8602_SurryCountyMtAiry_CDLFOverMSWLF_ASDAddendumRequest_DIN28727_20180125

Emailed: January 25, 2018
Ms. Jaclynne Drummond
Solid Waste Section (SWS)
Division of Waste Management
North Carolina Department of Environmental Quality
2090 US Highway 70
Swannanoa, NC 28778
Re: ASD Addendum Workplan/Timeline -Metals
Surry County Landfill
Permit No. 86-02 and 86-06
MESCO Project No. G17014.0
Dear Ms. Drummond,
On behalf of Surry County, Municipal Engineering Services Company, P.A. (MESCO) intends to submit
an Alternative Source Demonstration (ASD) Addendum in fulfillment of the request outlined in a letter
issued by the NC Solid Waste Section (SWS) dated July 6, 2017 (DIN:28119). The ASD Addendum will
address metals detected in groundwater samples collected at the Surry County Landfill. To satisfy
turbidity level criteria described in the guidance document, that was revised since the original ASD was
drafted, we request that a phased approach be taken. We request approval of a temporary monitoring
schedule in order to collect additional background samples with turbidity values less than 10 NTUs which
maybe used to statistically derive site-specific groundwater protection Standards.
We intend to perform analysis of water samples for Appendix I metals collected from wells located
hydraulically up-gradient of waste units. At least 10 samples with a turbidity less than 10 NTUs will be
used in the statistical analysis to develop new site-specific Standards. Samples may also be collected
during other seasons rather than the routine Spring and Fall to account for potential seasonality. In
addition to designated background well at the lined (MW-1) and adjacent closed landfill (MW-1) samples
may also be collected from other up-gradient locations to better account for spatial variability of naturally
occurring metals. Several observation wells that are suitable to obtain background data are located west
of the existing lined landfill (OW4-) which have been installed in support of a hydrogeologic Design
Study for lined Phase 4.

Additional background samples may be tested from “OW4-” wells that are screened entirely in bedrock
which is consistent with the vast majority of down-gradient wells or beyond a 150 foot up-gradient
periphery of the lined landfill to improve certainty that the area has not been impacted.
Any well designated by “OW4-”, with the exception of OW4-16 and OW4-18, may be tested as shown on
a potentiometric map as Sheet 1. Each sample will be collected using methodology contained in the
Water Quality Monitoring Plan and generally consistent with previous and future events. Slow recharge
rates are expected which may necessitate up to 24 hours between purge and collection to allow recharge
to reach 90% of static which provides a more representative sample.
Turbidity levels will be quantified for each metal sample in a manner that meets or exceeds requirements
of EPA Method 180.1. Our research indicates that field turbidity measurements are more accurate than in
the lab since levels may increase over time.
The background data collected during the temporary monitoring period will be reported to the SWS along
with the routine water quality monitoring reports submitted semi-annually.
We request SWS approval of a time extension of two years (November 2, 2019) so we may have time to
collect and further evaluate the data. The ASD-Addendum is planned to be submitted in 2020.
Please respond in writing so we can plan accordingly. If you have any questions or need any additional
details please contact us at [phone] or by email at [e-mail] or [e-mail].
Sincerely,
MUNICIPAL ENGINEERING SERVICES CO., P.A.
Jonathan Pfohl
Senior Environmental Specialist
cc: Mr. Dennis Bledsoe
[e-mail]
Surry County
2