HomeMy WebLinkAboutSP202100007 Staff Report 2021-06-01Jefferson Mill Hydroelectric Project
Appendix C: CONCEPTUAL PLANS
0 1 2 3 4 5 6 Miles
0 1 2 3 4 5 6 T 8 9 Kilometers
Prepared by: Department of Community Development
Office of Geographic Data Services
This Map is for Display Purposes Only.
MNPCRETED 011IN2020
County of
Albemarle �Tnraa�
V1WG65 0 VA Primary Highway
L _'
RUR AR6
C VA Secondary Highway
Roads
r i Incorporated Town or
L _ City Boundary
rr—rns
Railroads
------ CountyBoundary
Sheama
113
114
115
'+u
,14-70
1/
22-18A1\`
�...t 114-72U�a
115-11G
114-67B
36
j
\
/
H%ROW4RE
38
R/V ,y.
%
35
123-59A
123-59B
1
j
34C aw
a
123-59C
34A
r:
j:
wh
y.
123-34C2
h
�
�
_
"
o
\i
123-34C
--
123-34C4
123-34C5
34
%
--
348
122-24
I
24-
J
i
124 9
12410p
7233,y
33 32 ..
3L..
28k 124-1 24
3
--
ybe 4
i30
r /
124-r5r
5
40G /
/--30i
�2j>
40H1
29
'
40E;
�.,.c
40J 40K
40D
278
i 123-50
A
53
27C
_`
_ 7B
\
40C
1
40A
u<.1
24F 123y
tp P
\' \
/
25
123-0
108
23-04
24 1zsas
m
10A
17A/
+ N
123-07
s
26B2
r2
3A1
ti
,6Ee�17B
'4'FldONmu n, 19B
B1 }
f 2M 231
nRM,�1L�
17
'j
21
j' 236
11A 16
_ -- 19
_. i =
za-z
JE
23-2
FE
a 123-13
\
r•l. 18A
23
\
�tlpoxl.x
123-19A
123
�e
123-15
16A
123-18C
49A 24B
131-24
�..-
7
2
130
0 800sCeie 1,600 21,2
Albemarle
131
County
Tax Map:
123
Feet
Not, This map is for display purposes only
f
and shows pemels as o11"1/2019,
1i
See Map Book Introdia lion for additional deteils.
123-40C 1
123-40B
123-40C
123-40A
�Z.
123-17A
CD
A
r
- \ 123-26
\I
ON
�� a r---- . - ■ .
e
lsovv
�e
123-17B
R
^� 123-19B
z`
1�,3
Jefferson Mill Road
123-19
N 123-17
A
J
v
0
ON
EN N
E m L r
Y + Q C
L 0 N O
0-0 0 u
Y QJ QJ C
C
CL V GJ
Y VI L
Qv
U 3 QJ
w m T N
O L t.QJ
7
aJ D Q to
cu
O L QJ o
0 i
o
O m QJ
Y 0" 0 Q
3 C Y V
o QJ
-O L C O
a O Q U
-0
0 M a QJ
O -0 L �
CLO E
Y i 1A
0 Y Q 60
aJ O
y ar C
o-0> =
N M O O'
L QJ
3QJJQ�
0 0 0
y o
0��
0
=�
al Y
CL
WQJ
O
t QJ C
-O U O C
a T p 0
CLM c 0
L N Q
V QJ L
vo
OMt'0C
n N m M
H QJ
v y QJ E
Q o
(D QJ N
m s �
L
� � m
QJ -0 0-
0 w v
O C O 0
C 2 QJ
y C "O
+� QJ CL
N iJ V
V
Q a L
CL i , QJ
(D L C
O Qj
QJ
n rQ) O QJ
Y N _ E
E
c tto
C O 0 y
-CQ
0 QJ o
QJ o
v s Q
r o
0 u
-o
o.
mE
=�vv
E 4
v� �s
vi E
i + m 3
0
a
J
0
Y
wa o
Y IV
Q txI
N Q
- o
L � Y
N
t0 0
M N
v r 0
L
0
x
171
C
� o v
w Y N
SINCE
F
PROJECT DESCRIPTION
In
JEFFERSON MILL DAM
THESE DRAWINGS AND DESIGN INFORMATION ARE FOR CONSTRUCTION OF THE
STRUCTURES NEEDED TO SUPPORT A HYDRAULIC POWER TURBINE INSTALLATION AT
JEFFERSON MILL. THE STRUCTURE WILL CONSIST OF ENCLOSING THE EXISTING MILL WHEEL
ROOM TO HOUSE THE TURBINE WITH NEW REINFORCED CONCRETE WALLS AND FLOOR
ALONG WITH THE PENSTOCK UPSTREAM TO A CONCRETE INLET STRUCTURE LOCATED AT THE
EDGE OF THE RIVER.
APPLICABLE BUILDING CODE: VA USBC 2012.
»_1►111111►117W:4
1. 1.0 Project Information Sheet
2. 2.0 Site Plan
3. 3.0 Turbine Room Details
4. 4.0 Inlet & Penstock Details
5. 5.0 Eel Ladder Details
6. 6.0 E&SC Site Plan
7. 6.1 E&SC Notes and Details
DESIGN
SCOTTSVILLE, VA
- PREPARED FOR -
Natel Energy
2401 Monarch St.
Alameda, CA 94501
360-949-8554
- BY -
Froehling & Robertson, Inc.
SUBMITTALS 540-344-7939
1. Pipe
2. Valves
3. Sluice Gate -PROJECT LOCATION-
4. Pipe supports
5. Access Hatch/Ladder 724 Jefferson Mill Ln
6. Trash Rack Scottsville, VA 24590
37050'29" Lat.
78°28'29" Long.
GENERAL NOTES
1. THE WORK SHALL INCLUDE THE FURNISHING BY THE CONTRACTOR OF ALL SUPERVISION, TRAINING, LABOR,
MATERIALS, TOOLS AND EQUIPMENT, AND THE PERFORMANCE OF ALL OPERATIONS NECESSARY FOR SITE EXCAVATION
AND GRADING, INSTALLATION OF THE NEW CONCRETE CUT-OFF WALL, EROSION CONTROL MEASURES, AND WORK
INDICATED IN THE CONTRACT DRAWINGS, SPECIFIED HEREIN, AND/OR AS DIRECTED BY THE ENGINEER.
2. THE CONTRACTOR SHALL HAVE ON THE JOB AT ALL TIMES DURING THE WORK AN EXPERIENCED SUPERINTENDENT
WHO SHALL HAVE CONTROL OVER ALL ASPECTS OF THE WORK.
3. THE CONTRACTOR SHALL VISIT THE SITE AND INDEPENDENTLY VERIFY ACCESS AND WORK -RELATED RESTRICTIONS.
4. CONTRACTOR SHALL VERIFY ALL DIMENSIONS OF EXISTING CONSTRUCTION AND REPORT ANY DISCREPANCIES FROM
THE CONTRACT DRAWINGS TO THE OWNER PRIOR TO COMMENCING WORK.
5. CONTRACTOR SHALL COORDINATE ALL WORK WITH OTHER WORK SHOWN ON ALL OTHER DRAWINGS.
6. CONTRACTOR SHALL BE RESPONSIBLE FOR ALL MEANS AND METHODS OF CONSTRUCTION INCLUDING, BUT NOT
LIMITED TO, DEWATERING, SHORING AND TEMPORARY BRACING. CONTRACTOR SHALL UNDERTAKE ALL NECESSARY
MEASURES TO ENSURE THE SAFETY OF ALL PERSONS AND STRUCTURES AT THE SITE AND ADJACENT TO THE SITE.
7. ALL PRODUCTS SHALL BE INSTALLED IN ACCORDANCE WITH THE MANUFACTURERS' WRITTEN INSTRUCTIONS AND
RECOMMENDATIONS, UNLESS NOTED OTHERWISE.
8. IF CERTAIN FEATURES ARE NOT SHOWN OR CALLED FOR ON THE CONTRACT DRAWINGS, THEIR CONSTRUCTION SHALL
BE OF THE SAME CHARACTER FOR SIMILAR CONDITIONS THAT ARE SHOWN OR CALLED FOR WITH APPROVAL OF THE
ENGINEER
9. THERE ARE NO GUARANTEED QUANTITIES ASSOCIATED WITH THIS WORK.
10. DEMOBILIZATION INCLUDES REMOVAL OF ALL TRASH, DEBRIS, EQUIPMENT, SUPPLIES, AND RESTORATION OF
DISTURBED AREAS TO SATISFACTORY CONDITIONS.
11. CONTRACTOR SHALL PROVIDE A RECORD SET OF AS -BUILT DRAWINGS UPON COMPLETION OF CONSTRUCTION.
DRAWINGS SHALL BE PROVIDED IN ELECTRONIC FORMAT COMPATIBLE WITH AUTOCAD. SURVEY SHALL PERFORMED BY
REGISTERED LAND SURVEYOR LICENSED IN THE STATE OF VIRGINIA.
648
795 cM���R Project Site
2
Jefferson Mill Dam
n �
al
7
J
al
3
20 sa 622
�SV�/7P d
Ry fie
726 / ➢a
/
6 Irish Rd v� /
Scottsville /
L7
\ Ra
/ i ames
\ i 6`
20
1
Vicinity Map
0 4000' 8000'
6
E
General Notes
No.I Revision/Issue I Date
r SINCE `
fs�
1881R
Froehling & Robertson, Inc.
1734 Seibel Drive, N.E.
Roanoke, Virginia
@ COPYRIGHT 2012
FROEHLING & ROBERTSON, INC.
ALL RIGHTS RESERVED
OOoO ZO O�
�
0
Jefferson Mill
Dam Design
Scottsville, VA
Proj ect
Information Sheet
Prepared For:
Natel Energy
2401 Monarch St.
Alameda, CA 94501
DR
KHH
CHK
DAK
REV
PROIECI
62Y-0257
SHLIII
1
DAIS
March, 2021
.0
SCALE
IL NA
1 of 7
J
v
c
ILI
EN N
E m r r
v= I
Y N O
o-ou EXI Y
v
1,,
o Q v
N
U 7 N
o t
vo-m
� L v O
MH'"'
O
N N Qj
Y `L O b
3 .
a a 0
v c o 0
s m t
v�M�
a o CL u
v M > c
y M ._
" M
d O E
H
MbL vim, b
♦ v p
71 O N
.� v C
--a a
O-0'j 7
3 CL
(U
Y + m O
O O m
U M L U
N 7 M
O. I/, ! L
0
(UE o
u E
C C
3 t 0
U
O U Y C
N j 0 O
CLN C CL
uNv, y
0
N
O N pp C
v y m 0
41
i +t N E
CIL x y0 O vO
Ql y v N
M L O
Y N Y C
C O t0
O O C
3 0 v
O C O Q
C O W y
a° C O
Y v Q
ho
W v U C
y O_ u =
m s
v
CL > N
v Coo
O O LL
Y E
Y N
� � m
EMS
to
= 0 -0
°voa
N 0 >
N L 0 O_
-0 H m O
O v U
K C N N
c vI 9
up
a vI w
�mE
Cl 7 L
N E
LL
0
m
u
0
i
w
N
n
N
O
Lo
N
0
i
v
J
Y
U
v
0
LL
J
Q
0
Y
d E N
Y CL N
Q Ln
N CL
y O
� � Y
-0 N N
Lo 0
rn N
Vx ti 0
t
b
2
N � It:
C i
v, O N
w + N
�C ]G U
General Notes
1. STRUCTURAL FILL: 95% MAX DRY
DENSITY ±3%OF OPT. MOISTURE,
GREEN AREA: 85% MAX DRY DENSITY
±5% OF OPT. MOISTURE, ALL LIFTS SHALL
BE 8" MAX. BEFORE COMPACTION.
