SEDIMENT CHEMISTRY............. .................
4-1
MATERIALS AND METHODS....................................................................................4-1
RESULTS AND DISCUSSION.....................................................................................4-3
Stream Flow Characterization......................................................................................4-3
SurfaceWater Quality..................................................................................................4-3
SeleniumLoading Rates..............................................................................................
4-6
Surface Water Trace Element Concentrations.............................................................
4-7
Sediment Trace Element Concentrations.....................................................................4-8
SUMMARY....................................................................................................................
4-8
LITERATURECITED ................................ ........................................................................ L-1
APPENDIX TABLES....................................................................................................... A-1
iii

r
EXECUTIVE SUMMARY
A decline in the Belews Lake fishery was observed during 1976 and was linked to trace
element (principally selenium) contamination and bioaccumulation resulting from discharge
of Belews Creek Steam Station (BCSS) ash basin effluent to the lake. In conjunction with
the conversion from a wet fly -ash to a dry fly -ash handling system, the ash basin effluent was
re-routed to the Dan River in November 1985 as one of several remedies to the
contamination problem. North Carolina Department of Environment and Natural Resources
(NCDENR) subsequently mandated that Duke Energy monitor the recovery of Belews Lake
and assess the impact of the new discharge on the ' biota, water quality, and sediment
chemistry in the ' Dan River. As required by NPDES permit number NC0024406,
environmental monitoring upstream and downstream of the BCSS ash basin discharge
continued during 2009.
Muscle selenium concentrations in suckers and sunfish collected from Dan River sample
locations both up- and downstream of the ash basin discharge remained within the normal
background ranges for fish skeletal muscle tissue. Although selenium concentrations in fish
downstream of the ash basin discharge are consistently twice that of fish from the upstream
location, the concentrations have been similarly low within and among years indicating no
appreciable bio -accumulation or impairment of the Dan River fish community due to the
operation of BCSS. All concentrations were well below the 10 µg/g, wet weight,
concentration that warrants issuance of a consumption advisory.
Mean zinc concentrations were highest for suckers downstream of and at the ash basin
discharge, and for sunfish downstream of the ash basin discharger The low concentrations of
zinc in fish among locations in 2009, and since the inception of this program, may reflect
regional background levels. Zinc concentrations in muscle tissue of fish collected from the
Dan River do not appear problematic, as concentrations continue to be lower than
concentrations (16.0 to 82.0 gg/g, wet weight) reported for several taxa of omnivorous
freshwater fish from other areas in the United States.
Selenium concentrations, in macroinvertebrate taxa analyzed from! Dan River in 2009 were
generally higher downstream than upstream from the ash basin discharge, as has been the
case during most previous- years and; most, often, similar, to, or lower than, concentrations.
` observed' in 2008: Concentrations among. Odonata. and Corbicula slightly increased'
downstream in 2009 and were generally in the low to central portion of the historical range.
iv

u.
Selenium concentrations in Plecoptera decreased downstream in 2009 and remained. in the
high historical range. The mean concentration of selenium in the Anderson Creek reference
site samples of 1999 (0.86 gg/g) was only slightly lower than that -for similar taxa at both
Dan River locations in 2009.
Zinc concentrations in macroinvertebrates were somewhat higher in.2009 than in 2008 and
generally lower downstream than upstream of the ash basin discharge. Values were typically
centralized within the historical range. - The zinc concentration from the Anderson Creek
reference site samples (24.48 gg/g) was higher than the concentration recorded for similar
taxa from both upstream and downstream of the ash basin discharge.
. I
Most arsenic concentrations in macroinvertebrates collected in 2009 were below detection
limits. However, detectable concentrations were slightly lower than or similar to those of
2008, and concentrations downstream from the ash basin discharge were higher than ,those
from upstream. Plecoptera from downstream of the ash basin discharge exhibited the highest
mean arsenic concentration since monitoring began in 2005. The arsenic concentration in
Trichoptera from upstream of the discharge was thelighest ever recorded. Although high in
comparison to previous values, these concentrations were below levels considered as
impaired and similar to levels found in some reference sites. The mean arsenic
concentrations in Corbicula, Ephemeroptera, and Odonata from downstream (0.57 µg/g) of
the ash basin discharge were considerably higher than at the Anderson Creek reference site
(0.30 µg/g).
Compared to the previous 13 years, the total number of macroinvertebrate taxa upstream of
and downstream of the BCSS discharge was the highest yet recorded. Ephemeroptera,
Plecoptera, Trichoptera (EPT) taxa increased upstream since 2008 and also represented the
highest number recorded in 13 years. Nevertheless, EPT taxa declined slightly downstream
of the BCSS discharge. The biotic index (an assessment of pollution tolerances among all
taxa) at the upstream location was lower than in 2008, while the. biotic index downstream of
the BCSS discharge was higher than in 2008. The bioclassification score (the mean of the
EPT score and the biotic index) upstream. of the BCSS discharge in 2009 increased since
2008 and was the highest recorded. in 13 years. Downstream. bioclassification were lower in
2009 but still in the "Good" range.
Based on total numbers of taxa, numbers of EPT taxa, and bioclassification scores; there do
not appear to be any long-term significant impacts of BCSS ash basin discharges on Dan
v

� r
LL
River macroinvertebrate communities. The data for 2009 indicate -that the Dan River in the
vicinity of BCSS supports balanced and indigenous macroinvertebrate-populations.
Dan River water quality in 2009 was generally comparable to that of other Piedmont streams
in the Duke Energy service area, as well as similar to historical data. Most Dan River water
chemistry indicators and analyte concentrations have remained comparable to those
measured prior to the diversion of the BCSS ash basin discharge to the Dan.River. Water
temperatures remained below the default North Carolina standard . (32 °C). Dissolved
Oxygen (DO) concentrations consistently exceeded DO standards (minimal 5 mg/L as a daily
average and 4 mg/L as an instantaneous value) in 2009, as in prior years.
As noted in the 2008 annual summary report, slight increases in specific conductance were
observed again in 2009 downstream of the BCSS ash basin discharge in the Dan River as
compared to upstream values. As previously reported, the increases in conductance can be
primarily attributed to the BCSS ash pond receiving treated process wastewater from a new
internal NPDES discharge point associated with operation of flue gas desulfurization (FGD)
systems.
In 2009, concentrations of calcium and magnesium measured downstream of BCSS remained
elevated both with respect to the upstream site, and compared to the years before FGD
system operation. Additionally, downstream of BCSS, concentrations of major anions,
sulfate and chloride, were slightly increased. These increases were consistent with the
aforementioned increases in specific conductance following operation of the BCSS FGD
systems. Recently observed downstream increases in calcium, magnesium; sulfate, and
chloride which appear linked to new BCSS FGD -related wastewater inputs, remained
substantially below water quality standards and are not anticipated to impair aquatic life or
other uses of the Dan River.
Similar to 2008,'a comparison of 2009 Dan River water quality for sample locations
immediately upstream and downstream of the BCSS ash basin NPDES outfall resulted in
slightly greater differentiation than observed in earlier years of monitoring. Significant (P <
0.05) concentration> differences- between° the. two sites. were primarily related,..to major
dissolved minerals, which as discussed previously, can be linked. to treated. BCSS FGD
wastewater inputs, Analytes. that displayed; a: significant increase; at -the, immediate
downstream site relative, to upstream included specific conductance, total solids (TS;
vi,

dominated by the total dissolved solids fraction) calcium, sulfate, manganese, magnesium,
sodium, and chloride. .
Estimated mass loading of selenium to the Dan River via the BCSS ash basin discharge in
2009 was within the range exhibited in recent years. The 2009 loading rate of 243 g/d
represented only a 1% increase compared to the long-term average of 241 g/d.
As noted in prior years, 2009 Dan River. (and lower Smith River) aqueous arsenic, cadmium,
lead, and selenium concentrations were consistently at or below laboratory reporting limits
and North Carolina water quality standards. Copper and zinc concentrations also remained
below the respective NCDENR water quality action levels for all 2009 samples.
Dry -weight selenium concentrations in Dan River' surficial fine (< 63.0 µm) sediments
measured at four Dan River locations were similar to long-term historical data, and were
within the range of concentrations measured before the routing of the BCSS ash basin
discharge to the river. Concentrations were nearly all below the sample dependent detection
limit. Only one sample yielded a concentration above detection, at 3.0 gg Se/g sediment.
Arsenic concentrations in sediment fines ranged from below the detection limit to a
maximum of 3.7 µg/g sediment and were among the lowest observed to date for the four Dan
River locations. Samples collected immediately downstream of the BCSS ash basin outfall
were only slightly greater than at the upstream location. Further downstream, samples had
similarly low arsenic concentrations.
Results of 2009 monitoring of Dan River biota, water quality, and sediment chemistry in the
vicinity of the BCSS ash basin discharge indicate that the effluent continues to have
negligible impact on the receiving stream. These results are similar to those observed since
1985 when this monitoring program began. Findings continue to indicate the absence of any
short-term and long-term negative impacts which would limit the perpetuation of balanced
indigenous aquatic communities.
vii:

e
1.
LIST OF TABLES
Table Title Page
1-1 Summary of environmental monitoring locations and sampling activity on
the Dan and Smith Rivers during.2009. ...................................................................... 1-3
1-2 Precipitation at Greensboro, NC during 2009 :......................................... ...............1-4
2-1 Species, total length (TL, mm), .and concentrations (wet weight) of selenium
and zinc in fish skeletal muscle tissue collected from three locations in the
DanRiver, NC, 2009................................................................................................... 2-4
3-1 Average daily Dan River flow corresponding to macroinvertebrate sample
4-1 Analytical methods for chemical,and physical constituents measured in the
DanRiver in 2009..................................................................................................... 4-10
4-2 Daily mean flow and corresponding percentiles within cumulative
distributions of monthly historical flows for the Dan River at Pine Hall, and
near Wentworth, NC (USGS Stations 02069000 and 02071000,
respectively) and the Smith River at Eden, NC (USGS Station 02074000)
for 2009 Water quality sampling dates .................................................. ...... :.............. 4-12
4-3- Water chemistry in the Dan and Smith Rivers in the vicinity of BCSS during
2009...........................................................................................................::.............. 4-13
4-4 Concentrations of arsenic and selenium (dry weight) in fine-suspendable
Dan River sediments collected in the vicinity of BOSS May 20, 2009 .................... 4-17
A-1 Macroinvertebrate taxa, collected. from Dan River Location:A from. 1996:-
2009 ............................................................................................................:............... A-1
A-1 Macroinvertebrate_ taxa,collected:from,Dan: River Location -.B, fr=1,996-
2009........................................................................................................................... A-8
viii
collection dates. Data were recorded from the USGS gauge station in
Wentworth, NC...........................................................................................................
3-8
3-2
Description of macroinvertebrate sampling locations on the Dan River ...:.................
3-8
'3-3
Water quality parameters measured at the time of macroinvertebrate sample
collection.......................................................... :..........................................................
3-8
3-4
Macroinvertebrates collected September 9, 2009 from the Dan River at
Location A and Location B relative to the Belews Creek Steam Station ash
basin discharge to the Dan River................................................................................
3-9
3-5
Concentrations (gg/g wet weight) of selenium, zinc, and arsenic in
organisms collected from the Dan River in September 2009 and
comparisons of mean elemental concentrations in Plecoptera and
Trichoptera from 2005 —2009....................................................................................
3-13
3-6
Concentrations (gg/g wet weight) of selenium, zinc, and arsenic in
organisms collected from Anderson Creek, Lincoln County, NC, in October
1999...........................................................................................................................
3-13
4-1 Analytical methods for chemical,and physical constituents measured in the
DanRiver in 2009..................................................................................................... 4-10
4-2 Daily mean flow and corresponding percentiles within cumulative
distributions of monthly historical flows for the Dan River at Pine Hall, and
near Wentworth, NC (USGS Stations 02069000 and 02071000,
respectively) and the Smith River at Eden, NC (USGS Station 02074000)
for 2009 Water quality sampling dates .................................................. ...... :.............. 4-12
4-3- Water chemistry in the Dan and Smith Rivers in the vicinity of BCSS during
2009...........................................................................................................::.............. 4-13
4-4 Concentrations of arsenic and selenium (dry weight) in fine-suspendable
Dan River sediments collected in the vicinity of BOSS May 20, 2009 .................... 4-17
A-1 Macroinvertebrate taxa, collected. from Dan River Location:A from. 1996:-
2009 ............................................................................................................:............... A-1
A-1 Macroinvertebrate_ taxa,collected:from,Dan: River Location -.B, fr=1,996-
2009........................................................................................................................... A-8
viii

LIST OF FIGURES
Figure Title Page
1-1 Monitoring locations in Dan River upstream and downstream of the ash
basin discharge of BCSS, NC . .................................................................................... 1-5
1-2 Hydrograph of 2009 daily average Dan River flows at Wentworth and Pine
Hall, NC (USGS Stations 02071000 and 02069000, respectively)............................1-6
1-3 Hydrograph of daily average flows for,the Dan River near Wentworth, NC
(USGS Station 02071000) from d 984 — 2009.............................................................1-6
14 Monthly median flows for the Dan River near Wentworth, NC (USGS
Station 0207100.0) from 1984 = 2009.......................................................................... 1-7
2-1 Mean selenium concentrations (wet weight) in suckers collected annually
from three locations in the Dan River......................................................................... 2-5
2-2 Mean selenium concentrations (wet weight) in sunfish collected annually
from three locations in the Dan River........................................................................ 2-5
2-3 Mean zinc concentrations (wet weight) in suckers collected annually from
three locations in the Dan River......::.......................................................................... 2-6
2-4 Mean zinc concentrations (wet weight) in sunfish collected annually from -
three locations in the Dan. River........................................................:......................... 2-6
3-1 Hydrograph of 2009 daily average Dan River flows at Wentworth and Pine
ix.
Hall, NC (USGS Stations 02071000 and 020690.00, respectively).. .....:..................
3-14
3-2
Total number of taxa collected from the Dan River at Locations A and B
during, 1997 — 2009 . .......................................... I .......................................................
3-14
3-3
Total number of EPT taxa collected from the Dan River at Locations A and
B during 1997 — 2009................................................................................................
3-15
3-4
Water quality bioclassifications based on macroinvertebrate collections
from the Dan River at Locations A and B during 1997 — 2009 ................................
3-15
3-5
Concentration of selenium in Ephemeroptera collected annually from
Location A, upstream of the BCSS ash basin discharge and Location B,
downstream of the BCSS ash basin discharge..........................................................
3-16
3-6
Concentration of selenium in Odonata collected annually from Location A
upstream of the BCSS ash basin discharge and Location B downstream of
the BCSS ash basin discharge...................................................................................
3-16
3-7
Concentration of selenium in Corbicula collected annually from Location A
upstream of the BCSS ash basin discharge and Location. B downstream of
the BCSS ash basin discharge...................................................................................
3-17
3-8
Concentration of selenium. in Plecoptera collected annually from. Location A
upstream of the BCSS ash basin discharge and Location B downstream: of
the BCSS ash; basin discharge....................................................................................
3-17
3-9
Concentration of selenium- in Trichoptera collected annually from Location
A upstream ofthe-BCSS,ash. basin, discharge and�Location,.B,<downstream;of
the BCSS;:.ash:basin;.discharge::..................................................................................
3-18,
ix.

LIST OF FIGURES, Continued
Figure Title
Page
3-10
Concentration of selenium in all organisms (excluding Diptera) collected
annually from Location A upstream of the BCSS ash basin discharge and
Location B downstream of the BCSS ash basin discharge .......................................
3-18
3-11
Concentrations of zinc in Ephemeroptera collected annually from Location
A upstream of the BCSS ash basin discharge and Location B downstream of
the BCSS ash basin discharge....................................................................................
3-19
3-12
Concentrations of zinc in Odonata collected annually from Location'A
upstream of the BCSS ash basin discharge and Location B downstream of
the BCSS ash basin discharge.......................................................... :........................ 3-19
3-13
Concentrations of zinc in Corbicula collected annually from Location A
upstream of the BCSS ash basin discharge and Location B downstream of
the BCSS ash basin discharge................................................................................... 3-20
3-14
Concentrations of zinc in Plecoptera collected annually from Location A
upstream of the BCSS ash basin discharge and Location B downstream of
the BCSS ash basin discharge................................................................................... 3-20
3-15
Concentrations of zinc in Trichoptera collected annually from Location A
upstream of the BCSS ash basin discharge and Location B downstream of
the BCSS-ash basin discharge...................................................................................
3-21
3-16
Concentrations of zinc in all organisms (excluding Diptera) collected
annually from Location A upstream of the BCSS ash basin discharge and
Location B downstream of the BCSS ash basin discharge .......................................
3-21
3-17
Concentrations of arsenic in all organisms (excluding Diptera) collected
annually from Location A, upstream of the BCSS ash basin discharge and
Location B, downstream of the BCSS ash basin discharge ......................................
3-22
4-1
Hydrograph of 2009 daily average flows for the Dan River at Pine Hall, and
near Wentworth, NC (USGS Stations 02069000 and 02071000,
respectively) and the Smith River at Eden, NC (USGS Station 02074000),
with water quality and sediment sampling dates indicated ............................:..........
4-18
4-2
Comparison of specific conductance among Dan River water quality
monitoring locations from the baseline period (1984 — October 1985)
through2009..............................................................................................................
4-19
4-3
Comparison of total alkalinity among Dan River water quality monitoring
locations from the baseline period (1984 — October 1985) through 2009 ................
4-19
4-4
Comparison of calcium among Dan River water quality monitoring
locations from -the baseline period (1984— October 1985) through 2009 ................
4-20
4-5
Comparison of magnesium among Dan River water quality monitoring
locations from 1988'through 2009............................................................:..............
4-20
4-6
Comparison of.sulfate, among, Dan .River water quality monitoring; locations .
from:the. baseline;period.(1984.1— October) 985) through12009 ....................... ........
4-21-
4-7
Comparismof chloride:among,.DawRiver water, quality -monitoring:
locations from 1-992 through -2009 ..............................................................................
4-21
x

LIST OF FIGURES, Continued
Figure Title
Page
4-8
Comparison of copper among Dan River water quality monitoring locations
from the baseline period (1984- October 1985) through 2009.': ..............................
4-22
4-9 .
Comparison of zinc among Dan River water quality monitoring locations
from the baseline period (1984 — October. 1985) through 2009... ...............................
4-22
4-10
Monthly mean ash basin discharge, flow and selenium,loading.to the -Dan.
River for -2006 — 2009. Loading:estimates are missing. -for months when
selenium analyses were not performed.....................................................................
4-23
4-11
Annual mean daily ash basin discharge and selenium loading to the Dan
River for 1985 —2009. Selenium loading for 1985 is based on November
and December data only............................................................................................
4-23
4-12
Arsenic and selenium concentrations (dry weight) in Dan River fine surficial
sediments collected 4.3 km upstream (Location A) of the BCSS ash basin
discharge. .............. :...................................................................................................
4-24
4-13
Arsenic and selenium concentrations (dry weight) in Dan River fine surficial
sediments collected 14.8 km downstream (Location B) of the BCSS ash
basindischarge..........................................................................................................
4-24
4-14
Arsenic and selenium concentrations (dry weight) in Dan River fine surficial
sediments collected 55.2 km downstream (Location D) of the BCSS ash
basindischarge..........................................................................................................
4-25
' 4-15
Arsenic and selenium concentrations (dry weight) in Dan River fine surficial
--
sediments collected 59.2 km downstream (Location E) of the BCSS ash
basindischarge...........................................................................................................
4-25
xi

CHAPTER 1
INTRODUCTION
BACKGROUND INFORMATION
Belews Creek Steam Station (BCSS) is a base -load, coal-fired electric generating facility
with two 1,110-MWe units, located on Belews Lake in Stokes County, NC. Unit 1 began
commercial operation in August 1974, followed by Unit 2 in December 1975. During early
operational years, a decline in the Belews Lake fishery became evident and was ultimately
associated with trace element (principally selenium) contamination and bioaccumulation
resulting from discharge of BCSS ash basin effluent to the lake.
In 1984 a dry fly -ash collection system was installed at BCSS to eliminate most wet ash
sluicing, thereby substantially lessening selenium and other trace element inputs to the ash
basin: Re -direction of ash basin effluent to the Dan River was implemented in November
1985. Related to these modifications, two required environmental monitoring programs were
stipulated by the North Carolina Department of Environment and Natural Resources
(NCDENR) in conjunction with the BCSS National Pollutant Discharge Elimination System
(NPDES) permit, and these permit requirements continue (NC0024406; NCDENR 2005b).
One program was designed to monitor the recovery of the Belews Lake ecosystem, while the
other was to assess the impact of the new discharge to the Dan River. Results of the Dan
River monitoring program, described in this report, are provided to NCDENR annually.
Environmental monitoring upstream and downstream of the BCSS ash basin discharge
continued in 2009 as required by the BCSS NPDES permit (Table 1-1; Figure 1-1). As in the
past, monitoring activities were designed to characterize potential impacts to selected Dan
River biota, water quality, and sediment chemistry resulting from BCSS ash basin effluent.
Details of monitoring methods and frequencies, as well as a discussion of 2009 monitoring
results; are provided in subsequent chapters of this report.

