20050688 Ver 2_Staff Report_20070125

FILE COP-
FIELD VISIT REPORT
By
David Goodrich
Hydrogeologist
Aquifer Protection Section
Division of Water Quality
Date of Field Visit: January 25, 2007
Location: Martin Marietta Materials: East Alamance Quarry, Proposed Expansion Area
Purpose: Evaluation of stream that runs through the proposed expansion area.
Personnel Attending: Wetlands Group: Periann Russell, Syndi Karoly, Ian McMillan,
Larry Eaton and Eric Kulz
Aquifer Protection Section: Rich Hayes and David Goodrich
Kimley-Horn and Associates, Inc.: Harlan Britt and Todd St. John
Reference: Individual Permit Application and Supporting Documentation for the U.S. Army
Corps of Engineers' Environmental Assessment, 404(B)(1) Analysis, Fining of No
Significant Impact (FONSI), and Statement of Findings, Martin Marietta Materials
East Alamance Quarry, Alamance County, North Carolina. Prepared by Kimley-Horn
and Associates, Inc. November 2006.
Field Readings:
Note: For sake of clarity, the field locations have been arranged in the order of the most upstream
location to the most downstream location, not in the order at which they were visited.
Location 1: Stream channel just below the property line, running through a wetland area at the
northern edge of the "Expansion Study Area" as presented in Figure 4 of Appendix 2 of the
reference document.
Water Temperature: 6.1 °C Dissolved Oxygen: 10.83 mg/1
Estimated Streamflow in channel: 288 cubic inches per second (75 gpm), with another
minor source contributing but not measurable.
Comments: Swift, narrow current.
Location 2: Stream as it emerges from the downstream opening of the 500-foot culvert, near the
geographic center of the yellow hatched "Proposed Mine Expansion Limits" presented in
Figure 4 of the Appendix 2 of the reference document.
Water Temperature: 4.8 °C Dissolved Oxygen: 11.4 mg/1
Estimated Streamflow out of culvert: 108 cubic inches per second (28 gpm), with a second
culvert pipe contributing but not measurable.

Location 3: Stream channel, approximately 60 feet downstream of the culvert opening at Location
2.
Estimated Streamflow in channel: 360 cubic inches per second (94 gpm).
Location 4: Stream channel, approximately 80 feet downstream of Location 3, and approximately
250 feet upstream of the upsteam opening of the 50-foot culvert presented in Figure 4 of
Appendix 2 of the reference document.
Water Temperature: 4.2 °C Dissolved Oxygen: 12.1 mg/1
Estimated Streamflow in channel: 384 cubic inches per second (100 gpm).
A small, entrenched tributary was observed to enter the stream from the,Northeast at a point
approximately 200 feet upstream from the upstream opening of the 50-foot culvert. No
Streamflow contributions were apparent from this tributary at the time of the field visit.
Location 5: Stream channel, approximately 100 feet downstream of the downstream opening of
the 50-foot culvert, and approximately 400 feet downstream of Location 4.
Water Temperature: 4.1 °C Dissolved Oxygen: 12.0 mg/1
Estimated Streamflow in channel: 384 cubic inches per second (100 gpm).
Location 6: Stream channel, approximately 200 feet downstream of the downstream opening of
the 50-foot culvert, and approximately 100 feet downstream of Location 5.
Estimated Streamflow in channel: 288 to 432 cubic inches per second (75 to 112 gpm).
Discussion
An examination was made of the stream just below the point at which it crossed the property line
at the northern edge of the site. An entire length of the stream, from the downstream end of
the 500-foot culvert to a point approximately 200 feet downstream of the downstream end
of the 50-foot culvert, was examined, and sampling was performed at a number of
locations. For most of this portion, the stream was entrenched to a depth of three to four
feet in a floodplain that was typically more than 100 feet in width. No seepage was
observed along the walls of the entrenched channel, and the small tributary that feeds the
stream from the Northeast appeared to be inactive.
Water temperature and dissolved oxygen readings were taken at four locations. The average
annual air temperature in the study area is approximately 58 degrees F, and "deep" ground
water would be expected to be near this temperature throughout the year. Conversely,
"shallow" ground water is subject to seasonal fluctuations in air temperature and the
temperature of infiltrating precipitation. The temperature of the streamwater was

approximately 40 degrees F, suggesting that most of the water in the stream was of
surficial, or near-surface origin. Weather conditions had been in the range of 25 to 50
degrees during the previous day and evening. Dissolved oxygen concentrations were
relatively constant, with a range of 10.83 to 12.1 mg/l. Ground water in this setting would
be expected to contain extremely low concentrations of dissolved oxygen. No waterfalls or
other features that would significantly increase the amount of dissolved oxygen in the
stream were observed.
Flow estimates were made at six locations along the stream. The first location (Location 1) was in
a wetland area, and there were obvious wetland contributions to the flow below this
location. An examination of the streamflow estimates (allowing for errors in estimation)
shows that the flowrate of the stream did not increase drastically with progressively
downstream measurements. There was no significant change in the flowrate between
Location 3 and Location 6, which were separated by approximately 580 feet of running
distance. Rainfall and runoff have recently been "typical" for this time of year, when damp
conditions and high groundwater elevations generally prevail. The expectation would be
that groundwater contributions would be generous, and that there would be a pronounced
increase in the streamflow as the stream descended to lower elevation.
In summary, the degree of the ground water contribution currently being received by the stream
along the stretch visited appears to be minimal, as evidenced by the consistent stream
temperature, the relatively high and consistent concentration of dissolved oxygen, and the
relatively consistent flowrate at points along the length of study. The extent of ground
water contribution to the stream would be expected to be less during the drier portions of
the year.
It should be pointed out that significant quantities of ground water could be transmitted through
the extensive adjacent flood plain formations in a direction parallel to the stream, provided
the sediments had sufficient thickness and a high hydraulic conductivity. Further
examination would be needed to support or discount this possibility.