NCG020943_Review of Hydrogeologic Issues_20190620

REVIEW OF HYDROGEOLOGIC ISSUES RELATED TO THE PROPOSED
ALAMANCE AGGREGATES QUARRY
SNOW CAMP
ALAMANCE COUNTY, NORTH CAROLINA
by
Alan Barry Nelson, PG
President and Chief Hydrogeologist
y No=w:--,.,,
P.Q. Box 6416, High Point, NC 27262
www.nort;hwestgaoscience.com
NCGeol ,"1CorporstA-ifcen"#442
Project No. ig-116

Table of Contents
INTRODUCTION
GROUNDWATER RESOURCES
3
3
General Considerations 3
Preliminary Hydrogeologic Investigation 4
Groundwater Monitoring Plan (Original and Revised Version) 6
Domestic Well Survey 7
SURFACE WATER RESOURCES 8
WETLANDS 8
CONCLUSIONS 9
REFERENCES CITED 11
APPENDIX A 12
APPENDIX B 13
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REVIEW OF HYDROGEOLOGIC ISSUES RELATED TO THE PROPOSED
ALAM[ANCE AGGREGATES QUARRY
SNOW CAMP
ALAMANCE COUNTY, NORTH CAROLINA
INTRODUCTION
Alamance Aggregates has filed a permit application with the North Carolina Department
of Energy and Mineral Resources (DEMLR) for a proposed rock quarry operation near
Snow Camp in Alamance County, North Carolina. The Snow Camp area is a rural area
that relies on groundwater resources for all domestic water supplies. There are no
municipal or community water systems in the area immediately surrounding the
proposed quarry and expansion of distribution systems from existing municipal or
community water systems is not economically viable. Therefore, protection of the
groundwater resources of existing and future homeowners in the area is of vital
importance. Water resource protection should be considered the most important issue
in determining the potential adverse impacts of the proposed mining operation. Due to
the importance of this issue, Northwest Geoscience, PC, (NWGS), a group of
professional hydrogeologic consultants, was retained to review documents and related
information concerning the proposed quarry and to evaluate the validity of the
hydrogeologic information and data submitted in support of the quarry permit
application. This review has been completed and the findings are presented herein. A
list of the documents and information reviewed by NWGS is provided in Appendix A.
The review was completed by Alan Barry Nelson, PG, president and Chief
Hydrogeologist of NWGS. Mr. Nelson's qualifications are presented in Appendix B.
This review includes comments on groundwater, surface water and wetlands.
GROUNDWATER RESOURCES
General Considerations
The adverse effects of large quarry operations are well documented in the literature. A
quick review identified many sites throughout the country where rock quarries have
caused a depletion of the local hydrologic systems including surface and groundwater
resources. This is due to the need to pump large quantities of groundwater from the
area of the quarry pit in order for the quarrying operation to "work in the dry." The
pumping of relief wells or sumps within the quarry pits causes the elevation of the local
water table to drop by tens to hundreds of feet in the quarry. As the local water table is
lowered in the pit, an area around the pit experiences a decline in the elevation of the
water table. This area of depression can extend many hundreds to a few thousand feet
from the dewatering wells around the pit depending on the rate of groundwater
withdrawal, the hydraulic and hydrologic characteristics of the groundwater system and
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geologic features in the area such as fractures, faults and discontinuities. Therefore, in
order to be able to predict whether the proposed quarry dewatering activities will have
any adverse effect on local groundwater resources, a comprehensive assessment of the
hydrogeologic and geologic framework of the area is required. This assessment must
also include testing of the groundwater system to determine hydraulic parameters such
as conductivity, transmissivity, storativity, distance-drawdown effects and yields, so that
a dewatering system can be designed that will allow for quarrying operations without
adversely affecting area groundwater resources.
It is important 'to understand that quarrying operations tend to continue over long
periods of time. In fact, the lifetime of the proposed Alamance Aggregate quarry is
approximately 50 years'. During the operation, as cited in the application , it will be
necessary to pump hundreds of thousands of gallons to dewater the quarry pit. The
groundwater withdrawal rate has been estimated at 500,000 gallons per day2.
However, no data has been supplied to substantiate this estimate. This estimate
contains no indication of whether this is the average withdrawal daily rate over the life
of the quarry, the rate of initial withdrawal or the maximum withdrawal rate.