DAN RIVER FLOW CHARACTERIZATION
Following the relatively dry calendar year of 2008, regional precipitation was near-normal in
2009. However, the year began with an appreciable precipitation deficit through February
(Table 1-2; NCDC 2010). July 2009 was also a relatively dry month, as indicated by 75%
below normal rainfall recorded at the nearby- Greensboro, NC airport. Compensating wet
periods occurred, however, including the months of March, June, and October — December,
with those final three months of the year providing 36% of the annual precipitation total
(NCDC 2010).
A resumption of near-normal precipitation patterns in the latter half of 2008 and throughout
most of 2009 led to Dan River flows that were representative of typical levels through most
of the year (USGS 2010; Figures 1-2 through 1-4). With the exception of short-term, storm
event associated peak flows, lowest 2009 Dan River flows occurred during January —
February, and July — October. Both low -flow periods were linked to below normal
precipitation within the river basin. Minimal flows occurring in the July — October period
were more reflective of a normal seasonal pattern, however, as compared to the more
atypically reduced flows recorded during the winter (January — February) period.
Monthly median Dan River flows in 2009 were representative of long-term patterns (Figure
1-4). The December 2009 peak monthly median, flow achieved at the Wentworth USGS
station, 46.4 m3/s (1,640 cfs), represented the highest monthly median flow encountered
since August 2003. The lowest monthly median flow, 10.2 n,3/s (359 cfs), occurred in
October 2009.
Flow data recorded at both the long-term USGS station near Wentworth, NC, (drainage area
= 2,727 km) and at the recently installed station at Pine Hall, NC, near BCSS (drainage area
= 1,298 km2), showed a high degree of concordance. Differences in magnitude, of base flow
between the two sites over comparable periods were reflective of their drainage area
proportionality. Findings of 2009 biological and chemistry monitoring programs are related
to Dan River hydrology where appropriate in subsequent chapters.
1-2

Table 1-1. Summary of environmental monitoring locations and sampling activity .on the
Dan and Smith.Rivers during 2009. (Locations displayed on Figure 1-1.)
a Latitude and longitude data obtained from T01301 USGS mapping software (National Geographic Holdings, Inc. 2001)
1-3
Duke
Energy
River
Location Description
Report-
Location
-------
----------------------
Latitudea
Longitude
Location
Number
County
Samples Collected
N
W
Designation .
Dan River
6.0 km (3.7mi) upstream of US-
360 22.133'
800 07.541'
A'
710.0
-------
Highway 311 bridge adjacent to
Stokes Co.
Hemlock Golf Course
----------------------
Fish
n
A
US Highway 311 bridge east of
36° 19.620'
800 05.724'
Walnut Cove, NC; 4.3 km (2.7
mi) upstream of BCSS ash basin
discharge
------------------------
Macroinvertebrates,
Chemistry (incl. sediments)
B
720.0
Dan River
Off SR 1138 at Pine Hall Brick
36° 22.436'
79° 59.764'
--------
factory, southeast of Madison,
Rockingham
NC; 14.8 km (9.2 mi)
Co.
downstream of BCSS ash basin
discharge
------------------------
Fish, Macroinvertebrates,
Chemist incl. sediments
C
729.0
Smith River
Kings Highway bridge in Eden,
36° 29.493'
79° 45.060'
--------
NC, 1.2 km (0.7 mi) upstream of
Rockingham
confluence with Dan River
Co.
---------------
Chemistry
D
733.1
Dan River
Dan River Steam Station, below
360 29.151'
79° 43.133'
--------
diversion dam and in thermal
Rockingham
discharge plume; 55.2 km (34.3
Co.
mi) downstream of BCSS ash
basin discharge
--------------------
Chemist incl. sediments
E
705.0
Dan River
NC Highway 700 bridge, east of
360 29.936'
79° 40.879'
------
Eden, NC; 59.2 km (36.8 mi)
Rockingham
downstream of BCSS ash basin
Co.
discharge
Fish, Chemistry, incl. sediments
a Latitude and longitude data obtained from T01301 USGS mapping software (National Geographic Holdings, Inc. 2001)
1-3

Table 1-2. Precipitation at Greensboro, NC during 2009. (Data from, NCDC 2010.) b
b Precipitation totals as water equivalent centimeters and inches
14
2009
Historical
Departure From
Departure From
Month
Precipitation
Average
Average
Average
(cm)
(in)
(cm)
(in)
(cm)
(in)
(°/,)
Jan
6.55
2.58
8.99
3.54
-2.44
-0.96
-27
Feb
4.01
1.58
7.87
3.10
-3.86
-1.52
-49
Mar
11.66
4.59
9.78
3.85
1.88
0.74
19
Apr
7.67
3.02 ,
8.71
3.43
-1.04
-0.41
-12
May
9.12
3.59
10.03
3.95
-0.91
-0.36
-9
Jun
14.40
5.67
8.97
3.53
5.43
2.14
61
Jul
2.82
1.11
11.28
4.44
-8.46
-3.33
-75
Aug
7.92
3.12
9.42
3.71
-1.50
-0.59
-16
Sep
10.34
4.07
10.92
4.30
-0.58
-0.23
-5
Oct
9.70
3.82
8.31
3.27
1.39
'0.55
17
Nov
19.96
7.86
7.52
2.96
12.44
4.90
166
Dec
12.78
5.03
7.77
3.06
5.01
1.97
64
Total
116.93
46.04
109.57
43.14
7.36
2.90
7
b Precipitation totals as water equivalent centimeters and inches
14

Figure 1-1. Monitoring locations in Dan River upstream and downstream of the ash basin discharge of BCSS, NC.

5
1,000
—Dan R @ Wentworth, NC
— Dan R 013ine Hall
100
E
10
310
10,000
3,531
1,000 N
353
100
35
rn rn 0) rn rn M M a) w M M M rn
0 0 0 0 0 0 0 0 0 0 0 0 0
r N r N r T T O O O O
M M yn M M M M N M
r 00 O O r .--
Figure 1-2.i Hydrograph of 2009 daily average Dan River flows at Wentworth and Pine Full,
NC (USGS Stations 02071000 and 02069000, respectively).
1,000
w
E
100
10
10,000
3,531
n
1,000 N
353
100
1 35
d' 40 W r- W O O r N M 4 W W f- M O O r N M "r LO CD t` O O
O o0 M M M W O O M M M 0 M M M 6) 0 0 0 0 0 0 0 0 0 0
O O O O O O M O 0) O O M O O M O O O O O O O O O O O
T T T T T T T T T T T T T- T T T N N N N N N N N N N ,
Figure l-3. Hydrograph of daily average flows for the 'Dan River- near Wentworth, NC
(USGS Station 02071000) from t984,— 2009.
1-6

80
rill
Lel
50
rn 40
co
E
30
20
10
2,500
2,000
1,500
y
1,000
500
0 0
'q U') CO 1- 00 CA O - N M V' CC) (O I- 00 CA O - N CO '7 to CO r- 00 CA
00 00 00 00 00 CC) CA CA CA CA CY) CA CA CY) CA CA C) C) O C7 O C) C7 CD O C7
CA CA CA CY) CA CA CA CA CA CF) CA CA CY) CY) CA CA C7 C) C) C) O C) C) C3 C7 C)
Figure 1-4. Monthly median flows for the Dan River near Wentworth, NC (USGS Station
02071000) from 1984 — 2009.
1-7

CHAPTER 2
FISH
MATERIALS AND METHODS
In July 2009, selenium and zinc concentrations were measured in skeletal muscle tissue of
golden redhorse sucker Moxostoma erythrurum and redbreast sunfish Lepomis auritus
collected by electrofishing at locations upstream (A') and downstream (B and E) of the
Belews Creek Steam Station (BCSS) ash basin discharge (Table 1-1 and Figure 1-1). The
upstream Location A was altered to Location A' during the 1999 drought for better boat
access to target species. Following the standard operating procedures for fish tissue
assessments (NCDENR 2006a), three replicate samples (each with three individuals) were
collected per species at each location such that the total length of the shortest fish was >75%
of the total length of the longest fish within each replicate. Fish were placed in labeled
polyethylene bags and remained on ice until returned to the lab. Once at the lab, they were
frozen until processed.
Sample processing in 2009 was similar to that conducted in 2008 (Duke Energy 2009), where
epaxial muscle tissue was dissected from each fish within each replicate and composited in
an acid -washed polyethylene vial. Selenium and zinc concentrations (µg/g, wet weight) were
determined by neutron activation analysis at the North Carolina State University Nuclear
Services Laboratory in Raleigh, NC. Graphical methods were used to examine temporal and
spatial trends of selenium and zinc concentrations in fish skeletal muscle.
RESULTS AND DISCUSSION
Selenium concentrations in the muscle tissue of composited samples of suckers and sunfish
collected from the Dan River in 2009 ranged from 0.18 to 1.19 µg/g (wet weight) and varied
by taxa and location (Table 2-1). Mean selenium concentrations in suckers and sunfish were
highest at Location B, intermediate at Location E, and lowest at Location A' (Figures 2-1 and
2-2). ,
2-1

Mean selenium concentrations in suckers from Locations A' and E have remained low since
1984, slightly higher and more variable at Location B. Concentrations at Location B rose in
2000 and 2001 due to the combination of elevated selenium loading from the BCSS ash basin
(Figure 4-11) and below normal river discharge, due to a prolonged drought. However,
concentrations have declined since 2001 as selenium loading rates returned to levels that
occurred prior to 2000. Concentrations in 2009 decreased slightly at Location A' and
increased slightly from 2008 levels at Locations B and E.
Mean selenium concentrations in sunfish at Location A' have remained low since 1984, but
have been slightly higher and more variable at Locations B and E. Selenium concentrations
in sunfish in 2009 increased slightly from 2008 levels at all locations, with the most notable
increases occurring downstream of the BCSS discharge.
Overall, mean selenium concentrations in suckers and sunfish remained below maximum
concentrations observed in 2001 and within or slightly above levels representing a normal
background range (0.2 to 0.6 gg/g, wet weight) for fish skeletal muscle tissue (Sorensen
1991). Concentrations are also well below levels considered toxic to, fish (Hamilton 2003;
Lemly 1993) and the 10-µg/g, wet weight, concentration considered as the level for issuance
of a consumption advisory (NCDHH 2007). Although Location B (downstream of the ash
basin discharge) has selenium concentrations that are consistently twice that of Location A'
(upstream), the concentrations have been similarly low within and among years indicating a
minimal level of bioaccumulation and no anticipated impairment of the Dan River fish
community due to the operation of BCSS.
Zinc concentrations (wet weight) in the muscle tissue of composited samples of suckers and
sunfish collected from the Dan River in 2009 ranged from 2.95 to 5.36 µg/g (Table 2-1) and
varied by taxa and location. Mean zinc concentrations were highest for sunfish ,at Location E
and for suckers at Locations B and E. Mean zinc concentrations were lowest for sunfish at
Location B and for suckers at Location A' (Figures 2-3 and 2-4).
Mean zinc concentrations in both taxa have remained low since 1984 and have rarely been
highest at Location B. Concentrations were not selectively affected by a concurrent increase
in zinc during, water quality monitoring in 2001 and 2003 (Figure 4-9). Zinc concentrations
continue to be well below, levels reported: for -several, tax& of omnivorous freshwater fish (16
to 82 gg/g, wet, weight) from other areas in the United States (Moore and: Ramamoorthy
1984) and probably reflect regional background levels. Zinc concentrations in fish tissue
2-2

collected from the Dan River continue to indicate no discernable zinc bioaccumulation or
associated impairment of the Dan River fish community due to the operation'of BCSS.
RECOMMENDATIONS
Fish tissue monitoring of selenium in suckers and sunfish will be continued to monitor the
potential impact of BCSS on the fish community downstream. With no apparent spatial
trend and consistent low concentrations of zinc since 1984, we recommend the
discontinuation of zinc concentration analyses in fish tissue.
2-3

0
Table 2-1. Species,. total length (TL, mm), and concentrations (wet weight) of selenium and
zinc in fish, skeletal muscle tissue collected from three locations in the Dan River,
NC, 2009.
2-4
(N9,9)
Location
Species
TL
Selenium
Zinc
A'
Golden redhorse
296, 322, 333
0.26
2.95
Golden redhorse
295, 300, 304
0.19
3.23
Golden redhorse
320, 325, 342
0.18
3.99
Mean
0.21
3.39
Redbreast sunfish
136, 139, 139
0.29
3.79
Redbreast sunfish
140, 142, 154
0.24
4.34
Redbreast sunfish
153, 159, 162
0.29
4.25
Mean
0.27
4.13
B
Golden redhorse
364, 372, 390
0.62
3.32
Golden redhorse
316,344,349-
0.71
3.99
Golden redhorse
249, 252, 262
0.85
4.63
Mean
0.73
3.98
Redbreast sunfish
126, 129, 134
0.77
3.46
Redbreast sunfish
116, 127, 129
0.89
3.60
Redbreast sunfish
99, 110, 111
1.19
5.16
Mean
0.95
4.07
E
Golden redhorse
273, 278, 326
0.48
3.60
Golden redhorse
258, 262, 275
0.44
4.16
Golden redhorse
214, 245, 258
0.60
4.19
Mean
0.51
3,98
Redbreast sunfish
180, 183, 185
0.68
5.36
Redbreast sunfish
174, 179, 183
0.61
4.90
Redbreast sunfish
162, 167, 167
0.70
4.93
Mean
0.66
5.06
2-4

2.0
1.5
rn
3 1.0
m
0.5
0.0
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
Year
Figure 2-1. Mean selenium concentrations (wet weight) in suckers collected annually from
three locations in the Dan River.
2.0
1.5
0.5
0.0
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
Year
Figure 2=2. Mean selenium concentrations (wet: weight) in sunfish collected° annually from
three locations in the Dan River.
2-5

1
10.O T- 0 A' -0-B * E
8.0
.M
rn
o�
s
N 4.0
2.0
J
0.0
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
Year
Figure 2-3. Mean zinc concentrations (wet weight) in suckers collected annually from three
locations in the Dan River.
10.0
8.0
Wk
2.0
--*—A' -0- B —a E
0.0 i '
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
Year
Figure 2-4. Mean zinc concentrations (wet weight) in sunfish collected annually from three
locations in the Dan River.
2-6
rn
z
C
N
4.0
2.0
--*—A' -0- B —a E
0.0 i '
1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
Year
Figure 2-4. Mean zinc concentrations (wet weight) in sunfish collected annually from three
locations in the Dan River.
2-6

CHAPTER 3
MACROINVERTEBRATES
MATERIALS AND METHODS
Annual benthic macroinvertebrate bioassessment sampling was conducted in the Dan River
on September 9, 2009 to assess potential effects of the Belews Creek Steam Station (BCSS)
ash basin discharge on macroinvertebrate communities in the Dan River. Samples were
collected at Location A, upstream of the ash basin discharge, and Location B, downstream of
the discharge (Table 1-1 and Figure 1-1). A complete listing of macroinvertebrate taxa
collected since 1997 along with abundance values is presented in Appendix A.
The standard qualitative method as outlined in the North Carolina Department of
Environment and Natural Resources (NCDENR) Standard Operating Procedures (SOP) was
used in collecting macroinvertebrate samples. This method involved the use of a variety of
nets to sample the major habitats available at a particular location. Organisms were sorted
from debris in the field and identified to the lowest practicable taxon in the laboratory.
Analysis resulted in a bioclassification for each location which gives equal consideration to
the number of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa present and the biotic
index value. Biologists with NCDENR have assigned tolerance values for benthic taxa based
on their relative tolerance to environmental perturbations, and a mean value was calculated
for all taxa collected from the same location. Following the NCDENR protocol, a score was
assigned to the EPT value and to the mean biotic index. The mean of these two scores was
used to assign one of five bioclassifications, from "Poor" to `Excellent" (NCDENR 2006b).
Bioclassifications were determined using the Piedmont criteria, as outlined in the NCDENR
SOP. An assessment of the balanced and indigenous nature of the benthic community was
determined by comparing both,total and EPT taxa abundance and the resulting water quality
bioclassifications at locations upstream and downstream of the BCSS ash basin discharge.
Whole organism composite samples representing two replicates, whenever possible, were
sent to the Nuclear Services Laboratory at North Carolina State University for neutron
• activation analyses to determine concentrations of selenium, zinc, and, arsenic in selected
macroinvertebrate taxonomic groups collected during- 2009 (Corbicula, Ephemeroptera,
Odonata, Plecoptera, and Trichoptera). It should be noted that samples for elemental
3-1

