740107_Compliance_20210211

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
Bobby Harris
Bobby Harris Farm
1272 Porter Road
Greenville, NC 27834
Dear Mr. Harris:
NORTH CAROLINA
Environmental Quality
February 11, 2021
Subject: Sludge Survey Testing Dates
Certificate of Coverage No. AWS740107
Bobby Harris Farm
Animal Waste Management System
Pitt County
The Division of Water Resources (Division) received your sludge survey information on
February 9, 2021. With the survey results, you requested an extension of the sludge survey
requirement for the lagoon at the Bobby Harris Farm facility. Due to the amount of treatment
volume available, and the rate of sludge accumulation for the lagoon, the Division agrees that a
sludge survey is not needed until December 31, 2024.
The next sludge survey for the lagoon at Bobby Harris Farm should be performed before
December 31, 2024. Please retain this letter and keep it with your farm records for reference.
Please call me at 919-707-3663 if you have any questions.
Sincerely,
3i,Uy A. -0l l Asap
Bill Dunlap
Animal Feeding Operations Program
cc: Washington Regional Office, Water Quality Regional Operations Section
Permit File AWS740107
DNorth Carolina Department of Environmental Quality Division of Water Resources
E Q��
_ 512 North Salisbury Street 1 1636 Mail Service Center I Raleigh, North Carolina 27699-1636
NORTH CARD OapartmeM ofEnviw
ronmenWl Uual� p ` 919.707.9000

Sludge Survey Evaluation Form
Today's Date2/11/2021
Facility #
740107
Owner:
Bobby Harris
Lagoon ID1
Sludge Survey Received:2/9/2021
Sludge Survey Performed:12/21/2020
Sludge Depth (Row O): (ft)
2
Existing Treatment Depth (Row P): (ft)
4.00
Start Date:01/01/80
Facility age at time of survey:(yr)41
Average Sludge Accumulation (ft/yr):0.05
3
Requested Extension: (yr)
Requested Due Date2024
Sludge Accumulation during extension period: (ft)0.15
3.85
Treatment Depth Available after Extension: (ft)
Sludge level OK?NO
Ratio Estimates Based on DepthEXISTINGEXEMPTION
Ratio of Sludge layer to total trmt depth
0.330.36
Ratio of Sludge depth OK?YES
EXISTINGEXEMPTION
Average Sludge layer thickness (T)22.15
Depth of the lagoon from top of bank to bottom soil surface (D)
10.110.1
Slope=Horizontal/vertical side slope (S)
33
Length at the top of inside bank (L)
375375
Width at the top inside slope (W)
175175
Thickness of existing liquid treatment zone (Y)
4.003.85
Lm
Length at midpoint of sludge layer ()=L-2S(D-(T/2))
320.40320.84
Wm
Width at midpoint of sludge layer ()=W-2S(D-(T/2))
120.40120.84
Vs
Volume of sludge ()=Lm*Wm*T
77152.3283213.39
Vsg
Volume in gallons ()=Vs*7.481
577176.51622436.15
Z
Thickness of total treatment zone ()=T+Y
6.006.00
Lz
Length at midpoint of total treatment zone ()=L-2(S)(D-(Z/2))
332.40332.40
Wz
Width at midpoint of total treatment zone ()=W-2(S)(D-(Z/2))
132.40132.40
Vz
Volume of total treatment zone ()=Lz*Wz*Z
264058.56264058.56
Ratio(R) of sludge layer volume to total trmt volume0.2920.315
Sludge Volume Ratio OK?YES
Maximum extension until end of permit cycle
Next survey to be done: (calendar yr)
12/31/2024
Notification letter mailed:
2/11/2021

Appendix 1. Lagoon Sludge Survey Form Revised August 2008
A. Farm Permit or DWQ Identification Number
B. Lagoon Identification
Bobby Harris
74-107
C. Person(s) Taking Measurements
D. Date of Measurement
E. Methods/Devices Used for Measurement of:
NCState University
A&T State University
COOPERATIVE
EXTENSION
Eve Honeycutt Empowering People • Providing Solutions
12/21/2020
a. Distance from the lagoon liquid surface to the top of the sludge layer.
Sonar
b. Distance from the lagoon liquid surface to the bottom (soil) of the lagoon.
Sonar
c. Thickness of the sludge layer if making a direct measurement with "core sampler".
Sonar
F. Lagoon Surface Area (using dimensions at inside top of bank): 7 (acres)
(Draw a sketch of the lagoon on a separate sheet, list dimensions, and calculate surface area. The lagoon
may have been built different than designed, so measurements should be made.)
G. Estimate number of sampling points:
a. Less than 1.33 acres: Use 8 points
b. If more than 1.33 ac. acres x 6 = , with maximum of 24.
(Using sketch and dimensions, develop a uniform grid that has the same number of intersections as the
estimated number of sampling points needed. Number the intersection points on the lagoon grid so that data
recorded at each can be easily matched.)
H. Conduct sludge survey and record data on "Sludge Survey Data Sheet" (Appendix 2). Also, at the
location of the pump intake, take measurements of distance from liquid surface to top of sludge
layer and record it on the Data Sheet (last row); this must be at least 2.5 ft. when irrigating.
I. At the time of the survey, also measure the distance from the Maximum Liquid Level to the Present Liquid
Level (measure at the lagoon gauge pole): 1.2
J. Determine the distance from the top of bank to the Maximum Liquid Level 1.6
(use lagoon management plan or other lagoon records)
K. Determine the distance from the Maximum Liquid to the Minimum Liquid level: 2.4
(use lagoon management plan or other lagoon records)
L. Calculate the distance from the present liquid surface level to the Minimum Liquid Level 1.2
(Item K Minus Item I, assuming the present liquid level is below the Maximum Liquid Level)
M. Record from the Sludge Survey Data Sheet the distance from the present liquid surface level to the
lagoon bottom (average for all the measurement points) 7.3
N. Record from the Sludge Survey Data Sheet the distance from the present liquid surface level to the top
of the sludge layer (average for all the measurement points): 5.2
O. Record from the Sludge Survey Data Sheet the average thickness of the sludge layer: 2.0
P. Calculate the thickness of the existing Liquid Treatment Zone (Item N minus Item L): 4.0
Q. If Item 0 is greater than Item P, proceed to the Worksheet for Sludge Volume and Treatment Volume.
If Item 0 is equal to or less than Item P, you do not have to determine volumes.
Completed by: Eve H. Honeycutt Date: 12/21/2020
Print Name /Signature