2. CONTRACTOR SHALL EXERCISE CARE IN
ALL TREE CLEARING EFFORTS TO
MINIMIZE CLEARING TO ONLY TREES
REQUIRED TO PERFORM WORK AND
SATISFY DESIGN REQUIREMENTS.
3. PROVIDE FLOWABLE FILL UNDER
PENSTOCK WHEN ON TOP OF BEDROCK.
No.I Revision/Issue I Date
SINCE
0
1881
Froehling & Robertson, Inc.
1734 Seibel Drive, N.E.
Roanoke, Virginia
@ COPYRIGHT 2012
FROEHLING & ROBERTSON, INC.
ALL RIGHTS RESERVED
OOoO O�
O �0
Jefferson Mill
Dam Design
Scottsville, VA
Site Plan
Prepared For:
Natel Energy
2401 Monarch St.
Alameda, CA 94501
DR
KHH
CHK
DAK
REV
PROJECT
62Y-0257
SHILII
290
DAIS
March, 2021
L CALL
NA
1 2 of 7
J
v
� v v
c -'cin
°1—��
E
m r Y
Y M G p
o °�
Y N I_
E y @
Y y
ova,N
u U C
Y U
M T
O L Y
N CL @
� v v�
� L O
bbD ~ Y
o
H C
o ° w
Q o
3 C Y
>o�
t�t=v
Mzs
v o °- U
.5 y C CC '0 `
CLT ,I E
Y L vvI @
MG! p
v o m —
.� Iv
w12 0 T
C v
� v a �
v ° m o
Y !_'' M O
oM
U = L u
a�
Eo
3�y72
"6 U O C
N T p O
QmCa
E 3 '^
-" U
v
`o M to C
N M N
_W
v v E
xCL o °
aM v
(b L @
V L Y
Q v U
'y N N C
c ° m
3o'v
O C O C
°oa,C
° m c o
Y V CL @
U
� -M
L
CL
`on O
O 1
0 Q;
V Y c N = E E
U @
E °=
to
r-0-
Y
.L
C ID
v o C
t v 0
IV L u CL
9 M O
O U
'= ,
°.`
,
ML—@
on N lu
�mEy
0 Y 7 L
N � y
LL y M 3
to
3
v
6FTX 8 FT TURBINE
ACCESS HATCH COVER
MANHOLE SHALL BE FIELD LOCATED
/DUB_ J �--�k�_ 1DD
-- EXISTING MI
- BUILDING
48" 90` ELBOW 30"0 ANW Y ACCESS — — — — _ 36"
TURBINE
HATC AND ADDER �� \ ROOM NEW CONCRETE — �� PENSTOCK
I F
CONDUIT
DOOR THRESHOLD
ELEV. 325.8
325
TOP OF WALL
ELEV. 323.0
BASEMENT FFE
ELEV. 321.33
320
LINER WALL-3 SI
\� (MIN 6"THICK)
D V1 1
r �,
D D
l C ^ 48" ADJUSTABLE
COUPLER
NATELENERGY T RBINE
3 WITH DRAFT TUBLL _ _ #5 REBA @ 8" O.C. 3 315
3.0 D IPE SUPPORT STAND 48" 0 OUTLET PIPE L — — 3.0
D
D DDD�DD DODD-3DODD D�DD D
Da 7ToDD oD o D
310
OUTLET 3" SUMP OUTLET
WITH CHECK VALVE 2 4 CONCRETE SHALL BE POURED IN
(4'-0" ASSUMED) 3.0 3.0 BOTTOM OF SPACE TO ESTABLISH
A LEVEL FLOOR AT ELEV. 312.0 —
TURBINE ROOM STRUCTURAL PLAN
OVERHANG
WITH DRIP
GROOVE
=1I11
1 315
310
1 305
2.0
NEW CONCRETE LINER 00 L 8" DECK SLAB UPSTREAM CONCRETE
CLOSURE WALL
WALL (MIN 6" THICK) 480" OUTLET PIPE NATEL ENERGY TURBINE #5 REBAR @ 8" O.C.
PIPE SUPPORT STAND WITH DRAFT TUBE (TYP VERT & HORIZ)
WWF 6x6 D20xD20 48" 0 ADJUSTABLE
COUPLER REMOVE EXISTING
48"0 900 ELBOW
4'-0"
TOP OF EXISTING OUTLET
OPENING - ELEV. 311.0 4' 0" I:N:j I
D
3" SUMP OUTLET
WITH CHECK VALVE
EXCAVATE DOWN 5' 0" MIN
TO ELEV. 306.
TURBINE ROOM ELEVATION VIEW
"N/2" ADDITIONAL BARS EACH FACE (TYP)
LENGTH - "W" + 2 SPLICE LENGTHS
3" (TYP)
IIWII
UPSTEAM STONE WALL
CL OF PIPE/TURBINE
AT ELEV. 315.0
Scale: 3/8" = P-0"
AS REQ'D
STEEL LEDGER BEAM
6'-0" HATCH OPENING
(SEE DET. 7)
ACCESS LADDER RUNGS
CAST INTO WALL
ANTICIPATED ROCK
SURFACE
SECTION THROUGH TURBINE ROOM
8" DECK SLAB
WWF 6x6 D20xD20
OVERHANG WITH
DRIP GROOVE
TOP OF WALL
ELEV. 321.5
DRIP GROOVE
^HAMFER 1
Scale: 1/4" = P-0"
DOOR THRESHOLD
STEEL LEDGER BEAM
ELEV. 321.33
325
OVERHANG WITH
8" DECK SLAB DRIP GROOVE
OVERHANG
WITH DRIP
TOP OF WALL
TOP OF WALL
GROOVE
ELEV. 323.0
ELEV.321.5
BASEMENT FFE
u�
ELEV. 321.33
TOP OF DAM
36"
(ELEV. 319.7
PENSTOCK
�
CONDUIT
320
LLL
_ \ full- EXTRA FLANGE
r FOR CONCRETE
D / ENGAGEMENT
/ 111
/�TTD DAD D
POTENTIAL FINISH FLOOR
' ELEV. 312.0
ROCK SURFACE (1% SLOPE TO SUMP)
SUSPECTED ROCK TO BE
EXCAVATED FOR OUTLET WWF 6x6 D20xD20
MASS CONCRETE SHALL
BE CAST AROUND ELBOW
FORM AND POUR STRUCTURAL CONCRETE TO SUPPORT
DOWNSTREAM END OF THE ELBOW SO THAT CL OF THE
UPSTREAM END ALIGNS AT ELEV. 315.0
l� L N = NUMBER OF BARS
A CUT-OFF BY OPENING
Ts� O�F9
(2) BARS EACH FACE (TYP) @ 6"
SIZE TO MATCH MINIMUM REINFORCING
LENGTH = 60 BAR DIA. (MINIMUM = 4'-0")
WALL PENETRATION REINFORCING DETAIL
Not to Scale
48"0 OUTLET
WITH ELBOWS
315
BASEMENT OF
MILL BUILLING
PIPE SUPPORT STAND
J�
310
MASS CONCRETE SHALL BE
POURED IN BOTTOM OF SPACE
TO ESTABLISH A LEVEL FLOOR
AT ELEV. 312.0
48"0 900 ELBOW
TURBINE ROOM OUTLET DETAIL
ROCK TO BE EXCAVATED _
FOR OUTLET
THICKENED SLAB TO SUPPORT
TURBINE AND HEADWALL
2.0
Scale: 1/4" = P-0"
�L EXTERIOR STONEWALL
(THICKNESS VARIES)
�D WWF 6x6 D20xD20
o FINISH FLOOR
\ / o ELEV. 312.0
�o��
TOP OF OPENING IN EXTERIOR
WALL AT APPROX ELEV. 311.0
TAIL WATER
ELEV. 310±
3" SUMP OUTLET WITH CHECK VALVE
64INVERTOF CONCRETE EXCAVATE DOWN TO
ELEV. 30 .0 (MAX) ELEV. 306.0 (MAX)
THROUGH OPENING
a D
MASS CONCRETE MIN 6" THICK
Scale: 1/4" = P-0"
315
310
BOTTOM OF SPACE TO ESTABLISH
A LEVEL FLOOR AT ELEV. 313.0
TURBINE ROOM UPSTREAM WALL RECONSTRUCTION
1/2" GALV. STEEL PLATE
1 3/4"
1 1/2" GALV. STEEL FRAME 1 /
1
COMPRESSIBLE
ELASTOMERIC
HATCH SEAL
HATCH RECESS DETAIL
Scale: 2" = P-0"
Scale: 1/4" = P-0" 1
l
General Notes
%No. Revision/Issue Date
SINCE
fad
1881
Froehling & Robertson, Inc.
1734 Seibel Drive, N.E.
Roanoke, Virginia
@ COPYRIGHT 2012
FROEHLING & ROBERTSON, INC.
ALL RIGHTS RESERVED
00
U DDDD
o �0
DDa
DD
Jefferson Mill
Dam Design
Scottsville, VA
Turbine Room
Details
Prepared For:
Natel Energy
2401 Monarch St.
Alameda, CA 94501
DR
KHH
CHK
DAK
REV
PROIECI
62Y-0257
SHLIII
3.0
DA IE
March, 2021
SCALE
NA
3 of 7
J
v
EH
E m r s
v= �y
Y M G p
0-0 O
Y N U
m y @
� I,I N
O " '^
� CLU
vI U C
m T
O L
v CLM
� L O
b M y
o
w H C ✓�
O m v
Y O_ O @
3 CILI Y
>o�
m t
v�m�
y O O- u
y
�
ov `
`o o E
M L Iil @
—
o
v!2o�
3 v d C
N O m Ou
Y !_'' m O
o
—-o—
Eo
U !=' L u
Q yl ++
'^ E o
v�Nw
C C T
Y � M y
N T p O
Q
E
Uv
`o m o`O
v y m
�v
v v E
zi
x o 1
vI/Iv�
V Y
y v u
'y N m C
c m
v-
y N O
3o"v
o c o a0
�o,C
O m c a
QC':
CL
IV v U ._
v CLm t
C `m v
w o
O N
O
C v
V Y
Y,CE
p = E
m " @
E m
to
= 0 -0
Y L
O O
v In >
IV L vl O
9 m O
O ,1 u
�2N@
nn E m o
c In iv v
s m E Y
0
N
+ � y
LLm ?
m
3
v
8" 0 STILLING WELL
it-oil10'-6" 2'-7" sr.
36" � PENSTOCK g"0 STILLING WELL Rl- 36"� PENSTOCK
CONDUIT
SLUICE GATE OPERATOR AND STEM 6„
STD PIPE HANDRAIL
PVC ENCASED IN CONCRETE
FOR STEM (LOCATION AND
N 325 SIZE TO BE COORDINATED
WITH SLUICE GATE SUPPLIER)
o C�l
E GATE #5 REBAR @ 8 SPA (TYP) -
„'., GROUND SURFACE 1O N
— — ELEV.322± m
�1�' ,o TOP OF WALL _ -
II ELEV. 321.5+ \\ \\ \� \\ \\ 6" BLOCKING
\\ \\ \\ \\IF it rl A3 CONCRETE
/ I I yv�vi��vivivi�v�
I I
NORMAL POOL/ 4'-2"
TOP OF DAM
p — \\,\\,\ 1�� ELEV.319.7 CONCRETE CRADLE DETAIL
7rnmrl
320 EXTRA FLANGE3scale: 3/4" = 1'-0"'FOR CONCRETE 36"0 PENSTOCK %�iENGAGEMENT CONDUITvEXPECTED EXISTING
GRADE
SLUICE GATE
TRASH RACK TRASH RACK
CL OF PENSTOCKoETE CRADLE ELEV. 315.5
SEE DETAIL
200 — 3/4" CHAMFER ON ALL
315 CONCRETE 2 EXPOSED CORNERS
CRADLE #5 REBAR @ -
rj-
8" SPA (TYP)
O
ti
EXCAVATEINTAKE
AREA DOWN TO 314±
LE
S.
