6013_GreenwayNorthMeckCDLF_20180110_WQMPResponse_DIN28715

January 10, 2018

Sent Via Email – [e-mail]
Mr. Mike Griffin
Greenway Waste Solutions at North Meck, LLC
19109 West Catawba Avenue, Suite 200
Cornelius, NC 28031

Re: Water Quality Monitoring Plan Updated August 14, 2017
North Mecklenburg C&D Landfill Infill Area and Closed Phase I Area
Mecklenburg County
Solid Waste Permit Number 6013
DIN 28715

Dear Mr. Griffin:

The Solid Waste Section (Section) has completed a review of the Water Quality Monitoring Plan dated August
17, 2017 (DIN 28684) and received on September 1, 2017. The plan was submitted on your behalf by CEC
Consultants, Inc. for the North Mecklenburg C&D Landfill (Infill Area and the Closed Phase I Area), NC Solid
Waste Permit Number 6013 and was included as part of the Permit Modification Amendment Application. The
Section issued a Determination of Completeness letter for the Permit Modification Amendment Application on
November 16, 2017 (FID 838911).

Within the Water Quality Monitoring Plan, CEC Consultants, Inc. has proposed to combine both the Active Infill
Area and the Closed Phase I Area together into one landfill for monitoring purposes. As stated within the Water
Quality Monitoring Plan, groundwater movement across the Active Infill Area is to the southeast toward the
on-site stream tributary along its southern boundary. Groundwater movement beneath the northern half of
the Closed Phase I Area is to the north and northwest toward the on-site stream tributary, and a local
groundwater divide is shown to bisect the Closed Phase I Area such that groundwater movement in the
southern half of this landfill area is to the southeast toward Cane Creek, which lies beyond the landfill property
boundary to the southeast.

Point of Compliance Wells
The proposed compliance monitoring network for the landfill would consist of 23 groundwater monitoring
wells designated as point of compliance (POC) wells at the relevant point of compliance as defined in 15A NCAC
13B .0544(b)(1)(B). It is also proposed that the Closed Phase I Area will meet the more stringent requirements
as designated in 15A NCAC .0545 instead of 15A NCAC 15A NCAC 13B .0503. While the landfill is in the
Assessment Monitoring Program, all the POC wells will be sampled for the Appendix II of 40 CFR constituents
and the C&D Parameters. Since POC wells in the Closed Phase I Area have not been sampled for Appendix II of
40 CFR constituents, a background sampling event will be conducted to determine the constituents requiring
future monitoring. The background event for the Closed Phase I Area will include constituents listed in
Appendix II of 40 CFR Part 258, and for mercury, chloride, manganese, iron, sulfate, alkalinity, total dissolved
solids, specific conductance, pH, and temperature.

The following lists the proposed POC wells:

POC Wells – Closed Phase I Area
MW-4, MW-4A, MW-4D, MW-6, MW-6D, MW-7, MW-7A, MW-7D, MW-8, MW-8D, MW-9, MW-10A,
MW-10D-1, MW-11B, and MW-11D.

POC Wells – Infill Area
MW-1(i), MW-2(i), MW-11(i), MW-11D(i), MW-12(i), MW-12D(i), MW-15(i), and MW-16(i).

Assessment Wells
Some groundwater monitoring wells for both the Active Infill Area and the Closed Phase I Area are proposed
to be Assessment wells added to the monitoring well network to characterize and delineate the groundwater
contamination. These Assessment wells do not include all the remaining groundwater monitoring wells at both
Areas of the landfill that are not designated as POC wells. Several existing groundwater monitoring wells are
proposed not to be sampled. In addition, the Water Quality Monitoring Plan states if that the landfill is
approved to return to the Detection Monitoring Program, only the proposed POC wells will be sampled and
the proposed Assessment wells will no longer be sampled.

The following lists the proposed Assessment wells:

Assessment Wells - Closed Phase I Area
MW-1, MW-5, MW-5D, MW-10, MW-10D, and MW-11.

