wq0005910_NOV-2018-LV-0839 Response_20190524 (2)

Avoca, LLC
The World's Premier Botanical Extraction Company
May 24, 2019
Mr. Robert Tankard
Assistant Regional Supervisor
Water Quality Operations Section
Washington Regional Office
943 Washington Square Mall
Washington, NC 27889
Subject: Response to Notice of Violation NOV-2018-LV-0839
Groundwater Quality
Ashland, LLC
Permit No. WQ0005910
Bertie County
Dear Mr. Tankard,
Avoca, LLC
PO Box 129
841 Avoca Farm Rd
Merry Hill, NC 27957
Phone: [phone]
Fax: [phone]
This letter serves as a follow-up response to the NOV that was issued on November 27, 2018 total
ammonia in Well MW -8 and nitrate nitrogen in MW -4 being above the groundwater standard. As we
had discussed previously, Avoca, LLC did consult a certified licensed geologist to review the issues and
report recommendations on this issue. Avoca, LLC hired Groundwater Management Associates (GMA)
and consulted with Mr. Kelly Smith, Project Hydrogeologist on reviewing the water levels in all
monitoring wells on site as well as mapping the flow of groundwater. Mr. Smith's final report is attached
with this letter.
According to GMA's research the following was, determined:
1) Well MWS, placed downgradient of Spray field 4, does not exhibit exceedances of the
groundwater quality standards for nitrate or ammonia, indicating that local wastewater
application at spray field 4 is not a source of groundwater standards exceedances for those
constituents.
Well MW4 has a history of groundwater standard exceedances for nitrate. This well lies across
an unnamed tributary of Salmon Creek from spray field 4. The unnamed tributary is a
groundwater discharge area for the Surficial Aquifer. Therefore, MW4 is not within the same
local groundwater system as spray field 4. Elevated nitrate concentrations observed at MW4 are
more likely associated with farming activities on, immediately adjacent properties to the south.
GMA's opinion is that the groundwater quality conditions exhibited by MW4 are a background condition
that is not associated with wastewater application at spray field 4.

2) spray field 5 has two local monitoring wells (MW7 and MW8) that lie side gradient and
downgradient (respectively) from spray field S. However, spray field Slacks a local upgradient
monitoring well to constrain the direction and gradient of groundwater flow in the area.
Furthermore, without a local upgradient monitoring well northwest of spray field 5, GMA cannot
determine the background concentrations of constituents of concern. Without this information,
we cannot determine if the reported ammonia concentrations at MW8 are associated with
wastewater application to spray field 5 or if the ammonia is related to background conditions
associated with farming activities north and west of spray field 5.
Therefor Avoca, LLC would propose to follow recommendations from GMA along with your guidance:
1) Construct one new monitoring well on the north-northwest side of spray field 5. This monitoring
well will serve as a local upgradient well to constrain the local groundwater flow direction and
gradient and to establish the background water -quality conditions in the area.
2) Survey the location and elevation of the top of the well casingforthe new monitoring well.
3) Conduct an updated monitoring event to include water level measurements and water -quality
sampling of all wells.
4) Utilize the new monitoring data to refine the groundwater flow understanding as well as to
determine the background water -quality near spray field 5.
5) If background monitoring near spray field 5 indicates that the ammonia at MW8 is associated
with wastewater irrigation activities, then steps should be taken to improve water treatment to
reduce TKN in the effluent before the effluent is land applied.
As always, Avoca, LLC wishes to work closely with NCDEQto continue to maintain compliance in all
aspects of its facility. Please let me know if you agree with the proposal and the installation of a new up
gradient monitoring well for field 5. Please do not hesitate to contact me with any comments or
questions.
Sincerely, n
Ccv'�V
Brian Conner
EHS Manager
Avoca, LLC/Ashland, LLC