4407_HaywoodCoMSWLF_ASDResp_DIN27868_20170608

June 8, 2017

Sent Via Email – rvail@santekenviro

Mr. Ron Vail, P.E.
Santek Environmental
650 25th St, NW Suite 100
Cleveland, TN 37311

Re: Alternate Source Demonstration for Total Metals in Groundwater
White Oak Landfill
Solid Waste Permit Number 4407-MSWLF-1993
DIN 27868

Dear Mr. Vail:

The Solid Waste Section (Section) has completed a review of the Alternate Source Demonstration for Total
Metals in Groundwater (DIN 26928) and submitted on behalf of Santek Environmental by Bunnell-
Lammons Engineering, Inc. (BLE) for the White Oak Subtitle D MSW Landfill, Solid Waste Permit Number
4407. The Alternate Source Demonstration was submitted in response to a Section letter titled Appendix
I Inorganic Constituent Exceedances dated August 8, 2016 (DIN 26550) and in accordance with 15A NCAC
13B .1633.

The White Oak Landfill’s groundwater monitoring system consist of two upgradient monitoring wells, nine
downgradient monitoring wells, four surface water sampling points, and a leachate lagoon sampling point.
BLE has performed groundwater monitoring at the facility since 2007 and during that time, 13 inorganic
constituents have been reported above the standards established in 15A NCAC 02L .0202(2L Standard) on
at least one occasion in one or more of the groundwater monitoring wells. As a result, BLE submitted an
alternate source demonstration(ASD) to prove that the inorganic constituents reported above the 2L
Standards are not a result of landfill impact.

BLE reviewed laboratory analytical results from the previous 16 years and observed that all 15 inorganic
constituents were reported in the background monitor wells. BLE also submitted soil samples collected
during the design hydrogeologic study for the phase 4 and 5 expansion. One soil sample from each of the
seven borings was submitted for laboratory analysis. The samples were collected at depths near the water
table and analyzed for Appendix I metals by EPA Method 6010. The soil analytical results indicated that
cadmium, selenium, silver, and thallium were the only constituents not reported in the soil samples. BLE
deduced that those constituents may be present in the soils, but at levels below the laboratory reporting
limits.

BLE concluded that all 15 Appendix I constituents that have been detected at the facility are a result of
naturally occurring conditions based on background monitor well and soil sample analytical data. The
presence of antimony, arsenic, beryllium, chromium, cobalt, copper, lead, vanadium, and zinc in both the
upgradient groundwater samples and soil samples serves as suitable evidence to support the conclusion
of those constituents as naturally occurring. A 2L Standard or an interim maximum allowable
concentration (IMAC) has been established for each of those constituents, so BLE should calculate a
statistical background level in accordance with 15A NCAC 13B .1634 (g)(5) for each constituent.

Since cadmium, selenium, silver, and thallium were not reported at detectable concentrations in the soil
samples, another supplemental line of evidence is needed to confirm those constituent concentrations
are a result of natural conditions. The supplemental line of evidence should meet the criteria listed in
https://ncdenr.s3.amazonaws.com/s3fs-
public/Waste%20Management/DWM/SW/Field%20Operations/Environmental%20Monitoring/NCSWSG
uidelinesForASD2017.pdf. Statistical background concentrations for cadmium, selenium, silver, and
thallium should also be calculated if the supplemental line of evidence validates the exceedances. In
addition, barium and nickel were reported at concentrations identified as statistically significant, so
statistical background levels should also be calculated for those two constituents to determine if the
elevated concentrations are a result of landfill impact. Please submit an addendum to this ASD containing
the requested information within 120 days of receiving this letter.

If Santek Environmental chooses not to submit an ASD addendum, the facility 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 919.707.8288. Thank you for your continued cooperation with this
matter.

Sincerely,

Ervin Lane
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
Deb Aja, Western District Supervisor
Lee Hill, Environmental Senior Specialist
Ed Mussler, P.E., Permitting Branch Head
Elizabeth Werner, Permitting Hydrogeologist
Ming Chao Permitting Engineer
Andrew Alexander, P.G., Bunnell Lammons Engineering,