NC0064050_Report_19870515

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DIVISION OF ENVIRONMENTAL MANAGEMENT
May 15, 1987
M E M O R A N D U M
TO: Steve W. Tedder
THROUGH: Ken Eagleso
Jimmie Overto
FROM: Dave Penrose)?
SUBJECT: Biomonitoring of Middle Creek (May 1986)
Several stations were selected in the Middle Creek watershed to assess gen-
eral water quality conditions prior to the implementation of the new Cary (pro-
posed 16 MGD) and Fuquay-Varina WWTP's. Sites were selected above and below the
proposed discharge points. These sites are listed in Table 1 and illustrated in
Figure 1. Station #4 (SR-1375) is located below the proposed discharge point for
the Cary WWTP and site #6 is below the discharge point for the Fuquay-Varina
WWTP. However, the exact location of the Fuquay-Varina discharge is still not
certain. In addition, Middle Creek #1 is located below the Apex WWTP which is
currently scheduled to increase its design flow from 1.8 to 3.6 MGD. Basal Creek
was selected as a reference station, however because of its small size, data from
this site cannot be directly compared to results from Middle Creek.
Table 1. Station Descriptions - Middle Creek Survey, Wake and Johnston Counties,
North Carolina. May
1986.
Middle
Middle
Middle
Middle
Middle
Middle
Middle
Station:
Cr #1
Cr #2
Cr #3
Cr #4
Cr #5
Cr #6
Cr #7
Location:
SR-1301
NC-55
near
SR-1375
near
SR-2739
SR-1507
Wake
Wake
Tallicad Rd
Wake
Airport
Wake
Johnston
Substrate
M
boulder
-
10
-
10
-
80
-
rubble
20
30
10
20
-
10
-
gravel
20
30
10
20
10
10
10
sand
40
20
70
40
80
30
70
Silt
20
10
10
10
10
20
20
Width (m)
4
3
3
9
5-6
4-5
12-15
Avg Depth
(m) 0.2
0.2
0.2
0.5
0.5
0.5
0.2
Bank erosion
Mod
Mod
Mod
Mod
Mod
Mod
Mod
Canopy (%)
80
80
70
80
80
60
80
Aufwuchs
Mod
Mod
None
None
Mod
Mod
Mod

RESULTS
Benthic macroinvertebrates were collected from each location using DEM's
standardized qualitative collection techniques. Taxa richness totals and bio-
classifications from each site are listed in Table 2. In addition, Appendices 1
and 2 list level 2 (orders) and level 3 (genus, species) data for each location.
Fair water quality conditions were noted from the three uppermost sites on
Middle Creek (Stations 1, 3 and 4). Note particularly the low SEPT values (9-14
taxa) at each of these sites. Many of the abundant taxa collected from Middle
Creek #1, below the Apex WWTP, are tolerant to the effects of low dissolved oxy-
gen and indicated the effects of the Apex effluent at this point. Several of
these taxa include Limnodrilus hoffineisteri, Chironomus and Physella.
Table 2. Taxa richness Totals and Bioclassification. Middle Creek Investigation
May 1986
Station #
#1
#2
#3
#4
#5
#6
#7
Total taxa (ST)
65
95
72
67
96
82
74
Intolerant taxa (SEPT)
9
16
10
14
26
13
13
Bioclassification
Fair
Good/
Fair
Fair
Good
Good/
Good/
Fair
Fair
Fair
Middle Creek Station #3 and 4 are below the overflow from Sunset Lake.
Station 3 is above and Station 4 is below the proposed discharge point for the
Cary WWTP (Figure 1). Taxa richness totals are similar and reflect Fair water
quality conditions. These fair water quality conditions may reflect the extent
of land disturbing (subdivision development) activities in the watershed, as well
as the effects of overflow from Sunset Lake.
An increase in taxa richness, and subsequent bioclassification, at Middle
Creek #5 (near the airport) is likely a response to the effects of dilution from
tributary streams. In particular, a large UT to Middle Creek immediately above
site #5. Note also the increase in stonefly taxa richness from only 1 at site #4
to 6 at site #5. Stoneflies are generally considered the most intolerant taxa.
Good -Fair water quality conditions were noted at Middle Creek sites 6 and 7.
Similar taxa richness totals were noted from each site (82/13 at #6, 74/13 at
V ).
In summary, Fair water quality conditions were noted from several stations
located in the upper Middle Creek watershed (above Highway 42). These conditions
are related to the effects of the Apex WWTP (site #1) and land disturbing acti-
vities plus overflow from Sunset Lake (sites 3 and 4).
Better water quality was noted from several lower Middle Creek locations
05-7). Dilution from a UT above site #5 is likely responsible for a Good bio-
classification at this site. Good -Fair water quality conditions were noted at
sites 6 and 7.
DP:ps

BASAL
STATION LOCATIONS ON MIDDLE CREEK, MAY 1986
0 PROPOSED CARY WWTP 16 MGD
O SAMPLING STATIONS
HI GHWAY 42
WAKE CO.
M IDDLE CREEK
1
JOHN STONICO. .