NC0036935_Instream Assessment_20211129

Jacob Fork, Pine Mountain Lakes WWTP Investigation
Burke County, North Carolina, 14 September 2021
North Carolina Department of Environmental Quality
Division of Water Resources
Water Sciences Section
Biological Assessment Branch
Chris Verdone, Aquatic Biologist, Biological Assessment Branch 22 November 2021
Eric D. Fleek, Supervisor, Biological Assessment Branch 22 November 2021

SUMMARY
Jacob Fork and White Oak Creek were sampled for benthic macroinvertebrates on 14
September 2021. The purpose of these samples was to determine the effect of the Pine Mountain
Lakes WWTP (Permit # NC0036935) on water quality in Jacob Fork. The effluent from this
WWTP is discharged into Jacob Fork below White Oak Creek. Three sampling sites were
selected, two on Jacob Fork, one approximately 100 in (328 ft.) downstream of the waste water
discharge pipe and one upstream of White Oak Creek to act as the reference site (Fig. 1). White
Oak Creek was also sampled to assess whether it was having any effect on water quality in Jacob
Fork.
Stream conditions on 14 September 2021 were ideal for conducting benthic samples,
water levels were near median and water clarity was high. No waste water was observed from
the discharge pipe on the day the samples were collected. The downstream location was sampled
first to avoid introducing organisms into the reach due to drift caused by sampling activities. The
upstream reference was sampled second and White Oak Creek was sampled last. Although these
sites are physically located in the Piedmont, they were assessed using mountain metrics as >95%
of their contributing drainage areas reside in the Blue Ridge level III Ecoregion. Full Scale
samples were taken at Jacob Fork and an EPT sample was taken at White Oak Creek.
The downstream Jacob Fork site received an EXCELLENT bioclassification, the highest
possible classification score (Table 2). Habitat score (75) was lower than the upstream reference
site (83) largely due to poorer riffle habitat (Table 1). However, Jacob Fork, below the waste
water discharge, recorded 40 EPT, two more than the reference site (38), which helped tip the
downstream site over the threshold for an Excellent bioclass rating, whereas the reference site
received a GOOD. Although these two reaches earned different bioclassifications, they score
more closely than the bioclass indicates.
Physiochemical parameters were nearly exactly the same between the two sites as well.
Dissolved oxygen, pH, and specific conductance were essentially the same between the two
locations (Table 1). As previously stated, the WWTP was not discharging during our sampling
activities. Based on the samples taken on 14 September 2021, there does not appear to be a
substantial difference in water quality between the upstream reference site and the reach
downstream of the Pine Mountain Lakes WWTP (Permit # NC0036935).
White Oak Creek received a Good -Fair bioclassification recording only 26 EPT taxa.
This location scored relatively well in the habitat assessment (86) (Table 1), but it appeared to
have been affected from recent flooding. Many large debris jams had converted much of the
sampling reach into pool habitat, which generally has lower EPT richness than riffle or run
habitats. Based on the bioclass rating from Jacob Fork, White Oak Creek does not appear to be
substantially impacting Jacob Fork. White Oak Creek should be sampled again during the next
Catawba Basin cycle to determine if the mediocre bioclassification it received was the result of a
stochastic high flow event or other possible stressors.
2

STUDY SITES
The three sampling locations are located approximately 0.3km east of SR 1901 (Wards Gap
Rd.), east of Pine Mountain Golf Course, in Burke County North Carolina (Fig. 1).
(CB413) Jacob Fork, below White Oak Creek (35.58761,-81.58161) (Fig. 2) is located
approximately 120 m downstream of White Oak Creek and about 100 m downstream of the
wastewater effluent pipe from the Pine Mountain Lakes WWTP. This site is in the
Northern Inner Piedmont (45e) level IV ecoregion at an elevation of 365m (1200 ft.) and
has a drainage area of 55.7 km2 (21.5mi). 95.5% of the contributing watershed resides in
the Blue Ridge Level III Ecoregion.
• (CB414) Jacob Fork, above White Oak Creek (35.58886,-81.58234) (Fig. 3) is located
approximately 70m upstream of White Oak Creek. This site is in the Northern Inner
Piedmont (45e) level IV ecoregion at an elevation of 365m (1200 ft.) and has a drainage
area of 42.7 km2 (16.5 mi2). 98.3% of the contributing watershed resides in the Blue Ridge
Level III Ecoregion.
• (CB415) White Oak Creek below SR 1901 (Wards Gaps Rd.) (35.58832,-81.58249) (Fig.
4) is located 360 m east of SR 1901. This site was sampled approximately 20 m upstream
of the confluence with Jacob Fork. This site is in the Northern Inner Piedmont (45e) level
IV ecoregion at an elevation of 365m (1200 ft.) and has a drainage area of 12.8 km2 (4.93
mi). 98.3% of the contributing watershed resides in the Blue Ridge Level III Ecoregion.
3