Regardless of the initial withdrawal rate, the dewatering operation increase as the
quarry pit is expanded both vertically and horizontally. For this reason, the increased
groundwater withdrawal will, in all likelihood, result in the continued expansion of the
area of depressed water table elevations away from the dewatering wells or system.
Therefore, it is critical that a quantitative analysis of the hydrogeologic system of the site
be performed prior to permit review. These data are necessary to establish the required
rate of groundwater withdrawals at various periods in the life of the quarry so that
potential effect of dewatering activities on area domestic water supplies can be
adequately evaluated.
Preliminary Hydrogeologic Investigation
A review of the Preliminary Hydrogeologic Investigation3 by Reinhardt was conducted
by NWGS. This review identified the following issues that deviate from standard
methods of hydrogeologic investigations:
• No hydrogeologic field testing or data collection was completed to characterize
the hydraulic parameters of the groundwater and surface water resources of the
area.
® No data or calculations have been provided to indicate the various groundwater
withdrawal rates during the planned quarrying operation.
® No predictions have been presented, based on actual field data, to determine the
distance—drawdown relationship needed to assess whether and how local
domestic water wells will be impacted during the quarry operation.
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® The report incorrectly states that the maximum depth of the quarry will be 200
feet, rather than the 300 feet cited in the application.
® The report does not include any groundwater modeling to predict long term
effects of groundwater removal due to dewatering on the surrounding domestic
water supply wells.
® While the report shows the locations of local fractures, faults and geologic
discontinuities in the area, it does not address their potential effect on
transmissivity of the fractured rock aquifer.
® LIDAR maps provided by the NC Geological Survey4 indicate a series of linear
traces identifying probable local and faults fractures that trend generally
northwest to southeast. The mapping provided in the preliminary hydrogeologic
assessment by Reinhardt5 illustrates a set of fractures and faults in a generally
northeast to southwest trend. In cases where fracture sets intersect as these
would, groundwater flow in the fractured bedrock aquifer becomes even more
complex. Further, groundwater models become less accurate; therefore, even
more intensive field investigations and hydraulic testing are required to
understand the hydrologic and hydraulic characteristics of the area.
® The area of depressed water tables due to dewatering of the quarry pit can be
significantly skewed because of these fractures and faults due to the formation of
major and minor transmissivity tensors.
® The report does not present any type of water balance calculations to illustrate
whether the water pumped from the ground will be more than can be used on site
or whether any quantity will need to be wasted through discharge, nor how this
may affect area surface and groundwater supplies.
® While the report presents water quality data from other wells in the fractured
bedrock aquifer in the piedmont, it does not present any water quality data from
the four on -site bedrock wells referred to in the report.
® The report does not address any potential changes on water quality due to the
withdrawal of large quantities of groundwater over time.
® The comparison of other quarries and their effects on the groundwater regime is
baseless due to the following:
1. Because no detailed hydrogeologic data are presented for the proposed mine
due to the lack of a comprehensive hydrogeologic assessment, the critical
parameters of hydraulic conductivity, transmissivity, distance-drawdown
effects, proposed pumping rates, methods of dewatering, water budgets etc.
are unknown.
2. None of these hydraulic parameters were presented for the quarries used in
the comparison.
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® The statement that no drawdown effects would be experienced in domestic wells
beyond a distance of l000 feet of the quarry pit is completely unsupported by
actual data.
® Reinhardt's6 report references a hydrogeologic report by Carolina Geological
Services that has been requested by DEMLR and this reviewer but never received.
In conclusion, the preliminary hydrogeologic report prepared by Reinhardt is simply a
literature review. While not without a place as a portion of a larger evaluation, it is
woefully inadequate to provide the level of detailed assessment needed to identify any
negative effects of the dewatering of the pit on local water wells, groundwater supplies
and surface water bodies. The lack of actual field data and testing prevents any
scientifically -based conclusions concerning the potential effect of the proposed quarry
on local water supplies.
Groundwater Monitoring Plan (Original and Revised Versions)
A Groundwater Monitoring Plan was originally prepared by Reinhardt in 20187. A
revised plan was submitted in May 20198. Comparison of the two documents indicates
that the latter version provides new information concerning a limited well survey of the
area and a generalized discussion of quarry dewatering effects at other facilities in the
North Carolina piedmont.