O% 1'-0" 1'-0" 1'-0"
310
PLAN -PENSTOCK INLET STRUCTURE o 1' z' 4' SECTION -PENSTOCK INLET STRUCTURE o 1' z' 4' TRASH RACK NOTCH DETAIL
JScale: 1/2" = P-0" �2) Scale: 1/2" = P-0" Scale: 6" = P-0"
8" 0 PVC WITH REMOVABLE CAP 8"0 PVC WITH REMOVABLE CAP
WITH 1/4"0 AIR RELEASE VENT WITH 1/4"0 AIR RELEASE VENT
j%/ W I NG WALL
> \//\\ > //
NORMAL POOL//\\ 0 /\\\%\\fie° e NORMAL POOL/
% 00 TOP OF DAM /%\i °° TOP OF DAM
ELEV. 319.7 //\\// \/\// ELEV. 319.7
XX
V/VA/ V/VA, AA/AA/AA/AA
INVERT ELEV. 318.0 AA; OVAAAAA INVERT ELEV. 318.0
VA//\ �//VAS
��/j \//\\ B I0 PVC
\/ \/\�' j�
8110 PVC ELBOW 6" VDOT #57
8 0 PVC ELBOW STONE BEDDING
5 STILLING WELLS
Scale: 3/4" = 1'-0"
General Notes
No.I Revision/Issue
SINCE
fs�
1881R
Date
Froehling & Robertson, Inc.
1734 Seibel Drive, N.E.
Roanoke, Virginia
@ COPYRIGHT 2012
FROEHLING & ROBERTSON, INC.
ALL RIGHTS RESERVED
OOoO O�
0�0
Jefferson Mill
Dam Design
Scottsville, VA
Inlet & Penstock
Details
Prepared For:
Natel Energy
2401 Monarch St.
Alameda, CA 94501
DR
KHH
CHK
DAK
REV
PROIECI
62Y-0257
SHLIII
4l.0
DA IE
March, 2021
SCALE
NA
4 of 7
J
v
0 V
c
ON
fb _N '— •O
EN
cb L L
Y N O
O V O u
1=
E v
o Q v
L
N
u 7 7J
�m>,�
o t
vo-m
� L v O
MH },
O
o m v
Y `O_ �O N
3 ara.
v o v
L M t
v�M�
71 o O- U
.5Mr�
y M QJ
" M ` no
n
Q o Mb E
Q) L b
♦ v p
voM—
m
Y v C
v N
OL'j 7
3 CL
(U
£ m a
o
u -M L u
N 3 " ,b
CL ^! L
0 E o
iU u E
L C C
3
6 U O C
N j Y O
CL` N d
E u N v
a,
O N bib C
v o QJ
E Q)QJ
v v E
O- O j 7
X V v N
cb L O
o
3 0 7E v
o C o a
C O Ol y
M c -o
Y v Q
vho
y O_ u =
b L
CL v > v
v m o
O O Qi LL
V Y E
Y N
E °=
u b=a3v
c
a
c Ln I «
° v 0
t a 0 >
N L v d
0 o
�o��
W
o
c r v a
:Em E +L
(V y 7 L
o N i_+
0
m
u
C
0
i
w
N
n
N
O
Lo
N
/
C
0
a,
J
Y
U
v
0
LL
J
Q
0
Y
a E N
Y CL N
Q Ln
N CL
y O
� � Y
L N a)
rn N
Vx ti 0
t
b
2
N � It:
C i
in O N
�C ]G U
USFWS R5 Fish Passage Engineering Design Criteria June 2019
control
S/ d section
substrate
Q HW 5J I crest
d h ace
- 22b �aA -
control section and eelway channel --
control
section
exit structure
v
dam crest z2(c . e.
HW
eelway channel 2 2 ft
a2ft 5200
• • dam
TW \i
entrance structure `-
Figure 22: Design parameters for a laterally sloped eel ramp
� r
'a„ p
13.1.5 Helical Eel Rama �.
A helical eel ramp consists of a water -retaining channel coiled around a central shaft, with
climbing substrate installed on the channel bottom. The unit is installed vertically, thereby 1
connecting the headpond to the tailwater at a climbing angle equivalent to the pitch of the helix.
Initial tests of this eel pass at a hydropower project on the Saco River (Lakeside Engineering,
2014) demonstrated passage above 90% for some treatments. Engineering recommends the
following:
• Limit total vertical lift to 12 feet; lift may be extended with inclusion of resting sections;
13-7
USFWS EEL PASSAGE CRITERIA �.,� PRELIMINARY EEL LADDER CONCEPT FOR JEFFERSON MILL
1 \ L
General Notes
No.I Revision/Issue
SINCE
fs�
1881R
Date
Froehling & Robertson, Inc.
1734 Seibel Drive, N.E.
Roanoke, Virginia
@ COPYRIGHT 2012
FROEHLING & ROBERTSON, INC.
ALL RIGHTS RESERVED
OOoO O�
O �0
Jefferson Mill
Dam Design
Scottsville, VA
Eel Ladder Details
Prepared For:
Natel Energy
2401 Monarch St.
Alameda, CA 94501
DR
KHH
CHK
DAK
REV
PROJECT
62Y-0257
SHLII
5.0
DATE
March, 2021
SCALE
NA
5 of 7
J
v
c
EN N
� O L t
v= � a
Y N O
o-ou
E A Y
E a
o Q v
L
U =
m7
�>.�
O t
= Qm
� L v O
bMH'"'
o
o m v
Y `OQ O b
3 va.
v O v
s m t
v�M�
v o CL u
.5 y C C
O M
C 6 O
Mb E
Q) L b
♦ v p
71 O N
vc
-0 a
O-0'j 7
3 CL
Y m `o
o-0 m
u -M L u
M
Qom. L
0 E o
iU u E
c c
3 t 0
"O U � C
N j YO O
CLN C O
�
E u vQv
a,0
`o m b`o c
�vM0
"a
v v E
x o N
(U V v N
M L O
C O �
t N O
3 0 7E v
O C O 0
C O W y
.2 a° C O
Y v CL
MID
(U U C
y CL M
m s
CL v > N
2 m o
O O Qi LL
Y E
Y m
M " m
EM
=0
(U C
v
rv0>
(U L v fl
9 m O
O v U
o c N m
o .`
wE °v
c v a
s m E +L
v = s
N i_+
General Notes
1. CONTRACTOR SHALL EXERCISE CARE IN
ALL TREE CLEARING EFFORTS TO
MINIMIZE CLEARING TO ONLY TREES
REQUIRED TO PERFORM WORK AND
SATISFY DESIGN SPECIFICATIONS.
2. ALL VEHICLES SHALL BE ADEQUATELY
CLEANED PRIOR TO LEAVING THE
CONSTRUCTION AREA AND ENTERING
ROADWAY.
CE CONSTRUCTION ENTRANCE
SF SILT FENCE
PS PERMANENT SEEDING
MU MULCH
CW CONCRETE WASHOUT
SB SEDIMENT BAG
LEGEND
(E) = EXISTING, (P) = PROPOSED
0 o SECURITY FENCE
(E) TREE LINE
—X X— SILT FENCE
DIVERSION
(E) MAJOR TOPO
(E) MINOR TOPO
PROPERTY LINE
EC-3 BLANKETS
i t SOIL MAP LIMITS
REGULATORY DISTURBED AREAS:
AREA A = 0.26 ACRES
No.I Revision/Issue I Date
SINCE
18810,
Froehling & Robertson, Inc.
1734 Seibel Drive, N.E.
Roanoke, Virginia
@ COPYRIGHT 2012
FROEHLING & ROBERTSON, INC.
ALL RIGHTS RESERVED
OOoO O�
O �0
Jefferson Mill
Dam Design
Scottsville, VA
E&SC Site Plan
Prepared For:
Natel Energy
2401 Monarch St.
Alameda, CA 94501
DR.
KHH
CHK.
DAK
REV.
PRO=
62Y-0257
DAM
Sill I I
6l.0
March, 2021
SCALE
NA
6 of 7
J
v
0 v v
c
E H N
M L Y
h
Y M G O
CO -0Qj
O
C Y M
+ u
o CL
U 3 (UM >.
o t
W o- `3
� L v O
0f0n
o
o CU
v
Y CLO M
3 7J OC . "m.r f0
(U C 0-0
L M r v
-0 " M
71 O CL U
'0 M C C
O �M I_
"o o o
p ,n M
W O U
v c
= -0 Q)
0-0 j 7
7 CL C
O m OU
Y + M O
O -0 o
J
U } L M
C 7
E O
(1)u vt �
C C
3 t 0
3
"0 U O C
71 j. ,0 O
CL M C CL
E U vQ Ili `
N
O M pp C
v y M M
QJ
E
CL x O O v0
(U
M L O
Y N Y C
c M
OJ -0 C
3o v
O C O 0
C 2 N =
.2 a° c
Y IV CL
bD
W v u
y CL
W p L
CL v >. N
W CO 00
O O LL
C Q n L
V W v
Y (Mp
E M J
C0-00
0�Lo
v ' >
71 L v O
-0 F- m o
c N M
m
m
00 E m ma
c n Ln a,
s ro E Y
0 Y y
N EnLL y M 3
3
v
0
m
u
0
0
i
v
n
N
0
N
i
0
u
0
0
v
v
J
u
v
0
CL
J
0
Y
a E N
Y CL N
Q In
N CL
- y O
� � Y
� N N
LDO
rn N
Vx ti 0
x
N � It:
C i
o v
w + H
v-�
�C ]G U
i
CE STONE CONSTRUCTION ENTRANCE
(Adapted from Virginia Erosion and Sediment Control Handbook, Plate 3.02-1)
70' MIN. EXISTING
A 3 PAVEMEENT
5:1 Y
FILTER CLOTH 6" MIN. A MOUNTABLE BERM
(OPTIONAL)
SIDE ELEVATION
EXISTING GROUND I
12' MIN. *
L 2 3"
COURSE AGGREGATE
* MUST EXTEND FULL WIDTH
OF INGRESS AND EGRESS
OPERATION
FILTER CLOTH
REI
70' MIN.
B WASHRACKAT DISCRETION
OF P WC SITE INSPECTOR
POSITIVE DRAINAGE
B TO SEDIMENT
TRAPPING DEVICE
PLAN VIEW
SECTION A -A
SECTION B-B
10'
EXISTING
PAVEMENT
10' MIN.
3" MIN.
3" MIN.
CW EXCAVATED PIT CONCRETE WASHOUT
THE CONTRACTOR SHALL SUBMIT FOR REVIEW TO THE ENGINEER A PROPOSED METHOD FOR
CLEANING OUT WASTE FROM CONCRETE TRUCKS DURING THE PROJECT. AT THE COMPLETION
OF THE PROJECT THE CURED CONCRETE WASTE SHALL BE DISPOSED OF OFF -SITE.
A SUGGESTED METHOD IS SHOWN BELOW.
SC-03
GRAVELFILLED
BAGS
EDGE OF PLASTIC
LINER
If -
TOP OF CUT
EARTHEN
BERM
B / EDGE OF PLASTIC LINER (SEE
/ NOTE 2)
EARTHEN BERM
PLASTIC LINER
OVER BERM
m GRAVEL -FILLED BAG
EARTHEN BERM
PLASTIC LINER PLACED
11-8.1 UNDER BERM (ENTRY
TV TOP OF CUT 5-4)"SIDE ONLY)
ORIGINAL GROUND
SECTION B-B
NOT TO SCALE
J 4 N PLASTIC LINER OVER PLASTIC LINER
ENTRY SIDE OF WASHOUT hh EARTHEN BERM BERM OVER BERM
FACILITY PLASTIC LINER PLACED UNDER BERM EARTHEN BERM EARTHEN BERM
PLAN (ENTRY SIDE ONLY) GRAVEL FILLED PLASTIC LINER GRAVEL FILLED BAG
BAG
TYPE "EXCAVATED PIT"
On T�Xl e e ORIGINALGROUND
1:1
4
} 3:1
t
NOT TO SCALE
LETTERS A MINIMUM OF
NOTES:
5" IN HEIGHT
1.
