1107_BuncombeCountyMSWLF_ASDAddendumExt_DIN28627_20171031

Environmental Consultants 5850 South Semoran Blvd. 407 204-3231 and Contractors Orlando, FL 32822 www.scsengineers.com
October 31, 2017 File No. 09204072.15
Jaclynne Drummond
Solid Waste Section- Division of Waste Management North Carolina Department of Environmental Quality 2090 US Hwy 70 Swannanoa, NC 2878
Re: Alternative Source Demonstration Addendum, Buncombe County Landfill, Buncombe County, Solid Waste Permit Number 1107-MSWLF-1996, DIN 28173
Dear Ms. Drummond:
On behalf of Buncombe County Solid Waste Section, SCS Engineers, PC (SCS) submits the following response to the Alternative Source Demonstration letter dated July 12, 2017 regarding
the Buncombe County Subtitle D MSW Landfill, Solid Waste Permit Number 1107-MSWLF-1996.
After reviewing the baseline and compliance monitoring well metals data and removing data associated with a turbidity of 10 NTUs or greater, it has been determined that the resulting data
set for the baseline monitoring well MW-1 has nine (9) valid groundwater samples or data
points. This does not satisfy the criteria of a minimum data set of ten (10) groundwater samples and therefore would make any statistical analysis of these data invalid.
The number of data points needed for the baseline monitoring well can be collected without deviating from the current groundwater sampling schedule in the two year period suggested by
NCDEQ in the Alternative Source Demonstration letter. Further, we believe that deviating from
the current semi-annual monitoring plan could introduce statistical bias to the data set.
The Fall 2017 groundwater sampling for this site has recently been completed. In order to reduce turbidity levels, the low-flow method was applied for this round of sampling. This method successfully reduced the turbidity to below 10 NTUs in all of the monitoring wells
sampled with this method. SCS plans to use this method for future groundwater sampling to
meet the turbidity criteria put forth by NCDEQ.
As we are still awaiting laboratory results from the fall 2017 sampling event, we respectfully request an extension of 90 days to submit the Alternative Source Demonstration Addendum.
Please contact the undersigned if you have any questions.
Sincerely,
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