The actual monitoring plan in the revised document is basically the same as the original
version. Because neither the plan nor any information provided by Alamance
Aggregates indicates the numbers or locations of dewatering wells or system, the actual
volume of water to be pumped from the dewatering wells or system as the operation
expands. Therefore, it is not possible, based on the provided information, to devise a
groundwater monitoring plan that can accurately address the effects of the dewatering
operation.
The proposed Groundwater Monitoring Plan is, therefore, wholly inadequate due to the
lack of a comprehensive hydrogeologic assessment on which to base a plan. Without
knowing the pumping rates, number of dewatering wells or system, and any calculations
or modeling results that determines the distance drawdown effects around the mine pit,
it is impossible to devise a monitoring plan capable of adequately providing the
necessary data to evaluate the on -going effects of dewatering of the groundwater
resources in the area and the potential impact on groundwater users in the area.
Multiple well nests that monitor the shallow water table aquifer, intermediate depths of
the fractured rock aquifer and the deep aquifer below the bottom of the pit are needed to
monitor the aquifers as the operation proceeds. The data collected from these wells
should be maintained and the long-term effects of the dewatering reviewed on a
quarterly basis to track the actual effect on the groundwater levels in the three water

bearing zones and project distance-drawdown effects to allow for adequate and timely
intervention should the area of influence of the dewatering system indicate local
domestic water wells are at risk.
The proposal to collect groundwater levels on a monthly basis falls short of current
hydrogeologic best practice. Low cost electronic water level data recorders that can be
programed to collect water levels at short time intervals are available and should be
installed in all the groundwater monitoring wells. The data from the loggers should be
maintained for review and inspection by the regulatory agencies on a regular basis.
The plan does not include any water quality monitoring. Baseline data should be
collected prior to the initiation of the dewatering and at least quarterly thereafter from
the monitoring wells, particularly those wells installed within the water bearing zones,
areas impacted by washing operations, and downstream of wasting/discharge areas.
The plan should identify the proposed sampling procedures and analytical parameters,
the certified laboratory to provide the analytical testing, and the consultant responsible
for evaluating the test results.
All reports should be submitted to the Alamance County Health Department, DEMLR,
and the Office of Water Resources. An annual report compiling and reviewing the
previous year's data should be submitted.
The revised plan includes a proposed "adverse impact letter" of notification to area
domestic groundwater users indicating that, in the event it is shown that the activities of
Alamance Aggregates has adversely affected domestic wells in the area, the company
will take measures to address the problem. While this is a positive proposal, it does not
indicate how or who will make the determination that the quarry activities were the
cause of the impacts, or how the problems will be solved. Therefore, it is unclear how
"adverse impacts" would actually be handled. Without more specificity regarding
remedies to potentially negative water usage or water quality impacts, area water users
remain at risk.
Domestic Well Survey
A survey of local domestic wells was provided with the May 28, 2o199 reply from
Alamance Aggregates. It has been estimated that nearly one hundred homes with
domestic wells are located within a distance of 1500 feet of the edge of the planned
quarry pit where dewatering will likely be centered. DEMLR requested information on
these wells in their response letter to Alamance Aggregateslo. Questionnaires were sent
to homeowners within a 15oo®foot radius of the pit. Out of a total of 89 properties that
were identified, only 41 responses were received. Attempts to obtain information on
properties that did not respond were unsuccessful. While questionnaires are helpful,
they place the responsibility of providing the critical information fully on the domestic
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well owner. Often, the well owner does not have the information such as well depth,
casing depths, pump capacity, yield, etc. readily available. Therefore, it is necessary to
obtain data from those individual wells in cases where the owner either did not reply to
the questionnaire or was unable to provide the needed data. If it becomes necessary for
the applicant to obtain these data directly in the field, it should be collected. All
information should be summarized in a database or GIS system that is easily accessible
so that, in the event the groundwater monitoring system indicates potential adverse off -
site effects of the dewatering, the local domestic well users can be identified and
advised.