ACTUAL LAYOUT DETERMINED IN FIELD.
CONCRETE
2.
INSTALL CONCRETE WASHOUT SIGN (24"X24", MINIMUM) WITHIN 30' OF THE
WASHOUT
TEMPORARY CONCRETE WASHOUT FACILITY.
3.
TEMPORARY WASHOUT AREA MUST BE AT LEAST 50' FROM A STORM DRAIN,
CREEK BANK OR PERIMETER CONTROL.
4.
CLEAN OUT CONCRETE WASHOUT AREA WHEN 50% FULL.
5.
THE KEY TO FUNCTIONAL CONCRETE WASHOUTS IS WEEKLY INSPECTIONS,
ROUTINE MAINTENANCE, AND REGULAR CLEAN OUT.
CONCRETE WASHOUT SIGN DETAIL
6.
SILT FENCE SHALL BE INSTALLED AROUND PERIMETER OF CONCRETE
WASHOUT AREA EXCEPT FOR THE SIDE UTILIZED FOR ACCESSING THE
WASHOUT.
7.
A ROCK CONSTRUCTION ENTRANCE MAY BE NECESSARY ALONG ONE SIDE OF
THE WASHOUT TO PROVIDE VEHICLE ACCESS.
GENERAL EROSION AND
MINIMUM STANDARDS
SEDIMENT CONTROL NOTES
MS-1
APPLY PERMANENT SOIL STABILIZATION TO DENUDED AREAS WITHIN SEVEN DAYS AFTER FINAL GRADE IS REACHED
ON ANY PORTION OF THE SITE. APPLY TEMPORARY SOIL STABILIZATION WITHIN SEVEN DAYS TO DENUDED AREAS
ES-1:
UNLESS OTHERWISE INDICATED, ALL VEGETATIVE AND
THAT MAY NOT BE AT FINAL GRADE BUT WILL REMAIN DORMANT (UNDISTURBED) FOR LONGER THAN 14 DAYS
STRUCTURAL EROSION AND SEDIMENT CONTROL PRACTICES
SHALL BE CONSTRUCTED AND MAINTAINED ACCORDING TO
MS-2
STABILIZE OR PROTECT TEMPORARY SOIL STOCKPILES WITH SEDIMENT TRAPPING MEASURES. PROVIDE TEMPORARY
MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA
PROTECTION AND PERMANENT STABILIZATION OF ALL SOIL STOCKPILES ON SITE AS WELL AS SOIL TRANSPORTED
EROSION & SEDIMENT CONTROL HANDBOOK THIRD EDITION
FROM THE PROJECT SITE.
1992
MS-3
ESTABLISH A PERMANENT VEGETATIVE COVER ON DENUDED AREAS NOT OTHERWISE PERMANENTLY STABILIZED.
ES-2:
THE LOCAL AUTHORITY HAVING JURISDICTION SHALL BE
PERMANENT VEGETATION SHALL NOT BE CONSIDERED ESTABLISHED UNTIL A GROUND COVER IS ACHIEVED THAT IN
NOTIFIED OF THE PRE -CONSTRUCTION CONFERENCE. LOCAL
THE OPINION OF THE ENGINEER, IS UNIFORM, MATURE ENOUGH TO SURVIVE AND WILL INHIBIT EROSION.
AUTHORITIES HAVING JURISDICTION WILL MAKE A
CONTINUING REVIEW AND EFFECTIVENESS OF THE METHODS
MS-4
CONSTRUCT SEDIMENT TRAPS AND DIVERSION DIKES, SEDIMENT BARRIERS AND OTHER MEASURES INTENDED TO
AND EFFECTIVENESS OF THE EROSION CONTROL PLAN.
TRAP SEDIMENT AS A FIRST STEP IN ANY LAND -DISTURBING ACTIVITY AND MAKE THESE MEASURES FUNCTIONAL
BEFORE UPSLOPE LAND DISTURBANCE OR TIMBERING TAKES PLACE.
ES-3:
ALL EROSION AND SEDIMENT CONTROL MEASURES SHALL BE
PLACED PRIOR TO OR AS THE FIRST STEP IN CLEARING,
MS-5
APPLY STABILIZATION MEASURES TO EARTHEN STRUCTURES SUCH AS DAMS, DIKES AND DIVERSIONS IMMEDIATELY
AFTER INSTALLATION.
GRADING, OR LAND DISTURBANCE.
MS-6
DESIGN AND CONSTRUCT SEDIMENT TRAPS AND SEDIMENT BASINS BASED UPON THE TOTAL DRAINAGE AREA TO BE
ES-4:
ALL EXISTING EROSION CONTROL MEASURES WHICH SERVE
SERVED BY THE TRAP OR BASIN..
THIS SITE SHALL REMAIN IN PLACE AND SHALL BE MAINTAINED
UNTIL THE AREAS THEY SERVE HAVE BEEN STABILIZED.
MS-7
CONSTRUCT CUT AND FILL SLOPES IN A MANNER THAT WILL MINIMIZE EROSION. PROVIDE SLOPES THAT ARE FOUND
TO BE ERODING EXCESSIVELY WITHIN ONE YEAR OF PERMANENT STABILIZATION WITH ADDITIONAL SLOPE
ES-5:
ALL STREETS AND ROADWAYS SHALL BE MAINTAINED FREE OF
STABILIZING MEASURES UNTIL THE PROBLEM IS CORRECTED.
MUD AND DIRT, AND CONTROL DUST AS NECESSARY.
MS-8
CONCENTRATED RUNOFF SHALL NOT FLOW DOWN CUT OR FILL SLOPES UNLESS CONTAINED WITHIN AN ADEQUATE
ES-6:
A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL
TEMPORARY OR PERMANENT CHANNEL.
PLAN SHALL BE MAINTAINED ON THE SITE AT ALL TIMES.
MS-9
WHENEVER WATER SEEPS FROM A SLOPE FACE, PROVIDE ADEQUATE DRAINAGE OR OTHER PROTECTION.
ES-7:
PROVIDE ADDITIONAL EROSION CONTROL MEASURES
NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS
MS-10
PROTECT ALL STORM WATER INLETS MADE OPERABLE DURING CONSTRUCTION SO THAT SEDIMENT -LADEN WATER
DETERMINED BY THE LOCAL AUTHORITY HAVING
CAN BE FILTERED BEFORE ENTERING CONVEYANCE SYSTEM.
JURISDICTION.
MS-11
PROVIDE ADEQUATE OUTLET PROTECTION BEFORE NEWLY CONSTRUCTED STORMWATER CONVEYANCE CHANNEL
ES-8:
ALL DISTURBED AREAS SHALL DRAIN TO APPROVED SEDIMENT
ARE MADE OPERATIONAL.
CONTROL MEASURES AT ALL TIMES DURING LAND -DISTURBING
ACTIVITIES AND DURING SITE DEVELOPMENT.
MS-12
WHEN WORK IN A LIVE WATERCOURSE IS PERFORMED, TAKE PRECAUTIONS TO MINIMIZE ENCROACHMENT,
CONTROL SEDIMENT TRANSPORT AND STABILIZE THE WORK AREA TO THE GREATEST EXTENT POSSIBLE DURING
ES-9:
DURING DE -WATERING OPERATIONS, WATER SHALL BE
CONSTRUCTION
PUMPED INTO AN APPROVED FILTERING DEVICE.
MS-13
WHEN CROSSING A LIVE WATERCOURSE MORE THAN TWICE IN ANY SIX-MONTH PERIOD, AN ADEQUATE
TEMPORARY STREAM CROSSING SHALL BE PROVIDED.
ES-10:
INSPECT ALL EROSION CONTROL MEASURES DAILY AND AFTER
EACH RUNOFF PRODUCING RAINFALL EVENT. ANY NECESSARY
REPAIRS OR CLEANUP TO MAINTAIN THE EFFECTIVENESS OF
MS-14
MEET ALL APPLICABLE FEDERAL, STATE AND LOCAL REGULATIONS PERTAINING TO WORKING IN OR CROSSING LIVE
WATERCOURSES.
THE EROSION CONTROL DEVICES SHALL BE MADE
IMMEDIATELY.
MS-15
STABILIZE THE BED AND BANKS OF A WATERCOURSE IMMEDIATELY FOLLOWING AFTER WORK IN THE
WATERCOURSE IS COMPLETED.
ES-11:
PRIOR TO ANY LAND DISTURBING ACTIVITIES THE CONTRACTOR
SHALL DESIGNATE A RESPONSIBLE LAND DISTURBER (RLD) TO
MS-16
UNDERGROUND UTILITY LINES SHALL BE INSTALLED IN ACCORDANCE WITH ALL APPLICABLE STANDARDS AND
THE DEPARTMENT OF ENVIRONMENTAL QUALITY (DEQ) IN
CRITERIA.
ACCORDANCE WITH THE VIRGINIA EROSION AND SEDIMENT
CONTROL ACT SECTION 62.1-44.15:55 B.
MS-17
WHERE CONSTRUCTION VEHICLE ACCESS ROUTES INTERSECT PAVED PUBLIC ROADS, MAKE PROVISIONS TO
MINIMIZE THE TRANSPORT OF SEDIMENT BY VEHICULAR TRACKING ONTO THE PAVED SURFACE. WHERE SEDIMENT
MAINTENANCE
IS TRANSPORTED ONTO A PUBLIC ROAD SURFACE, CLEAN THE ROAD THOROUGHLY AT THE END OF EACH DAY.
REMOVE SEDIMENT FROM THE ROADS BY SHOVELING OR SWEEPING AND TRANSPORT TO A SEDIMENT CONTROL
ALL EROSION AND SEDIMENT CONTROL MEASURES SHALL BE CHECKED
DISPOSAL AREA, STREET WASHING SHALL BE ALLOWED ONLY AFTER SEDIMENT IS REMOVED IN THIS MANNER.
DAILY
AND AFTER EACH RUN OFF PRODUCING RAINFALL. THE
FOLLOWING
ITEMS SHALL BE CHECKED IN PARTICULAR:
MS-18
REMOVE ALL TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES WITHIN 30 DAYS AFTER FINAL SITE
STABILIZATION OR AFTER THE TEMPORARY MEASURES ARE NO LONGER NEEDED, UNLESS OTHERWISE AUTHORIZED
BY THE LOCAL AUTHORITY HAVING JURISDICTION. PERMANENTLY STABILIZE TRAPPED SEDIMENT AND THE
A
R SHALL BE CHECKED FOR UNDER MINING
THE SILT FENCE BARRIER
DISTURBED SOIL AREAS RESULTING FROM THE DISPOSITION OF TEMPORARY MEASURES TO PREVENT FURTHER
OR DETERIORATION OF FABRIC. SEDIMENT SHALL BE
EROSION AND SEDIMENTATION.
REMOVED WHEN THE LEVEL OF SEDIMENT DEPOSITION REACHES
HALF WAY TO THE TOP OF THE BARRIER.
MS-19
ALL DOWNSTREAM PROPERTIES AND WATERWAYS SHALL BE ADEQUATELY PROTECTED FROM EROSION AND
B.
SEEDED AREAS SHALL BE CHECKED TO ENSURE THAT A GOOD
SEDIMENT DEPOSITIONS DUE TO INCREASES IN PEAK STORMWATER RUNOFF RESULTING FROM UPSTREAM LAND
STAND IS MAINTAINED. AREAS SHALL BE FERTILIZED AND
DISTURBING ACTIVITIES IN ACCORDANCE WITH ALL APPLICABLE STANDARDS AND CRITERIA.
