WQ0039181_Report_20170418

Table 2. KsAT Test Results for Soil Unit 2 in the study area.
Soil Unit 2 Soil Series
KsAT #
Profile/Boring #
Depth
Horizon
In/Hr
1
P6
36
C
0.1459
2
P6
10
B/C
0.0152
5
B4
9
B/C
0.1006
6
B4
37
C
0.0182
7
P3
9
B/C
0.0223
8
P3
35
C
0.0365
Geomean of B/C: 0.0324 in/hr
Geomean of C: 0.0459
in/hr
Generally, all KsAT test results provided consistent measurements. The measured rate for
the BC horizon (0.109 in/hr) and B/C (0.0324 in/hr) are deemed the most limiting for Soil
Unit 1 and Soil Unit 2, respectively, and should be used in calculating the water balance.
Data sheets are attached.
Drainage Coefficients
The measured KsnT rate must be modified by an appropriate drainage coefficient to
determine the hydraulic loading rate. Typical drainage coefficients for large surface
irrigation spray systems range from 0.04 to 0.10. However, sites with favorable
parameters that promote infiltration into surface horizons and percolation through
subsurface horizons, lack evidence of soil wetness conditions, and occur along favorable
landscapes can utilize drainage coefficients near the upper range.
Soil Unit 1 - The well -established duff (wooded) and fescue (pasture) and moderate
granular structure allows for quick infiltration into A horizons. The deep argillic
horizons with strong to moderate structure that typically extend below 42 inches with no
apparent soil wetness condition and long linear slopes (typically occurring between 5% to
20%) permit vertical percolation and lateral flow of wastewater from the application
fields. As such, a drainage coefficient of 0.10 is recommended for this soil unit.
Soil Unit 2 - The well -established duff (wooded) and fescue (pasture) and moderate
granular structure allows for quick infiltration into A horizons. The overall deep profile
with favorable saprolite textures that extend to greater than 84 inches with no apparent
soil wetness condition and long linear slopes (typically occurring between 6% to 15%)
permit vertical percolation and lateral flow of wastewater from the application fields. As
such, a drainage coefficient of 0.08 is recommended for this soil unit.
Recommended Loading Rates
Based upon the results of the site investigation and our professional experience, we
recommend the following loading rates:
Soil Unit 1:
• Weekly Loading Rate of 1.1 inch/week (0.00654 in/hr)
• Instantaneous Loading Rate of 0.1 in/hr
• Maximum irrigation -event loading rate of 0.25 in/hr not to exceed 0.1 inches of
wastewater applied per hour
Carolina Malt House -Draft Report
Spray Irrigation System January 31, 2017

Soil Unit 2:
• Weekly Loading Rate of 0.4 inch/week (0.00238 in/hr)
• Instantaneous Loading Rate of 0.1 in/hr
• Maximum irrigation event loading rate of 0.25 in/hr not to exceed 0.1 inches of
wastewater applied per hour
The instantaneous loading rate of 0.1 in/hr is recommended to reduce runoff of applied
wastewater. The design engineer has stated application of wastewater at this rate is not
possible due to the low flow rate. As such, a maximum instantaneous application rate of
0.25in/hr is recommended. The duration of the irrigation event should be set not to
exceed the 0.1 inches of total wastewater application in one hour. The well -established
duff and grass covers will allow for infiltration and prevent runoff from these short
irrigation events.
The above recommended loading rates should be used in engineering wastewater
application throughout the study area. The maximum allowable annual irrigation could
likely be increased based on field performance and operation practices. Applications
above those shown in the water balance can likely be made during periods of less
frequent rainfall.
Soil Fertility Results
A composite soil sample for the proposed irrigation area was sent to Waypoint Analytical
for analysis per the NCDA&CS Agronomic Division fertility analysis standard. The
results are typical for a piedmont soil and are attached.
Setbacks
Potential jurisdictional wetlands and a stream were identified within the study area and
will require 100-ft setbacks to apnlication areas (Figure 3 & 4). Gullies and channelized
drainages were observed in the study area and will require 25-ft setbacks. The typical
setback for a property boundary is 150-ft. This setback is allocated for the west property
line. The east property boundary consists of the NCDOT ROW for US HWY 70. A
setback of 50-ft is shown from the ROW
Other Site Considerations
The irrigation area should be properly managed to maintain a well -established vegetative
(grass) crop and forest stands while limiting major site manipulation. Installation and
maintenance activities should only be completed during dry soil conditions so that the
surface is not manipulated or compacted and soil structure is not damaged.
An old farm path is proposed to be included in the irrigation area located east of HWY 70
in Soil Unit 1. As such, a soil boring was advanced in the path to determine if this area is
adequate for wastewater application. Soil boring B20 was advanced to 42 inches below
the path surface. Soil properties detrimental to wastewater application were not
observed.
CONCLUSION
Carolina Malt House -Draft Report
Spray Irrigation System January 31, 2017

Two soil units were mapped within the study area based on observed soil characteristics.
A weekly loading rate of 1.1 inch/week and 0.4 inch/week is recommended for Soil Unit
1 and Soil Unit 2, respectively. An instantaneous loading rate of 0.1 inch/hr is
recommended for both soil units with a maximum application loading rate of 0.25 in/hr,
not to exceed 0.1 inches of total wastewater per hour. These application rates are
recommendations determined using in -situ KsAT measurements for the most limiting soil
horizon within seven feet of surface.
The findings presented herein represent TEC's professional opinion based on our Soil
Scientist Evaluation Report and knowledge of the current laws and rules governing
surface irrigation for on -site wastewater systems in North Carolina. The North Carolina
DWR must issue the final permit. Any concurrence with the findings of this report would
be made at this time. Soils naturally change across a landscape and contain many
inclusions. As such, attempts to quantify them are not always precise and exact. Due to
this inherent variability of soils and the subjectivity when determining limiting factors,
there is no guarantee that a regulating authority will agree with the findings of this report.
Carolina Malt House -Draft Report
Spray Irrigation System January 31, 2017