G
analyses were collected- separately from samples collected for taxa abundance and
bioclassification and; on, occasion, insufficient material was, collected -for, elemental: analyses:
Analytical results were expressed as gg/g.wet weight. Elemental; concentrations originating
in the literature as dry weights and cited in -the discussion were converted to wet weights by
multiplying dry weights by 0.2 (Saiki,and Lowe 1987). Beginning, in 2005, Diptera were
discontinued from the trace element analysis due to difficulties associated with obtaining
adequate sample mass to permit analyses. Plecoptera and Trichoptera were added for trace
elemental analyses in 2005. Beginning in 2007, copper analyses were discontinued. These
changes were approved by NCDENR staff.
Anderson Creek, in Lincoln County, NC, was used as a reference site because there were no
known inputs of trace elements from point sources .(Table 3-6). Samples from this site were
collected in October 1999.
RESULTS AND DISCUSSION
Habitat
The gauge station at Pine Hall access area was added in December 2008, and daily average
flow rates from both Pine Hall and the further downstream Wentworth site are presented.
Flow rates from June through early September 2009 gradually declined from approximately
100 to 200 M% (-- 3,500 to 7,000 cfs), to approximately 6 to 10 m3/s (Z 210 to 350 cfs)
based on both stations (Figure 3-1). There were occasional minor, transient increases in flow
during the two weeks prior to sampling, but these were not significant. On the day of
sampling, the flow rate was 5.7 to 8.1 m3A (204 to 286 cfs) (Table 3-1). This provided for a
fairly stable flow prior to and during sampling.
Habitat varied somewhat between the two locations. Location A was characterized primarily
by sand with some gravel and cobble, while Location B consisted of riffle areas composed of
large cobble and• bedrock covered by sand (Table 3-2). Water temperatures were higher than
those recorded; in, 2008 (Table 3-3). Temperatures and dissolved; oxygen concentrations
showed, no consistent differences, between,the•two locations since monitoring.was initiated, in
2003; however; specific, conductance, values were consistently higher- at> Location. B- tl an; ate;
Location A (Table 3=3). In 2008' and 2009; the specific- conductance values: at Location B'
✓ were approximately four and three times higher, respectively, than at Location A. From
3-2

2003 — 2007, specific conductance values at Location B. ranged from 10.4 — 16.5 µS/cm
higher than at Location A. The unusually high conductivities at Location B over the last two
years were the result of the use of flue gas desulfurization (FGD), or "scrubbers" at BCSS
and the subsequent effects on the effluent (see Chapter 4). The measurement of pH did not
accompany macroinvertebrate sampling until 2008. To date, pH values at Location A are
slightly higher than at Location B.
Bioclassification
Macroinvertebrate samples collected in 2009 at Locations A and B yielded a total of 109 and
91 taxa and 36 and 22 EPT taxa, respectively (Table 3-4). At both locations the numbers of
total taxa collected in 2009 were the highest recorded in 13 years (Figure 3-2). EPT taxa
increased at Location A since 2008 and also represented the highest number recorded in -13
years. The number of EPT taxa at Location B was slightly lower than in 2008 (Figure 3-3).
The biotic index values from Locations A and B were 5.12 and 5.62, respectively. The index
at Location A was lower than in 2008, while the value from Location B was higher than that
of the previous year (Table 3-4).
Since 1997, the Dan River macroinvertebrate community upstream of the BCSS discharge
(Location A) has exhibited water quality bioclassifications ranging from "Good/Fair" in 1999
and 2008, to "Excellent' in 2001 and 2009 (Figure 3-4). The bioclassification at Location A
increased considerably from 2008 to 2009 and was the highest recorded in 13 years. The
bioclassification at Location B was slightly lower than during the previous year but still in
the "Good" range. Bioclassifications downstream of the BCSS discharge (Location B) were
always in the "Good/Fair" to "Good" ranges.
Elemental Concentrations in Organismsa
A variety of factors may affect the concentration of various elements in aquatic
macroinvertebrates and can contribute to variability in the data. Factors unique to the
organism include: body size, gut content, and food habits (Dixit and Witcomb 1983; Smock
1983a; 1983b; Lobel et al. 1991; Cain et al. 1995; Munger and Hare 1997; Farag et al. 1998).
External environmental factors which may affect elemental concentrations include:
temperature; salinity, and, pH (Gerhardt, 1993; Bervoets et al. 1995, 1996a, 1996b; Bervoets
a All references cited present elemental data in µg/g wet weight.
3-3

and Blust 1999, 2000). Additionally, certain characteristics of the sediments themselves,
such as organic and, mineral content, as well as concentrations of contaminants may have a.
significant influence (Bendell-Young et al. 1994; Van Derveer and Canton 1997; Song and
Breslin 1998; Malloy et al. 1999; Filion and Morin 2000; Nelson et al. 2000). Finally, the
potential for synergism in the uptake of various elements available to macroinvertebrates
should be considered (Casini and Depledge 1997).
Of the samples collected for elemental analyses of selenium, zinc, and arsenic in 2009, one-
fifth were at or below detection limits and most were below detection for arsenic. Detection
limits are dependent on a number of factors and have often varied from year to year as well
as among samples within a given year. These factors include the presence of other elements
that may mask the detection of the element of concern, residual sediments on or in the
specimen, and limited mass of certain samples. If the mass of a sample is extremely small, as
it was for the Diptera samples in 2000 and 2002 — 2004, the error related to other factors is
magnified, resulting in a very high detection limit for the sample. In such cases, detection
limits may range up to two orders of magnitude or more for the same element within a given
taxonomic group (Scott .Lassell, Northf Carolina State University, Nuclear Services
Laboratory, personal communication). For this reason sampling of Diptera was discontinued
in 2005.
Selenium
Based on current and historical data, selenium concentrations in all taxa analyzed from Dan
River locations in 2009 were generally higher at Location B than at Location A (0.93 gg/g
and 0.35 µg/g, respectively) (Figures 3-5 through 3-10). The concentration at Location B for
similar taxa was not substantially higher than at the Anderson Creek reference site (0.86
gg/g). Concentrations of selenium in Ephemeroptera were similar to or lower than those of
2008 and were in the low historical range (Figure 3-5). Concentrations among Odonata at
Location B were slightly higher than in 2008, while values from Location A were similar to
or lower than those of 2008. Concentrations at both locations were in the low historical
range (Figure 3-6). Concentrations among Corbicula were slightly higher at both locations
in 2009 as compared., to 2008• and- were in the low to near center of historical ranges- (Figure
3-7). Concentrations among Plecoptera from Location A averaged slightly higher in 2009
than in 2008; while concentrations, att Location B were-, lower than° observed, during, the
previous year (Figure 3=8). Selenium concentrations in Plecoptera from Location• A were in
the low historical range, while those from Location B were in the high range. Concentrations
3-4:

A
among Tricoptera from Location B had declined. since 2008'. There was an insufficient
sample for.; determination of selenium from Location.A in 2008 (Figure 3-9). Concentrations
among Tricoptera at both locations were within historical ranges. Concentrations among all
taxa, including Plecoptera and Trichoptera, were most often similar to, or lower than those of
2008 (Figure 3-10). Additionally, the mean concentration of selenium in the Anderson Creek
samples from 1999 (0.86 gg/g) was only slightly lower than that for similar taxa at Location
B (Tables 3-5 and 3-6).
Several authors have suggested that selenium concentrations within ranges similar to those
found in Dan River macroinvertebrates during years of sampling might be a cause for
concern. Lemly (1993) stated that selenium levels as low as 0.6 µg/g in food organisms can
be toxic to fish and birds that feed on them. He also stated that food -chain organisms such as
benthic, invertebrates could accumulate up to 6 gg/g (some taxa up to 74 gg/g) with no
apparent effect on survival or reproduction. Henderson et al. 1995 (cited in Engberg et al.
1998) reported that concentrations of selenium that ranged from 0.6 to 1.4 gg/g in food chain
organisms were "levels of concern," while at concentrations above 1.4 µg/g "toxicological
and reproductive effects are a certainty." The California Department of Fish and Game
define concentrations greater than 0.8 gg/g in dietary items of fish and birds as
"concentrations of concern" (Maier et al. 1998). Hamilton (2004) surveyed the literature on
selenium toxicity in the aquatic food chain, and from the reviewed studies, listed threshold
levels of concern in fish food organisms that ranged between 0.4 and 1.6 gg/g. The mean
concentrations of selenium in 2009 among all organisms from Locations A and B were 0.35
gg/g and 0.93 µg/g, respectively (Table 3-5). Dan River selenium concentrations in selected
macroinvertebrates are generally at the lower end of reference ranges above.
Zinc
Zinc concentrations among all taxa analyzed were generally lower at Location B than at ..
Location A. This trend was also observed in 2008 and to a lesser extent in 2007 (Table 3-5
and Figures 3-11 through 3-16), but was not consistent over the long term. Zinc
concentrations among all constituents analyzed were generally higher in 2009 than in 2008
and values, were typically centered within the historical range. Mean concentrations of zinc
in 2009 for all groups collectively were 33.78 µg/g and 1&03 gg/g at Locations A and B,
respectively; while, concentrations, for: Corbicula; Ephemeroptera; and Odonata; . collectively,
at Locations,A and' B were 28.l'0' gg/ , and; -23:16- gg/g; respectively (Table 3-5). The zinc
concentration from the Anderson Creek reference site samples, 24.48 gg/g; was higher than
3-5

the concentration recorded for similar taxa from Location B, but lower than at Location A
(Table 3-6).
Saiki et at. (1995) reported that zinc concentrations in Ephemeroptera ranged from 260 to
340 gg/g in a California river polluted with agricultural irrigation sub -surface tile drainage.
At the control site in that study, zinc in Ephemeroptera ranged from 13.0 to 17.2 gg/g.
Poulton et al. (1995) randomly selected macroinvertebrates collected at increasing distances
downstream of a source of metals pollution in a Montana. stream. They reported a mean zinc
concentration of 333 gg/g closest to the source and 71.8 gglg 198 km downstream.
Macroinvertebrates from a control location contained 42.4 gg/g of zinc. Farag et al. (1998)
reported zinc concentrations in macroinvertebrates from Idaho stream reference sites that
ranged from 51 to 78 gg/g. At sites that were affected by past mining operations the
concentrations ranged from 77 to 610 µg/g. The zinc concentrations reported in
macroinvertebrates from the locations. of the cited studies were more often much higher than
concentrations in macroinvertebrates analyzed from the Dan River locations in 2009.
Arsenic
Most arsenic concentrations among Ephemeroptera, Odonata, and Corbicula, in 2009 were
below detection limits; however, values above the limits were slightly lower than or similar
to those of 2008, and values at Location B were, except for Trichoptera, higher than at
Location A (Table 3-5 and Figure 3-17). Concentrations among all but Plecoptera and
Trichoptera were well within historical ranges. The mean arsenic concentration among
Plecoptera from Location A was in the high range, while that value at Location B was the
highest recorded since monitoring began in 2005 (Table 3-5). The mean arsenic
concentration among Trichoptera at Location A was the highest yet recorded, while the
concentration at Location B was in the high historical range (Table 3-5). The mean arsenic
concentrations in all organisms collected upstream and downstream of the BCSS ash basin
discharge in 2009 were 0.28 gg/g and 0.54 pg/g, respectively (Table 3-5). The mean arsenic
concentration in Corbicula, Ephemeroptera, and Odonata from Location A (0.23 µg/g) was
lower than at the Anderson Creek reference site (30 gg/g), while the value from -Location B
(0.57 gg/g) was considerably higher, (Table., 3-6). However; care must be taken when making
these comparisons with many arsenic concentrations at or below detection limits.
Poulton et al. (1995) reported arsenic concentrations that- ranged from 6.8• gg/g nearest a
source of pollution to 0.68 gg/g 198 km downstream, while the concentration at the control
3-6,

site was 0.54. gg/g. Farag•,et al. (1998) found arsenic concentrations from 0.42 to 0.48 gg/g at
reference'sites and 0.44. to 19:40 gg/g at impacted sites. The mean arsenic concentration for
all taxa at Location B (0.54 µg/g) was similar to, or slightly higher than at the reference sites
mentioned above (Table 3-5) and was generally well below concentrations at impacted sites.
Although some elemental concentrations in macroinvertebrates increased from 2008 to 2009
and a few were comparatively high, most concentrations observed in 2009 were well within
historical ranges. Selenium and arsenic concentrations in macroinvertebrates downstream
were typically higher than at the upstream location. The opposite was. true of zinc. Based on
total numbers of taxa, numbers of EPT taxa, and bioclassifications, there do not appear.to be
any long-term significant impacts of BCSS ash basin discharges on Dan River
macroinvertebrate communities. The water quality bioclassifications at the upstream
location were higher than those downstream, but downstream bioclassifications have
continued to be in the "Good" range over the past three years, again an indication of minimal
impacts. The data for 2009 indicate that the Dan River in the vicinity of BCSS supports
balanced and indigenous macroinvertebrate populations. Additional Plecoptera and
Trichoptera sampling will occur at the reference site (Anderson Creek) in 2010 for
comparison of elemental data.
RECOMMENDATIONS
Macroinvertebrate bioassessment monitoring will be continued in an effort to determine
potential impacts of BCSS ash basin discharges on the macroinvertebrate community
downstream. Elemental analyses of selenium and arsenic will also be continued in an effort
to determine bioaccumulations among macroinvertebrates in the Dan River both upstream
and down- stream of the BCSS ash basin discharge. Additional sampling at the reference site
(Anderson Creek) is recommended to get elemental data for. all appropriate taxa including
Plecoptera and Trichoptera to compare with, historical data collected. from. the Dan River.
Discontinuation of zinc sampling is also recommended since analyses over the last 26 years -
have shown no consistent .bioaccumulation differences between upstream. and downstream -
locations.
3-7

Table 3-1. Average daily Dan River flow corresponding to macroinvertebrate sample
collection dates. Data were recorded from -the USES gauge station in Wentworth, NC.
Year
Flow: m. /s
Flow cfs
10/4/2000.
12.4.
440
9/26/2001'
14.9,.
527'
9/20/2002
10.8
382
9/16/2003
30.3
1,070
11/5/2004
37.91,340
9/14/2005;."
11.8'
417
9/12-13/2006
18.8
664
9/10/2007
5.7•
204
9/11/2008
9.8
345
9/9/2009
8.1
286
Table 3-2. Description of macroinvertebrate sampling locations on the Dan River.
Location A
(upstream of BCSS ash basin discharge)
Location B
downstream of BCSS ash basin discharge)
Upstream of BCSS at Highway 311 Bridge.
Downstream of BCSS at SR1138 Bridge, just
Large cornfield adjacent to south bank, with a
downstream of low -head dam. Pine Hall Brick
buffer of grass and trees present. Sand
Factory is just upstream on the north bank, and the
dredging operation on north bank and only a
south bank is a parking area for fishermen. There is
narrow buffer of grass and brush present (actual
some buffered area on the south bank, and little on
dredging takes place downstream of the
the north bank. Riffle areas composed of large
sampling location). Composed primarily of sand
cobble and bedrock; riverbed primarily sand.
with some gravel and small Coble.
Table 3-3. Water quality parameters measured at the time of macroinvertebrate sample
collection.
Location
Parameter
2003
2004
2005
2006
2007
2008
2009
7emperature3t
Dissolved
9.2
10.6
6.6
8.8
10.2
8.7
9.0
Location
Oxygen m /L
A
a {Czonduct�nces
r h45
54 8
'j�52 4
>50 f;41`
f?/tt�A�G.i.
Yh. ir�•^n d
° 5 97�r
�.
53 31k
t
,z
pH
pH not recorded until 2008
7.04
7.05
Dissolved-
8.8
9.6
8.1
8.5
7.6
8.4
8.2
Location
Ox en m /L
B
pK
pH notrecorded;until20087
7.02
:6:.:9:5,:]
b Mean streamflow of both sampling dates.
3-8

Table 3-4.. Macroinvertebrates collected September 9, 2009 from the Dan River at Location
A and Location B relative to the Belews Creek Steam Station ash_ basin discharge
to the Dan, River. "R" = Rare (1 to 2, individuals), "C" = Common. (3 to 9
individuals), and "A" = Abundant (10 or more individuals).
Taxon
Upstream of
Downstream of
BCSS (Al
BCSS (B)
Annelida
Oligochaeta
Tubificida
Naididae
Nais behningi
R
R
Naididae
Nais communis
R
Naididae
Nais variabilis
R
C
Naididae
Pristina leidyi
R
Naididae
Pristina sima
R
Naididae
Pristinella jenkinae
R
Tubificidae
Tubificidae
C
R
Tubificidae
Branchirua sowerbyi
R
A
Tubificidae
Limnoddlus hoffineisteri
R
Tubificidae
Tubifex tubifex
R
Lumbriculida
Lumbriculidae
Lumbriculidae
C
C
Lumbdculidae
Lumbriculus spp.
C
Arthropoda
Crustacea
Decapoda
Cambaridae
Cambarus spp.
C
C
Insecta
Coleoptera.
Dryopidae
Helichus spp.
C
A
Dytiscidae
Neoporus spp.
R
R
Elmidae
Ancyronyx variegatus
C
R
Elmidae
Macronychus glabratus
A
A
Elmidae
Promoresia elegans -
A
R
Elmidae
Stenelmis spp.
R
C
Gyrinidae
Dineutus spp.
A
A
Hydrophilidae
Enochrus spp.
R
Hydrophilidae
Sperchopsis tessellatus
R
Psephenidae
Psephenus herricki
R
Diptera
Ceratopogonidae
Palpomyia-Bezzia complex
R
A
Chironomidae-Chironominae
Chironominae
Chironomus spp.
C
Chironominae
Cladopelma spp.
R
Chironominae
Cladotanytarsus spp.
C
C
Chironominae
Cryptochironomus spp.
C
A
Chironominae
Cryptotendipes spp.
R
A
Chironominae
Demicryptochironomus spp.
C
Chironominae
Dicrotendipes neomodestus
C
A
Chironominae.
Nilothauma,spp.
C
Chironominae
Paracladopelma-spp.
R
Chironominae
Paralauterbomiella nigrohalterale
R
R
3-9

