20081319 Ver 3_Closeout Letter_20140930

PotashCorp
Helping Nature Provide
Federal Express
September 26, 2014
Mr. Tom Steffens
U.S. Army Corps of Engineers
Washington Regulatory Field Office
2407 West 5t' Street
Washington, North Carolina 27889
RE: Official Closeout of Rutman Creek Mitigation Project Phase 1
Dear Mr. Steffens:
PotashCorp - Aurora
FSEP3 0 2014
The 5t' year of monitoring the Rutman Creek Phase 1 mitigation site was complete as of the
end of 2013, and the annual monitoring report was submitted to you on April 2, 2014, with a
request for closeout of that portion of the project. On May 12, 2014, you, Eric Kulz, Anthony
Scarbraugh and Maria Dunn met with me and personnel from Land Management Group on the
site. A verbal determination was made that Phase 1 has met the success criteria and could be
closed out. This submittal requests written confirmation of the closeout determination.
i.
There was one well (Well 55) that did not meet the hydrology success criteria, and in an email
from you to me on May 12, you stated that agency personnel agreed that the area in question
around Well 55 should not be included in the final mitigation credit calculations of the site. In
order to determine how many acres were represented by the data collected from Well 55, Land
Management Group completed a field evaluation of the area around that well. Attached is the
report of that field evaluation, titled " Rutman Creek Watershed Restoration Project, Hyde
County, North Carolina, Summary of Estimated Non - Wetland Area in Vicinity of Well #55 ".
Based on the field evaluation, it was determined that the non - wetland area within the
restoration project is approximately 5.3 acres. Subtracted from the 680 -acre restoration project
area, this results in a successfully restored acreage of 674.7 acres. However, the report
concludes with a discussion of the benefits of the functional uplift that has occurred within the
non - wetland zone. PCS still believes that small areas of non - wetland around an individual,
scattered well should be counted in the overall mitigation credit, as allowed in 33 CFR Part 332
(Compensatory Mitigation for Losses of Aquatic Resources).
If you still determine that the non - wetland area around Well 55 should not be counted, then the
closeout totals for Rutman Creek Phase 1 would be 674.7 acres of wetland restoration and
142 acres of wetland preservation. If however, the area around Well 55 can be counted, then
the totals are 680 acres of wetland restoration and 142 acres of wetland preservation.
1530 NC Hwy 306 South, Aurora, NC USA 27806 T (252) 322 -4111
PotashCorp. I www.potashcorp com
1�

If you have any questions, please call me at (252) 322 -8249, or Christian Preziosi of Land
Management Group at (910) 452 -0001.
Sincerely,
J rey . Furness
Senior Scientist
PC:
Karen Higgins, DWR- Raleigh
w /encl.
Anthony Scarbraugh, DWR -Wash.
w /encl.
S.M. Jordan
w/o encl.
M. Brom
w/o encl.
Cal Miller, WRC -Ohio
w /encl.
C. Preziosi, LMG -Wilm
w /encl.
23 -11 -018
w /encl.

RUTMAN CREEK WATERSHED RESTORATION PROJECT
HYDE COUNTY, NORTH CAROLINA
SUMMARY OF ESTIMATED NON - WETLAND AREA
IN VICINITY OF WELL #55
Prepared for:
PCS Phosphate Company, Inc.
Prepared by:
?Ik�LMG
LAND MANAGEMENT GROUP INC.
Environmental Consultants
Wilmington, NC
July 2014