RESEEDED AS NEEDED.
SF CONSTRUCTION OF A SILT FENCE
(WITH AND WITHOUT WIRE SUPPORT)
(Adapted from Virginia Erosion and Sediment Control Handbook, Plate 3.05-1 and 3.05-2)
1. SET POSTS AND EXCAVATE A 4"X4" 2. ATTACH FILTER MATERIAL TO STAKES 3. BACKFILL AND COMPACT
TRENCH UPSLOPE ALONG THE LINE (WITHOUT WIRE SUPPORT), TO WIRE THE EXCAVATED SOIL.
OF POSTS. FENCE (WITH WIRE SUPPORT) AND
EXTEND IT INTO THE TRENCH.
WI _
f 1 /
FLOW �-
FLOW II
�II�� �W.
4" III
SURVEY
1. CONTRACTOR SHALL LOCATE AND MARK ALL LOCATING FEATURES BEFORE
PROCEEDING WITH SITE CLEARING AND CONSTRUCTION ACTIVITIES.
2. CONTRACTOR SHALL ESTABLISH TEMPORARY BENCHMARKS AS REQUIRED TO
ADEQUATELY CONTROL CONSTRUCTION.
LAKE LEVEL CONTROL
1. LAKE LEVEL IS CURRENTLY FULL. COFFER DAMS SHALL BE INSTALLED AND WORK
AREAS PUMPED EMPTY UNTIL WORK IS COMPLETE.
UTILITIES
1. THE CONTRACTOR SHALL CALL MISS UTILITY 8-1-1 AND LOCATE ALL UTILITIES
PRIOR TO ANY WORK.
STONE
1. STONE USED FOR CONSTRUCTION ENTRANCE SHALL BE 2-3" COURSE
AGGREGATE.
EARTHWORK
1. CLEARING AND GRUBBING
1.1) THE CONTRACTOR SHALL CLEARLY MARK ALL AREAS TO BE CLEARED IN
ADVANCE.
1.2) THE CONTRACTOR SHALL INSTALL ALL EROSION AND SEDIMENT CONTROLS
PRIOR TO GRADING THE RESPECTIVE AREAS.
1.3) CLEAR AND GRUB ALL WORK AREAS TO AT LEAST 5 FEET BEYOND THE LIMITS OF
CONSTRUCTED WORKS.
2. TOPSOIL
2.1) TOPSOIL FROM ON -SITE SOURCES SHALL BE REMOVED DURING SITE CLEARING
AND GRUBBING OPERATION ONLY FROM DISTURBED AREAS, AND PLACED IN
TEMPORARY STOCK PILES.
2.2) FINAL 4 INCHES OF NEW FILL SHALL CONSIST OF ON -SITE TOPSOIL PREVIOUSLY
STRIPPED FROM THE SITE, FREE OF GRASS, ROOTS, WEEDS, STICKS, ROCKS AND
COBBLES.
3. GRADING
3.1) EXCAVATION REQUIRED FOR THIS PROJECT WILL BE UNCLASSIFIED. THERE WILL
BE ANTICIPATED ROCK EXCAVATION ON THIS PROJECT.
3.2) EXCAVATED SOILS ARE TO BE USED FOR BACKFILL FOR THE PENSTOCK AND
INLET STRUCTURE AS SHOWN ON THE PLANS.
3.3) FILL MATERIAL SHALL BE APPROVED SATISFACTORY SOIL MATERIAL. SUFFICIENT
QUANTITIES OF EXISTING SOIL IDENTIFIED ON THE PROPERTY IS EXPECTED TO
BE SUITABLE.
3.4) FILL MATERIAL SHALL BE LAID IN MAXIMUM 6 INCH LAYERS AND
MECHANICALLY COMPACTED. IF HAND OPERATED EQUIPMENT IS USED, LIFT
SHALL BE MAXIMUM OF 4 INCHES. BACKFILL FOR THE PARAPET WALL SHALL BE
4" LIFTS WITH 95% COMPACTION.
3.5) ALL FILL SHALL BE COMPACTED TO AT LEAST 95% OF ITS MAXIMUM DENSITY
(ASTM D 698). COMPACTION TESTS SHALL BE PERFORMED ONCE FOR EVERY
2500 S.F. OR FOR EVERY 50 LINEAR FEET OF EXCAVATED TRENCH.
3.6) CONTRACTOR SHALL CONTROL MOISTURE CONTENT OF ALL FILL MATERIAL TO
WHITHIN ±3% OF OPTIMUM AS DETERMINED BY ASTM D698, STANDARD
PROCTOR.
3.7) EXCAVATION AND TRENCHING PROCEDURES SHALL BE IN ACCORDANCE WITH
OSHA STANDARDS.
3.8) ANY EXCESS SOILS SHALL BE PLACED AS DESIGNATED BY THE ENGINEER.
4. DEWATERING
4.1) THE CONTRACTOR IS RESPONSIBLE FOR CONTROLLING SEEPAGE WATER INTO
THE SITE EXCAVATIONS AND FOR MAINTAINING THE AREAS IN AN "IN -THE -DRY"
CONDITION.
4.2) THE CONTRACTOR IS RESPONSIBLE FOR ALL MEANS AND METHODS RELATED TO
THE DEWATERING ACTIVITY.
5. INSPECTIONS
SOILS:SITE PREPARATIONS, PENSTOCK AND INLET STRUCTURE SUBGRADE,
PLACEMENT OF FILL MATERIALS, AND EVALUATION OF IN -PLACE -DENSITY BY
TESTING LAB RETAINED BY OWNER.
A
SHEET FLOW INSTALLATION
(PERSPECTIVE VIEW)
FLOW 1 FLOW
/z, \\\
POINTS A SHOULD BE HIGHER THAN POINT B.
DRAINAGEWAY INSTALLATION
(FRONT ELEVATION)
PROJECT SPECIFICATIONS
CONCRETE
1. CONCRETE: 4,000 PSI, 4.5-7.5% AIR, SLUMP 3-5 INCHES. CONTRACTOR SHALL
SUBMIT A MIX DESIGN
FOR APPROVAL.
2. CONCRETE REFERENCE STANDARDS:
(1) ACI 301 "SPECIFICATIONS FOR STRUCTURAL CONCRETE FOR BUILDINGS."
(2) ACI 304 "RECOMMENDED PRACTICE FOR MEASURING, MIXING,
TRANSPORTING, AND PLACING
CONCRETE."
(3) ACI 315 "MANUAL OF STANDARD PRACTICE FOR DETAILING CONCRETE
STRUCTURES."
(4) ACI 318 "BUILDING CODE REQUIREMENTS FOR REINFORCED CONCRETE.,-
(5) ASTM C94 "STANDARD PRACTICE FOR READY -MIX CONCRETE."
3. REINFORCING:
3.1) STEEL BAR REINFORCEMENT SHALL CONFORM TO ASTM A615, GRADE 60 FOR
ALL BARS.
3.2) REINFORCEMENT SHALL BE FABRICATED ACCORDING TO PROVISIONS OF ACI
315 "MANUAL OF STANDARD PRACTICES FOR DETAILING REINFORCED
CONCRETE STRUCTURES.
3.3 ALL REINFORCEMENT STEEL SHALL BE FREE FROM MUD OIL OR NON-METALIC
COATINGS AT TIME OF CONCRETING.
3.4) EMBEDMENT OF LAP SPLICE LENGTHS FOR ALL REINFORCING STEEL BARS SHALL
BE 48 BAR DIAMETERS.
3.5) FABRICATED BARS NOT CONFORMING TO DIMENSIONS AND DETAILS SHALL BE
REJECTED.
3.6) WELDING OF CROSSING BARS FOR ASSEMBLY OF REINFORCEMENT IS NOT
PERMITTED. THE FOLLOWING MINIMUM COVER WILL BE PROVIDED FOR
REINFORCING BARS:
CAST AGAINST & PERMANENTLY EXPOSED TO EARTH MIN COVER
EXPOSED TO EARTH OR WEATHER: #6 BARS AND LARGER 3"
#5 BARS AND SMALLER 1 1/2"
4. TESTING REQUIREMENTS:
4.1) ONE SET OF COMPRESSION TEST CYLINDERS IS REQUIRED FOR EACH POUR OF
MORE THAN 5 CY AND FOR EACH 50 CY OF EACH CONCRETE MIX.
4.2) ONE SET OF FIVE COMPRESSION CYLINDERS SHALL BE CAST FROM THE SAME
TRUCKLOAD OF CONCRETE. TWO CYLINDERS SHALL BE BROKEN AT 7 DAYS AND
TWO CYLINDERS SHALL BE BROKEN AT 28 DAYS. THE FIFTH CYLINDER SHALL BE
HELD FOR RE -TESTING, OR FOR A 56 DAY STRENGTH TEST, SHOULD THE 28 DAY
TEST FAIL TO MEET THE REQUIREMENTS. TESTS SHALL BE MADE BY AN
INDEPENDENT LABORATORY RETAINED BY OWNER.
4.3) SLUMP TEST SHALL BE MADE WHENEVER CYLINDERS ARE MADE.
4.4) CYLINDERS SHALL BE PLACED IN A FIELD STORAGE BOX CONTAINING A
THERMOMETER. THE TEMPURATURE IN THE BOX SHALL BE KEPT BETWEEN 70*F
TO 75'F WHEN POSSIBLE. IN NO EVENT SHALL THE STORAGE BOX
TEMPERATURE BE ALLOWED TO FALL BELOW 40*F OR RISE ABOVE 90°F
CONTRACTOR SHALL PROVIDE THE BOX.
5. NOTES TO CONCRETE PLACEMENT SCHEDULE:
5.1) AIR -ENTRAINED CONCRETE MIX THAT DOES NOT MEET THE MINIMUM
AIR -CONTENT REQUIREMENTS SHALL BE REJECTED.
5.2) CONCRETE DISPATCHED MORE THAN 90 MINUTES BEFORE PLACEMENT SHALL
BE REJECTED.
5.3) CONCRETE MORE THAN 5" SLUMP SHALL BE REJECTED.
VEGETATIVE PRACTICES
1. TOPSOILING (TEMPORARY STOCKPILE)
TOPSOIL SHALL BE STRIPPED FROM AREAS TO BE GRADED AND STOCKPILED
FOR LATER SPREADING ON DAM EMBANKMENT, BERM, EMERGENCY
SPILLWAY OR OTHER DISTURBED AREA. STOCKPILE LOCATIONS SHALL BE
LOCATED ONSITE AND SHALL BE STABILIZED WITH TEMPORARY VEGETATION.
2. TEMPORARY SEEDING
EXTENSION OF FDAKIC INTO THE TRENCH.
ALL DENUDED AREAS WHICH WILL BE LEFT DORMANT FOR EXTENDED PERIODS
OF TIME SHALL BE SEEDED WITH FAST GERMINATING TEMPORARY
VEGETATION IMMEDIATELY FOLLOWING GRADING OF THOSE AREAS.
SELECTION OF THE SEED MIXTURE SHALL DEPEND ON THE TIME OF YEAR IT IS
APPLIED.
3. MAINTENANCE
RE -FERTILIZE IF GROWTH IS NOT FULLY ADEQUATE. RESEED, RE -FERTILIZE AND
MULCH IMMEDIATELY FOLLOWING EROSION OR OTHER DAMAGE.
4. FINAL SEEDING
4.1) REMOVE ALL ROOTS, LIMBS, ROCKS GREATER THAN 6 INCHES, AND OTHER
DELETERIOUS MATERIALS FROM THE SEEDBED. REMOVED MATERIALS MAY BE
DISPOSED OF IN DESIGNATED ON -SITE WASTE ARES.