Table 34. (Continued).
Taxon
Upstream of
Downstream of
BCSS W
BCSS M
Chironominae
Phaenopsectra spp.
R
R
Chironominae
Polypedilum fallax
C
R
Chironominae
Polypedilum flavum
A
A
Chironominae
Polypedilum halterale
C
C
Chironominae
Polypedilum illinoense
R
A
Chironominae
Polypedilum scalaenum
C
C
Chironominae
Pseudochironomus spp.
C
Chironominae
Rheotanytarsus spp.
C
R
Chironominae
Robackia claviger
R
Chironominae
Robackia demeijerei
R
R
Chironominae
Stelechomyia perpulchra
C
R
Chironominae
Stenochironomus spp.
C
C
Chironominae
Stictochironomus spp.
C
Chironominae
Tanytarsus spp.
C
A
Chironominae
Tribe/os spp.
C
R
Chironomidae-Orthocladiinae
Orthocladiinae
Cardiocladius spp.
R
Orthocladiinae
Corynoneura spp.
C
Orthocladiinae
Cricotopus bicinctus
A
Orthocladiinae
Cricotopus infuscatus gp.
R
Orthocladiinae
Cricotopus politus
R
C
Orthocladiinae
Cricotopus varipes gr.
C
Orthocladiinae
Cricotopus vierriensis
R
C
Orthociadiinae
Eukiefferiella gracei
C
C
Orthocladiinae
Lopescladius spp.C
Orthocladiinae
Nanocladius downesi
C
C
Orthocladiinae
Rheocricotopus robacki
C
A
Orthocladiinae
Thienemanniella xena
C
C
Orthocladiinae
Tvetenia vitracies
C
A
Chironomidae-Tanypodinae
Tanypodinae
Ablabesmyia mallochi
C
C
Tanypodinae
Ablabesmyia parejantaranta
C
Tanypodinae
Ablabesmyia simpsoni
R
C
Tanypodinae
Nilotanypus spp.
C
Tanypodinae
Procladius spp.
R
R
Tanypodinae
Rheopelopia spp.
C
A
Empididae
Empididae
R
Simuliidae
Simulium spp.
A
A
Tanydehdae
Protoplasa fitchii
R
Tipulidae
Antocha spp.
C
A
Tipulidae
Hexatoma spp.
R
Tipulidae
Tipula spp.
R
C
Ephemeroptera
Baetidae
Acentrella spp.
R
Baetidae-
Baetis flavistriga
C
Baetidae
Baetis intercalaris
A
R
Baetidae•
Centroptilum spp:
R
C
Baetidae
Heterocloeon curiosum
A
A
Baetidae
Plauditus dubius grp
C
Baetidae
Pseudocentroptiloides usa
R
3-10 -

Table 3-4. (Continued).
Taxon
Upstream of
Downstream of
BCSS (A)
BCSS•IB)
Baetidae
Pseudocloeon frondale
R
C
Caenidae
Caenis spp.
C
R
Ephemerellidae
Serratella deficiens-
C
Ephemerellidae
Serratella serratoides
C
Ephemeridae
Hexagenia spp.
A
A
Heptageniidae
Heptagenia marginalis
R
Heptageniidae
Leucrocuta spp.
A
Heptageniidae
Maccaffertium exiguum
A
A
Heptageniidae
Maccaffertium modestum
A
A
Heptageniidae
Rhithrogena spp.
R
Heptageniidae
Stenacron interpunctatum
C
R
Oligoneudidae
Isonychia spp.
A
A
Tricorythidae
Tricorythodes spp.
A
A
Megaloptera
Corydalidae
Corydalus comutus
A
A
Corydalidae
Nigronia serricomis
R
R
Sialidae
Sialis spp.
C
Odonata-Anisoptera
Aeshnidae
Boyeria vinosa
R
Corduliidae
Epicordulia spp.
R
Gomphidae
Dromogomphus spp.
A
C
Gomphidae
Gomphus spiniceps
R
R
Gomphidae
Gomphus spp.
C
Gomphidae
Hagenius brevistylus
R
Gomphidae
Ophiogomphus spp.
C
R
Macromiidae
Macromia spp.
A
R
Odonata-Zygoptera
Calopterygidae
Calopteryx spp.
R
Calopterygidae
Hetaerina spp.
R
Coenagdonidae
Argia spp.
A
A
Plecoptera
Perlidae
Acroneuria abnormis
C-
C
Perlidae
Agnetina capitata
C
Perlidae
Agnetina flavescens
A
Perlidae
Paragnetina fumosa
C
C
Perlidae
Paragnetina ichusa
C
Trichoptera
Brachycentridae
Brachycentrus laterafis
C
Brachycentridae
Brachycentrus numerosus
C
R
Hydropsychidae
Cheumatopsyche spp.
A
A
Hydropsychidae
Cheumatopsyche etrona
c
Hydropsychidae
Hydropsyche.incommoda
A
C
Hydropsychidae
Hydropsyche morosa
R
C
Hydropsychidae
Hydropsyche phalerata
C
Hydropsychidae
Hydmpsyche venulads,
A
A
Hydroptilidae
Hydmptila spp.
A
Hydroptilidae•
Orthotrichia:spp:
R
Leptoceridae
Ceraclea spp:
R
Leptoceridae
Nectopsyche'exquisita
C
Leptoceridae
Oecetis spp.
C
3-11

Table 3-4. (Continued).
Taxon
Upstream of
BCSS (A)
Downstream of
BCSS (B)
Philopotamidae
Chimarra spp.
R
Polycentropodidae
Polycentropus spp.
R
Mollusca
Pelecypoda
Heterodontida
Corbiculidae
Corbicula fluminea
R
A
Total Taxa Collected
109
91
Total EPT Collected
36
22
Biotic Index Value 2009
5.12
5.62
Biotic Index Value 2008
5.87
5.47
Biotic Index Value 2007
5.30
5.65
Biotic Index Value 2006
5.40
5.86
Bioclassifications in 2009
5.0
3.7
Excellent
Good
3-12

Table 3-5. Concentrations (gg/g wet weight) of selenium; zinc; and arsenic im organisms
collected,, from, the Dan River in September. 2009 and comparisons of mean
elemental concentrations in Plecoptera and Trichoptera from 2005 - 2009.
Taxon Location
Selenium,
Zinc.
Arsenic,
Corbicula AL
0.41
25.57
0.28
Corbicula B
1.02
25.00
0.64
E hemero tera A
0.30`
34.96
0.22°
E hemero tera . B,
0.74,
23.79:
0.62:.
Odonata, A •
0.24
23.77.
0.18:
Odonata� B,
0.92. `.
20.70
0.45.
Mean A: Corb.,E hem., Odon.
0.32°
28.10
0.23°
Mean B: Corb.,E hem., Odon.
0.89
23.16
0.570
Pleco tera A
0.36
41.56
0.26°
Pleco tera B
1.13
39.03
0.55°
Trichoptera A
0.45
43.04
0.45°
Tricho tera B
0.53
31.64
0.42
Mean A: Of all organisms
0.35°
33.78
0.28r
Mean B: Of all organisms
0.93
28.03
0.54°
Table 3-6. Concentrations (gg/g wet weight) of selenium, zinc, and arsenic in organisms
collected from Anderson Creek, Lincoln County, NC, in October 1999.
Taxon
Selenium
Selenium
Arsenic
Corbicula
Zinc
35.99
0.44
Arsenic
0.63
Loc. A
Plec.
Tric.
Mean
Plec.
Tric.
Mean
Plec.
Tric.
Mean
2005
0.80
0.58
0.69
55.44°
43.94`
49.69°
0.17`
0.20
0.18-
2006
0.42
0.46°
0.44`
40.56
45.84
43.20
0.14°
0.260
0.20°
2007
0.92
0.64
0.78
36.30
34.50
35.40
0.18°
0.22°
0.20`
2008
0.28°
ISO
0.280
33.28
IS
33.28
0.30°
ISO
0.30°
2009
0.36
0.45°
0.40°
41.56
43.04
42.30
0.26c
0.45;
0.36°
Loc. B
2005
0.39
1.46°
0.92°
42.00
226.0°
134.0°
0.09°
0.71c
0.40`
6
0.83
0.72°
0.78°
38.55
39.52
39.03
0.14°
0.31°
0.22°
7
0.41
0.68°
0.54°
32.41
42.20
37.30
0.12`
0.39°
0.26°8
t
1.35
1.32
1.34
33.18
30.91
32.04
0.29°
0.42
0.36°
9
1.13
0.53
0.83
39.03
131.64
35.34
0.55
0.42
0.48`
Table 3-6. Concentrations (gg/g wet weight) of selenium, zinc, and arsenic in organisms
collected from Anderson Creek, Lincoln County, NC, in October 1999.
Taxon
Selenium
Zinc
Arsenic
Corbicula
0.88
35.99
0.44
Corbicula
0.63
22.98
0.44
E hemero tera,
0.66
7.43
0.28:
E hemero tera
1.05
13.71
< 0.04
Odonata
0.36 1
39.08
1 < 0.05
Odonata
1.55
27:67
1 0:54'
Mean
0.86 T
24.48
1 0.30
'Means include detection limit values.
dIS = insufficient sample
3-13

d�
E
1,000
100
1G
-,s10
POO
IJ�
00 F
3
I
UD ID
Figure 3-1. flydrograph of 2009 daily average Dan River flows at Wentworth and Pine ball,
NC (USGS Stations 02071000 and 02069000, respectively).
110 r-----------------------------------------------------------------------------------------------------------
IM
9B
9a
FIR
40
30
20
10
a
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
UA M®
Figure 3-2. Total number of taxa collected from the Dan River at Locations A and B during
1997 —2009.
3-14

40
35
30
1z25
x
a. 20
15
10
5
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
MA IOB
Figure 3-3. Total number of EPT taxa collected from the Dan River at locations A and B
during 1997 — 2009.
5.5
5.0
4.5
4.0
c 3.5
CD
,, 3.0
ti
S 2.5
M
M
ra
2.0
1.5
1.0
13.5
0.0
1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
OA mB.
Figure 3-4. Water- quality bioclassifications based on Snacroinvertebrate collections from the
. Dan River at Locations A and B during 1997 — 2009.
3-15

L
5.0
4.5
4.0
3.5
m
3.0
m 25
20
9.5
9.0
0.5
OA
•W.-ation A • A Detection &T is ❑Location B ❑ B: Detection fun=ds
4" m W W �rWs MW cuss (SY rn rn rn rn rn of rn ai o 0 0 0 C) 0 4 0 0 0
rn rn rn rn rn rn rn rn rn rn rn rn rn rn D rn o o In 0 0 0 0 0 0 0
r r r r r r r r r r c- r r r r r" CV . N N N N N N N
Figure 3-5. Concentrations of selenium in Ephemeroptera collected annually from Location
A upstream of the BCSS ash basin discharge and Location B downstream of the
BCSS ash basin discharge (red data points represent concentrations at or below
detection limit, each point represents data from individual replicates).
5.0
4.5
4.0
3.5
3.0
D 25
N,
T 2.0
rn
15
1.0
0.5
0.0
«Location A • A Detection Gmks ❑ Location B ❑ B: Detection Nmits
¢ 4A (U F- W rn oN ah b- W (s f- W rn O N th *.¢ U> W C+- W M
W M W M W W CMrn rn rn rn rn rn rn rn rn O O O O O O O O O O
rn (� rn rn rn rn rn rn rn OS rn rn rn rn rn O O o1:31 O (� C) O O C)
r r r r r r r r r r r r r r r N N N . N N N N N .
Figure 3-6. Concentration of selenium in Odonata collected annually from Location A,„
upstream of the BCSS ash, basin discharge and Location B downstream of the
BCSS ash basin discharge (red.data points represent -concentrations at or below
detection limit, each point represents data from individual replicates)
3-16

• Location A • A.Detection limits ❑ Location B ❑ B: Detection limits
5.0 ------ -------------------------------- _ _ —_----------------------------------------
4.5 -- –----------------- --- – – --- – – – --- –=– —_ –_-- --- –—------ –
4.0 – --- –-------- – — – – – –------------------ — – – -- – – • __ ---- –_ - – – –
3.5 –---------- --------- –--------- ----- —---------------------------
t
m 2.5 ------------------------------------------ — --------- – ------- - -------- – - – – ------------ – - – ---
– – – -- – - ---
2.0 -------------------- ------ –--------- –------ –_–--- –--------- ------------ -------
----------------------- - –-------- ---- - – – – —_ –
1.0 – a------------------------------- – – °-------- –e –=------------ – ------ – ----------
®
13 a CI 9
13
0.5 - – - ♦–u – –+– +A
'Tin (D N m OO N (7 w 41 (O N co m c) N (n V 4] (O r- m O
W m m m m O M O O O C" O O] O O O OO O O O O O O O O
O O O O Oy O O O O O> O Of W O7 !1.2 O' O O O O O O O O O O
N N N N N N N NN N
Figure 13-7. Concentration of selenium in Corbicula collected annually from Location A
upstream of the BCSS ash basin discharge and Location B downstream of the
BCSS ash basin discharge (red data points represent concentrations at or below
detection limit, each point represents data from individual replicates).
•Location A •A: Detection Limits 13 Location B ❑ B: Detection Limits
1.6 T------- _----- ____----- _------------ ____----- _----- _________---- _--------- _----- _------ _-------------------- __-__- ----- - ----- -__
1.4
1.2
1.0
0.8
i 0.6
0.4
0.2
0.0 -
C m
o_ o:. o; o 0
0 0,
N'.. N N _ N N
Figure 3-9'.. Concentration of selenium, in Plecopteral collected annually. from. Location. A.
upstream of the BCSS ash basin discharge and Location B-` downstream of the
BCSS- ash basin discharge. (red data points. represent co ncentrations at or below
detection limit, each point represents data from individual replicates).
3-17'
M

1.6
1.4
1.2
o, 1.0
m
CD 0.8
rn
i 0.8
0.4
0.2
0.0
un
0
0
N
• Location A •A: Detection Limits o Location B 13 B: Detection Limits
(o r- m rn
0 0 0 0
0 0 0 0
N N N N
Figure 3-9. Concentration of selenium in Trichoptera collected annually from Location A
upstream of the BCSS ash basin discharge and Location B downstream of the
BCSS ash basin discharge (red.data points represent concentrations at or below
detection limit, each point represents data from individual replicates).
5.0
4.5
4.0
3.5
m
3.0
V 2.5
rn
2.0
z
1.5
1.0
0.5
0.0
• Location A • A: Detection limits ❑ Location B o B: Detection limits
IT (() (o (+- m m O a- N M IT� (or- W M O N M V' b (O f+ m T
m m m M m m M rn rn M M M M M M M o 0 0 0 0 0 0 0 0 0
rn rn rn rn rn w rn rnrn rn a� rn rn rn rn rn o 0 0 0 0 0 0 0 0 0
N N N N N N N N N N
Figure 3-10. Concentration of selenium in all organisms (excluding Diptera) collected
annually from Location, A upstream of the BCSS ash. basin discharge- and
Location. B- downstream of the BCSS ash basin discharge (red data. points
represent concentrations at or below detection limit, each point represents
data from individual replicates).
3-18

65
60
55
50
45
1 40
35
30
25
M 20
15
10
5
0
• Location A • A: Detection limits o Location B o B: Detection limits
IO (ON m O O N M S W) (O f+ m O O N (h V to CO N m CD
W dp m m m m O O O O O T O O O O O O O O O O O O O O
O) O O O O O O CD O O O O O O' O O O 0 0 0 0 0 0 O O O
r N N N N N N N N N N
Figure 3-11. Concentrations of zinc in Ephemeroptera collected annually from Location A
upstream of the BCSS ash basin discharge and Location B downstream of the
BCSS ash basin discharge (red data points represent concentrations at or
below detection limit, each point represents data from individual replicates).
65
60
55
50
45
40
35
30
�25
20
15
10
5
0
b m N m O O N M W) (D N m O O N N a kQ m, r- m- O
W m m m m m O O O O O O O O O OM C O O O. O. O O O O
O O O O O O O O O O. O
NW N N N N N N N N
Figure 3-12. Concentrations of zinc in, Odonata. collected.- annually from. Location A,
upstream of the BCSS ash basin discharge. and, Location -B- downstream -of the
BCSS ash, basin discharge (red- data points represent concentrations at or
below- detection limit, each point represents data from individual replicates).
349
r -

Figure 3-13. Concentrations of zinc in CoYbicula collected annually from location A
upstream of the BCSS ash basin discharge and location B downstream of the
BCSS ash basin discharge (red data points represent concentrations at or
below detection limit, each point represents data from individual replicates).
60
56
50
45
s
40
n is
1
M
30
16
90
*Location A ♦A. Detection Limits ❑Location B ❑ E3_ Detection limits
KO
0
0
N
I
R
Q o o
N N N N
Figure 344. Concentrations of zinc in Plecoptera collected, annually from location A
upstream of the BCSS ash basin discharge and Location .B downstream of the
BCSS ash basin discharge (red data points represent concentrations at or
below detection limit, each point represents data from individual replicates).
3-20
• Location A • A Detection 6rnits
❑ Location B 13 B -Detection Emits
-
---
- -- -- - -- - - - -- ----=------------
--
va-
- -- -
- -- -- -----------------•---------------50
--_
_—_-
---
- --
— _ -- -- - - ----
---- — --
------
- — — ___ ` --------
45 - --
45
-- - -- --_—_-
—-----------------
- a - — -- ---- -- --� -
---
40 ---
�•------------------
35 -° - - -- - -- - - t__
-- — -__ _—__-
- - - --n—_—_ - - --o
-
.- ❑
❑ Q •
r
0
13
a 11
la - ♦ - --- - ---...
---------�- t� E3
13
M0------------------------
2A�0
0
-g
— -_
--------n------ ----------- -•-----;- M -------
--
®�G
_-_♦ 11
- - - - --3O --- -------- - ----- -------- - --- -- - ---------------
13y0
-----------------
---------1 -
o
—- - W ------------------------------------------
o
- —-------
- - --
13
0
St• 70 tU
(' - 117 rn O N
M rn rn
an S u0 an
rn W rn rn
P-- W M C3 N tom! r 7() cU r^-
rn rn rn O a7 a7 43 131 Q (J O
W
O
M
O
W W i17
rn rn w
W 177 177
rn rn rn rn rn rn
rn rn rn al
UI d3i m® rn rn o o as o 0
0
0
Figure 3-13. Concentrations of zinc in CoYbicula collected annually from location A
upstream of the BCSS ash basin discharge and location B downstream of the
BCSS ash basin discharge (red data points represent concentrations at or
below detection limit, each point represents data from individual replicates).
60
56
50
45
s
40
n is
1
M
30
16
90
*Location A ♦A. Detection Limits ❑Location B ❑ E3_ Detection limits
KO
0
0
N
I
R
Q o o
N N N N
Figure 344. Concentrations of zinc in Plecoptera collected, annually from location A
upstream of the BCSS ash basin discharge and Location .B downstream of the
BCSS ash basin discharge (red data points represent concentrations at or
below detection limit, each point represents data from individual replicates).
3-20