Legend North Carolina
• Ben thic s
Stream
County
Blue Ridc
Piedmont
Coastal Plain
NCFMR NCDOT, NCCGIA
Figure 1. Benthic sampling sites on Jacob Fork and White Oak Creek, Burke County, North
Carolina.
4

Figure 2-4. Benthic sites, Burke County, North Carolina, 14 September 2021. (2) CB413, Jacob
Fork, below White Oak Creek. (3) CB414, Jacob Fork, above White Oak Creek. (4) CB415,
White Oak Creek, below SR 1901.
METHODS
Benthic Macroinvertebrate Community Assessment
The downstream location was sampled first to avoid introducing organisms into the reach
due to drift caused by sampling activities. The upstream reference was sampled second and
White Oak Creek was sampled last. Benthic macroinvertebrate data were collected according to
North Carolina Division of Water Quality (DWQ) Benthic Macroinvertebrates Standard
Operating Procedures (NCDENR 2015). All sampling procedures involve various techniques
(riffle kicks, leaf packs, sweeps, rock/log washes, visual inspections) to collect benthic
macroinvertebrates from different stream habitats. After collection, organisms are sorted in the
field and preserved in 95% ethanol. In the laboratory, specimens are identified to the lowest
possible taxonomic level and assigned values based on their relative abundances (rare, 1-2
specimens; common, 3-9 specimens; or abundant, >10 specimens). The semi -qualitative method
5

pertinent to the current study are described below. All invertebrate taxonomic data resulting from
this study are listed in Appendix 1.
Full Scale Method
The Full Scale method can be used to assign water quality ratings (bioclassifications) to most
wadeable flowing streams and rivers in North Carolina. This methodology is applicable for
most between -site and/or between -date comparisons and should be used for all evaluations of
impaired streams (those on the state 303(d) list) for which the drainage area is over 3.0
square miles. For the Full Scale method, the following collections are made: two riffle -kicks,
three sweeps, one leaf -pack, two rock- and log -washes, one sand, three visuals.
EPT Method
The EPT method is an abbreviated version of the Full Scale method and is used to quickly
determine between -site differences in water quality. It is particularly useful for watershed or
basin assessment studies with large numbers of sites, or emergency sampling where it is
desirable to rapidly assess the effect of spills, unusual discharges, etc. The collection and
analysis time for the EPT method has been decreased from the Full Scale method in two
ways. First, collections focus solely on a subset of the benthic community composed of taxa
in the taxonomic orders Ephemeroptera, Plecoptera, and Trichoptera. These orders usually
include the most intolerant species among benthic invertebrates. Field notes also are made
concerning the abundance of other groups, especially any pollution indicator species.
Secondly, the number of collections is decreased from 13 to six: one riffle -kick, one sweep,
one leaf -pack, three visuals.
Data Analyses and Bioclassifications
Criteria
Streams in different ecoregions vary in gradient, geology, and flow regimes. Assessment
criteria specific to each ecoregion (Griffith et al. 2002) have been developed by DWQ
biologists (NCDENR 2015). These criteria control for natural variations in organism
distributions, stream flows, and local geography inherent in some systems. Separate criteria
exist for both habitat evaluations (Mountain, Piedmont and Coastal Plain) as well as for the
metrics used to assign water quality ratings (Mountain, Piedmont, and Coastal Plain). Sites
that occur in multiple ecoregions are typically assessed with criteria in which the majority of
the watershed resides. Additionally, the presence of taxa specific to a certain ecoregion (i.e.,
mountain specific taxa) and the general characteristics of the stream (i.e. gradient and
substrate type) are taken into account when deciding the appropriate criteria. For example, if
a stream physically lies in the Piedmont but the presence of mountain taxa is noted and the
majority of stream catchment resides within the mountains, it would be appropriate to use
Mountain criteria to rate the sampling site. All samples collected as part of this study were
assigned bioclassifications based on mountain criteria.
11

