Appendix IV

Appendix IV

DWQ Water Quality
Monitoring Programs
in the
Savannah River Basin

Appendices

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DWQ Water Quality Monitoring Programs in the Savannah River Basin

Staff in the Environmental Sciences Section (ESS) and
Regional Offices of DWQ collect a variety of
biological, chemical and physical data. The following
discussion contains a brief introduction to each
program, followed by a summary of water quality data
in Savannah River basin for that program. For more
detailed information on sampling and assessment of
streams in this basin, refer to the Basinwide Assessment
Report for the Savannah River basin, available from the
Environmental Sciences Branch website at
http://www.esb.enr.state.nc.us/bar.html or by calling [phone].
DWQ monitoring programs for the
Savannah River Basin include:

• Benthic Macroinvertebrates
• Aquatic Toxicity Monitoring
• Lake Assessment
• Ambient Monitoring System

Benthic Macroinvertebrate Monitoring

Benthic macroinvertebrates, or benthos, are organisms that live in and on the bottom substrates
of rivers and streams. These organisms are primarily aquatic insect larvae. The use of benthos
data has proven to be a reliable monitoring tool, as benthic macroinvertebrates are sensitive to
subtle changes in water quality. Since macroinvertebrates have life cycles of six months to over
one year, the effects of short-term pollution (such as a spill) will generally not be overcome until
the following generation appears. The benthic community also integrates the effects of a wide
array of potential pollutant mixtures.

Criteria have been developed to assign a bioclassification to each benthic sample based on the
number of different species present in the pollution intolerant groups of Ephemeroptera
(Mayflies), Plecoptera (Stoneflies) and Trichoptera (Caddisflies), commonly referred to as EPTs.
A Biotic Index (BI) value gives an indication of overall community pollution tolerance. Different
benthic macroinvertebrate criteria have been developed for different ecoregions (mountains,
piedmont, coastal plain and swamp) within North Carolina and bioclassifications fall into five
categories: Excellent, Good, Good-Fair, Fair and Poor.

Overview of Benthic Macroinvertebrate Data

Based on benthic macroinvertebrate data, water quality in the Savannah River basin is Excellent
to Good. Since 1999, 14 benthic macroinvertebrate basinwide samples have been collected with
three (21%) receiving Good bioclassifications and 11 (79%) resulting in Excellent
bioclassifications. Comparisons of benthos data from 1999 to 2004 between repeat sites show
that one site (Indian Creek at US 64) improved from Good to Excellent while two sites
(Horsepasture River at NC 281 and Norton Mill Creek at SR 1107) declined in bioclassification
from Excellent to Good. Overall, water quality in this basin is unchanged since 1999. The
decline in the Horsepasture River may be the result of natural variation. This site has received
four different bioclassifications from eight samples since 1985. This site also supports an
ambient chemistry site and analysis of that data show no significant adverse trends in water
quality. The decline at Norton Mill Creek is possibly related to upstream development
associated with the town of Cashiers. Additional monitoring at both sites will help discern
whether the changes in bioclassification from 1999 to 2004 were anthropogenic or natural.
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Several rare invertebrate taxa were collected in the Savannah River basin in 2004 including the
mayflies Drunella longicornis (Thompson and Whitewater Rivers), Danella lita (Thompson
River), Litobrancha recurvata (Thompson River), Serratella spiculosa (Thompson and Chattooga
Rivers), Rhithrogena fuscifrons (Big Creek and Whitewater River), the caddisflies Mayatrichia
ayama (Horsepasture and Chattooga River), Oecetis avara (Chattooga River), and the stonefly
Beloneuria (Thompson River, Big Creek, Norton Mill Creek). In addition, the Chattooga River at
SR 1100 had among the highest total taxa (124) and EPT taxa (64) ever collected in North
Carolina and were the highest ever recorded in the Savannah River basin. For detailed
information regarding the samples collected during this assessment period, refer to the tables at
the end of this appendix.

Assessing Benthic Macroinvertebrate Communities in Small Streams

The benthic macroinvertebrate community of small streams is naturally less diverse than the
streams used to develop the current criteria for flowing freshwater streams. The benthic
macroinvertebrate database is being evaluated and a study to systematically look at small
reference streams in different ecoregions is being developed with the goal of finding a way to
evaluate water quality conditions in such small streams.

Presently, a designation of Not Impaired may be used for flowing waters that are too small to be
assigned a bioclassification (less than 4 meters in width) but meet the criteria for a Good-Fair or
higher bioclassification using the standard qualitative and EPT criteria. This designation will
translate into a use support rating of Supporting. However, DWQ will use the monitoring
information from small streams to identify potential impacts to small streams even in cases when
a use support rating cannot be assigned.