60
'�7
5o
45
40
t
m 35
1
csp 30
Q1
26
15
•LocationA •A- Detection Limits ❑Location B 116: (Detection Limits
0
In P- no M
C3 o 0 0
C3 o 0
Cq cv cv cv
Figure 3-15. Concentrations of zinc in Trichoptera collected annually from Location A
upstream of the BCSS ash basin discharge and Location B downstream of the
BCSS ash basin discharge (red data points represent concentrations at or
below detection limit, each point represents data from individual replicates).
• Loca on A • A Detection limb o Location B ❑ B. Detection limits
65 Q-----------------------------------------------------------------------------------------------------------------------------
60 -
---------------------------------------a---------------
5 I------------------------------------------------------------------------------------�------------
50 --------------------------------------------------------------------Q- ® — ! — —
--------------- — n — —
13
n = - 9 ::13:
-
t 35 - �� - s--------� -__ -� a+-
-----------------------------
° L 1a ❑ o - ❑
l3t1---------,�---*---A ,II - n - - -------- �r---------------------- - a ------- -- �--ti
6' ° * -° ---- �- 1` -9
ET -
13
zo.•----
❑ •
--------------------
°---------------
10
------- -
1U ---------------4 ------------ - ♦---------------------
- - ----s
-` ---13 o •
5 ---------0-------------------------- -----------
--------
0 -- ---------------------------------------------
Q
rsi�D w w as, ass ss� m rss o� sss a� asp ss� tss m C ® o aZ� o O o C) ao ao
Figure 3-16. Concentrations of zinc in all organisms (excluding Diptera) collected annually
from. Location. A upstream of the BCSS ash basin discharge and. Location B -
downstream of the. BCSS ash basin discharge (red data points represent
concentrations at or below detection limit, each point represents data from
individual replicates).
3-21

+Location.# +A Detection limits ❑Location B 0 B_ Detection limits
---------
15- ----- - ---------------------------------- - ------------------- - -------------------------------------------------------------------------------------
25 -------------------------------------------------- ----------------------------------------------------------------------------- ---------------
2.0 --------------------------------------------------------------------o,----------------------------------------------------------------------------
1.5 ----------------------------------------------------------------------- ----------------------------------------------------------------------------
1-0
----------------------------------------------1_p ----♦----------------- n ---------© ©- a------------ --------------------------------
------------------------------------------------------
0-5 ----------------------- o =--42 ------------® --- ---� -0 ------- --
0.0 —a
m �r 4" w O w
w w w o a� 0 0 0 0 0 0 0 0
+ss w w w w w w cs, w w w w w w w w o o w w o 0 0 0 0 0
Figure 3-17. Concentrations of arsenic in all organisms (excluding Diptera) collected
annually from Location A upstream of the BCSS ash basin discharge and
Location B downstream of the BCSS ash basin discharge (red data points
represent concentrations at or below detection limit, each point represents
data from individual replicates).
3-22
VA
n

CHAPTER 4
WATER AND SEDIMENT CHEMISTRY
MATERIALS AND METHODS
Dan River water chemistry was sampled quarterly in 2009 at one location upstream (A) and
three locations downstream (B, D, and E) of the Belews Creek Steam Station (BCSS) ash
basin discharge (Table 1-1; Figure 1-1). An additional water chemistry sampling site
(Location C) was monitored on the Smith River, 1.2 km (0.7 mi) upstream of its confluence
with the Dan River. Quarterly sampling during 2009 occurred January 26, April 29, July 28,
and October. 28.
Water chemistry parameters were analyzed using standard analytical procedures (Table 4-1).
Near -surface (0.3 m) temperature, dissolved oxygen`(DO), pH, and specific .conductance
were measured in situ by Duke Energy Scientific Services personnel' using a calibrated
Hydrolab DataSondeo (Hach Company 2006). Water grab samples for laboratory analyses
were also collected at a depth of 0.3 meters at each sample location. Samples for soluble
nutrients (i.e., ammonia -N, nitrite+nitrate-N, and orthophosphate) and dissolved copper were
filtered (0.45 gm) on site. All samples were preserved on site immediately after collection
per Table 4-1. With minor exceptions, laboratory analyses were performed by Duke Energy
Scientific Services Analytical Laboratory, Huntersville, NC (North Carolina Department of
Environment and Natural Resources [NCDENR] Certificate No. 248). All 2009 total solids
(TS), total suspended solids (TSS), and turbidity analyses were performed by Prism
Laboratories, Charlotte, NC (NCDENR Certificate No. 402).
Since 2001, trace element concentrations of river water samples have been analyzed as "total
recoverable" elemental concentration, which incorporates a dilute acidic digestion of the
sample (USEPA 1994). This technique was distinct from the analytical method for trace
elements employed during the period 1988 — 2000, when acid -preserved samples were
analyzed by -atomic absorption spectroscopy direct injection, i.e., samples were not acid -
digested.
'The Duke Energy Scientific Services organization is presently certified by the North Carolina Division of
Water Quality (DWQ) under the Field Parameter Certification program (certificate number 5193).
4-1

Sediment cores (two replicates per location) were collected from wadable depths at the four
Dan River locations (A, B, D, and E) on May 20, 2009. Cores were collected in cellulose
acetate butyrate core liner tubes. Upon collection, sediment core tubes were sealed with
polyethylene end caps, with site water overlaying the intact water -sediment interface. Core
tubes were maintained upright to preserve the water -sediment interface, covered on site with
ice, and subsequently refrigerated upon return to the lab. Fine surficial sediments at the
sediment -water interface were siphoned from the top 2-3 mm of each core sample, sieved
through a 63-µm Nitex® screen, and deposited on a pre -weighed, 0.45-µm Millipore acetate
membrane filter. Filters were dried at room temperature and analyzed for dry weight -based
selenium and arsenic concentration by neutron activation, as previously described (Duke
Power Company 1987).
Daily mean Dan and Smith River stream flows were obtained from the US Geological
Survey National Water Information System (NWIS) web site (USGS 2010). , October
through December 2009 data were classified as provisional at the time of this report.
Temporal estimates of selenium mass loading to the Dan River from the BCSS ash basin
discharge were calculated from NPDES discharge monitoring report discharge flows and
selenium analyses, supplemented with ash basin in -process selenium analyses.
Graphical methods were used to examine selected water quality and sediment elemental
concentrations for temporal and spatial trends. Statistical comparisons of water quality
parameters were made among sample locations, sample years, and historically referenced
low flow versus high flow sampling conditions using an analysis of variance (ANOVA) with
Duncan's multiple range test (SAS Institute Inc. 2009). Sampling events associated with
flows exceeding the 75th percentile for the entire Wentworth USGS gauge period of record
were deemed "high-flow" events in the analysis. For all statistical tests, a significance level
of P < 0.05 was utilized. Dan River sediment arsenic and selenium concentrations and
arsenic, cadmium, lead, and selenium concentrations from aqueous samples for 2009 were
not analyzed statistically due to the prevalence of analytical values below laboratory
reporting limits in both the 2009 and historical data.
4-2

RESULTS AND DISCUSSION
Stream Flow Characterization
The January, April, and July 2009 quarterly water quality sampling events occurred under
low to moderate Dan River flows, whereas the October sampling was associated with
somewhat higher flows (i.e., slightly in excess of the 75th percentile, as gauged at the
Wentworth, NC USGS station (Table 4-2; Figure 4-1). Similar to previous years, variations
in Smith River flows as measured at Eden, NC were largely indicative of fluctuations in
hydroelectric generation releases from the upstream Philpott Reservoir. Although Smith
River flow is on average approximately one half the flow of the•Dan River at the confluence
of the two rivers, during the April 29 sampling, Smith River flow exceeded that of the Dan
.River, and was therefore more influential than normal in terms of water quality at the
downstream -most locations.
Surface Water Quality
Dan River water quality in 2009 (Table 4-3; Figures 4-2 through 4-9) was generally
comparable to that of other Piedmont streams in the Duke Energy service area. With minor
exceptions, Dan and lower Smith River water quality constituent variability in 2.009 also was
generally within the range observed in previous ' years, and the data tended to reflect
previously documented historical spatial and temporal relationships (Duke Power 1999,
2000, 2001, 2002, 2003, 2004, 2005; Duke Energy 2006, 2007, 2008, 2009). With minor
exceptions, Dan River water chemistry indicators and analyte concentrations have remained
comparable to those measured during the baseline (i.e., pre -discharge) period (January 1984
to October 1985).
Temperature and DO displayed typical seasonal variability in both the Dan and Smith Rivers
during 2009 (Table 4-3). Summer meteorological conditions generally present the greatest
challenges for compliance with thermal and DO water quality standards. Quarterly sampling
indicated that both temperature and DO met applicable water quality standards (NCDENR
2007) in 2009, as has consistently been the case during this monitoring program. All. water
temperatures remained below the default North Carolina standard (32 "C). A minimum DO
concentration of 1.0 mg/L was recorded during the July quarterly sampling: at Location. E, -
approximately 59 km downstream- of the> BCSS ash basin discharge. Applicable DO
standards for this part of the Roanoke Basin, minimal 5 mg/L as a daily average and 4 mg/L
4-3

as an instantaneous value, were consistently exceeded in 2009 and in prior years, as was also
observed by NCDENR (2005a).
Dan River and lower Smith River pH (Table 4-3) remained near -neutral throughout 2009,
consistent with results from monitoring in recent years,, with all values ranging from pH 7.0
to 7.7. Smith River pH values tended to be marginally greater (i.e., more alkaline) than
upstream Dan River pH values, and Dan River pH values measured below. the Smith River
confluence were likewise only slightly above up -river pH values.
Specific conductance, a surrogate measurement for total dissolved solids (TDS), had
remained relatively constant upstream of the Smith River confluence over the course of 1984
2007 monitoring, with somewhat greater variability observed in Smith River and further
downstream Dan River samples (Figure 4-2). As noted in the prior year annual summary
report, however, slight increases in specific conductance were observed in the Dan River,
beginning. in 2008, downstream of the BCSS ash basin discharge (Duke Energy 2009).
Compared to upstream Location A, slightly higher levels of specific conductance were again
observed in 2009 at Location B, directly downstream of the BCSS ash basin outfall (Table 4-
3 and Figure 4-2). As previously reported (Duke Energy 2009), the increases in conductance
can be primarily attributed to the BCSS ash pond receiving a BCSS internal NPDES-
permitted outfall (002) comprised of flue gas desulfurization (FGD) process wastewater,
which is characterized by elevated levels of dissolved solids. This new internal outfall is
linked to the operation of recently installed air emissions control systems designed to remove
sulfur oxides (Duke Energy 2009). Greater levels of Dan River specific conductance were
generally observed at times of lower river flow, due to reduced dilution of watershed -derived
dissolved solids. Further specific conductance increases at more distant downstream Dan
River locations (D and E), with respect to Location B, resulted from additional watershed
inputs unrelated to BCSS.
Before 2008, it was evident that Dan River total alkalinity (Figure 4-3)`and calcium (Figure
4-4) concentrations had gradually increased over the course of this monitoring program, both.
up- and downstream of BCSS (Duke Energy 2008). Beginning with the latter half of 2008,
downstream of BCSS, concentrations of major cations, calcium and magnesium (Figure 4-5),
and to a lesser extent, major anions, sulfate (Figure 4-6) and -chloride (Figure 4-7), increased,
more abruptly. These increases were consistentwith the aforementione& increases, in specific
conductance- following operation of the BCSS FGD systems.. In 2009; concentrations of -
calcium and magnesium measured downstream of BCSS (Location B), although not
44

achieving: maximal levels observed the prior year, remained clearly elevated both with
respect to the upstream, site (Location-A),and compared- to the years- before FGD system,
operation. As noted previously (Duke Energy 2009)`calcium=and magnesium concentrations
measured much further downstream of BCSS (i.e., Locations D and E) were also elevated
with respect to historical data, although the relative magnitude of increase. was diminished
due to further dilution of dissolved solids by downstream flow accretion.
As reported previously (Duke Energy 2009), recent total alkalinity concentrations (as CaCO3
equivalents) have not shown a comparable increase as was observed for calcium. This lack
of concordance can likely be attributed to ionic equilibrium -driven compensatory reductions
in bicarbonate anions in- response to concurrent increases in other anions (i.e. sulfate' and
chloride). , While slightly elevated immediately downstream of BCSS, overall, Dan River
sulfate and chloride concentrations have remained relatively consistent within historical
trends, which display considerable temporal variability, especially at sample Locations D and
E, near Eden, NC.
Recently observed Location B increases in calcium, magnesium, and sulfate which appear
linked to new BCSS FGD -related wastewater inputs remained substantially below water
quality standards (NCDENR 2007) and are not anticipated to impair aquatic life or other uses
of the Dan River. Presently applicable water quality standards, based on. human health
criteria, include limits for Class WS -IV waters for TDS (500 mg/L), sulfate (250 mg/L), and
chloride (250 mg/L). Maximal measured sulfate and chloride concentrations during 2008 —
2009 remained well below the 250 mg/L standards (Table 4-3; Figures 4-6 and 4-7). An
estimate of the maximum TDS concentration (131 mg/L) encountered in 2008 (Location B,
October 2008) derived from total solids (TS) minus TSS data was also well below the human
health -based TDS standard (Duke Energy 2009).
Similar to 2008, a comparison of 2009 Dan River water quality for sample locations
immediately upstream (Location A) and downstream (Location B) of the BCSS ash basin
NPDES outfall resulted in slightly greater dissimilarity than was observed in earlier, years of
monitoring: Significant (P < 0.05) concentration differences between the two sites were
primarily related, -to major dissolved minerals;. which as discussed previously, can, be linked,to
treated BCSS FGD wastewater inputs. Analytes, that. displayed a. significant increase at the
immediate downstream. site relative• to upstream . included' .specific conductance;_ TS
(dominated, by the TDS. fraction) calcium;. sulfate, manganese, magnesium; sodium, and.
chloride.
4-S
I

Results from previous years have, collectively illustrated• a number of water quality
constituents for which concentrations typically'increase from. upstream. to downstream in: the
entire segment of the Dan River assessed by this sampling program. For 2009, this spatial
trend proved significant (P < 0.05) for pH (slight increase in alkaline pH down -river), total
alkalinity (Figure 4-3), sodium, total nitrogen, orthophosphate, and total phosphorus. As
previously documented in this ongoing study (Duke Power 1999, 2000, 2001, 2002, 2003,
2004, 2005; Duke Energy 2006, 2007, 2008, 2009) and as supported elsewhere (NCDENR
2000, 2001, 2005a), the Smith River has typically affected water quality of the Dan River
downstream of their confluence at Eden, NC. Compared to upstream Dan River locations (A.
and B), 2009 Smith River (Location C) pH, and concentrations of total alkalinity,
nitrate+nitrite, ,total nitrogen, orthophosphate, and total phosphorus, iron, manganese, and
zinc (Figure 4-9) were significantly (P < 0.05) greater. However, fewer analytes exhibited
significant inter -location differences, as a consequence of Smith River inputs compared to
recent years. For example, major cations (e.g., calcium and magnesium) and anions (e.g.,
sulfate and chloride) were not spatially dissimilar (P < 0.05), as had been the case in many
prior years. This was largely due to the influence of BCSS FGD -related TDS inputs in the
upstream Dan River.
Substantial temporal variability within water quality analytes commonly associated with
suspended material has occurred in response to short-term Dan River discharge fluctuations
(NCDENR 2000, 2005a). Historically, temporal fluctuations in Dan River suspended solids
loads and related changes in various physico-chemical properties associated with storm event
runoff are frequently of greater magnitude than any observed spatial heterogeneity in these
parameters. Three of the four quarterly 2009 water quality samplings were conducted during
relatively low Dan River. flows, while Dan River flow at the time of the fall sampling
matched the 77th percentile of historical flows (Table 4-2 and Figure 4-1). Due to the lack of
exceptionally high flows encountered on 2009 water quality sampling dates, considerably
less temporal variability was observed in turbidity or TSS concentrations compared with
many prior years (Table 4-3).
Selenium Loading Rates
The estimated mass loading- rate of selenium to the Dan River- via the BCSS ash basin
discharge in 2009; averaging, 243 g/d, was, within the range exhibited, in recente years, and=
represented. only a 1 %" increase comparedJo the long=term average estimated: loading rate of
241 g/d (Figures 4-10 and 4-11). The estimated selenium loading rate has increased slightly
4-6,

since 2007 (179 g/d). Median and average NPDES discharge selenium concentrations for the
year, based on. monthly estimates, were 6.8 and 7.1 gg/L, respectively. Individual sample
effluent selenium concentrations ranged between an annual minimum of 4.9 µg/L in January
to a maximum of 11.3 µg/L in July.
The March 2009 monthly selenium loading rate estimate, 476 g/d, was considerably elevated
with respect,to the 11 -month balance of the 2009 calendar year. This can be attributed to a
substantially increased estimate of the ash basin discharge flow rate derived from a single
flow measurement (74,200 m3/d) on March 3, 2009. There is certainly potential that this
flow estimate, at a magnitude of 235% of the average flow estimated for the other 11 months
of the year, over represents the March discharge flow. As a result of this elevated flow
estimate, the March 2009 estimated selenium loading similarly appeared to be 214% of that
estimated for the balance of 2009.
Because ash basin effluent flow rates, except as described above, remain relatively consistent
from year to year, temporal variations -in selenium loading to the Dan River have historically
been driven by temporal fluctuations in the selenium concentration of the ash basin effluent,
a which in turn, is influenced by changes in quantities of fly -ash sluiced to the basin over time
(Duke Power 2003). With the second year of continued operation of BCSS FGD systems in
2009, once again appreciable increases in selenium loading were not evident at the final
NPDES outfall. This is confirmatory of the highly successful treatment afforded to FGD
wastewater by the upstream fixed bed bioreactor.
Surface Water Trace Element Concentrations
Aqueous trace element concentrations remained low in 2009 Dan and lower Smith River
samples. Similar to the previous year, slightly elevated trace metal (e.g., copper, zinc, or
lead) concentrations noted in several recent years were not observed in 2009, primarily due
to the absence 'of higher flow -associated sampling events (and lack of elevated TSS levels
that often contribute to particulate -bound metal. concentrations). Dan River and lower Smith
River' analytical results: for arsenic, cadmium; lead, and selenium (Table 4-3) were
consistently at .ori,: below laboratory reporting limits and North Carolina water quality
standards (arsenic: 50 gg/L based on aquatic life, and 10 µg/L basedon human health;
cadmium: 2.0 jig/L; lead: 25 µg/L; selenium: 5 µg/L; NCDENR .2007). Copper: and, zinc
concentrations (Table 4-3; Figures 4-8 and 4-9) likewise consistently remained below the
4-7

