20091236 Ver 1_USACE Correspondence_20091221

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?s. UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
A rW REGION 4
o Q ATLANTA FEDERAL CENTER
Z;F ?o? 61 FORSYTH STREET
?rq4 PROI ATLANTA, GEORGIA 30303-8960
December 17, 2009
Colonel Jefferson Ryscavage
District Engineer
Attn: Mr. Mickey Sugg, Project Manager
Wilmington District, Corps of Engineers
69 Darlington Avenue
Wilmington, North Carolina 28403
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DEC 2, 1 2009
DENR • WATER QUAU-f y
WETLANDS AND STORMATER BRANCt1
Subject: Lower Cape Fear Umbrella Mitigation Bank. Action I.D. #SAW-2009-02054
Dear Colonel Ryscavage:
This is in response to the Public Notice, dated November 17, 2009, for the Lower Cape
Fear Umbrella Mitigation Bank, sponsored by Tri-County Properties. According to the public
notice, the bank sponsor proposes to conduct activities on two separate mitigation sites: the
Sneeden Tract and the White Springs parcel. Other sites may be added in the future. At the
Sneeden Tract, the bank sponsor proposes to enhance 2,200 linear feet of stream, and restore 0.5
acres, enhance 18 acres, and preserve 420 acres of cypress-gum swamp. At the White Springs
parcel, the bank sponsor proposes to restore up to 1,000 linear feet of zero-order stream, and
restore 63 acres of wetlands that have been ditched and drained. The U.S. Environmental
Protection Agency (EPA), Region 4 Wetlands and Marine Regulatory Section reviewed the
public notice, the bank prospectus, and other information related to the project. We also visited
the site on December 10, 2009. We have the following comments for your consideration, and
the consideration of the Interagency Review Team (IRT).
Prospectus and General Comments:
1. In general, we believe that the sponsor's proposal for an umbrella bank is acceptable.
2. The prospectus adequately addresses all of the items required by the 2008 Mitigation Rule (40
CFR Part 230 and 33 CFR Part 332) for a complete prospectus.
3. The Sneeden Tract and White Springs parcel appear to be good candidates for mitigation
sites.
Internet Address (URL) • http://www.epa.gov
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4. The, recommended Geographic Service Area (GSA) encompasses the entire 8-digit
Cataloguing Unit (HUC) for the Lower Cape Fear River (03030005). However, this HUC
includes more than one Level III ecoregion (Middle Atlantic Coastal Plain and Southeastern
Plains),. Beth the Sneeden Tract and the White Springs parcel are located in the Middle Atlantic
Coast`al' Aanl.?coregion. In the past, the IRT has limited the GSA of mitigation banks to the 8-
digit HUC and'the ecoregion in which the site resides. EPA recommends that the GSA for both
the Sneeden Tract and the White Springs parcel be limited to those portions of 03030005 that are
viwittzin ?#b---Middle Atlantic Coastal Plain. We note that if other sites are added to the bank in the
future, the GSA for those sites should also be based upon the GSA and the ecoregion.
5. Table 2 on Page 7 (Proposed GSA) lists several 14-digit RUCs that are proposed to be
included in the GSA. EPA recommends this list be revised to reflect our comments above
concerning ecoregion. We also recommend that a figure be included here to show those 14-digit
HUCs on a map.
White Springs Tract:
1. This site is a Tulloch-ditched pocosin-pine flat. There are also areas of wet pine savannah.
Although the hydrology is noticeably absent, vegetation is largely still present. There are areas
where the trees are young, due to past disturbance to dig the ditches. EPA recommends that
vegetation planting be kept to only the areas that are disturbed during ditch filling and plugging
activities. It appears that the remainder of the site will revegetate well on its own.
2. EPA understands that improvements and repairs will be made to the ditch plugs on the
adjacent Brunswick Airport Mitigation Site, in order to improve hydrology.
3. The bank sponsor indicates that the property to the west must be drained adequately through
this site, in order to avoid hydrologic trespass. The bank sponsor proposes to potentially widen
and deepen the ditch on the northern end of the site to allow water to drain. EPA understands
that the area drained by this ditch will not be included in the mitigation credit calculations.
4. As the U.S. Army Corps of Engineers (Corps) representative indicated at our December 10,
2009, field meeting, it is important to ensure an appropriate water budget for the site, given that
the historic extent of the wetland includes areas across the road that must continue to be drained.
5. As we discussed on the site, there should be multiple ditch plugs on each of the lateral
ditches. Ditch plugs should be staggered as needed.
6. EPA agrees that the proposal to restore a zero-order stream on the site is acceptable. We
recommend that earthwork be limited, particularly outside of the channel itself. The 100-foot
wide streamside area of wetlands along the restored stream will count toward stream credit, and
should not be counted in the wetland credits.
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7. As we.discussed on-site, the hydrologic criteria should be based upon the soil type in the
various wetland communities proposed for restoration.
Sneeden Tract:
1. EPA understands that the Wilmington Bypass bisects the southern portion of the preservation
area on this site. This area should be clearly shown on the site plan and the acreage removed
from the credit estimates. Any other areas that are proposed for development or other activities
should also be shown on a site plan as outside the easement.
2. As discussed on-site, mature cypress-gum areas such as this are not typically envisioned as
"under threat." However, given the landowners' previous hand-timbering activities, EPA
believes that the cypress-gum swamp is a good candidate for preservation.
3. EPA recommends that an upland buffer be provided, if possible along the western edge of the
cypress-gum swamp. However, we acknowledge that any additional mitigation credit for upland
buffers may be minimal.
4. EPA is not opposed to the removal of the dam and road for stream enhancement credit.
However, we note that there appear to be at least two beaver dams in the channel upstream of the
soil road and dam. It may be difficult to keep this area free of beaver and free-flowing in order
to receive credit. Based upon the length of time the area has been impounded, EPA may
consider restoration credit for the stream length. However, the bank sponsor should provide
more information on the age of the dam, and management and maintenance of the impoundment.
We also look forward to reviewing flow and water height data from the area.
Thank you for the opportunity to review this prospectus. If you have any questions or
comments, please contact Kathy Matthews, of my staff, at [phone] or
[e-mail].
Sincerely,
klia(
Jennifer S. Derby
Chief
Wetlands and Marine Regulatory Section
cc: USFWS
NCDWQ
NCWRC
NMFS
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