DWQ will use this monitoring information to identify potential impacts to these waters even
though a use support rating is not assigned. DWQ will continue to develop criteria to assess
water quality in small streams.

Aquatic Toxicity Monitoring

Acute and/or chronic toxicity tests are used to determine toxicity of discharges to sensitive
aquatic species (usually fathead minnows or the water flea, Ceriodaphnia dubia). Results of
these tests have been shown by several researchers to be predictive of discharge effects on
receiving stream populations. Many facilities are required to monitor whole effluent toxicity
(WET) by their NPDES permit or by administrative letter. Other facilities may also be tested by
DWQ’s Aquatic Toxicology Unit (ATU). Per Section 106 of the Clean Water Act, the ATU is
required to test at least 10 percent of the major discharging facilities over the course of the
federal fiscal year (FFY). However, it is ATU’s target to test 20 percent of the major dischargers
in the FFY. This means that each major facility would get evaluated over the course of their
five-year permit. There are no requirements or targets for minor dischargers.

The ATU maintains a compliance summary for all facilities required to perform tests and
provides monthly updates of this information to regional offices and DWQ administration.
Ambient toxicity tests can be used to evaluate stream water quality relative to other stream sites
and/or a point source discharge.
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Four facility permits in the Savannah River basin currently require whole effluent toxicity
(WET) monitoring. Both facility permits have a WET limit. Across the state, the number of
facilities required to perform WET has increased steadily since 1987, the first year that WET
limits were written into permits in North Carolina. Consequently, compliance rates have also
risen. Since 1996, the compliance rate has stabilized at approximately 90 percent. The
following graph summaries WET monitoring compliance in the Savannah River basin from 1987
to 2002. Facilities with toxicity problems during the most recent two-year review period are
discussed in subbasin chapters.
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Lakes Assessment Program

Two lakes were sampled in the Savannah River Basin during the 2004 Ambient Lakes
Monitoring: Cashiers Lake and Lake Toxaway. Each of these lakes were sampled three times
during the summer (June, July and August). Lakes with noted water quality impacts are
discussed in the appropriate subbasin chapter.

Ambient Monitoring System

The Ambient Monitoring System (AMS) is a network of stream, lake and estuarine stations
strategically located for the collections of physical and chemical water quality data. North
Carolina has more than 378 water chemistry monitoring stations statewide, including 1 station in
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the Savannah River basin. Between 23 and 32 parameters are collected monthly at each station.
The locations of these stations are listed in the following table and shown on individual subbasin
maps. Notable ambient water quality parameters are discussed in the subbasin chapters. Refer
to 2005 Savannah Basinwide Assessment Report at http://www.esb.enr.state.nc.us/bar.html for more
detailed analysis of ambient water quality monitoring data.

Locations of Ambient Monitoring Stations in the Roanoke River Basin by Subbasin
Subbasin/
Station ID Location Class

Lat.

Long. County
Map
ID
01 Chattooga River
No Stations
02 Toxaway, Horepasture, Thompson, and Whitewater Rivers
H6000000 Horsepasture River at NC 281 near Union B Tr 35.0922 -82.9764 Transylvania A1

Benthic Macroinvertebrate Data Collected in the Savannah River Basin, 1999 – 2004
(Current basinwide sampling sites are in bold print.)
Waterbody Location County Index No. Date ST EPT BI EPT BI Rating
01
Chattooga R SR 1107 Jackson 3 8/04 ----- 48 ----- 2.2 Excellent
Chattooga R SR 1100 Jackson 3 8/04 124 64 3.5 2.8 Excellent
7/99 ----- 48 ----- 1.5 Excellent
Norton Mill Cr SR 1107 Jackson 3-3 8/04 108 40 4.2 2.7 Good
6/99 119 51 4.0 2.7 Excellent
Big Cr SR 1608 Macon 3-10-3 8/04 ----- 45 ----- 2.4 Excellent
7/99 118 53 3.7 2.6 Excellent

02
Toxaway R At Auger Hole
Trail (Gorges
State Park)
Transylvania 4-(4) 8/04 ----- 36 ----- 2.7 Excellent
Indian Cr US 64 Transylvania 4-5-(3) 8/04 ----- 40 ----- 2.4 Excellent
7/99
Bearwallow Cr At Auger Hole
Trail (Gorges
State Park)
Transylvania 4-7-(2) 8/04 ----- 41 ----- 2.4 Excellent
Horsepasture R NC 281 Transylvania 4-13-(12.5) 8/04 98 41 4.1 2.9 Good
7/99 73 36 4.4 3.5 Good
Whitewater R NC 281 Transylvania 4-14-(1.5) 8/04 ----- 46 ----- 2.3 Excellent
7/99 ----- 38 ----- 2.9 Excellent
Thompson R NC 281 Transylvania 4-14-6 8/04 ----- 46 ----- 1.9 Excellent

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