applicable NCDENR (2007) water quality action levels. (7 µg Cu/L; 50 gg Zn/L) for all 2009
samples.
Sediment Trace Element Concentrations
Dry -weight selenium concentrations in Dan River surficial fine (< 63 gm) sediments
measured at four Dan River locations in May 2009 were similar to long term historical data,
and were within the range of concentrations measured before the routing ofthe BCSS ash
basin discharge to the river (Table 4-4; Figures 4-12 through 4-15). Sediment selenium
concentrations in 2009 were all less than 3 gg Se/g sediment, with all but one of the
analytical results remaining below sample -dependent detection limits.
Arsenic concentrations in sediment fines ranged from below the detection limit to a
maximum of 3.7 µg/g sediment and were among the lowest observed to date for the four Dan
River sites (Table 4-4; Figures 4-12 through 4-15). Samples collected immediately
downstream of the BCSS ash basin outfall (Location B) were only marginally greater
(averaging 3.5 gg/g) than Location A samples collected upstream (averaging < 2.3 gg/g).
Samples collected from sites further downstream in the Dan River had similarly low arsenic
concentrations in 2009.
Although slightly elevated arsenic, and to a lesser extent, selenium concentrations have
occasionally occurred among annual fine sediment samples. in past years, trace elemental
concentrations in Dan River fine sediments have not shown a consistent increase after
diversion.of BCSS ash basin effluent to the Dan River. Additionally, sediment trace element
concentrations to date have not revealed spatial trends that would potentially implicate the'
1 BCSS ash basin discharge as a significant source to stream bed sediments.
SUMMARY
Dan River water quality in the vicinity of BCSS in 2009 was substantially similar to previous
years. Beginning with the initial. operation of FGD air emissions "scrubbers" at BCSS
occurring in 2008 and, continuing.. into 2009, increased, concentrations .of several -dissolved
solids constituents immediately, downstream: of the. ash basin discharge; includingF calcium,
magnesium, chloride, and, sulfate, were evident: These, slightly elevated' -cation, an&anion
concentrations, however, were not of a magnitude anticipated to affect resident Dan River
4-8-

k
biological communities: Mass loading of selenium and, arsenic to. the Dan- River- via the
BCSS ash basin, discharge in 2009 was of similar magnitude as- observed-. in prior years;
reflecting the highly effective treatment of upstream, high -dissolved solids BCSS FGD
system wastewater. All monitored' water quality indicatorsand constituent concentrations
observed in 2009 Dan and lower Smith River- samples, including those of trace elements,
remained within applicable North Carolina water quality standards or action levels. Fine
sediments collected from the Dan River„ in 2009 in the vicinity of BCSS yielded low
concentrations of selenium and arsenic, similar to previous years. Slightly elevated fine
sediment arsenic concentrations observed infrequently among Dan River samples, including
in 2008, were absent from 2009 samples. The 2009 results of the BCSS Dan River water
quality monitoring program continue to indicate no appreciable detrimental effects
attributable to the BCSS ash basin outfall, even given the addition of major engineering and
wastewater treatment system changes implemented at BCSS in recent years. The logical
conclusion to be derived from this ongoing water and sediment monitoring program ,is that
the Dan River, both up- and downstream of the BCSS'ash basin discharge, remains capable
of maintaining diverse, indigenous aquatic communities.
4-9

Table 4-1. Analytical methods for chemical and physical constituents measured in the Dan
River in 2009.
Reporting
Parameter
Method (EPA/APHA)b
Preservation
Limit
Alkalinity, Total
Total inflection point titration
< 6 °C
0.1 meq/L
EPA 310.1
CaCO3
Aluminum
Atomic emission / ICP
0.5% HNO3
0.05 mg/L
Arsenic, in
Neutron activation -analysis
< 6 °C
variable,
Sediments
(NC State Univ. Nuclear Serv. Lab)
per sample
Arsenic, Total
ICP mass spectrometry
0.5% HNO3
1.0 pg/L
Reboverable
EPA 200.8
Cadmium, Total
ICP mass spectrometry
0.5% HNO3
0.5 pg/L°
d
Recoverable
EPA 200.8
1.0 pg/L
Calcium
Atomic emission / ICP
0.5% HNO3
0.03 mg/L
EPA 200.7
Chloride
Colorimetric
< 6 °C
1.0 mg/L
APHA 4500 -CI" E
Conductance, Specific
Temperature -compensated
in situ
0.1 NS/cme
nickel electrode
APHA 2510 B
Copper, Dissolved
ICP mass spectrometry
0.5% HNO3
1.0 pg/L
EPA 200.8
Copper, Total
ICP mass spectrometry
0.5% HNO3
1.0 pg/L
Recoverable
EPA 200.8
Iron
Atomic emission / ICP
0.5% HNO3
0.01 mg/L
EPA 200.7
Lead, Total
ICP mass spectrometry
0.5% HNO3
1.0 pg/L
Recoverable
EPA 200.8
Magnesium
Atomic emission / ICP
0.5% HNO3
0.03 mg/L
EPA 200.7
Manganese, Total
ICP mass spectrometry
0.5% HNO3
1.0 pg/L
Recoverable
EPA 200.8
Nitrogen Ammonia
EPA 350.1 Rev. 2
< 6 °C;
0.02 mg/L
I
Nitrogen,
Nitrite+Nitrate-N Colorimetric / flow injection
EPA 353.2 Rev. 2
b References: USEPA 1983 or APHA et'al. 1998
° January samples
d April, July, and• October samples -
e Instrument sensitivity furnished in lieu of reporting limit
0.5% H2SO4
< 6 °C; 0.02 mg/L
0.5% H2SO4
4-10

Table 4-1. (Continued).
Sulfate
Temperature
Turbidity
Zinc, Total
Recoverable
Ion chromatography
< 6 °C
0.1 mg/L
Reporting
Parameter
Method (EPA/APHA)
Preservation
Limit
0.01 'Ce
APHA 2550 B
Nitrogen, Total
EPA 351.2 rev. 2
< 6 °C;
0.1 mg/L
Kjeldahl
0.5% H2SO4
0.5% HNO3
Oxygen, Dissolved.
Temperature -compensated
in situ
0.01 mg/Le
polarographic cell
APHA 4500-0 G
pH
Temperature -compensated,
in situ
0.01 unite
glass electrode
APHA 4500-H+ B
Phosphorus,
Colorimetric / flow injection
< 6 °C
0.005 mg/L
Orthophosphate
EPA 365.1 Rev. 2
Phosphorus, Total
Colorimetric / flow injection
< 6 °C
0.005 mg/L
EPA 365.1 Rev. 2
Potassium
Atomic emission / ICP
0.5% HNO3
0.25 mg/L
EPA 200.7
Selenium, in
Neutron activation analysis
< 6 °C
variable,
Sediments
(NC State Univ. Nuclear Serv. Lab)
per sample
Selenium, Total
ICP mass spectrometry
0.5% HNO3
1.0 pg/L
Recoverable
EPA 200.8
Silica -Si
APHA 4500 -Si E
< 6 °C
0.5 mg/L
Sodium
Atomic emission/ICP
0.5% HNO3
0.1 mg/L
EPA 200.7
Solids, Total
Gravimetric, dried at 103-105 °C
< 6 °C
20 mg/L
EPA 160.3
Solids, Total
Gravimetric, dried at 103-105 °C
<6 °C
2.0 mg/L°
Suspended
EPA 160.2
5.0 mg/Ld
Sulfate
Temperature
Turbidity
Zinc, Total
Recoverable
Ion chromatography
< 6 °C
0.1 mg/L
EPA 300.0
NTC thermistor
in situ
0.01 'Ce
APHA 2550 B
Nephelometric
<6 °C
0.4 NTU
EPA 180.1
ICP mass spectrometry
0.5% HNO3
1.0 pg/L
EPA 200.8
4-11

Table 4-2. Daily mean flow and' corresponding percentiles within cumulative distributions of
monthly historical. flbws,for. the, DawRiver at.Pine Hall,' and.near Wentworth; NC
(USGS Stations. 02069000 and 02071000; respectively) and= the: Smith River at
Eden, NC (USGS- Station 02074000) for 2009 water quality sampling dates.
Sampling
Dan River- Pine Hall
Dan River- Wentworth
Smith River - Eden
Flow
Flow
Monthly
Flow
Flow
Monthly
Flow
Flow
Monthly
Date
(m3/s)
(cfs)
Flow
(m'/s)
(cfs)
Flow
(m3/s)
(cfs)
Flow
Percentile
Percentile
Percentile
January 26
5.47
193
ND'
15.5
546
10
10.8
382
29
April. 29
'8.47
299
ND
19.8
698
12
24.4
860
67
July 28
6.09
215
ND
11.8
418
20
10.2
361
36
October 28
13.7
484
ND
23.9
843
77
23.0
812
88
t Not Determined; Historical monthly flow percentiles were not determined for the Pine Hall, NC station due to insufficient
historical record.
4-12

on
C".
b
rVr^I
VI
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m
4-40
N
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T T

Table 4-3. (Continued).
4-14,
Dan River at•,
DawRiver at
Smith River at,
Dan River- tahe:
Dan River at
US=311
SR -1138
W. Kings Hwy.
DRSS' CCW,
NC -700
Analyte
Discharge:
Date
(Location A)
(Location B)
(Location C)
(Location D)
(Location E)
Nitrate+Nitrite m -N/L
1/26/2009
0.38
0.39
0.90
0.74
0.65
4/29/2009
0.21
0.19
0.59
0.34
0.18
7/28/2009
0.28
0.28
0.38
0.33
0.30
10/28/2009
0.01
0.03
032
0.29
0.50
Ammonia-(mg-N/L)
1/26/2009
0.02
0.05
0.04
0.03
0.03
4/29/2009
0.04
< 0.02
0.02
0.03
0.02
7/28/2009
0.04
0.06
0.08
0.07
0.10
10/28/2009
0.07
0.09
0.08'
0.11
0.11
Total Kjeldahl
Nitrogen (mg/L)
1/26/2009
< 0.10
< 0.10
0.11
0.15
0.11
4/29/2009
0.36
0.29'
0.28
0.27
0.28
7/28/2009
0.15
0.21
0.31
0.33
0.32
10/28/2009
0.37
0.36
0.43
0.48
0.38
Orthophosphate
(mg-P/L)
1/26/2009
< 0.005
0.005
0.033
0.037
0.025
4/29/2009
< 0.005
< 0.005
0.016
0.011
0.012
7/28/2009
0.007
0.007
0.022
0.014
0.017
.10/28/2009
< 0.005
< 0.005
0.030
0.025
0.037
Total Phosphorus
(mg/L)
1/26/2009
0.013
0.015
0.069
0.061
0.047
4/29/2009
0.017
0.018
0.046
0.036
0.037
7/28/2009
0.026
0.030
0.049
0.041
0.047
10/28/2009
0.034
0.024
0.130
0.098
0.090
Silica (mg-Si/L)
1/26/2009
6.1
6.7
7.7
7.7
7.8
4/29/2009
4.9
5.4
5.8
5.9
5.9
7/28/2009
5.3
5.5
5.1
5.3
5.5
10/28/2009
5.3
5.5
6.6
. 6.3
5.8
Calcium (mg/L)
1/26/2009
4.3
16.6
7.2
8.8
9.2
4/29/2009
4.7
10.9
6.4
6.9
6.8
7/28/2009
4.4
15.1
7.0
8:2
9.2
10/28/2009
4.6
17.6
0
7.6
9.6
Aluminum (mg/L)
1/26/2009''.
0.136
0.14.1
0.170
0.122
0.123
4/29/2009,
0.063
0.123
0.118
0.112
0.111
7/28/2009`
0.112
0.168
0.105
0.137
0.135
10/28/2009.'
0324
0.336
0.329
0.341
0.430
4-14,

Table 4-3. (Continued).
4-15
DanRiveuat�
Dan Riveuat.
Smith River at,
Dam River at -the
Dan River at -
US -311
SR -1138
W. Kings Hwy.
DRS&CCW
NC -700 -
Analyte
Discharge,
Date
(Location A)
(Location B)
-(Location C)
(Location D)
(Location E)
Iron m /L
1/26/2009
0.36
0.50
0.87
0.55
0.52
4/29/2009
0.29
0.51
0.87
0.62
0.59
7/28/2009
0.56
0.73
0.47
0.60
0.60
10/28/2009
0.88
0.70
2.66
1.57
1.30
Magnesium (mg/L)
1/26/2009
1.6
4.2
3.0
3.0
3.0
4/29/2009
1.8
3.3
2.8
2.8
2.7
7/28/2009
1.8
4.2
2.9
3.1
3.3
10/28/2009
1.8
4.9
2.7
2.8
3.2
Manganese /L
1/26/2009
12.4
34.0
50.1
40.3
34.9
4/29/2009
_ 15.4
32.6
50.5
44.3
33.6
7/28/2009
17.5
48.3
39.0
45.7
46.0
10/28/2009
34.8
44.4
173.0
120.0
78.3
Potassium (mg/L)
1/26/2009
1.3
1.6
1.9
2.1
2.0
4/29/2009
1.5
1.7
1.7
1.7
1.6
7/28/2009
1.6
2.0
2.2
2.1
2.1
10/28/2009
2.4
2.7
2.6
2.7
2.8
Sodium (mg/L)
1/26/2009
3.4
4.0
6.8
19.2
13.6
4/29/2009
3.5
4.2
5.7
5.0
5.2
7/28/2009
3.1
3.8
7.2
6.0
6.6
10/28/2009
3.5
4.1
5.1
5.0
6.8
Chloride (mg/L)
1/26/2009 3.5
28.0
6.6
31.0
23.0
4/29/2009 4.1
16.0
5.7
6.7
6.7
7/28/2009 3.8
25.0
7.2
10.0
12.0
10/28/2009 3.8
30.0
5.8
8.2
13.0
Sulfate (mg/L)
1/26/2009 3.8
8.6
9.1
7.6
7.1
4/29/2009 3.4
5.6
4.4
4.5
4.1
7/28/2009 2.7
7.1
5.6
5.3
5.4
10/28/2009 2.7
7.5
4.2
4.7
5.6
Arsenic, Total Recoverable /L
1/26/2009
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
4/29/2009
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
7/28/2009
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
10/28/2009
< 1.0
< 1.0
< 1.0
< 1.0
< 1.0
4-15

V
M
O
E-�
4
Ln O o o
M N N
q: (O 14: M
o 0 0 0
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t. f- st
^
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G C
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4

Table 4-4. Concentrations of arsenic and selenium (dry weight) in fine-suspendable Dan
River sediments collected; in the vicinity of BCSS May 20, 2009.
Location
Replicate
Core
Arsenic
(11gg)
Selenium
/ )
Dan River at US -311 (A)
1
< 2.1
< 1.8
2
< 2.4
< 1.3
r
Dan River at SR -1138 (B)
1
3.7
2.8
2
3.3
< 2.1
Dan River at the DRSS CCW Discharge (D)
1
2.7
< 2.0
2
2.9
< 1.7
Dan River at NC -700 (E)
1
2.5
< 1.3
2
< 3.4
< 2.2
447

1,000
100
10
35,310
10,000
3,531
0
,000 m
353
100
1 ; ti 4 1 , '35
=ami `m n >. S IM a >
u 2 ¢ g -' < CA O z n
Figure 4-L Hydrograph of 2009 daily average flows for the ®an River at Pine Hall, and near
Wentworth, NC (USGS Stations 02069000 and 02071000, respectively) and the
Smith River at Eden, NC (USGS Station 02074000), with water quality and
sediment sampling dates indicated.
4-18

500
450
400
350
U
to 300
250
U
200
C
O
U 150
900
50
b' an W t- W W O r N M b' LO W 1— OD W O r N M ";r "') W 1,- W W
W W W W W W M OM W O W W W W W O O O O O O O O. O O
p) W O O M W W W. W W W W W O W W O' O O O O O O O O O
r r r r r — r r r r r — r r r r N N N N N N N N N N
Figure 4-2. Comparison of specific conductance among ®an River water quality monitoring
locations from the baseline period (1984 —October 1985) through 2009.
C37
50
40
C 30
a
20
10
C
-;r i1) SO f- 00 W ON co 'GT on W 1, 00 6) O — N M � to to I- 00 W
W 00 O M M 00 W W O M O W W W' W W O O O O O O O O O O
W W W W W W W W W W W W W W W W O O O O O O O O O O
r r r r r r r r T T P r r r r r N N N N N N N N N N
Figure 4-3. Comparison of total alkalinity among ®an River water quality monitoring
locations from the baseline period (1984 — October 1985) through 2009.
4-19

25
20
a�
15
E
E
10
U
5
7
,;r U') O n O O ON M I- "') W P- M O O r N M q' in <D 1- W O
= W W aO M OO M O O O O O O O O O O O O O O O O O O O
O O O O O O O OO O O O O O M M O O O O O O O O O O
r r r r r r r r r r r r r r N N (L1 N N (y (1A N N N
Figure 4-4. Comparison of calcium among Dan River water quality monitoring locations
from the baseline period (1984 —October 1985) through 2009.
L
5
-4
rn
E
= 3
N
C
M
R
3
I
0
tit ot) CD 1� GO O O r N M IT on (D P- M O O r N M d' 1d7 CD 9- M O
M M O M O O O O M M M O O O O O O O O M M M M M O O O O O O O O O O O O
O O O O O O O O O O O O O O O O
r r r r r r r r r r r r T T r r " N (M (b " N N N N N
Figure 4-5. Comparison of magnesium among Dan River water quality monitoring locations
from 1988 through 2009.
4-20