Evaluation of the responses indicates that 12 wells have depths between 5o and 150 feet,
15 wells have depths between 15o and 250 feet, and 16 wells have depths greater than
250 feet. The casing depths ranged from 20-63 feet below ground surface, illustrating
the variability in the depth to fractured rock. Well yields varied from 2 gallons per
minute (gpm) to 10o gpm. Of the 43 wells on which data were provided,19 had yields of
2-10 gpm, 16 yielded 10-20 gpm and 8 yielded greater than 20 gpm. Well yields
reported by drillers are typically very inaccurate. Long-term pump tests are not
required when a domestic well is drilled. Therefore, short-term performance tests
typically exaggerate the actual yield of the aquifer. Further, deeper wells have
significant borehole storage that further complicates the actual determination of the
aquifer yield to the well.
SURFACE WATER RESOURCES
There are several perennial and intermittent streams located within or adjacent to the
proposed quarry property. These are first and second order streams with limited
drainage areas. It is certainly a possibility that the dewatering operation will intersect
the baseflow of the groundwater that discharges to these streams. If this occurs, the
streams would lose their source of water and go dry. There have been no data provided
or assessment performed to assess the potential effect of the dewatering on these
streams or other surface water bodies in the vicinity. In fact, surface water resources
have not even been identified as an area of possible concern. This deficiency clearly
requires investigation and assessment. It can easily be completed through a
comprehensive investigation of the hydrogeological system near the planned facility and
through standard computational means or computer modeling.
WETLANDS
Numerous wetland areas have been identified by the consultant" for Alamance
Aggregates. These have been reviewed and deemed as jurisdictional by the US Army
Corps of Engineers. The current plan will destroy these wetlands and as mitigation,
Alamance Aggregates will purchase wetlands through the wetland banking program.
While this is within their rights and fully complies with the wetland regulations, the
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result is still a net loss of wetland resources in the Piedmont. This practice virtually
guarantees a continued loss of smaller wetland resources, results in degraded water
quality of local streams and further reduces wetland habitat. All efforts should be made
to require Alamance Aggregates to identify suitable wetland resources within Alamance
County in order to mitigate the wetland losses that occur due to their planned activities.
CONCLUSIONS
At this time, NWGS concludes that there remains a complete lack of hydrogeological
assessment of the proposed mining operation and an incomplete and baseless
monitoring program. Specifically, the application is woefully inadequate due to the
following major deficiencies:
® It does not include any quantitative hydrogeologic data from any type of
groundwater pumping tests or modeling, both necessary steps that are
critical in evaluating potential distance-drawdown effects from the
dewatering on local residential wells.
® It does not indicate the method of dewatering the pit, the number or
location of any dewatering wells or system.
® It does not provide any field data as a basis for determining the actual
volume of water required to be pumped to allow for the quarry operation
to proceed.
® It does not include any water quality data or provide a plan for monitoring,
evaluating and addressing water quality issues.
® It does not address potential effects on the surface water bodies near the
property.
® It does not outline a groundwater monitoring program that is capable of
adequately assessing the impact of dewatering, due to a complete lack of
hydrogeologic data and a lack of a proposed design for a dewatering
system.
® It does not properly address remedies for local domestic well users in the
case that their wells are adversely affected by the quarry operation.
It should also be noted that the lack of key information cited herein was described in the
December 2018 response letter to Alamance Aggregates from NCDEMLR and the
information was requested to be provided within six months. Unfortunately, the recent
response by Alamance Aggregates (May 2019)11 still does not provide the requested
hydrogeological information. This brings to question whether the company plans to
comply with the request or whether NCDEMLR should even consider the permit due to
a lack of the needed information to properly review the application.
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Finally, it deserves repeating that Alamance County does not have a comprehensive
water supply for the rural areas in the county. Further, no local community well
company provides water in the vicinity of the area. The Alamance County
Commissioners have stated unequivocally that, in the case the domestic wells are
adversely affected by the dewatering of the quarry at any time in the future, no
alternative water supply is available. Therefore, common sense calls for submittal of a
comprehensive hydrogeological assessment by Alamance Aggregates, as requested by
NCDEMLR, in order to process its mining application. If this information is not
provided, NCDEMLR should deny the permitting of the proposed quarry.
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REFERENCES CITED
'Letter Response to NCDEMLR dated May 30, 2019 from Alamance Aggregates.
AAlamance Aggregates Mining Permit Application dated September 28, 2018.