Metrics
Benthic community metrics measure the relative tolerance of a system to stress. Pollutants
such as urban runoff, WWTP discharge, sediments, or large temperature variations, can
adversely affect aquatic biological communities. Streams that are biologically degraded will
typically have lower invertebrate diversity and a lower proportion of pollution sensitive
species relative to streams that are pristine. The most common metrics used by the BAU to
measure community tolerance are taxa richness (S) and the biotic index (BI).
Species Richness and Abundance
A useful metric used in assessing stream water quality is the total number of species or
"richness" of benthic organisms present in the stream. A subset of benthic organisms,
Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies) are "EPT"
taxa. These three orders of aquatic insects, as a group, are more sensitive to pollution than
other macroinvertebrates, although taxa within EPT do have differing tolerance values. A
high diversity of EPT (EPT S) and abundance (EPT N) generally indicates higher water
quality.
Biotic Index
The biotic index is the summation of the tolerance values of all benthic species present
relative to their abundance in the community as a whole. This index ranges from 0-10, with
higher numbers suggestive of more polluted conditions within the stream. The North
Carolina Biotic Index (NCBI) was developed over many years by NC biologists to reflect the
tolerances of the entire invertebrate assemblage found in North Carolina streams (Lenat
1993), although it has been adapted for use by other states. Conversely, the EPT biotic index
(EPT BI) reflects only the tolerance of the EPT community and not the entire benthic
macroinvertebrate community.
RESULTS
Habitat data are in Table 1 (next page). Summary of benthic results are in Table 2. Lists
and categorical abundances of taxa collected from each site are in Appendix 1.
7

Table. 1 Habitat assessments for CB413, CB414 and CB415.
Mountain/Piedmont Habitat Table
Stream
JACOB FK
JACOB FK
WHITE OAK CR
Site Location
BE WHITE OAK CR
AB WHITE OAK CR
BE SR 1901
County
Burke
Burke
Burke
Site ID
CB413
CB414
CB415
Collection date
9/14/2021
9/14/2021
9/14/2021
BAU sample number
12766
12767
12768
Habitat Scores
Channel modification (5)
5
5
5
In -stream habitat (20)
18
18
18
Bottom substrate (15)
11
11
11
Pool variety (10)
6
6
8
Riffle habitats (16)
7
14
14
Bank erosion (7)
6
7
6
Bank vegetation (7)
7
7
7
Light penetration (10)
7
7
7
Left riparian (5)
5
5
5
Right riparian (5)
3
3
5
Total Habitat (100)
75
83
86
Other Habitat
Average stream width (m)
14
10
5
Average stream depth (m)
0.4
0.3
0.1
Canopy (%)
70
80
50
Substrate (%)
Boulder
0
15
10
Cobble
30
30
30
Gravel
40
30
30
Sand
20
20
30
Silt
10
Other
5
description
bedrock
mical
Temperature (°C)
19.8
1 21.2
1 21.7
Dissolved oxygen (mg/L)
8.6
8.7
8.2
Specific conductance (pmhos/cm)
23.7
22.7
26
DH
5.8
5.8
6.3
M

Table 2. Bioassessment metrics for sites C13413, CB414 and C13415.
JACOB FK
JACOB FK
WHITE OAK CR
JACOB FK
JACOB FK
WHITE OAK CR
Site Location
BE WHITE OAK CR
AB WHITE OAK CR
BE SR 1901
County
Burke
Burke
Burke
Site ID
CB413
CB414
CB415
Collection date
9/14/2021
9/14/2021
9/14/2021
BAU sample #
12766
12767
12768
Method
Full Scale
Full Scale
EPT
Richness
Ephemeroptera
15
18
11
Plecoptera
11
9
8
Trichoptera
14
11
7
Odonata
7
8
0
Megaloptera
2
2
0
Coleoptera
10
9
0
Chironomidae
17
21
0
non-Chironomidae Diptera
6
7
0
Oligochaeta
2
1
0
Mollusca
0
0
0
Othertaxa
1
0
0
TotalTaxa
85
86
26
TotaIEPT
40
38
26
EPT N
145
116
71
Biotic Index
3.91
3.8
3.11
EPT BI
1 2.86
1 2.89
1 3.11
Bioclassification
I EXCELLENT
I GOOD
I GOOD -FAIR
DISCUSSION
The benthic macroinvertebrate community in (CB413) Jacob Fork, downstream of the
discharge from Pine Mountain Lakes WWTP (Permit # NC0036935) did not indicate signs of
biological degradation based on the sample taken on 14 September 2021. On the contrary, all
biotic metrics suggests high biotic integrity. With a biotic index score of 3.91, and EPT BI of
2.86, the benthic macroinvertebrate community at CB413 is largely composed of organisms
intolerant of poor water quality. Boasting 40 EPT, including 11 stonefly taxa (BI range: 0.2-4.7),
CB413 supports many highly intolerant taxa.
No substantial differences were observed regarding the physiochemical parameters
between CB413 and the upstream reference (CB414). Dissolved oxygen, pH, and specific
conductance were essentially the same between the two locations (Table 1). It should be noted,
that these measurements were obtained during zero discharge from the WWTP. The habitat score
0