4.2) SEEDING MIX, APPLICATION RATE, AND PLANTING TIMES:
ALL AREAS
KENTUCKY 31 FESCUE 108 POUNDS PER ACRE
RED TOP GRASS 2 POUNDS PER ACRE
SEASONAL NURSE CROP* 20 POUNDS PER ACRE
CROWNVETCH 20 POUNDS PER ACRE
*VARIES MARCH THROUGH MAY 15 USE ANNUAL RYE
MAY 16 THROUGH AUGUST 15 USE FOXTAIL MILLET
AUGUST 16 THROUGH OCTOBER USE ANNUAL RYE
NOVEMBER THROUGH FEBRUARY USE WINTER RYE
4.3) ALL SEED SHALL BE CERTIFIED IN CONFORMANCE WITH CURRENT RULES AND
REGULATIONS OF VIRGINIA CROP IMPROVEMENT ASSOCIATION AND SHALL BE
THE LATEST CROP AVAILABLE. SEED
SHALL BEAR AN OFFICIAL "CERTIFIED SEED" LABEL.
4.4) SEEDING APPLICATION SHALL INCLUDE:
a. FERTILIZER AT THE FOLLOWING RATES: N-50 Ibs/ACRE; P/20/2 - 120 Ibs/ACRE;
K/20 - 90 Ibs/ACRE.
THE NITROGEN SHALL BE 50 PERCENT SLOWLY AVAILABLE NITROGEN (SAN). THE
WATER INSOLUBLE NITROGEN (WIN) OF 50 PERCENT SHALL BE STATED ON THE
CONTAINER OR BAG LABELS.
b. FIBER MULCH COMMONLY USED IN HYDROSEEDING APPLICATIONS AT A
MINIMUM OF 0.75 TONS PER ACRE.
c. GUAR BASED TACKIFIERS AT A RATE APPROPRIATE FOR THE SLOPE AND
WATERING CONDITIONS EXPECTED AT THE TIME OF APPLICATION.
4.1) INSTALL SEED OVER ALL DISTURBED AREAS.
5. MAINTENANCE PLAN:
THE CONTRACTOR SHALL REVISIT THE PROJECT TO CHECK ON THE EFFECTIVENESS OF
THE VEGETATIVE GROWTH AT 30 DAY INTERVALS. ANY AREAS THAT DO NOT SHOW
SUFFICIENT VEGETATIVE PROGRESS SHALL BE PREPARED AND RESEEDED ACCORDING
TO THESE SPECIFICATIONS.
E&S CONTROLS
EROSION AND SEDIMENT CONTROLS SHALL BE INSTALLED IN ACCORDANCE WITH
THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK AND THESE PLANS
AND SPECIFICATIONS.
IN
General Notes
No.I Revision/Issue I Date
SINCE
f
1881R
Froehling & Robertson, Inc.
1734 Seibel Drive, N.E.
Roanoke, Virginia
g COPYRIGHT 2012
FROEHLING & ROBERTSON, INC.
ALL RIGHTS RESERVED
Jefferson Mill
Dam Design
Scottsville, VA
E&SC Notes and
Details
Prepared For:
Natel Energy
2401 Monarch St.
Alameda, CA 94501
DR
KHH
CHK
DAK
REV
PROIECI
62Y-0257
DA IE
SHLIII
6al
March, 2021
SCALE
NA
7 of 7
E
Jefferson Mill Hydroelectric Project_Special Use Permit Application
Let It Go, LLC
Jefferson Mill Hydroelectric Project
Table of Contents
List of Appendices 11
PROJECT PROPOSAL
12
Introduction
12
Existing facilities
12
Proposed facilities
13
Construction
19
PUBLIC NEED OR BENEFIT OF THE PROJECT 20
1011:1:I:7ev'lUXi1Oti721:I:MaX41/_\ILIA lle]
CONSISTENCY WITH THE COMPREHENSIVE PLAN 21
IMPACTS ON PUBLIC FACILITIES & PUBLIC INFRASTRUCTURE 22
11519_C40IP1111111!141!1v/18.1971!15141!1V_1IaA_N01.1:P
0%
MEASURES/ CONDITIONS PROPOSED TO ADDRESS IMPACTS FROM THE
PROPOSED PROJECT 23
CONCEPTUAL STORMWATER DETENTION FACILITY
CK01►[41:1iILOl_1Ire1:L1C110410
23
Appendix A: Confirmation of Performance Standards of the Proposed Equipment 27
Appendix B: List of other permits 29
Jefferson Mill Hydroelectric Project -Special Use Permit Application
List of Appendices
Appendix A: Confirmation of Performance Standards of the Proposed Equipment
Appendix B: List of other permits
Appendix C: Conceptual Plan
Appendix D: Environmental Assessment
Appendix E: Draft Study Plan
Appendix F: Floodplain Development Permit Application
Appendix: G: No -rise Certificate
Appendix H: Section 106 Application
Appendix I: Dam Inspection Report
Appendices C to I are submitted separately as supplemental documents to the
application.
11
Jefferson Mill Hydroelectric Project_Special Use Permit Application
PROJECT PROPOSAL
A. Introduction
The proposed Jefferson Mill Hydroelectric Project is a 20 kW repowering of a historic mill
on the Hardware River in Scottsville, VA. The original structure was built in 1800 as a flour
mill. The proposed project will be constructed by Natel Energy, Inc., on behalf of the
property owners.
B. Existing facilities
The Jefferson Mill building was built around 1800 and is a brick structure supported by
wooden beams. The mill was a working mill until 1945. The original water wheel was set
in a chamber adjacent to the mill. It was later replaced by three small vertical turbines.
Those turbines were later removed.
Fig. 1: The historic mill building with the dam on the bottom right corner.
12
Jefferson Mill Hydroelectric Project -Special Use Permit Application
The existing dam is a 140 ft long and 9 ft high masonry structure, with a crest width
between 4 and 5 feet. The powerhouse consists of a single, narrow chamber, built against
the outer wall of the Mill building. The millrace has been filled in and is no longer in use.
Based on survey data, the dam controls a 0.7 mile long section of the Hardware River, the
primary source of water for the project. The impoundment has a surface area of 4.53
acres, storage capacity of 16.3 acre-feet and a normal water surface elevation of 320 feet
above mean sea level (MSL).
All entrance conductors serving the buildings on the property are underground. The
project will electrically connect to the existing 120/240VAC load centers at the mill
building. There is an existing Appalachian Power Company pad -mounted service
transformer on the site. The only electrical modification planned for the interconnection
of this project is a new utility metering pedestal with meter and 120/240VAC circuit
breaker, which will be located next to the service transformer. The access to the electrical
system is exterior to the physical structures on the property.
C. Proposed facilities
The proposed project will operate strictly in "run -of -the -river" mode on the Hardware
River. The hydraulic head needed for power generation is provided by the existing dam.
No additional water impoundment is proposed. The new turbine will be located in the
water room, a sunken chamber attached to the river side of the mill.
A single D062 Restoration Hydro Turbine, engineered by Natel Energy, is proposed for
installation with a capacity of 20 kW. The proposed turbine is a fish -friendly propeller
turbine ,with 8.5 feet of design head. The estimated average annual generation of the
proposed project is 111,000 kWh.
Please see Appendix C, submitted with the application, which illustrates the Conceptual
Plan with detailed drawings and maps of the project structure and related components.
Intake
The project proposes to construct a reinforced concrete intake structure, upstream of the
dam, on the west side of the river. The structure will be approximately 14' long x 12' wide
x 10' tall. Most of the intake will be below grade, with only the top couple of feet
extending above the existing ground surface. Water will be diverted through a debris
rack and into a penstock. The penstock will be 3 feet in diameter and 70 feet long.
Median headwater elevation is 320 feet. The top of the penstock will be 317.5 feet. The
2.5 feet of submergence will provide sufficient depth to prevent vortex formation.
13
Jefferson Mill Hydroelectric Project -Special Use Permit Application
A 12.5-foot wide by 4-foot tal I rack, angled at approximately 70 degrees from horizontal,
will prevent river debris from entering the intake. There will be a 0.75-inch wide clear gap
between the vertical bars. The approach velocity will be less than 1 fps (ft per second)
across the face of the rack. Debris will be manually cleared from the intake rack as
needed.
Flow into the penstock will be controlled by a slide gate equipped with an electric
actuator. Conduits carrying power and control circuits will run back to the powerhouse
alongside the penstock. The penstock will enter the powerhouse through the same
opening used by the old mill race.
Penstock
A 3-foot diameter penstock will run from the intake to the water room. The pipe will
extend away from the river for 50 feet, then turn 90 degrees and run another 20 feet to
the headwall of the water room. The elevation of the pipe centerline, at the intake, will be
315.5 feet. It will slope down at 1%, ending at elevation 315.0 feet. The trench for the
penstock will vary from 8 to 10 feet deep. The trench will be excavated in ground that has
been disturbed multiple times. It was used as a staging area when the water wheel was
removed and the first generation of turbines were installed. Later the original mill race
channel was filled in with soil and a raised path built to access the house deck.
Water Room
The original milling operation was driven by an overshot water wheel. The wheel was
mounted in the water room. A mill race channel led from the pond, above the dam, to the
top of the wheel. After spinning the wheel, the water exited through a slot at the far end
of the room. The chamber is 33' long x 8.5' wide. The outer masonry wal I varies from 2.5'
to 5' thick and is 15' tal I. The overshot wheel was replaced with a set of three vertical
turbines. The turbines were later removed and the mill race opening filled with cinder
blocks. The chamber currently sits empty.
The project proposes to construct a concrete box inside the water room, with the goal of
providing a clean, dry and protected location for the new turbine. The new 6 inches thick
walls will provide additional support to the older masonry walls. Vertical and thrust forces,
generated by the turbine, will be transmitted through the reinforced concrete to the
bedrock floor.
The original opening in the headwall has been filled in with a combination of cinder blocks
and concrete. This material will be removed to accommodate the 3 foot diameter
14
Jefferson Mill Hydroelectric Project -Special Use Permit Application
penstock. A new concrete headwall will be built, with a web of reinforcing bar
surrounding the penstock opening.
Draft Tube
Water will exit the turbine through a draft tube. The tube has an expansion section and an
elbow section. The elbow is pointed downward into a water filled trough. The end of the
draft tube will be below the water surface. The entire length of the draft tube will be
located in the water room. The 4 ft deep trough will be excavated down into the bedrock.
The trough exits out beneath the water room wall and then turns downstream. The floor
of the trough will slope upwards at a 6:1 H:V ratio to match the natural river bed. The
trough and enlarged opening will be below water level, so the outward appearance of the
structure will remain mostly unaltered.
Upstream Fish Passage - Eel & Sea Lamprey Ramp
Upstream passage for eels and sea lamprey will be improved by a new ramp, located on
the left bank of the river. It will be a "Laterally Sloped Eel Ramp" as described by the U.S.
Fish and Wildlife Service (USFWS) in their 2019 Fish Passage Engineering Design Criteria
in section 132.1.4. The ramp will be approximately 2 feet wide x 25 feet long. The ramp
will start at an existing notch in the dam and run parallel to the river, following the natural
dip slope of the sedimentary rocks. At its base, the ramp will angle back to the river,
extending below the water's surface to elevation 309.5'. The ramp will be a concrete
structure with an exposed aggregate finish. Natural rock will be used to disguise the
concrete where possible. The notch will be given a rectangular cross section, with
provision for stop logs to regulate flow. The substrate will be designed to accommodate
eels between 0.5 to 3.0 feet in length. The design is passive, requiring no active pumping.
Impact on the dam will be minimal. The existing notch will be modified for stop logs and
the upper end of the ramp will be attached to the dam face. Neither of these activities will
impact the dam's structural integrity. The ramp will have a minimum visual impact, as seen
from the deck of the Mill Building. The area is currently exposed bedrock.