3>5,6Preliminary Hydrogeologic Investigation of the Proposed Alamance Aggregates
Quarry, Snow Camp, Alamance County, North Carolina by Christian Reinhardt, PG
dated September 22, 2018.
4Personal Communication from Dr. Ken Taylor, PG, NC Geological Survey.
GGroundwater Monitoring Plan for the Proposed Snow Camp Quarry, Snow Camp,
Alamance County, North Carolina by Christian Reinhardt, PG dated September 22,
2018.
$Revised Groundwater Monitoring Plan for the Proposed Snow Camp Quarry, Snow
Camp, Alamance County, North Carolina by Christian Reinhardt, PG dated March 22,
2019.
9Survey of Wells Within 1500 feet of the Proposed Alamance Aggregate Quarry, Snow
Camp, NC.
IOResponse Letter to Alamance Aggregates Mining Permit Application from NCDEMLR
dated December 21, 2018.
"Wetland Identification Map for the Proposed Alamance Aggregates Quarry, Snow
Camp, NC by Brown Associates.
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APPENDIX A
LIST OF DOCUMENTS REVIEWED BY
NORTHWEST GEOSCIENCE, PC
RELATED TO ALAMANCE AGGREGATES PROPOSED QUARRY, SNOW
CAMP, NC
• North Carolina Mining Permit Application from Alamance Aggregates dated
Septmeber 28, 2018.
• Groundwater Monitoring Plan for the Proposed Snow Camp Quarry, Snow Camp,
Alamance County, North Carolina: Robert C. Reinhardt, PG, September 22, 2018.
• Public Hearing Oral Comments 2018
• Public Hearing Summary 2019
• Written Comments Alamance Aggregates
• Alamance Aggregates Vibration and Sound Study
• Review Comments from North Carolina State Agencies
• Letter to Alamance Aggegtates from NC DEMLR dated December 21, 2018
Requesting Additional Information
• Maps and Information provided by Dr. Ken Taylor to Jane Lea Hicks
• Alamance Aggregates Quarry and Construction Materials Engineering Plans
dated September 24, 2018 by LaBella Associates
• Review Sheet for Alamance Aggregates Proposed Snow Camp Quarry
• Alamance Aggregates Written Response to NC DEMLR dated May 30, 2019 with
26 attachments
• Preliminary Hydrogeologic Report by Christian Reinhardt dated September 22,
2018
• Wetland Evaluation by Brown's Environmental Group and Letter of Findings
from US Army Corp's of Engineers
• Domestic Well Survey Results for areas within 1500 feet of Proposed Quarry
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APPENDIX B
Curriculum Vitae
ALAN BARRY NELSON, LG
President and Chief Hydrogeologist
Northwest Geoscience, PC
P.O. Box 6418
High Point, North Carolina 27262
336 885 4381
SUMMARYOF PROFESSIONAL EXPERIENCE
Mr. Nelson has over 32 years of diversified professional experience in water resource consulting including ground -water resource
and pollution investigations, surface water resource evaluation, storm water evaluations for industrial and commercial sites,
physical and chemical hydrogeology, reservoir management and dam safety evaluations. He also has extensive experience in surface
water hydrology, hydrometry, stormwater management and fluvial geomorphology. Mr. Nelson has modeling experience using HEC
1, HEC 2 and HMS. His application of hydrologic analysis to waste management problems including underground storage tank
releases plus solid and hazardous waste remediation, have led to the cleanup and restoration of numerous sites throughout North
and South Carolina. Mr. Nelson has applied his knowledge of the geology of the southern Appalachian and coastal plain regions to
engineering projects ranging from major expressways and bridges in West Virginia to large structures including high rise buildings
and schools in North Carolina. Additionally, he has also conducted over 200 Phase I and II Environmental Site Assessments, Mr.
Nelson was instrumental in developing an Environmental Consulting Group within an existing geotechnical consulting company in
1985 and managed the group for 19 years. In this capacity, he was responsible for staff training and development, business
development, technical oversight and financial management of the group. Finally, Mr. Nelson has authored numerous research
papers for professional journals, is a regular speaker at college and university environmental and engineering geology classes, and
has provided expert witness testimony on issues dealing with surface and groundwater issues as well as waste management and
geologic hazards in numerous court cases. He is also an instructor in the USEPA Brownfields Program at Durham Technical
Community College.