(75) was lower at CB413 than CB414 (83) largely due to poorer riffle habitat (Table 1).
However, CB413 recorded 40 EPT taxa, two more than the reference site (38), which helped tip
the downstream site over the threshold for an Excellent bioclass rating, whereas CB414 received
a GOOD. Although these two sites earned different bioclassifications, they score more closely
than the bioclass indicates. Referencing the table 2 metrics, both sites had approximately the
same total number of taxa, similar EPT richness, biotic index and EPT BI. These metrics are
used to calculate the bioclass and their respective scores were 4.7 for CB413 and 4.5 for CB414.
Scores are rounded up if they include a value greater than .5 (e.g. 4.7). Scores that include a ".5"
are subject to rounding criteria based on EPT abundance and in this case the reference site did
not meet the threshold to round up to an Excellent bioclass. Notably, CB413 would not have met
the abundance criteria either had it required rounding.
White Oak Creek (CB415) received a Good -Fair bioclassification recording only 26 EPT
taxa. This location scored relatively well in the habitat assessment (86) (Table 1), but it appeared
to have been affected from recent flooding. Many large debris jams had converted much of the
sampling reach into pool habitat, which generally have lower EPT richness than riffle or run
habitats. The EPT taxa that were present were generally intolerant with a collective EPT BI of
3.11. Based on the low EPT BI at White Oak Creek and the bioclass rating from C13413, White
Oak Creek does not appear to be substantially impacting Jacob Fork.
In closing, based on the benthic macroinvertebrate samples taken on 14 September 2021
at Jacob Fork, there does not appear to be a substantial difference in water quality between the
upstream reference site CB414 and CB413 located downstream of the Pine Mountain Lakes
WWTP (Permit # NC0036935). While not the primary subject of the present investigation,
White Oak Creek should be sampled again during the next Catawba Basin cycle to determine if
the mediocre bioclassification it received was the result of a stochastic high flow event or other
possible stressors.
REFERENCES
Griffith, G. E., J. M. Omernik, J. A. Comstock, M. P. Schafale, W. H. McNab, D. R. Lenat, T. F.
MacPherson, J. B. Glover and V. B Shelburne. 2002. Ecoregions of North Carolina and
South Carolina. Reston, VA, U.S. Geological Survey (map scale 1:1,500,000).
Lenat, D. R. 1993. A biotic index for the southeastern United States: derivation and list of
tolerance values, with criteria for assigning water quality ratings. Journal of the North
American Benthological Society 12: 279-290.
NCDENR. 2015. Standard Operating Procedures for the Collection and Analysis of Benthic
Macroinvertebrates. December 2015.
NCDENR. 2009. Biocriteria for the small streams of the North Carolina Mountains and
Piedmont. Memorandum. May 29, 2009. Ibid.
10

Appendix 1. Taxa collected from benthic sites sampled on Jacob Fork and White Oak Creek
on 14 September 2021. Categorical abundances are also shown (R = 1 or 2 specimens
collected; C = 3 to 9 specimens collected; A = 10 or more specimens collected).
m Q Z N
O O N
O
3wU 0)
co= a)CO
j
U wm
0�
m Q Z N
O O N
O
a�U a)
>= a) U
> j
Umm
Q
O O z N
w N
H O
=U)U aa)i
W Y CO
�_ m j
m
M
U
Baetidae Acentrella alachua
Acentrella turbida gr
Baetis flavistri a
Baetis intercalaris
Baetis pluto
Heterocloeon curiosum
Labiobaetis propinquus
Plauditus dubius gr
Procloeon spp
Baetiscidae Baetisca carolina
Caenidae Caenis spp
Ephemerellidae E hemerellidae
Eurylophella spp
Telo ano sis deficiens
Ephemeridae Hexa enia spp
Heptageniidae E eorus vitreus
Hepta enia mar inalis gr
Leucrocuta spp
Maccaffertium modestum
Nixe spp
Stenacron pallidum
Stenacron spp
Isonychiidae Ison Chia spp
Leptohyphidae Tricorythodes spp
Leptophlebiidae Paraleptophlebia spp
R
R
R
R
R
C
C
C
C
C
C
R
C
R
C
C
C
R
C
R
R
R
R
R
A
C
C
C
A
C
A
A
A
R
C
A
C
A
A
C
R
R
C
R
Plecopt
Chloroperlidae Sweltsa spp
Leuctridae Leuctra spp
Peltoperlidae Tallaperla spp
Perlidae Acroneuria abnormis
Acroneuria I corias
C
C
C
C
C
R
R
A
A
A
C
C
11