Downstream Fish Passage - Plunge Pool
The project has been designed to ensure that 100% of river flows are not diverted to the
turbine and that there will always be flow available for downstream fish passage. The
downstream fish passage will be located at the existing notch toward the west end of the
spillway and falls into a naturally -occurring 4-foot deep plunge pool located at the base of
the dam. Design will be in accordance with USFWS 2019 Fish Passage Engineering Design
Criteria - Section 9, and in consultation with USFWS and VA DWR.
15
Jefferson Mill Hydroelectric Project_Special Use Permit Application
Table 1: Features of the proposed project
Proposed Turbine Type
D062 Restoration Hydro Turbine
Number of Turbines Proposed
1
Proposed Generator Type
Synchronous PMG with Variable -Frequency
AC Drive
Estimated Total Installed Capacity (kW)
20
Estimated Average Annual Generation(kWh)
111,000
Gross Head (ft)
9
Design Head (ft)
8.5
Minimum Hydraulic Capacity (cfs)
20
Maximum Hydraulic Capacity (cfs)
45
Water Source
Hardware River
326
324
322
$ 320
p 318
m
y 316
w
314
312
310
308 -
0
Jefferson Mill Rating Curves
Dam Crest Elevation
+Forebay Curve
• Observed Tailwater Elevations
—Tailwater Curve
Tailwater channel bottom
Soo 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 5,000
Streamflow (cfs)
Fig. 2: Estimated tailwater rating curve based on scaling from representative photographs and video clips.
16
Jefferson Mill Hydroelectric Project_Special Use Permit Application
322
321.5
321
c
320.5
m
a
W
320
319.5
319
0
326
325
324
323
c
322
w
w
321
320
319
318
0
Jefferson Mill Forebay Low Flow Rating Curve
50 too 150 200 250 300 350 400 450 500
Streamflow (cfs)
Jefferson Mill Forebay Rating Curve
2,000 4,000 6,000 8,000 10,000 12,000 14,000
Streamflow (cfs)
Fig. 3: Estimated forebay rating curve based on broad crested weir equation for flows less than 500 cfs (top curve)
and flood flows upto 13,000 cfs (bottom curve).
17
Jefferson Mill Hydroelectric Project -Special Use Permit Application
D. Construction
Pending receipt of all permits, the project is planned to begin construction in August 2021
with a duration of four months. No in -stream construction will occur between Feb 15 and
June 30 for protection of anadromous species and from May 15 through July 31 for
protection of James Spinymussel per Virginia Department of Game and Inland Fisheries
regulations.
Cofferdams
Temporary cofferdams will be constructed to isolate the intake and outlet areas from the
river. Cofferdams are used to reduce construction -related water quality impacts, protect
aquatic life, and to provide a safe construction area. The upstream cofferdam will extend
from the riverbank to the spillway. This will block off a third of the spillway length,
allowing the intake, wing walls, buoy line supports and downstream passage to be built in
the dry. Water depths are expected to be from 5 to 6 ft. The dam will be 25-ft long x 9-ft
tall.
It will be constructed with large bags packed with gravel, called Super Sacks. A 3-ft x 3-ft x
3.5-ft bag will hold 1 ton of gravel. The bags are made from woven polypropylene with
reinforcing straps and hoisting loops. The cofferdam will be built up in a pyramid fashion.
A 9-ft tall cofferdam would require three layers of sacks. It would have a 9 ft wide base
and a 3 ft wide crest. Sacks can be placed with an excavator or crane. Gravel to fill the
bags will be sourced locally and will be cleaned. When it comes time to remove the
construction cofferdam, the sacks can be hoisted out of the water, leaving minimal trace.
The downstream cofferdam will extend from the base of the dam to a small island that
forms a channel along the right side of the river. A second segment of dam will block off
the lower end of the side channel. The upper segment will be 30-ft long x 9-ft tall. The
lower segment will be 12-long x 6-ft tall. Water depths will vary from 2 to 5 ft.
Once the cofferdams are complete, the water behind the dams will be pumped out.
Fisheries biologists experienced with isolation of ESA listed species in the construction
area will provide industry approved direction on ways to safely manage the dewatering.
All cofferdams will be removed using techniques to minimize turbidity releases. This
includes allowing for the slow reintroduction of water into the work area and utilizing
dirty water treatment systems for turbid water. If James spinymussel are identified in the
construction area during the pre -construction survey, all mussels will be relocated per
federal and state guidelines.
IE
Jefferson Mill Hydroelectric Project -Special Use Permit Application
To avoid damaging any unidentified archeological deposits on the project area, the
designated laydown areas will be covered with 6" of crushed rock over geotextile fabric.
Silt fences will be installed around the downslope perimeters of the construction zone and
the laydown areas to prevent soil erosion, as detailed in the State of Virginia handbook as
best management practices. The bottom of the silt fence fabric will be buried in a shallow
6" wide x 6" deep trench. Fence, geotextile and crushed rock will be removed once the
construction is complete. A monitor will be present to document archeological resources
that may be exposed during excavation activities, including removal of the gravel and
fabric.
In accordance with Federal regulations, should unexpected archaeological resources be
encountered during project implementation, all work in the immediate area will cease and
the Virginia Department of Historic Resources will be contacted to provide guidance on
the treatment of the discovery. Natel Energy plans to contract with a local environmental
firm to provide a qualified archeologist to monitor all construction activities that might
impact historical artifacts.' The monitor will be empowered to stop work and preserve
artifacts until they can be properly examined.
Iall :31let .IAAll 0.4a:121ladIll r 1a1:1:11111a.1031x41
The Jefferson Mill Hydroelectric Project is the vision of the owners to revitalize a historic
use of their property, while contributing to the conservation of resources through clean
energy. The proposed hydropower project does not alter the Hardware River flows or
water quality.
The project will generate power year-round to produce 100% carbon -free electricity for
the residents and any excess generation will be distributed on the grid to provide clean
energy to the community.
OTHER ASPECTS OF THE SPECIAL USE
The Jefferson Mill Hydroelectric Project special use causes no detriment to adjacent lots,
as it is located entirely within private property owned by the applicant. As stated in the
no -rise certificate attached as Appendix G, the project will not result in an increase in
flood elevations for any adjacent property owners along the Hardware River. As noted in
Appendix A, neither noise nor vibrations from the project will be detectable on adjacent
lots. There will be no visual impact to adjacent lots, as the project is in the center of a large
' Natel has received a proposal from Cox McLain Environmental Consulting Inc. for such monitoring
services.
19
Jefferson Mill Hydroelectric Project -Special Use Permit Application
private parcel. The project is 380 feet from the closest adjacent lot and 580 feet from the
closest public road. During construction there will be occasional trucks with concrete and
equipment on local roads between 8 AM and 5 PM. The project will have a construction
entrance so that vehicles do not track mud onto the public road. There will be no increase
in dust during construction that will be detectable on neighboring parcels.
As noted in the section below, "Consistency with the Comprehensive Plan", the Jefferson
Mill Hydroelectric project does not change the rural character of the zoning district;
rather the special use enhances the historic nature of the zoning district and further
protects natural resources. The project complies with the purpose and intent of the
zoning ordinance and is permitted by right in Section 5.1.26 - Hydroelectric Power
Generation. As noted elsewhere in this application, the special use will be in harmony
with the public health, safety and general welfare.
CONSISTENCY WITH THE COMPREHENSIVE PLAN
The Comprehensive Plan emphasizes the importance of the intelligent use of local
resources. This project supports using land to produce local, clean energy while
reinvigorating a historical use of the mill and maintaining the rural landscape. As stated in
Objective 1 of the Natural Resources section of the Comprehensive Plan, the project
supports the conservation of clean water and safe waterways.
The mill is located on Rural Area private property and will contribute to the conservation
of natural resources by producing 100% renewable energy and improving fish passage in
the Hardware River. Natel Energy, the project developer, is working with Froehling &
Roberts and R2 Resource Consultants (now part of Kleinschmidt Group) to improve fish
passage along this stretch of the river. Froehling and Roberts, based in Roanoke, VA, is a
civil and geotechnical engineering firm. R2 Resource Consultants is an environmental and
engineering firm that specializes in fisheries biology, riparian ecology and hydrology.
The Jefferson Mill Hydroelectric Project helps fulfill Objective 4 of the Comprehensive
Plan's Natural Resources section: Protect the biological diversity and ecological integrity
of the County in both the Rural Area and Development Areas. As described in Section C -
Proposed Facilities above, the Jefferson Mill Hydroelectric Project has been carefully
designed to improve both upstream and downstream passage for eel and sea lamprey and
other species at the project dam. At the entrance to the hydro penstock, an extra wide
grate was designed to lower the intake velocity, making it easier for fish to swim past. The
grate's bar spacing was narrowed to % inch, to prevent ingress by most species of fish.
20
Jefferson Mill Hydroelectric Project -Special Use Permit Application
By providing clean, renewable energy to the electric grid in Albemarle County, the Project
also helps fulfill Objective 8 of the Comprehensive Plan's Natural Resources section:
Recognize changes occurring to the earth's climate to anticipate and mitigate impacts to
the County.
IMPACTS ON PUBLIC FACILITIES & PUBLIC INFRASTRUCTURE
The project will be entirely located on private property. There will be no impact to public
facilities or public infrastructure.
IMPACTS ON ENVIRONMENTAL FEATURES
The two structures associated with the project purchase their electric power thru the
local grid. That power is produced from a combination of coal, natural gas, pumped
storage, wind and hydro. Electricity generated by burning coal or gas makes up
approximately 84 % of the total. Burning fossil fuels produces carbon dioxide, a
greenhouse gas. Assuming that mix, 0.94 tons of CO2 would be produced for every 1
MWh of generation. The Jefferson Mill Hydroelectric Project is designed to produce 111
MWh/year of carbon free electricity. This will offset production of 104.34 tons/year of
CO2.
The proposed turbine and generator use biodegradable lubricants and the mechanical
parts of the project are enclosed in a casing that is separated from the water. The bearings
are lubricated using non -toxic, biodegradable, food -grade grease and the bearings have
three seals (an air gap separates two lip seals from the mechanical seal) to prevent grease
from ever reaching the water.
The project will not change the flow of water in the river. It will take water from just
above the dam and discharge it just below the dam. No bypass reach will be created. Most
of the year, the turbine flow will be minor compared to the overall river flow. In the late
summer, when river flows are low, a minimum flow will be dedicated to the eel ramp and
downstream passage. If sensors detect a drop in water level behind the dam, the turbine
will be automatically throttled back or shut off completely.
To prevent erosion around the intake, the riverbank will be protected by a wing walls
made from a combination of concrete and natural stone. The area disturbed by
construction will be reseeded. Silt fences will remain in place until the new grasses have
gotten established.
21
Jefferson Mill Hydroelectric Project -Special Use Permit Application
R2 Resource Consultants produced a report which expands on the environmental impact
of the project. Please see appendix D to read the full assessment and recommended
measures to minimize the impact of the project works.
In addition, the project owner's family members are stewards of the watershed and have
sponsored educational programs for local farmers to understand fertilizer application and
runoff impacts on the watershed. This project is funded on the understanding that daily
actions lead to meeting environmental goals.
MEASURES/ CONDITIONS PROPOSED TO ADDRESS IMPACTS FROM
THE PROPOSED PROJECT
None proposed.
CotsP►[y:12r9L1�01C07:7u1Ti%V1a:7•]:0ra2r1WZI VAT4111IIIVA
There will be no stormwater detention facilities, as the project will only create a minor
increase in impervious surface areas:
Impervious surfaces:
Intake and wingwalls Concrete 152 sf
Control room Concrete 192 sf
Gravel roads no new roads
Total 344sf (0.008ac)
Based on NOAA point precipitation frequency estimates, the 100-yr storm would drop
8.57 inches of rain over a 24 hr period on the project area. The Hardware River normally
flows between 50 and 400 cfs. During the 100-yr storm event, its flows would increase to
an estimated 31,530 cfs.