40
35
30
25
E
y 20
JW_
un 15
10
5
0
,It Lo M f- W O ON M C u) W 1- 00 M O r N M� LO W� W M
00 W W 00 W W M rn M M M M M M M M o 0 0 0 0 0 0 0 0 0
M M M M M M M M M M M M M M M M o 0 0 0 0 0 0 0 0 0
r r r r r r r c- r r r r r r c- r N N N N N N N N N N
Figure 4-6. Comparison of sulfate among Dan River water quality monitoring locations from
the baseline period (1984 —October 1. 985) through 2009.
Figure 4-7. Comparison of chloride among Dan River water quality monitoring locations
from 1992 through 2009.
4-21
------ --------------
------ -----------------------------------
- --- - --- - - ------------------
-0-Loc. A; at US Hwy 311
(Loc C; 6/1/99 - 135.5 mg/L)
-� Loc. B; at SR 1138
90
-"" '"
�- Loc. C; Smith River at Kings Hwy
-
-
--- _ ---------- -- ---- - —
e Loc. D; at DRSS
80
- ---•-•------- � Loc. E; at NCH 700
i
- - — — ---- -
70
4—
-- a -Initial $CSS Ash Basin
Initial
_
IDischargetoDanR.
___ --- -- -- - - --_
cn
60
-- — - ------------ -
E
50
—----------•-------------
---------------•------
-
- - - - - - -- - - - - - -- -
:
40
— i ----- _ - --- --
- ---
- --_ -- -- _-- -
U
I
30
- ------------ -------------- -- -- -- --- - ---- -----• .
----- --- -------- - •
•-------- -
20
i
— - �--- ------ -- -
k
- - — - -
10VA
i
fl
d' in CD 1_ 00 M O N M Q• CC) W I-
m 00 W W 00 co M O. M O O M M M
00 M O r "n C In W 1- 00 M
M M O O O O O O O O O O
M C) W M O O M O O M M M O M
T T r r r r r r r r r r r r
O O O O O O O O O O O O
r r N N N N N N N N N N
Figure 4-7. Comparison of chloride among Dan River water quality monitoring locations
from 1992 through 2009.
4-21

50
45
40
35
30
a�
a�
25
CL
CL
U 20
15
10
5
0
SP to 10 1` 00 0) O N M d- to t0 1` 00 M O N M ^r LO 'Co 11, W M
00 W 00 W W W M O O O M M M M M O O O O O O O O O O O
O O CA CA a1 O O O O a7 CA (A [A O d7 O O O O O O O O O O O
r r r r r r r r r r r r r r r r N N N N N N N N N N
Figure 4-8. Comparison of copper among Dan River water quality monitoring locations from
the baseline period (1984 — October 1985) through 2049.
150 _ - ------ ------------
c�---- --
7(Lo1/1-4 - 240 µg/L)
i
(Loc B: 3/22/84 - 260 µg/L;
125 -- --Is'- - - 7!7187 =158 8-N9
100
25
$CSS Ash Basin
arae to Dan R.
--a-•Loc. A; at US Hwy 311
-f- Loc. $; at SR 1138
-A- Loc. C; Smith River at Kings Hwy
2 Loc. D; at DRSS
--o- Loc. E: at AIC Hwv 700
tr) t0 1'- 00 O O r N M -cr to W W 0) O r N M Ct U) t0 1- 00 O
00 Op 00 t1p �. 0p [A d7 d7 d7 CA T a1 O O O) O O O O O O O O O O
O O O O. M O O O M M O O M O O M O O O O O O O O O O
r r r r r r r r r r r r r r r r N N N CM N N N N N N
Figure 4-9. Comparison of zinc amongDan. River water quality monitoring locations from
the baseline period (1984 — October 1985) through 2009.
4-22

80
C 70
0
0
X 60
T
50
m
rn
40
s
U
N
30
O 20
m
a�
10
800
700
600
500 cn
r-
0
W
CL
400'
CO
3006-1
200
100
0 0
to CO co to t -
n P- f- � 00 a0 00 00 rn M rn rn
C) O o q o 0 09 o oCDRo 003 3 = = a
O -n U a 0 0
Q --3, Q O Q O
Q O
Figure 4-10. Monthly mean ash basin discharge flow and selenium loading to the Dan River
for 2006 — 2009. loading estimates are missing for months when selenium
analyses were not performed.
60
0 50
0
X
T
40
E
m
a�
30
s
U
N
0
20
la
2 10
0
M
500
400
200
100
0
to
Q
W W r- M O O r N M -T W 0 1- W O O r N M V- dn W t� 00 O
00 X00 W W W M W O O O O M O O: O O O O O O O O O O O
O O O O M O O O O O O O O O O O O O O O O O O O O
Figure 4-1 1. Annual mean daily ash basin discharge and selenium loading to the Dan River
for 1985 — 2009. Selenium loading for 1985 is based on November and
December data only.
4-23

50 ---• -1 T— - -
i
1 {1r i i
*As (DL value)
45 ! ------•_---- !I
------
0
! --
Se
❑ Se (DL value)
40 --- ........
Ii Ti
----
-----
'V -----
-- -i!f_—:�- l - I _ 1T1 _--- ; _ _� ! -•--•- -II'
-- -- -�I--------
= 35 i - ----1-------------i--- -------
I 1 II
T- -
-i -
-
313 � --„-----•-+-------, -,•-- ,--•----------�-------,------�-- - -, - �---; • -1-----T-----
G> I I' Initial 13 CSS Asip Basin -
I iI Diichal-get)D,*R.l I f { I I I { I
25 J.. ja --' F -_i-_i------------
f - '-------i-----!
1 II l i l j i
I I
-_ -
i _--•
-
20 --- -
- - +
a) 15 ........ 4 ----------- -� ____ 1 .__.ff _-__-�__.___I__-_-�____. ------ -__.._;_._.-_--__-
�IM
fl e❑a; ii
W••t-tj iom-��+fiiIi---�- ��-- T�Ia---rI�• •--- rii�-■■-----tmoi ----tIi -;—tIi -�----ti -- ---Ii tIIrIIi❑g �iIn•• -.rI�i
90 ------------- •--�!I-o• -• --•- •-�iI5 o -❑
❑ � to 4
®1 I= ®
—� --FIii-❑®-- -- -�i'I-
�--
-
---
•r CD 1- 00 O O CD 1- 00 M O r N CO d• U) fD 11- M O
00 0p 00 00 00 00 (A a7 O O d7 O CA (A O O O O O O O O O O O O
- O D) - O D) - O - - O - - O O W O O O O O O O O O O
r r r r r r r r r r r r r 7 r r N N N N N N N N N N
Figure 4-12. Arsenic and selenium concentrations (dry weight) in Dan River fine surficial
sediments collected 4.3 km upstream (Location A) of the BOSS ash basin
discharge. (DL denotes values reported as below detection limit.)
-- - - -- --- - --- - ---- --
5� - - T---•Tr------i--- - T--T-----T -- •T----T-1------�----r---T----i------T----j-----r---�--- T-----
As i I 15/6T3 4s: 3 7.41µg/q i ii ! i i�-
I I 1 0As(DL value)
45i-
i■Se
I I I o Se (DL value) I i 1
- '--•--•- ---- I -----------------------------•-- — - i- I _----------
40i- -
o : '
1I I i -- ! ! I i I i
35 I ... Ir ! ! ! ! 1- -- r--I--•---7---7--j----1---••- �--r---;------r----- ----•- -•---�—; --
iTj--
- i fifi� -1--r i- _
-- -�G- -- -
II DSC•flal iCNA nti Bi'sin�-•--i----•-; ' ' r----r_.-r----
in
30 r tr --1--- - r 9 0 n F�-i---T--
In
--L - j - --'
jp --- 1 i
o f ! I I I I
a' 25 1----��-------- - ---
i
� 20� - -------t----rt7l-•----7. r---- Ir----- ----.}__---1--_
w�- -I' j- l I_ __ i■ I I I I i I----
� i, I -�• �--- I i I ----
jo
- :
9 0 F----,i-----t------- tt--- --t---1------- Y' ----- 1- - r'•--•-t--t--_t- - -t-'--tfl.._1.._-t---i------1_.--_t------7----t-- -
f■ i �--- I f i■ I❑ I i i 1 I. - f-
5—�
• 1 III a B t®Ifr
!� 1
■��4i1'i®og to i8 t
o
fl
V- U) CD 1- 00 O O r N M 4? In CD 1- 00 a) O r N M 'r U) fD 4� 00 M
W W W W o W M M M M M M M M M M o 0 0 0 0 0 0 0 0 0
,� rn rn rn
- oD) -- 0 0 oD) - 0 0 0 0 0 0 0 0 0 0
T r r r c- r - r r - r N N N N N N N N N N
Figure 4-13. Arsenic and selenium concentrations (dry weight) in Dan River fine surficial
sediments collected 14.8 km downstream (Location B) of the BOSS ash basin
discharge. (DL denotes values reported as below detection limit.)
4-24

50
45
40
= 35
E
,-0^ 30
CD
v/
rn 25
C
E 20
d
LJ
CM 15
10
5
a
'
I
i '
I
As
o As (DL value)
■
i
i i i
!
i i
1.
C t06�67
I
-
❑ Se (DL value)
-�
I
-i -(
II
I
I I I
I
•_•___
i
i � i !
� 1
� I i I
j- ! I•-i----�
I I s i
---�-
I Se (DL value)
--- i - — - ------t
j I
! !
,
'
InitialB-,SS'As Ba In
,,
Discha et Da; R.
I
!
i
i
I i i
l i i
l i l l
l i i
'�
Ini
Di
al BSS Ast�Bas
ate t Darr�hR.
iin
il
! II
I ilNo`Sedir�enlldat
!
1199
for Is;ite.
No�edi{nenidaI pri}xto
199 3 for�this,site
i�-
j�
�I
-----
�
I i (
�-
-
�,
— --
I
-i Il
i j j --
i I
- i
1�
i
♦ I i■ I•
I♦ i i
i i i i
�1
�2
O j, jo
i
V- CO W 1- W O ON M V- U') CD I- M M O N M V•") to n W M
pp pp pp pp pp Op (A ()) M O O M M M M M O O O O O O O O O O
O O O O O O (A O O O O O O O O O O O O O O O O O O O
r r r r r r r - — r — — — — — N N N N N N N N N N
Figure 4-14. Arsenic and selenium concentrations (dry weight) in Dan River fine surficial
sediments collected 55.2 km downstream (Location D) of the BCSS ash basin
discharge. (DL denotes values reported as below detection limit.)
50
45
40
= 35
19E
30
CO
25
20
m
IL
m 15
10
5
a
II
AS
*As DL value
E Se!
I !
I
I
I
II
i
II
---�-
I Se (DL value)
--- i - — - ------t
j I
,
I
I l i
i
I i i
l i i
l i l l
l i i
'�
Ini
Di
al BSS Ast�Bas
ate t Darr�hR.
iin
! II
I ilNo`Sedir�enlldat
!
!
1199
for Is;ite.
I
I i
i�-
pri�rto
-----
�
- ----'
�-
-
�,
— --
,
�-_, i -�-_._
I j
I i I
I
j
ii
i
i j j
i to I�
I'
:
CD f- W O O r N M V fn CD I- O M ON M V- U) CD n W O
up Cb O M 00 W M O O O O O to O M O O O O O O O O O O O
O M O M M M M O O O M O O O O O O O O O O O O O O O
Figure 4-15. Arsenic and selenium concentrations (dry weight) in Dan River fine surficial
sediments collected 59.2 km downstream (Location E) of the BCSS ash basin
discharge. (DL denotes values reported as below detection limit.)
4-25

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L-5
T

APPENDIX TABLES
Appendix Table A-1. Macroinvertebrate taxa collected from Dan- River Location A from
1996 — 2009. An "R"= Rare (1 to 2 individuals), "C"= Common (3
to 9 individuals), and an "A"= Abundant (10 or more individuals).
Taxon
1997 1.998
1999 2000
2001
2002 2003
2004 2005 2006 2007 2008
2009
Annelida
Branchiobdellida
Branchiobdellidae
R
R
Hirudinea
Rhynchobdellida
Glossiphoniidae
Helobdella spp.
R
Oligochaeta
Tubificida
Naididae
Bratislavia unidentata
R
Dero spp.
R
Homochaeta naidina
R
Nais behningi
R
Nais communis
R
R
Nais variabilis
R
R
Pristina leidyi
R
PHstina sima
R
R
PHstinella jenkinae
R
Prisdnella osbomi
C
R
Tubificidae
R
C
C
R
R
C
Aulodrilus limnobius
R
Bothnoneurum vejdovskyanum
R
Branchirua souterbyi
R
R
Limnodrilus spp.
C
LimnodHlus hotfineisterei
C
R
R
R
R
Limnodrilus udekemianus
R
Spirosperrna spp.
R
Tasseriddrilus ha►mani
R
Tubifex tubifex
R
Lumbdeulida
Lumbdculidae
C
C
R
C
R
A
C
A
C
Kinncaidiana freiddus
R
Lumbriculus spp.
C
R
C
R
C
Arthropoda
Acari
R
R
Crustacea
Decapoda
Cambaridae
R
R
R
R
Cambarus spp.
R
R C
C
C
C
C
Insecta
Coleoptera:
Dryopidae
Helichus spp.
R
R
C
C
R
C
Helichus Iithophilus
R
C
R
R
R
A-1

Appendix Table A-1. (Continued).
Taxon
1997 1998
1999 2000 2001
2002
2003
2004 2005 2006 2007
2008
2009
Dytiscidae
Bidessus spp.
R
Laccophilus spp.
R
R
Neoporus spp.
R
R
Elmidae
Ancyronyx vadegatus
A
R
A
R
R
R
C
C
C
C
Dubiraphia spp.
R
R
R
Dubiraphia vittata
R
Macronychus glabratus
A
A
A
R
A
A
C
R
C
A
A
A
A
Optioservus spp.
C
Promoresia elegans
A
A
C
A
Stenelmis spp.
R
R
R
R
R
Gyrinidae
Dineutus spp.
C
A
A
R
R
R
C
A
A
A
Gyrinus spp.
C
Haliplidae
Peltodytes spp.
R
R
Hydrophilidae
Sperohopsis tessellatus
R
Diptera
Athedcidae
Atherix lantha
C
R
C
R
R
R
Ceratopogonidae
Palpomyia-Bezzia complex
R
C
R
C
R
C
C
C
A
R
Chironom idae-Chironominae
Chironomus spp.
C
C
R
A
A
Cladotanytarsus spp.
R
C
A
R
C
A
A
C
Cryptochironmus spp.
R
R
R
C
C
C
R
C
A
A
C
Cryptotendipes spp.
R
C
R
A
R
R
Dicrotendipes neomodestus
C
A
C
A
A
C
Hamischia curtilamellata
R
Microtendipes spp.
R
R
R
Nilothauma spp.
R
R
R
R
Paracladopelma spp.
C
Paralauterbomiella nigrohalterale
R
R
Paratendipes spp.
R
R
Phaenopsecim spp.
R
R
R
R
C
R
R
R
Polypedilum fallax
R
C
R
R
R
R
R
C
Polypedilum flavum
C
R
R
C
A
A
C
A
C
A
A
A
Polypedilum halterale
A
A
A
R
C
Polypedilum illinoense
R
R
R
R
A
R
A
A
C
R
R
Polypedilum laetum
R
R
Polypedilum scalaenum
R
R
C
C
R
C
Polypedilum simulans/digitifer
A
C
C
Pseudochironomus•spp.
R
Rheotanytersus spp:
C
A
A
C
A
C
A
R
C
Robackia claviger
A
R
A
Robackia deme#erei
R
C
R
R
Saetheria lylus .
C
A-2

Appendix Table A-1. (Continued)
Taxon
1997 1998
1999 2000
2001
2002 2003 2004 2005 2006 2007 2008
2009
Stelechomyia perpulchra
C
R
C
Stenochironomus spp.
R
C R
C
C
C
A
C
Stictochironomus spp.
R
A
A
C
C
Tanytarsus spp.
C
R
A R
A
C
A
A
C
Tribelos spp.
C
A
C
Chironom idae-Orthocladiinae
Cardiocladius spp.
C
Corynoneura spp.
R
R
R
R
R
C
Cricotopus annulator
C
C
A
Cricotopus bicinctus
C
R
C
A
Cricotopus infuscatus gp.
A
R
Cricotopus politus
R
C
A
R
Cricotopus vanpes gp.
C
Cricotopus vierriensis
R
R
C
R
Eukiefferiella spp.
C
C
R
R
Eukief enella gracei
C
Lopescladius spp.
A
R
A
C
Nanocladius spp.
A
C
R
C
C
R
A
R
Nanocladius dotmnesi
C R
C
Orthocladius spp.
A
Orthocladius carlatus
C
A
Parametdocnemus spp.
R
R
Rheocricotopus spp.
R
Rheocricotopus robacki
C
A
R
C
Rheocricotopus tuberculatus
C
Rheosmittia spp.
C
R
Thienemanniella spp.
R
C
R
C
Thienemanniella xena
C
A
C
Tvetenia spp.
R
R
Tvetenia bavarica
R
Tvetenia discoloripes
R
C
A
Tvetenia vitracfes
C
Chironom idae-Tanypodinae
Ablabesmyia spp.
R
Ablabesmyia annulata
R
R
R
Ablabesmyia janta
C
A
C
Ablabesmyia mallochi
C
C
C
C
R
C
A
C
Ablabesmyia parajantaranta
C
Ablabesmyia simpsoni
R
Clinotanypus pinguis
R
Conchapelopia gp.
R
C
C
C
Labrundinia spp.
R
C
Natarsia spp.
R
Nilotanypus spp.
R
C
R
A
R
Procladius spp.
R
C
R
Rheopelopia spp.
R
C
Thienemannimyia gp.
R
Culicidae
Anopheles spp.
C
R
A-3