Agnetina spp
Beloneuria spp
Eccoptura xanthenes
Para netina immar inata
Paragnetina spp
Perlidae
Perlodidae Malirekus hastatus
Pteronarcyidae Pteronarc s proteus
Pteronarc s scotti
hoptera
Brachycentridae Brachycentrus ni rosoma
Calamoceratidae Hetero lectron americanum
Dipseudopsidae Ph locentropus spp
Helicopsychidae Helico s the borealis
Hydropsychidae Cheumatops the spp
Di lectrona modesta
H drops the C. bronta
H dro s the C. s arna
Hydroptilidae H droptila spp
Lepidostomatidae Le idostoma spp
Leptoceridae Nectops the exquisita
Oecetis avara
Triaenodes i nitus
Triaenodes spp
Limnephilidae P cnops the spp
Philopotamidae Chimarra spp
Dolophilodes spp
Polycentropodidae Nyctiophylax spp
Pol centropus sensu lato spp
Rhyacophilidae Rhyacophila fuscula
Uenoidae Neoph lax oli ius
Odonata
Aeshnidae Bo eria vinosa
Calopterygidae Calopteryx spp
Coenagrionidae Ar is spp
Cordulegastridae Cordulegaster maculata
Corduliidae E itheca spp
Gomphidae Gomphus spp
O hio omphus spp
Progomphus spp
Stylogomphus
albist lus/si mast lus
Macromiidae Macromia spp
R
R
R
R
C
C
A
R
R
R
R
R
C
R
R
R
R
R
R
C
C
A
C
C
R
R
A
C
R
R
R
C
R
R
R
R
C
C
C
A
C
R
R
R
C
C
A
A
C
A
C
C
R
R
R
R
A
C
R
R
R
C
C
12

Megaloptera
Corydalidae Corydalus cornutus
Ni ronia serricornis
Dryopidae Helichus basalis
Helichus fasti iatus
Elmidae Ancyronyx variegatus
Macron chus glabratus
Optioservus ovalis
Promoresia ele ans
Promoresia tardella
Stenelmis spp
Gyrinidae Dineutus spp
Psephenidae Ecto ria nervosa
Psephenus herricki
Chironomidae Ablabesm is mallochi
Brillia flavifrons
Corynoneura spp
Cricoto us vierriensis gr
Cryptochironomus spp
Microtendi es pedellus gr
Microtendipes rydalensis gr
Natarsia sp A
Nilotan pus fimbriatus
Orthocladius lignicola
Parametriocnemus spp
Paratendipes albimanus
Phaenopsectra obediens gr
Phaenopsectra punctipes gr
Polypedilum aviceps
Polypedilum fallax/sp A
Polypedilum illinoense gr
Polypedilum spp
Rheocricotopus robacki
Rheopelopia acra gr
Rheotan tarsus spp
Robackia demeijerei
Saetheria t lus
Stempellina sp A
Stenochironomus spp
Tanytarsus sp M
Tan tarsus sp U
A
A
C
R
A
4
R
C
R
C
R
C
R
R
R
A
A
A
A
R
C
C
C
R
R
C
R
R
R
R
C
C
R
C
R
C
C
R
R
R
R
R
C
C
R
R
R
R
R
R
R
R
R
R
R
13

Diptera, other
Ceratopogonidae
Dixidae
Rhagionidae
Simuliidae
Tabanidae
Tanyderidae
Tipulidae
Oligochaeta
Lumbriculidae
Tubificidae
Hydracarina
Thienemanniella spp R
Thienemannim is gr C
Tribelos jucundum C R
Tvetenia vitracies R
ae
Dixa spp
Dixella spp
Atherix lantha
Simulium spp
Protoplasa fitchii
Hexatoma spp
Lumbriculidae
Limnodrilus hoffmeisteri
na
14
C