WQ0003824_More Information (Requested)_20190708

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
LINDA CULPEPPER
Director
TONYA A. MANN — UTILITIES DIRECTOR
CITY OF GRAHAM
POST OFFICE DRAWER 357
GRAHAM, NORTH CAROLINA 27253
Dear Ms. Mann:
NORTH CAROLINA
Environmental Quality
July 8, 2019
Subject: Application No. WQ0003824
Additional Information Request
City of Graham Residuals Land
Application Program
Land Application of Class B
Residuals
Alamance County
Division of Water Resources' Central and Regional staff has reviewed the application package
received May 10, 2019. However, additional information is required before the review may be completed.
Please address the items on the attached pages no later than the close of business on August 7, 2019.
Please be aware that you are responsible for meeting all requirements set forth in North Carolina
rules and regulations. Any oversights that occurred in the review of the subject application package are
still the Applicant's responsibility. In addition, any omissions made in responding to the outstanding items
in Sections A through C, or failure to provide the additional information on or before the above requested
date may result in your application being returned as incomplete.
Please reference the subject application number when providing the requested information. All
revised and/or additional documentation shall be signed, sealed and dated (where needed), with two paper
copies and one electronic copy submitted to my attention at the address below.
If you have any questions regarding this request, please do not hesitate to contact me at (919) 707-
3659 or [e-mail]. Thank you for your cooperation.
Sincerely,
XSaunders, YEric Engineer
Division of Water Resources
cc: Winston-Salem Regional Office, Water Quality Regional Operations Section (Electronic Copy)
Permit Application File WQ0003824
�7 North Carolina Department of Environmental Quality I Division of Water Resources
_ J� 512 North Salisbury Street 11617 Mail Service Center I Raleigh, North Carolina 27699-1617
g+Z091.1-0 919.707.9000

Ms. Tonya A. Mann
July 8, 2019
Page 2 of 3
A. Application:
Item III.4.b. of the submitted Residuals Land Application Program (RLAP 06-16) application states
that there is 13.1 acres of incorporation/injection fields. However, the areas of two
injection/incorporation fields, NC-AM-01-08 and NC-AM-0I-10, is 13.8 acres according to the
previous permit. Please clarify if there have been any changes to these fields which would affect
their areas since the previous permit. Please also see C.1. of this request regarding the area of field
NC-AM-01-10.
2. Item III.7 of the RLAP 06-16 application claims that this is a non -dedicated system. However,
based on the cover page of the previous permit, this is a dedicated system. Resubmit page 3 of the
RLAP 06-16 form to show that it is a dedicated site due to the residuals land application and submit
the supporting documentation (i.e. the Program Information and Site Maps as listed in the RLAP
06-16 instructions page).
3. The Status Codes of the fields in the Land Application Site Certification (LASC 06-16) form are
all listed as new. Please clarify whether this was a typo or if there are any changes to the permitted
fields from the previous permit.
4. There was not a Residuals Source Certification (RSC 06-16) application submitted for either
residuals source. Submit the RSC 06-16 form and all associated documents as listed in the
instruction pages for the water and wastewater treatment plants individually.
B. Ap-ronomic Evaluation:
Item III.5.c. of the RLAP 06-16 application states that more than 81.9 acres of surface application
area is required for a plant available nitrogen (PAN) application rate of 200 lbs. PAN/ac-yr.
However, there are only 71.3 acres of total application area from existing fields, 58.2 acres of
surface application and 13.8 acres injection/incorporation application. It is unclear whether the
permitted area of land will be enough to maintain agronomic loading of the permitted 855 annual
dry tons of residuals applied onto the fields given the nutrient data provided.
In accordance with 15A NCAC 02T .11109(a)(1)(K), residuals shall not be land applied if the
application exceeds agronomic rates. Provide an explanation of how agronomic application rates
will be maintained with the permitted volumes of residuals as listed on Attachment A of the October
27, 2014 permit. This explanation must include calculations proving that application rates of PAN
do not exceed agronomic rates at the permitted volumes of residuals.
If agronomic rates are found to be exceeded, either a plan to meet agronomic rates or an application
meeting the requirements of 15A NCAC 02T .1104(d) to allow application at greater than
agronomic rates as stated by Condition II.10. of the October 27, 2014 permit shall become a
schedule of the new permit.
C. Site Man:
1. A recent site visit to evaluate the dedicated land application fields found that there are two locations
within field NC-AM-0I-10 where the seasonal high water table (SHWT) is between 4-10 inches.
In accordance with 15A NCAC 02T .11090), there must be at least one foot of separation between
the depth of residuals application and the SHWT. The attached site map shows the two unsuitable

Ms. Tonya A. Mann
July 8, 2019
Page 3 of 3
land application locations in the red hash marks. A revised site map for Field NC-AM-01-10 shall
be submitted with the updated acreage for the field included.
D. Recommendations: (Response not reguired)
The methods of finding the PAN concentration for the water treatment plant (WTP) and wastewater
treatment plant (WWTP) residuals are correct, but the weighted average is incorrect and overreports
the PAN concentration in the residuals. The combined PAN concentration calculation method in
the submitted application, which is reported in the section III.4.a. of the RLAP 06-16 form, does a
weighted average of the inputs of the system PAN equation, like the Total Kjeldahl Nitrogen values,
the ammonia values, the nitrate values, and the mineralization rates. However, the weighted average
of the mineralization rate does not reflect the actual mineralization rate of the two separate residuals
and skews the final result of the PAN concentration. Instead, the weighted average should be
performed on the PAN concentration outputs for the WTP and WWTP residuals. For instance, in
the case of the I't Year surface pounds of PAN per dry ton:
lb PAN lb PAN lb PAN
PAN = 0.65 * 23.0 +0.35*9.0 =18.1
dry ton dry ton dry ton
The I' year PAN concentration in the case of surface disposal was found to be 19.1 lb PAN
dry ton . As you
can see, the method from the application reports a larger PAN concentration. Items III.4.a. and
IIL4.c. of the RLAP 06-16 form can be amended to correct these discrepancies.

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