FIELDS OF SPECIALIZATION
Environmental Geology; Restoration and remediation of solid and hazardous waste sites; Ground -water hydrology, fluvial
geomorphology, hydraulic and hydrologic analyses, dam safety evaluations, stormwater management, Industrial Stormwater
Permiting and Best Management Practices, wetland evaluations, FEMA flood insurance studies, slope stability analyses, solid and
hazardous waste management, pollution control and remediation, environmental investigations and monitoring and engineering
geology.
PAST AND CURRENT PROFESSIONAL AFFILIATIONS
Geological Society of America
Association of Groundwater Scientists & Engineers
Association of Engineering Geologists
Carolina Geological Society
American Institute of Professional Geologists
American Society of Civil Engineers
Board of Directors, Piedmont Land Conservancy
Instructor, Durham Technical Institute
USEPA Brownfields Program
PROFESSIONAL REGISTRATIONS
Licensed Professional Geologist in North Carolina (#o165)
Registered Professional Geologist in South Carolina (#825)
Certified Professional Geologist in Virginia (#276).
EMPLOYMENT HISTORY
Northwest GeoScience, PC, President and Chief Geologist
High Point, NC (2009-present)
Engineering Tectonics P.A., Chief Geologist
Winston-Salem, NC (1985 —1991 & 1997 - 2008)
Bain, Palmer & Associates, Senior Hydrologist
Greensboro, NC (1991 — 1997)
Black & Veatch Engineers, Staff Hydrologist
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Former Chairman Guilford Co. Board
for Environmental Quality
Instructor, Forsyth Technical Institute
USEPA Brownfields Program
Scientist in the Classroom Program, Forsyth
County Schools & GSA
Board of Directors, Guilford County
Partners in Public Health
Piedmont Land Conservancy Board
Of Directors

Asheboro, NC (1979 —1985)
US Geological Survey District Office, Hydrologic Field Assistant
Raleigh, NC (1978 —1979)
CONTINUING EDUCATION
Urban Stormwater Management
New Methods in Engineering Geology
Depositional Sequence Analysis
Geochemistry
Environmental Law in North Carolina
Geology of the Sauratown Mountain Window
American Groundwater Trust Groundwater Institute
Stream Repair in the Urban Environment
TEACHING EXPERIENCE
ASTM Risk Based Corrective Action
Sampling Methods in Environmental Geology
Visual Display of Quantitative Information
Slope Stability and Landslide Hazards
Geology of the Central NC Piedmont
Geology of Dam Breaches in SC 2015
Water Surface Profiles Using HEC-2
Soil Evaluation of Embankment Dams
Continuing Education Guidebook Author: History of Geologic Thought in the Carolina Terrane (2oi9)
OSHA Safety Trainer, Northwest GeoScience, PC (20o9-present)
OSHA Safety Trainer, Engineering Tectonics, P.A. (1987-1991 & 1998-present)
Brownfields Instructor, Forsyth Technical Community College, 2005-2oo8
Brownfields Instructor, Durham Technical Community College, 20o9-present
Continuing Education Instructor, Engineering Tectonics, P.A. (1998-present)
High School Mentor in Geology, Forsyth County Schools, 20o8
Scientist in the Classroom, Forsyth County Schools,1998-2000
PUBLICATIONS
Nelson, A.B.,1984, Use of Vacuum Tanks with Soil Lysimeters; Environmental Geology: Association of Engineering Geologists
Octbober,1984.
Nelson, A.B. and Stewart, John S.,1992, Waste Management in the Piedmont: Geological Society of America Southeastern Regional
Meeting Fieldtrip Guides.
Nelson, A. B., 2002, The Geology, Hydrology and Geomorphology of the Haw River Basin, North Carolina: Engineering Tectonics,
Special Report to Dr. Anne Cassebaum, Elon University
Nelson, A. B, and Meijboom, A.F., 2oo6, Too Little Too Late; Use of Geology in Planning Transportation Corridors in the
Appalachian Plateaus of West Virginia: 54th Geology and Geophysics in Highway Engineering Symposium, Charlotte, NC.
Nelson, A. B., 2018, History of Geologic Thought in the Carolina Terrane: NC Geology Licensing Board Fieldtrip Guidebook.
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