Appendix 2. Sludge Survey Data Sheet* Revised August 2008
Lagoon Identification
Completed by:
Print Name
Signature
Date:
12/21/2020
(A)
Grid Point
No.
(B)
Distance from liquid surface
to top of sludge
( C )
Distance from liquid surface
to lagoon bottom (soil)
(C)-(B)
Thickness of sludge layer
Ft. & in.
Ft. (tenths)
Ft. & in.
Ft. (tenths)
Ft. & in.
Ft. (tenths)
1
0.0
0.0
0.0
2
0.0
0.0
0.0
3
0.0
0.0
0.0
4
0.0
0.0
0.0
5
0.0
0.0
0.0
6
0.0
0.0
0.0
7
0.0
0.0
0.0
8
0.0
0.0
0.0
9
0.0
0.0
0.0
10
0.0
0.0
0.0
11
0.0
0.0
0.0
12
0.0
0.0
0.0
13
0.0
0.0
0.0
14
0.0
0.0
0.0
15
0.0
0.0
0.0
16
0.0
0.0
0.0
17
0.0
0.0
0.0
18
0.0
0.0
0.0
19
0.0
0.0
0.0
20
0.0
0.0
0.0
21
0.0
0.0
0.0
22
0.0
0.0
0.0
23
0.0
0.0
0.0
24
0.0
0.0
0.0
Number of points with readings
X X
X X
Average of
points
x X
5.24
X X
7.25
X X
2.01
At pump
intake
0.0
X X X X X X
*AII Grid Points and corresponding sludge layer thicknesses must be shown on a sketch attached to this
Sludge Survey Data Sheet.

Appendix 3. Worksheet for sludge volume and treatment volume Revised August 2008
The average thickness of the sludge layer and the thickness of the existing liquid (sludge -free) treatment zone are determined
from the information on the Lagoon Sludge Survey Form ( Items 0 and P, respectively). In this example, the average sludge
layer thickness is 2.5 feet and the existing liquid treatment zone is 3.5 feet. If the lagoon has a designed sludge storage volume,
see notes at end of the worksheet. The dimensions of the lagoon as measured and the side slope are needed
for calculations of sludge volume and of total treatment volume. If the lagoon is a standard geometric shape, the sludge
volume and the treatment volume in the lagoon can be estimated by using standard equations. For approximate volumes
of rectangular lagoons with constant side slope, calculate length and width at the midpoint of the layer, and multiply by layer
thickness to calculate layer volume, as shown in the example. For irregular shapes, convert the total surface area to a square
or rectangular shape. For exact volumes for lagoons with constant side slope, the "Prismoidal Equations" may be used.
Example Your Lagoon
1. Average sludge Layer Thickness (T) 2.5 ft. 2.0 ft.
2. Depth of the lagoon from top of bank to bottom soil surface (D) 11 ft. 10.0 ft.
3. Slope = Horizontal/ vertical side slope (S) 3 3.0
4. Length at the top of inside bank (L) 457 ft. 923.0 ft.
5. Width at top inside slope (W) 229 ft. 355.0 ft.
6. Length at midpoint of sludge layer Lm = L-2S(D-(T/2)) 398.5 ft. 869.0 ft.
7. Width at midpoint of sludge layer Wm= W-2S(D-(T/2)) 170.5 ft. 301.0 ft.
8. Volume of sludge (Vs) Vs=Lm Wm T 169,860 ft3 525,683 ft3
9. Volume in gallons: Vsg=V*7.5 gal./ft3. 1,273,950 gal. 3,942,624 gal.
10. Thickness of existing liquid tmt. zone (Y) 3.5 ft 4.0 ft
11. Thickness of total treatment zone (Z) Z= T+Y 6 ft 6.0 ft
12. Length at midpoint of total tmt. zone LZ = L-2(S)(D-(Z/2) 409 ft. 881.0 ft.
13. Width at midpoint of total tmt. Zone WZ = W-2(S)(D-(Z/2) 181 ft. 313.0 ft.
14. Volume of total treatment zone (Vz) Vz = LZ WZ Z 444,174 ft3 1,657,060 ft3
15. Ratio ( R ) of sludge layer volume to total Treatment Volume
R = Vs/Vz 0.38 0.32
If the ratio R exceeds 0.50, than a sludge Plan of Action may be required. Check with DWQ for information
on filing the Plan of Action.
Note: If the lagoon has a designed sludge storage volume (DSSV), subtract that volume from both the volume
of sludge (Vs) (Item 8) and from the volume of total treatment zone (Vz) (Item 14), and take the ratio.
Then, R = (Vs-DSSV) / (Vz - DSSV)
Example: If DSSV = 85,000 ft3, then R = (169,860 - 85,000) / (447,174 - 85,000) = 84,860 / 362,174 = 0.24.
16. Design sludge storage volume (DSSV) 85,000
17. Ratio (R) of sludge layer volume to treatment volume adjusted
for designed sludge storage volume
0.24 0.32