Assessment Wells – Infill Area
MW-3(i), MW-4(i), MW-4D(i), MW-5(i), MW-5D(i), MW-6(i), MW-7(i), MW-7D(i), MW-8(i), MW-8D(i), MW-9(i),
and MW-9D(i).

Surface Water Monitoring Locations
Six surface water monitoring points have been routinely sampled along the on-site Cane Creek tributary that
separates the Closed Phase I and Active Infill Areas. The Water Quality Monitoring Plan states that SW-1, SW-
2, SW-3, and SW-4 are sampled along the tributary to evaluate the potential impact to surface water quality
from surface runoff or groundwater discharge from the two landfill Areas. Two additional surface water
monitoring points ,SW-inf and SW-eff, are located at the inlet (upstream) and outlet (downstream) areas of
the buried pipes that convey surface water beneath the Infill Area. Surface water samples will be analyzed for
the constituents listed in Appendix I of 40 CFR Part 258, mercury, specific conductance, pH, temperature, and
turbidity.

Based upon the information provided within the Water Quality Monitoring Plan, the semiannual monitoring
reports for both the Closed Phase I and Active Infill Areas, and the Assessment of Corrective Measures, the
Section is requiring modifications to the Water Quality Monitoring Plan to address the following
requirements to ensure compliance with the rules.

• There are currently no surface water monitoring locations monitoring the sidegradient and
downgradient surface water features near the Closed Phase I Area. Include additional surface water
monitoring locations associated with the Closed Phase I Area to be protective of human health and
the environment.
• The Section agrees with the proposal that the Closed Phase I Area shall meet the more stringent
requirements as designated in 15A NCAC .0545, and a background event will be conducted for the
Closed Phase I Area. This proposed monitoring approach will be protective of human health and the
environment.
• The Section does not approve the proposal to combine both the Active Infill Area and the Closed Phase
I Area into one landfill utilizing the proposed POC wells. Separate monitoring systems for each Area

are still required. As has been discussed for several years, it has not demonstrated that both the Active
Infill Area and the Closed Phase I Area are hydrogeologically connected. It also has not been
demonstrated that the vertical component of the groundwater contamination in the bedrock fractures
are interconnected between the Active Infill Area and the Closed Phase I Area.
• The Section does not approve the proposal for the two-different groundwater monitoring well sets
consisting of the POC wells and the Assessment wells. In addition, several existing groundwater
monitoring wells are missing from both proposed well sets. All existing groundwater monitoring wells
must continue to be monitored as the analytical data from all the existing wells are important for the
site conceptual model and for groundwater corrective action for both the Active Infill Area and the
Closed Phase I Area.
• Within 30 days of receipt of this letter, resubmit a Water Quality Monitoring Plan that reflects the
above-mentioned modifications that will be protective of human health and the environment.
• Within 45 days of receipt of this letter, resubmit the Assessment of Corrective Measures that will be
protective of human health and the environment and that reflects the above-mentioned modifications
to the Water Quality Monitoring Plan. The Assessment of Corrective Measures dated November 17,
2017 (DIN 28683) utilized the information and monitoring approach proposed in the Water Quality
Monitoring Plan.

If you have any questions, please contact me by email at [e-mail] or by phone at
828.296.4706.

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

cc sent via email: Ellen Lorscheider, Division Deputy Director
Jason Watkins, Field Operations Branch Head
Adam Ulishney, Environmental Compliance Branch Head
Deb Aja, Western District Supervisor
Teresa Bradford, Environmental Senior Specialist
Ed Mussler, Permitting Branch Head
Perry Sugg, Permitting Hydrogeologist
Larry Frost, Permitting Engineer
John Brown, Griffin Brothers
Ed Stephens, CEC, Inc.
Scott Brown, CEC, Inc.
Joe Hack, Mecklenburg County Solid Waste Management
Aaron Caudle, Mecklenburg County Solid Waste Management
Jack Simoneau, Town of Huntersville