The Intake will be built on previously disturbed ground, immediately adjacent to the river.
The top of the structure will be 2 feet above normal water level in the river. Currently
rainfall is partially absorbed by the silty clay soil, while the remainder travels a few feet
before entering the Hardware river. The 100-year storm would result in 109 cf of water
flowing off the intake's impervious surface over a 24 hour period. However, flooding
caused by the 100-year storm would raise the level of the river by a minimum of 5 feet,
22
Jefferson Mill Hydroelectric Project -Special Use Permit Application
completely inundating the intake. The rain would fall directly into the river, making the
nature of the intake's surface composition moot.
The Control Room will be located 120 feet from the Hardware River and 20 feet from the
intake to a drainage culvert. The control room floor will be located 10 feet higher than
the dam crest, keeping the electronic equipment above the river's flood level. The
100-year storm would result in 137 cf of water flowing off the impervious roof over 24
hours, at an average flow rate of 0.002 cfs. This is a negligible amount. There is the
potential for the culvert to get clogged by debris, causing local flooding. The berm around
the culvert intake is 2 feet tall. If a blockage causes water to overflow the berm, it will flow
downhill towards the river, away from the Control room. The Control room floor is 4 feet
higher than the culvert intake.
CONCEPTUAL GRADING
The project will require 0.07 acres of excavation. To seal the work areas off from the river,
a string of cofferdams will be set along the edge of the river. Once the temporary dams
are in place, the areas behind them will be dewatered. The intake cut will be excavated
into the riverbank. The soil is a silty clay with layers of sand. The cut will have a surface
footprint of 700 sf (square feet), an average depth of 6.4 feet and a max depth of 10 feet.
The penstock cut will run from the intake to the turbine room. It will have a surface
footprint of 1500 sf, an average depth of 6.4 feet and a max depth of 12 feet. At its west
end, the cut will encounter bedrock 9 feet below the surface.
The outlet trench starts at the end of the turbine room, exits under the wall and then
turns downstream (see Figure 4 below) . Most of the trench will be excavated into
bedrock. It will be 5 feet wide x 4 feet deep x 37 feet long. The downstream portion will
slope up to meet the natural riverbed at a 6:1 slope.
The 54' long cable trench will run around the southside of the Mill building and across the
yard to the new Control Room building. Three sets of conduit will be placed in the trench.
Per code for buried electrical lines, the trench will be 3' deep. It will be 2' wide to maintain
a minimum of 12 inch horizontal separation between power and sensor cables. Care will
be taken where the new trench crosses over the existing 15-inch diameter rigid concrete
culvert.
23
Jefferson Mill Hydroelectric Project_Special Use Permit Application
The Control Room excavation will be just deep enough to pour a foundation slab. It will be
15' wide x 23' long x 2' deep.
Fig. 4: Project Layout showing location of Control Room and conduit trench
Once the new structures, conduits and penstock are complete, the excavations will be
filled in with either native soil or engineered fill. The native soil is currently being tested
to see if its mechanical properties will qualify it as backfill. Fill will be compacted to 90%
or better of its maximum density, as determined by modified Proctor tests. Fill areas will
be graded to match surrounding terrain. Excavated ground that will remain exposed for
more than two weeks, will be covered by straw or other erosion control measures. The
outlet trench will remain open. It will flood once the cofferdams are removed.
After grading, the inlet and penstock areas will be seeded with species suitable for poorly
drained soils. The conduit trench and control room areas will be seeded with traditional
lawn grasses like Kentucky bluegrass, per Virginia DEQ guidelines below.
24
Jefferson Mill Hydroelectric Project_Special Use Permit Application
TABLE 3.32-D
SITE SPECIFIC SEEDING MIXTURES FOR PIEDMONT AREA
Total Lbs.
Per Acre
"inimum Care Lawn
- Commercial or Residential 175-200 lbs.
- Kentucky 31 or Turf -Type Tall Fescue 95-100%
- Improved Perennial Ryegrass 0-5%
- Kentucky Bluegrass 0-5%
High -Maintenance Lawn 200-250 lbs.
Kentucky 31 or Turf -Type "Fall Fescue 100%
Gcneral Slope (3:1 or less)
Kentucky 31 Fescue 128 lbs.
- Red Top Grass 2 lbs.
- Seasonal Nurse Crop ' 20 lbs.
150 lbs.
IFIM3 �.� .. �•_t
Kentucky 31 Fescue 108 lbs.
- Red Top Grass 2 lbs.
Seasonal Nurse Crop ' 20 lbs.
- Crownvetch '" 20 lbs.
150 lbs.
' Use seasonal nurse crop in accordance with seeding dates as stated below:
February 16th through April ...................... Annual Rye
May 1st through August 15th ..................... Foxtail Millet
August 16th through October ...................... Annual Rye
November through February 15th ................... Winter Rye
" Substitute Sericea lespedeza for Crownvetch east of Farmville, Va. (May
through September use hulled Sericea, all other periods, use unhulled Sericea).
If Flatpea is used in lieu of Crownvetch, increase rate to 30 lbs./acre. All legume
seed must be properly inoculated. Weeping Lovegrass may be added to any slope
or low -maintenance mix during warmer seeding periods; add 10-20 lbs./acre in
mixes.
Table 2: Virginia DEQ Permanent Seeding Guidelines
h ttps://www.deq.virgini a.gov/homelshowpu blisheddocumen t?id=2436
25
Jefferson Mill Hydroelectric Project_Special Use Permit Application
Appendix A: Confirmation of Performance Standards of the Proposed
Equipment
March 10,2021
Frank Pohl
County Engineer
Albemarle County, VA
401 McIntire Road
Charlottesville, VA 22902
Re: Confirmation of performance standards of the proposed equipment for Jefferson
Mill Dam Hydroelectric Project.
Dear Mr. Pohl,
Let It Go, LLC is applying for a Special Use Permit for Hydroelectric Power Generation
under Albemarle County Code of Ordinance Chapter 18. This letter is produced in lieu of
a certified engineer's report to address the concerns stated under Chapter 18 Section
5.1.26 of the Albemarle County Code of Ordinance.
zr=
Section 4.18.04 sets the maximum sound levels in Rural Areas and Residential at 60 dBA
during the daytime and 55 dBA during nighttime. The project will have two devices that
produce sound: the turbine / generator and the variable frequency drive (VFD). The
turbine/generator will produce approximately 55 dBA, equivalent to a dishwasher. It will
run both night and day. The turbine /generator will be fully encapsulated in a concrete
room. The concrete will be surrounded by masonry walls up to 3 feet thick. The double
walls should attenuate the turbine noise. The turbine room is immediately adjacent to the
dam, where the Hardware River pours over the spillway. The ambient noise level can be
fairly high.
The VFD uses fans for cooling, which can produce up to 62 dB. The VFD and other
electronic equipment will be located in a control room, a separate structure located
approximately 40 feet away from the closest residence. Sound levels outside the control
room will be below the County's nighttime maximum.
Electrical Disturbance
The electrical equipment will connect to the existing Appalachian Power Co. service. The
installation will comply with all applicable Appalachian Power, federal, state and local
standards and regulations. This compliance will ensure no adverse impacts to other
Appalachian Power customers.
26
Jefferson Mill Hydroelectric Projec Special Use Permit Application
Vibration
The turbine generates a vibration with a peak velocity < 2mm/s (0.079 in/s), as measured
at the surface of the equipment. To calculate the attenuation with distance, the U.S.
Federal Transit Administration's Noise and Vibration Manual uses the formula:
P(lot line) = P(equip) x (25/D)^1.5
P = peak vibration in inches/s.
D = distance in feet
The County code lists the maximum allowable peak velocity for continuous
operation as 0.015 in/s at the closest lot boundary. The closest lot boundary is the NW
corner of Lot 123-19B. The distance from the turbine is 377 ft. The turbine vibration
would be attenuated to 0.0013 in/s. This is an order of magnitude lower than the County
standard. Jefferson Mill Road is 579 feet from the turbine. Vibration there would be
0.0007 in/s.
Glare and heat
All project equipment will be completely enclosed within buildings and will neither create
glare that would adversely affect the navigation or control of aircraft, nor cause public
nuisance or hazard to abutting parcels. The heat produced by the turbine and generator
should be contained within the concrete room.
From the description stated above, Let It Go, LLC believes that the proposed equipment
complies with the performance standards outlined by the county ordinance and will be of
low impact.
If you have any questions regarding this submission, please do not hesitate to contact
Tatiana Marzan, JeffersonMiII@natelenergy.com.
Sincerely,
Aaron Van Duyen
Let It Go, LLC
%Van Duyne, Bruno & Co, P.A.
18 Hook Mountain Road, Suite 202
P.O. Box 896
Pine Brook, NJ 07058
27
Jefferson Mill Hydroelectric Project_Special Use Permit Application
Appendix B: List of other permits
Along with the Special Use Permit application for hydroelectric power generation under
Albemarle County Code of Ordinance Chapter 18 Section 10.2.2 and Section 30.3.11,
below is the list of permits the project has applied for and is required to apply for:
Table B-1: List of permits required for Jefferson Mill Hydroelectric Project
Permit
Authorizing
Submission
Completion
Comments
Agencies
Date
Date
FERC 10MW
FERC
10/20/2020
8/30/2021
The Initial Consultation Document
Exemption
(ICD) was submitted to FERC under
Docket #P-15038. Agency comments
were received on the ICD by
1/25/2021; draft study plans were
submitted in response on
03/01/2021. Please see Appendix E
for the study plan. The applicant
anticipates filing the final exemption
application with FERC by April 23,
2021,with FERC issuing the
exemption in August 2021. FERC
requires issuance of the Joint Permit
under Sections 401 and 404 of the
Clean Water Act before it can issue
the exemption.
Section 106
VADHR
2/26/2021
5/10/2021
Application submitted for review,
(National
awaiting comments within 30 days of
Historic
submission. Please see Appendix H
Preservation
for the Section 106 application.
Act)
Joint Permit
USACE,
4/14/2021
7/16/2021
Awaiting proof of compliance with
Section 401 and
VMRC,
Section 106 of the National Historic
404 (Clean
VADEQ
Preservation Act and Section 7 of the
Water Act)
Endangered Species Act, and other
study results required by the
Agencies
County Building
Albemarle
7/1/2021
7/30/2021
Receipt of the building permit is
Permit
County VA
conditioned upon receipt of the
County Special Use Permit.
Application for the building permit
will be submitted upon completion of
the construction drawing set.
SP202100007 and SP202100008 Jefferson Mill Hydroelectric Project
Attachment C
Sec. 5.1.26 - Hydroelectric power generation
a. These provisions are intended to encourage the use of water power as a natural and
replenishable resource for the generation of electrical power. While serving energy conservation
and natural resource goals, these provisions are also intended to limit such use so as: not to be
objectionable in the area in which it is located; not to unreasonably interfere with the passage of
boats, canoes, fish and other aquatic life; not to unreasonably degrade the riverine and aquatic
habitat or water quality, in general;
b. The applicant shall submit with his application for special use permit, plans, profiles, studies
and other supporting information addressing the issues in (a) above. No such application shall be
approved until comment and recommendation has been received from the State Water Control
Board, the Commission of Game and Inland Fisheries, and other appropriate federal, state and
local agencies;
c. Whether or not a site development plan is required, the applicant shall submit to the county
engineer a certified engineer's report as described in section 4.14.8. In review of such report, the
county engineer shall be particularly mindful of the requirements of section 4.14.1, noise, and
section 4.14.7, electrical interference;
d. Except as specifically permitted in a particular case, no auxiliary or accessory method of power
generation shall be permitted nor shall any pump storage or rechannelization be permitted.