Appendix Table A-1. (Continued)
Taxon
1997 1998
1999 2000
2001
2002
2003 2004 2005 2006 2007 2008 2009
Simuliidae
Simulium spp.
C
A
R
C
A
C
R
R
A
A
R
A
Tabanidae
Chrysops spp.
R
R'
Tabanus spp.
R
Tipulidae
Antocha spp.
R
R
A
R
R
C
Hexatoma spp.
R
R
Limnophila spp.
R
'
Tipula spp.
R
A
C
R
R
Ephemeroptera
Baetidae
Acentrella spp.
C
R
C
R
Acentrella femorella
R
BaeSs anoka
R
Baetis ephippiatus
A
Baetis flavistdga
C
R
C
Baetis intercalaris
C
C
C
R
C
C
R
C
A
C
C
A
Baetis pluto
R
Baetis pmpinquus
R
R
C
C
Centroptilum spp.
C
C
R
R
Heterocloeon curiosum
C
R
R
C
R
C
C
A
Plauditus dubius gp.
•.
'
C
Pseudocloeon frondale
R
Pseudocloeon propinquum
R
Baetiscidae
Baetisca caroling
R
Caenidae
Caenis spp.
R
R
C
C
C
C
R
C
C
Ephemerellidae
Serratella deflciens
C
C
Serrate/la mo/ita
R
C
R
Serratella serratoides
C
Ephemeddae
Hexagenia spp.
R
A
A
C
A
A
R
R
A
A
R
A
A
Heptageniidae
Heptagenia marginalis
R
A
R
R
Leucrocuta spp.
R
A
A
Maccaffertium exiguum
R
C
C
R
C
C
A
Maccaffertium meririvulanum
R
Maccaffedum modestum
A
A
C
C
A
A
A
A
A
A
A
A
A
Maccaffertfum terminatum
C
Rhithrogena.spp.
R
Rhithrogena uhad
R
R
Stenacron interpunctatum
R
R
C
Oligoneudidae
Isonychia spp.
A
A
C
R
A
A
A.
A
A
A
A
A
A
Polymitarcyidae
Ephoron leukon
R
.
A-4

Appendix Table A-1.
(Continued)
Taxon
1997 1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
Tdcorythidae
C
Tricorythodes spp.
C
C
R
A
A
C
A
A
Tricorythodes robacki
R
R
Hemiptera
Cod)ddae
A
Gen idae
Metrobates hespedus
R
Nepidae
Ranatre spp.
R
R
Ranatra nigra
R
C
R
Wgaloptera
Corydalidae
Corydalus comutus
A
A
A
C
A
C
A
C
A
A
A
A
A
Nigronia fasciatus
R
Nigronia serricomis
R
R
R
C
R
Sialidae
Sialis spp.
R
R
R
R
C
C
Odonata-Anisoptera
Aeshnidae
Boyeria grafiana
R
Boyeria vinosa
C
R.
R
C
C
A
C
R
Corduliidae
Helocordulia spp.
R
Neurocordulia spp.
R
Gomphidae
R
Dromogomphus spp.
R
C
C
A
Gomphurus spp.
C
Gomphus spp.
R
R
R
C
A
C
R
C
C
Gomphus spiniceps
R
R
Hagenius brevistylus
R
C
R
C
R
R
Hylogomphus spp.
R
Ophiogomphus spp.
C
C
A
R
C
Progomphus spp.
R
R
C
Progomphus obscures
R
C
Siylogomphus albistylus
R
R
Stylurus spiniceps
C
R
R
Wcromiidae
Macromia spp.
C
R
A
Macromia georgina
R
A
R
R
C
A
A
A
A
Odonata-Zygoptera
Calopterygidae
Calopteryx spp.
R
R
C
A
R
R
R
Calopteryx dimidiata
R
Calopteryx maculata
A
Hetaerina spp.
R
Coenagdonidae
Argia spp.
R
R
R
C
A
C
A
A
Ischnura spp.
C
C
Plecoptera
.
A-5

Appendix Table A-1. (Continued)
Taxon
1997 1998
1999 2000 2001
2002 2003 2004 2005
2006 2007 2008
2009
Peltopedidae
Tallaperla spp.
R
R
R
Perlidae
Acroneuria abnormis
A
C
R
R
R
C
C
A
A
A
A
C
Agnetina annulipes
C
R
Agnetina flavescens
C
A
+•
A
Eccoptura xanthenes
R
Paragnetina fumosa
C
R
R
C
R
C
C
C
Paragnetina ichusa
C
C
R
C
Paragnetina immarginata
R
A
C
Perlodidae
Isoperla spp.
R
R
Pteronarcyidae
Pteronarcys spp.
R
C
A
R
Pteronaroys dorsata
C
A
C
A
C
R
R
Trichoptera
Brachycentridae
Brachycentrus lateralis
C
A
C
C
Brachycentrus nigrosoma
R
A
C
R
Brachycentrus numerosus
C
Micrasema spp.
C
Micrasema bennetti
R
Micrasema sprulesi
R
Micrasema volaga
R
Calamoceraiidae
Anisocentropus pyraloides
R
Hydropsychidae
Cheumatopsyche spp.
C
A
C
A
A
C
A
A
A
A
A
C
A
Cheumatopsyche etrona
C
Hydropsyche incommoda
R
R
R
R
A
Hydropsyche morosa
R
C
C
C
C
C
R
Hydropsyche pha/erata
R
R
R
R
Hydropsyche simulans/rossi
C
A
A
Hydropsyche spama
A
A
C
Hydropsyche venulads
C
R
A
A
A
C
A
A
A
C
A
Hydroptilidae
Hydroptila spp.
R
Orthotrichia spp.
R
Lepidostomatidae
Lepidostoma spp.
R
C
R
R
C
Leptoceidae
Ceraclea spp.
R
R
Ceraclea cancellata
R
Nectopsyche exquisita
R
C
A
R
R
C
A
A
A
A
C
Oeceds spp.
R
R
R
R
R
C
Setodes incerta
R
Triaenodes spp.
R
R
Piaenodes ignitus
R
C
C
R
R
A
L'imnephilidae
A-6
I

Appendix Table A-1. (Continued)
Taxon
1997 1998
1999 2000 2001
2002
2003 2004 2005 2006 2007 2008
2009
Pycnopsyche spp.
R
Odontoceidae
Psilotreta spp.
C
Philopotamidae
Chimarra spp.
R
R
R
R A
R
R
Polycentropodidae
Neureclipsus spp.
R
Polycentropus spp.
C R
R
Mollusca
Gastropoda
Basommatophora
Physidae
Physella spp.
R
C
Limnophila
Ancylidae
Fenissia spp.
R
R
Mesogastropoda
Hydrobiidae
R
Pleuroceridae
Leptoxis spp.
A
A A
A
A
C C
R
Pulmonata
Planorbidae
Helisoma spp.
A
C
C
Pelecypoda
Heterodontida
Corbiculidae
Corbicula fluminea
A A
A C
A
C
A A R
A
R
Veneroida
Sphaedidae
Pisidium spp.
R
Nemertea
Enopla
Hoplonemertea
Tetrastemmatidae
Prostoma greecens
R R
Platyhelminthes
Turbellada
Tdcladida
Planadidae
Dugesia spp.
R
A-7

Appendix Table A-2.
Macroinvertebrate taxa collected from Dan River Location B from
1996 - 2009.
An, "R"=
Rare:
(1: to: 2 individuals);
"C"= Common (3
to 9 individuals), and an
"A"= Abundant (10 or more individuals).
Taxon
1997 1998 1999 2000
2001
2002 2003 2004 2005 2006 2007 2008 2009
Annelida
Hirudinea
Rhynchobdellida
Glossiphoniidae
Helobdella spp.
R
Oligochaeta
Tubificida
Naididae
Nais behningi
R
R
Nais communis
R R
R
Nais variabilis
R
C
Tubificidae
R
R
C R
C C R
Bothrioneurum vejdovskyanum
R
Branchirua swerbyi
R
C A
Limnoddlus hofteisterei
R
R R
Monopylephorus helobius
R
Potamothrix vejdovskyi
R
Lumbdeulida
Lumbriculidae
C
C R
C
C R
C C C C
Lumbriculus spp.
R
R
A R R
Arthropoda
Acari
R
A
Crustacea
Decapoda
Cambaddae
C C
' R
Cambarus spp.
C
R C R R
C R C
Isopoda
Asellidae
Caecidotea spp.
R
Insecta
Coleoptera
Dryopidae
Helichus spp.
R R R
C C R A
Helichus lithophilus
R R
C C
Dytiscidae
Bidessus spp.
R
Laccophilus spp.
R
Neoporus spp.
R
Elmidae
Ancyronyx vadegatus.
R
R
R R C
R R A R
Macronychus glabratus
_C C
C
C
A C A
A A A A
Promoresia elegans
C R
C
A
C R
C A R
Stenelmis spp:
R
C
R
R C C
Gyrinidae -
Dineutus spp.
R R
A
A
R C
A C A A
Hydrophilidae
Enochrus spp.
R
A-8
I

Appendix Table A-2. (Continued)
Taxon
1997 1998
1999 2000 2001
2002 2003 2004 2005 2006 2007 2008 2009
Sperchopsis tessellatus
R
Tropistemus spp.
R
Psephenidae
Ectopria nervosa
R
Psephenus henicki
R
R
R
Diptera
Athericidae
Atherix lanthe
R
R
R
Ceratopogonidae
Palpomyia-Bezzie complex
C
C
R
A
Chironom idae-Chironom inae
Chironomus spp.
R
R
C
R
R
R
C
Cladopelma spp.
R
Cladotanytarsus spp.
R
A
A R
C
C
A
A
C
Cryptochironmus spp.
C
R
C
C
C
A
A
A
Cryptotendipes spp.
R
C
A
Cryptotendipes emorsus
A
Demicryptochironomus spp.
C
Demicrypiochironomus cuneatus
R
Dicrotendipes neomodestus
R
R
A
C
A
A
A
Microtendipes spp.
R
R
C
Nilothauma spp.
C
A
C
Paracladopelma spp.
R
A
R
Paralauterbomiella nigrohaltera/e
R
Paratendipes spp.
R
C
Phaenopsectra spp.
R
C
R
A
A
C
R
Polypedilum fallax
R
R
R
R
A
C
A
R
Polypedilum flavum
R
C
A A
R
A
C
A
A
A
Polypedilum halterale
R
A
C
A
C
Polypedilum i/linoense
R
R
R
C
C
R
A
C
C
A
Polypedilum laetum
R
R
Polypedilum scalaenum
R
C
R
C
C
C
Polypedilum simulans/digitifer
R
Pseudochironomus spp.
C
A
C
Rheotanytarsus spp.
R
C
A
A
R
A
A
R
Robackia spp.
R
Robackia claviger
R
Robackia deme#erei
R
R
R
R
Saetheda spp.
C
Stelechomyis perpulchra
R
R
Stenochironomus spp.
R
R
R
A
R
C
C
Stictochironomus•spp.
C
A
C
C
Tanytarsusspp.
R
R
C
A
C
A
A
A
Tribelos spp.
R
R
A
C
R
Chironom idae=Orthocladiinae
Brillia •spp.
R
R
Cardiocladius,spp.,
R
C
R
Corynoneura spp.
R
C
R
Cricotopus: spp.
R
A-9

C
Appendix Table A-2. (Continued)
Taxon
1997 1998 1999 2000 2001
2002 2003 2004 2005 2006 2007 2008 2009
Cdcotopus annulator
R
C
A
A
Cdcotopus bicinctus
A
R
R
C
C
A
Cdcotopus cylindraceus
C
Cdcotopus infuscatus gp.
C
R
Cdcotopus politus
A
A
C
Cricotopus vierriensis
A
C
Diplocladius cultriger
R
Eukieffedella spp.
C
Eukieffedella gracei
C
Lopescladius spp.
R
Nanocladius spp.
C
R
R
R
C
C
C
A
C
Nanocladius doHnesi
R
C
Orthocladius spp.
A
Orthocladius carlatus
C
Orthocladius obumbratus
R C
A
Parakieffedella spp.
C
R
Parametriocnemus spp.
R
R
Paratrichocladius spp.
R
Psectrocladius spp.
R
Rheocdcotopus spp.
R
R
C
C
R
A
Rheocricotopus robacki
A
A
A
A
Rheosmittia spp.
R
Synorihocladius spp.
R
Thienemanniella spp.
R
C
Ft
R
R
R
Thienemanniella xena
C
A
A
C
Tvetenia spp.
C
C
Tvetenia discoloripes
R
Tvetenia vibacies
C
R
A
Xylotopus par
R
Chironom idae-Tanypodinae
Ablabesmyia spp.
R
R
R
Ablabesmyfaianta
C
A
C
C
Ablabesmyia mallochi
R
R
C
C
C
C
A
C
Ablabesmyia simpsoni
C
Clinotanypus pinguis
R
Conchapelopia gp.
R
R
C
C
C
Labmndinia spp.
R
R
R
Natarsia spp.
R
Nilotanypus spp.
R
C
R
R
C
C
C
Procladius spp.
C
R
R
Rheopelopia spp.
R
R
R
A
Thienemannimyia.gp.
R
R
Zavrermyia gp.
A
Empididae
R
Hemerodromia spp.
R
Simuliidae
Simulium.spp.,
R
C
A
A
R
A
R
A
A
A
C
A
Tabanidae"
R
R
Tabanus spp.
R
A-10

Appendix Table A-2. (Continued)
Taxon
1997
1998
1999 2000 2001
2002 2003 2004 2005 2006 2007 2008 2009
Tanyderidae
C
R
Protoplasa fitchii
R
R
Tipulidae
Antocha spp.
R
C
R
A
Limonia spp.
R
Tipula spp.
C
R
C
R
R
C
Ephemeroptera
Baetidae
Acentrella spp.
C
R
R
C
Baetis spp.
R
Baetis anoka
R
Baetis flavistriga
R
R
Baetis intercalaris
C
R
A
R
R
C
R
A
C
A
C
R
Baetis pluto
R
R
Baetis propinquus
R
R
R
C
Centroptflum spp.
A
C
C
Heterocloeon curiosum
C
R
R
C
R
C
A
A
A
Pseudocentroptiloides usa
R
Pseudocloeon spp.
R
R
C
Pseudocloeon frondale
C
Pseudocloeon propinquum
R
Baetiscidae
Baetisca carolina
R
Caenidae
Caenis spp.
R
R
R
{C
C
C
A
C
C
R
Ephemerellidae
Serratella deficiens
R
R
Timpanoga simplex
R
Ephemeddae
Hexagenia spp.
R
R
R
A
R
A
Heptageniidae
Heptagenia spp. ,
R
Heptagenia marginalis
R
C
R
Heptagenia pulls
C
Leucrocuta spp.
R
Maccaflerdum exiguum
R
C
R
R
R
C
A
A
A
A
A
Maccaffertlum lend
R,
Maccaffedum mexicanum
R
A
,
Maccaffedum modestum
A
A
C.
A
A
A
A
A
A
A
A
Maccaffer ium terminatum
C
A
C
Stenacron interpunctatum
R
C
R
Oligoneuaidae
isonychia spp.
A
A
R
C
A
A
A
A
A
A
A
A
A
Tdcorythidae
Tricorythodes.spp.
C
C
R
C
R
C
A
A•
R
C
A
Tricorydrodesrobackb
R
R
Hemiptera
Corixidae
Siaars soc
R
A-11

Appendix Table A-2. (Continued)
Taxon
1997
1998
1999 2000 2001
2002 2003
2004 2005 2006 2007 2008 2009
Gemdae
Metrobates hesperius
R
C
A-
Nepidae
Ranatra spp.
R
Veliidae
R
Megaloptera
Corydalidae
Corydalus comutus
A
A
C
A
A
A C
R
A
A
A
A
A
Nigronia serricomis
R
R
C
C
R
R
Sialidae
Sialis spp.
R
Odonata-Anisoptera
Aeshnidae
Boyeria vinosa
R
R
R
R
C
Corduliidae
Epicordulia spp.
R
Neurocordulia obsoleta
R
R
Gomphidae
R
R
R
Dromogomphus spp.
C
C
C
Dromogomphus arrnatus
R
Gomphus spp.
R
R
C
R
R
C
Gomphus spiniceps
R
Hagenius brevistylus
R
R
LanMus vemalis
R
Ophiogomphus spp.
C
R
R
Progomphus spp.
R
C
R
Progomphus obscurus
R
Stylogomphus a/bistylus
R
Macromiidae
Macromia spp.
R
R
R
R
Macromia georgina
R
C
R
C
C
C
Odonata-Zygoptera
Calopterygidae
Calopteryx spp.
R
R
Hetaerina spp.
R
R
Coenagdonidae
Argia spp.
R
R
R
R
R
A
A
A
Ischnura spp.
R
R
R
R
Plecoptera
Capniidae
Allocapnia spp.
A
Peftopedidae
Peltoperla spp.
R
Pedidae
Acroneuria abnormis
C
C
R
R
C
R
C
A
A
C
C
Agnetina:annulipes
A
Agnedna capitata
A
C
C
Agnedna flavescens
C
R
C
Paragnetina fumosa
C
C
R
C
C
C
C
A-12

I
Appendix Table A-2. (Continued)
Taxon
1997
1998
1999
2000 2001
2002 2003 2004 2006 2006 2007 2008 2009
Paragnedna ichusa
A
A
R
C
Paragnetina immarginata
C
R
C
R
Paragnedna kansensis
R
Pedodidae
Helopicus subvarians
C
Isoperla spp.
R
Pteronarcyidae
Pteronarcys spp.
A
R
R
R
Pteronarcys dorsata
C
R
C
C
C
R
C
Trichoptera
Brachycentddae
Brachycentrus nigrosoma
R
R
Brachycentrus numerosus
R
R
Hydropsychidae
C
Cheumatopsyche spp.
A
A
C
A
A
A
C
A
C
A
A
A
Hydropsyche betteni
R
C
Hydropsyche incommoda '
C
R
C
C
C
C
C
Hydropsyche morosa
R
C
A
C
Hydropsyche phalerata
R
R
R
R
C
R
C
C
Hydropsyche simulans/rossi
A
A
A
Hydropsyche spama
R
C
R
R
C
C
C
Hydropsyche venularis
A
C
R
C
A
A A
A
A
A
A
A
A
Hydroptilidae
Hydroptila spp.
R
A
Lepidostomatidae
Lepidostoma spp.
R
Leptoceddae
R
Nectopsyche exquisita
R
R
C
R
Oecetis spp.
R
R
Triaenodes spp.
R
Philopotamidae
Chimarra spp.
R
R
R
R
R
Polycentropodidae
Neureclipsus spp.
C
Mollusca
Gastropoda
Basommatophora
f
Physidae
Physella spp.
C
R
Limnophila
Ancylidae
Ferrissia spp.
R
Mesogastropoda'
-.
Hydrobiidae
R
Pleuroceddae
Leptoxis spp.
R
R
C
R
A
Pelecypoda
Heterodontida
Corbiculidae
A-13

i
Appendix Table A-2. (Continued)
Taxon 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009
Corbicula flumina A A A A C A C A A A A A
Platyhelminthes
Turbellaria
Tdcladida
Planariidae
Dugesia spp. R
a
A-14