1107_BuncombeCounty_MSWLF_Subtitle D_ASDResponse_DIN28173_20170712

July 12, 2017

Sent Via Email - [e-mail]

Mr. Stephen Hunter
Buncombe County
Interim Solid Waste Manager
81 Panther Branch Road
Alexander, NC 28701

Re: Alternate Source Demonstration
Buncombe County Subtitle D MSW Landfill
Buncombe County
Solid Waste Permit Number 1107-MSWLF-1996
DIN 28173

Dear Mr. Hunter:

The NC Solid Waste Section has completed a review of the Alternate Source Demonstration dated January
3, 2017 (DIN 27396) and submitted on behalf of Buncombe County by SCS Engineers, PC for the Buncombe
County Subtitle D MSW Landfill, Solid Waste Permit Number 1107-MSWLF-1996. The Alternate Source
Demonstration was submitted in response to a NC Solid Waste Section letter titled Appendix I Inorganic
Constituent Exceedances dated August 8, 2016 (DIN 26545) and in accordance with 15A NCAC 13B .1633.

The Alternate Source Demonstration includes a geological review, total and dissolved metals groundwater
sampling, and statistical analyses using historical baseline groundwater data and compliance monitoring
data from upgradient and downgradient groundwater monitoring wells. The metals antimony, arsenic,
barium, beryllium, cadmium, chromium, cobalt, iron, lead, manganese, nickel, thallium, and vanadium
have been detected above the NC regulatory groundwater standards. In addition, the metals arsenic,
barium, beryllium, cadmium, chromium, cobalt, copper, lead, nickel, vanadium, and zinc were all detected
in the baseline sampling events prior to the beginning of waste operations.

Based upon the information provided within the County’s Alternate Source Demonstration, the NC Solid
Waste Section is requiring additional information to be submitted in an Alternate Source Demonstration
Addendum. Within 120 days of receipt of this letter, please submit an Alternate Source Demonstration
Addendum that meets all the criteria described in the NC Solid Waste Section guidance document titled
NC Solid Waste Section Guidance for Alternative Source Demonstration Submittals for Solid Waste
Management Facilities - 2017.

Within the Alternate Source Demonstration Addendum, Buncombe County should provide the following:
 Determine if a new background monitoring well should be installed and/or if the groundwater
sampling procedures should be changed for this landfill and/or if the groundwater monitoring
wells at the landfill should be periodically developed to reduce the impact of suspended sediment.
 Determine if seasonality plays a role.
 Turbid samples will not be accepted to calculate new background levels. Statistical background
levels derived from turbid samples may not accurately reflect background conditions. Statistical
background levels should be calculated using monitoring data where the turbidity values are less
than 10 Nephelometric Turbidity Units (NTUs). Turbidity measurements must be submitted along
with the sample data to demonstrate whether suspended sediments are playing a role.
Buncombe County should calculate statistical background concentrations using analytical data
from a minimum of 10 groundwater samples with turbidity values less than 10 NTUs. If there is
an insufficient number of previous background samples with turbidity values less than 10 NTUs
or no field notes to verify the turbidity values, Buncombe County should establish a temporary
groundwater monitoring schedule to collect the required minimum number of samples from the
background well within a two-year period, and turbidity values should be recorded and submitted
to the NC Solid Waste Section during the temporary monitoring period.
 If utilizing Upper Tolerance Limits to establish new background levels for the constituents of
concern, calculations should follow the distribution hierarchy preference.
 If statistical outliers have been detected, review the values to determine if they should be
removed from the data set or are representative of background and should be retained for
statistical analysis. Provide technical reasons why a statistical outlier should be included or
excluded from either groundwater background data sets.

If Buncombe County chooses not to submit an Alternate Source Demonstration Addendum, the landfill
will be required to initiate Assessment Monitoring in accordance with 15A NCAC 13B .1634. If you have
any questions or concerns regarding this letter, please feel free to contact me by email at
[e-mail] or by phone at 828.296.4706. Thank you for your continued
cooperation with this matter.

Sincerely,

Jaclynne Drummond
Compliance Hydrogeologist
Solid Waste Section, Division of Waste Management
NCDEQ

cc sent via email: Ellen Lorscheider, Solid Waste Section Chief
Jason Watkins, Field Operations Branch Head
Ed Mussler, Permitting Branch Head
Deb Aja, Western District Supervisor
Perry Sugg, Permitting Hydrogeologist
Kris Riddle, Environmental Senior Specialist
Allen Gaither, Permitting Engineer
Ed Hilton, SCS Engineers
Jon Creighton, Buncombe County