RUTMAN CREEK WATERSHED RESTORATION PROJECT
HYDE COUNTY, NORTH CAROLINA
SUMMARY OF ESTIMATED NON - WETLAND AREA IN VICINITY OF WELL #S5
A. Background
Based upon five years of hydrologic monitoring of Phase 1 of the Rutman Creek Watershed
Restoration Project, one well (Well #55) repeatedly did not meet the stated hydrologic success
criterion for the non - riverine bay forest wetland community type. Over the five -year period, Well #55
exhibited a mean hydroperiod duration (consecutive days of groundwater within 12 inches of the soil
surface during the growing season) of 7 days (equivalent to 2.6% of the growing season). After Year 1
(a period of gradual groundwater recharge across the site), Well #55 exhibited a mean hydroperiod of
8.5 days (equivalent to 3.2% of the growing season). The stated success criterion for the bay forest
wetland community is the establishment of a static water table at, or within, 12 inches of the soil
surface for 10% of the growing season (equivalent to 26 days based upon a March 11 to November 27
growing season).
B. Assessment of Field Indicators and Potential Drainage Influence
Upon review of available maps and a field evaluation of the area in the vicinity of Well #55, it is
apparent that the well is situated in a slightly higher topographic position and may be adversely
affected by the large canal adjacent to New Lake Road. Additional information regarding field
indicators of wetland hydrology (i.e. oxidized rhizospheres along living roots), hydrophytic vegetation,
and hydric soils has been documented in the vicinity of the well. This information was collected
utilizing methods consistent with the 1987 Corps of Engineers Wetland Delineation Manual and the
2008 Atlantic and Gulf Coast Regional Supplement. The ditch depth and Ordinary High Water Mark
(OHWM) indicators of the roadside collector canal were also evaluated at the time of the recent site
evaluation (in May 2014). The OHWM within the canal provides indication of the effective drainage
depth influencing hydrology in the zone adjacent to the canal. This information, in conjunction with
soil properties of the mapped soil unit, can be utilized to determine a lateral effect distance (or lateral
drainage effect) of the canal. The following is a brief summary of the findings related to the site
evaluation and predicted lateral drainage effect of the New Lake Road canal.
Rutman Creek Watershed Restoration Project 1
Summary of Non - Wetland Area in Vicinity of Well #55
July 2014

C. Summary of Findings
The hydric soil criterion was met across the entire 20 -acre former field block (surrounding'Well #55)
via the presence of a depleted matrix (F3) and /or depleted horizon below a dark surface (A11), with
redoximorphic features noted within the upper 6 to 8 inches along live roots. Soils of the area appear
to be consistent with the mapped soil unit, Roper muck, a very poorly drained series occurring on
broad flats, depressions, and on the edge of pocosins in Hyde County (NRCS 2001). Vegetation within
the block consists of Facultative -Wet (FACW) species such as soft rush (Juncus effusus) to Facultative -
Up (FACU) species such as dog fennel (Eupatorium capillifolium). Shrub -scrub and emergent
vegetation dominate the block with groundsel tree (Baccharis halimifolia), bushy - bluestem
(Andropogon glomeratus), soft rush, dog fennel, and goldenrod (Solidago conadensis) the dominant
species within these strata. All areas evaluated within the block exhibit conditions satisfying the
hydrophytic vegetation criterion (i.e. dominance test >50% and /or Prevalence Index <_3.0). However, it
should be noted that the dominant species tended to consist predominantly of FAC species.
In the vicinity of Well #55, the roadside collector canal is approximately 10 -ft wide by 4 -ft deep. At the
time of the most recent field observation (May 2014), water depth in the canal was 42 inches below
the ground surface. Note that according to NC Division of Water Resources (DWR) Drought Monitoring
Program, a moderate (D1) drought was recorded for the month of May 2014. Observed OHWM
indicators were recorded at 30 inches below the field ground surface. OHWM indicators included
deposition, shelving, impression on banks, and change in plant community. In order to identify the
effective lateral drainage of the canal, a transect was established perpendicular to the canal, and
unlined bore holes were evaluated for determination of static water levels at prescribed distances in
the zone adjacent to the canal. At the time of the evaluation, groundwater levels were documented at
40 inches, 38 inches, and 32 inches below the soil surface at 75 -ft, 150 -ft, and 300 -ft, respectively. In
addition to the roadside canal, there is a former field collector ditch located approximately 800 ft
northeast of Well #55. This collector ditch was plugged as part of the restoration work performed at
the outset of the project. The ditch itself is approximately 6 -ft wide by 3 -ft deep. At the time of the
recent site assessment, water depth in the lateral ditch was 24 inches below the field surface.
Observed OHWM indicators within the lateral ditch were recorded at 6 inches below the field surface.
It is believed that this lateral ditch exerts little drainage influence (if any) on the area around Well #55.
Rutman Creek Watershed Restoration Project
Summary of Non - Wetland Area in Vicinity of Well #55
July 2014
0)

