NC0041696_NOV-2020-LV-0925 Response_20210222

TOWN OF VALDESE
LAKE RHODHISS WWTP
2100 Lake Rhodhiss
P.O. Box 339
Valdese, N.C. 28690
(828) 879 - 2131
February 15, 2021
NCDEQ / DWR
Asheville Regional Office
2090 US Highway 70
Swannanoa, NC 28778
)73C3
FEB 2 2 2021
Water Quality Regional Operations
Asheville Regional Office
RE: NOV-2020-LV-0925
Dear Mr. Boss,
Per your request, this letter is the response to the above listed NOV
conditions.
The event in question pertains to Hurricane Eta coming through the
region (November 11 - 13, 2021). During the timeframe, we experienced
and recorded 6.6 inches of rain, which lead to extreme flooding and
numerous manholes under water within the collection system.
Ultimately, a hydraulic overload of the WWTP occurred and
subsequently, a weekly TSS violation.
On 11 / 12 / 2020, 4.75 inches of rain in approximately 5 hr. period
throughout the area. Flow rate at plant went from 8 MGD to 20 MGD in
1-hr timeframe and remained at "max reading" for another 6-8 hours
following (detailed in initial upset report). Also reported in original
document were two (2) instances whereby wastewater entered storm
drains /ground within the confines of the WWTP. This was remedied by
opening a clean aeration basin and providing temporary hydraulic relief
to the plant; basin filled up in under 1.5 hours and flows resumed.

All aspects of the WWTP operations were normal and usual prior to and
following this weather event. We wasted 0.39 MG to thickeners and
recycling was adjusted prior to the anticipated event, and during the
scenario, aerators shut off in an attempt to "hold" solids within the
basins. A copy of the monthly operational report is included for
reference of flow data indicated.
If I can be of further assistance during the review period, please contact
me as needed.
Regards,
Christopher J. Bortnick
WWTP Superintendent
cbortnick(a),valdesenc.gov
(828) 879 - 2131

DAILY LAKE RHODHISS WWI? SO2 USAGE
MONTH: N DU
YEAR '2.0D.0
CARRY OVER: 3 I
0
122o
DATE
TIME
CYLINDER 1
CYLINDER 2
CLYINDER 3
CYLINDER 4
SO2 USED
1
.1():00n,n
4--(549er 0
1ISO
'4O
2
(,'. z.o
0
1150
3 0
3
id; ts
0
Ito°
40
4
- b'.2S
0
1os o
2_0
5
V•'3o•
0
1b4o
¢b
6
(o'• 3 a
0
-I o 0 0
40
7
t,407D
,ti
170
70
8
04 e-t)
-or
4 t}0
3 0
9
(c'oo
0
Rto
3 a
to .
lords
a
t-to
4b
11
7; Io
1
840
30
12
- -:oJ
°G 2oluD
i'•q0
s0 1
13
(o'.o0
'lobe
-1- 40
So
14
6:3O
02000
680
‘O
15
7.30
a066
GGo
Do
16
S'OO
gci20
630
36
17
to'oo
-Cabo
Sqo
A-0
18
lo'"o0
2030
5 8o
I o
19
bloc
2020
410
►oo
20
G I. 4 S
20 L o
4-20
40
21
: j.0
;020
35h
'>n
22
/' -A r,
20 a
a To
/60 •
23
(0.30
21=2_6
1L0
CIO.
24
(;WS-
2o2.o
90
$O
25
7:oo
Z•D;_0
5-0
30
26
(edi
020 e20
t10
10
27
7YC
aoov
3o "
30
28
/6!15-
M170 -
3o
3o
29
S:2-0
/4d0
30
CO
30
i,: So
i 6So
30
Flo
31
•-b =fit'
-k4-15-
4,g_
180
I�S6
TOTAL USED
MAX USED
MIN USED
AVERAGE
1
17-Asa
. a S
%1 133o
1/9

\b
Lake Rhodhiss Waste Water Treatment Plant Monthly Operation Report
7fe Influent Flow Effluent Flow Sludge Flow to Cent.#1Sludze Flow to Cent.02 Return Sludge Flow Primary WAS Flow Secondary WAS Flow
(x1000 gallons) (x1000 gallons) (x1000 gallons) (x1000 gallons) (xl000 gallons) (x1000 gallons) (x1000 gallons)
11/1/20 2746 2211 1 7 2071 0 8
11/2120 2232 1697 0 7 1977 1 4
11/3120 3155 2330 121 8 1936 0 55
11/4120 717 7/7 717 77? 777 777 777
1116120 2897 2327 98 7 1915 0 4
1118120 2751 2289 135 8 1921 1 79
111720 2282 1940 93 7 1921 0 12
111820 1481 1293 0 6 1948 1 40
1119/20 1815 1373 1 7 1947 0 121
11/1020 2319 2112 4 7 1908 1 109
11/1120 2802 2525 1 8 1918 0 88
11/12/20 8846 7485 0 7 2720 5 74
11/1320 11092 10371 0 0 3003 1 e
11/1420 4774 4080 1 6 2335 0 24
11I1520 3201 2858 0 7 2044 0 7
11/1820 2477 2125 0 8 2072 0 6
11/1720 3228 3878 7 7 2050 0 12
11/1820 2895 2554 111 7 2037 1 6
11/19/20 3082 2458 80 7 2057 0 2
112020 3022 2417 0 8 2088 0 1
112120 2742 2288 0 7 2070 0 0
11/22/20 2229 1750 1 0 2105 1 1
11/23/20 1993 1894 0 7 2113 4 0
11/24/20 2972 2205 0 8 2108 1 1
11/25120 2828 2161 0 0 2099 1 12
11/26/20 2148 1870 1 7 2103 0 37
112720 1698 1433 0 6 2117 0 0
112820 1839 1348 0 7 2105 1 0
11/29/20 1884 1382 1 8 2103 0 0
11/30/20 2251 1909 0 6 2089 0 0
Min 1481 1293 0 6 1908 0 0
Average 3064 2827 23 7 2099 1 24
Max 11092 10671 135 8 3003 5 121
Total 88577 76197 856 103 80872 19 708
Y