Collectively, the information gathered indicates that the roadside collector canal has a pronounced
drainage effect on the adjacent former field area that includes the area of Well #55. This is evidenced
by the lack of observed water tables and the prevalence of FAC species within an approximate 200 -ft
zone along the canal. However, a primary indicator of wetland hydrology (i.e. oxidized rhizospheres
along living roots) persists across the entire block. Areas beyond 200 ft were characterized by a
predominance of FAC and FACW vegetation and observed water tables were observed closer to the
soil surface. Based upon the North Carolina Scope and Effect Guide (NRCS 1998), the predicted lateral
drainage effect for a 5 -ft canal in Group B, non -sandy soils (i.e. Roper series) is 105 ft. Based upon well
data, field indicators (with the exception of the presence of oxidized rhizospheres), and landscape
position, it is believed that the actual effective lateral drainage is greater. It is estimated that there is
an approximate 200- to 220 -ft zone adjacent to the canal that is non - wetland. When accounting for
the existing 100 -ft offset from the canal in which no wetland restoration was proposed, the remaining
non, wetland area within the restoration project is approximately 5.3 acres. Refer to the attached
figure (Figure 1) depicting the 100 -ft offset for the project boundary and the additional 110 -ft zone of
non - wetland area (equivalent to approximately 5.3 acres) within the project limits.
D. Functional Uplift of Non - Wetland Zone
The area in the vicinity of Well #55 consisted of former row crop agricultural land located immediately
adjacent to New Lake Canal (aka Old State Canal), a blue -line tributary draining directly to Rutman
Creek. Given the intensive land -use practices of the area prior to restoration work, the canal and
downstream receiving waters were susceptible to water quality impairments via nutrient (e.g. N and P)
loading, sediment run -off, and herbicide /pesticide contamination. Restoration work has removed the
intensive land -use practice and associated stressors to Water quality. In addition, planting of the entire
field zone (up to the edge of the canal) has provided a functional buffer that benefits water quality via:
(1) reducing overland flow velocities; (2) stabilizing soil; and (3) promoting the uptake and
transformation of nutrients /contaminants. In addition, an increase in water table levels allows
groundwater to be intercepted by the root zone of the planted vegetation (thereby enhancing nutrient
uptake). While the area does not meet the wetland hydrologic criterion, groundwater levels do rise to
within 12 inches of the soil surface for many weeks throughout the year. Subsequent to Year 1 (when
much of the site was beginning to recharge), the mean total days of groundwater levels within 12
inches of the soil surface was 50 days.
Rutman Creek Watershed Restoration Project 3
Summary of Non - Wetland Area in Vicinity of Well #55
July 2014

The non - wetland zone not only provides a protected buffer along New Lake Canal, but also provides an
ecotone for resident and transient fauna. As indicated above, this area is of slightly higher topographic
position than other portions of the site. Changes in microtopography can provide benefits by
contributing to niche habitat or habitat heterogeneity particularly within a large wetland mosaic
landscape. In addition, the entire non - wetland area will be protected in perpetuity via a conservation
easement.
Based upon the landscape conditions of the area and the restoration work completed, it is believed
that the non - wetland zone in the vicinity of Well #55 provides several water quality and habitat
benefits that were absent under the former land use of the site. In addition, sources of water quality
impairment have been removed along the length of the zone adjacent to New Lake Canal. While the
identified area has not met the wetland hydrologic criterion, it is believed that water quality and
habitat functions have been provided as a result of the work performed.
E. Literature Cited
Natural Resources Conservation Service (NRCS). 1998. North Carolina Scope & Effect Guide. NRCS
Southeast Coastal States Wetlands Team (June 1998). 9 pp.
Natural Resources Conservation Service (NRCS). 2001. Soil Survey of Hyde County, North Carolina.
209 pp.
Rutman Creek Watershed Restoration Project
Summary of Non - Wetland Area in Vicinity of Well #55
July 2014
4