19930931 Ver 1_COMPLETE FILE_19930313

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AMPAD REORDER
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AMPAD REORDER
EFFICIENCY' #23-006
DIVISION OF WATER QUALITY
WATER QUALITY SECTION
401 COMPLIANCE MONITORING
FORM
DWQ Investigator: 1 t,+-c Ff ee y i 60 ?+ 0 l DWQ # 3 9 J??
Date : l6 7 Time: '31(0 Regional Office: County:
Project Name: :TVviPei'(`a,1 Ceo+ er
Permittee: I'lam p- f NA,5s,eyl
Location of Project: _ 11 e dl L - l
Type of Development Authorized: Gom k ev^ a 1 140016(51 f, I--,/ A -r
Type of Permit / Water Quality Certification: 7-67 / z?71 D' 73Z
Type of Impact:
Wetland Type and DWQ Rating: ?y/ 7 1'f
Nearest Stream: 51?il?l(-IjO Ivan CrA Basin/Sub.:
Distance of Wetland Impact from Nearest Surface Water:
Specific 401 Conditions: 5l0U`M q,6 f6- I'`et1 w ?4
?0 of k v4wr ?,er /0 APu, sue (,
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701 GGi`l? /I - /[ ,, /5 /!e/lc
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Is project in compliance with all conditions:' Y / N
Comments / Description: MOH O ?? Q? o j eGf pv ?lt Or a key R i?k2
04 j2 ev?Ar ? la)l GI S Goy?s ?1 T&0 ,ola ? s
(2 SG'ltiP?c? 5????0? ?ave G?geaf,
d (.ua 4? ? # 10 i h 0 to r,? (l f Q?? & A re,,, a v,,&,
P©r ?t2?Cer^ e??vr/' e, ?/r"r,6 9r yn??y? ?A, - adG ve 4,,
?JeQv, re?DG/ i //t ```
Is there a violation of the 401 Certification authorization ? a re)a G lea lo' l ??-0 p7'
If so complete the enforcement section on the back of this form and forward copy to
the Central / Regional Office.
Signature: Date: 3<?1-7
520(_ le ??e? a 5 ?i0 ?a d G?? ?a ?P??(lGtS/ ?tL? ?s DWQ 12/96
PoSSid?e a /J/ / qr?a? ???`v2sS G?vrGQvr?S' a?
?. {^. Dn !! i ,w w ,/ni. rn? CAP. .?-inn{w_a Tls'{/ L?iv 6r?
ENFORCEMENT
1. Is there a previous history of 404 / 401 activity on the property?
If so, give any details:
Nature of Violation (fill, excavation, etc.):
Acres:
Wetland Rating (if possible):
Significant uses impacted: _
Were downstream uses impacted?
Could the impacts have been avoided or significantly minimized?
Could the activity have been authorized?.
Is restoration or mitigation appropriate for the unavoidable impacts?
Staff Recommendations for Future Action:
.K ?
State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Water Quality
James B. Hunt, Jr., G ove mor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E., Director
A&?j 0 ;
?EHNF?
April 7, 1997
Durham County
DWQ Project # 93931
COE #199301842
Mr. Harry Massey, Jr.
Tri Properties Inc.
P. O. Box 19067
Raleigh, NC 27619
Re: Compliance Inspection of Imperial Center
Dear Mr. Massey:
On January 25, 1994 you were issued General Water Quality Certification Nos. 2671 and
2732 authorizing 2.88 acres of wetland or water impacts for road crossings and lot fill needed to
develop the Imperial Center commercial park located off Page Road at I-40 near Research
Triangle Park. This certification was issued only for the impacts shown in your original
application. The certification carried the additional conditions that a stormwater plan be approved
by the Division, the shoreline of the detention pond shall be planted with emergent wetland
species, and that wetland are number 10 shall not be filled.
As part of an ongoing compliance monitoring and enforcement program for 401 Water
Quality Certifications, Eric Fleek from the Division's Raleigh Regional Office and myself made a
compliance inspection of the Imperial Center site on March 3, 1997. From our inspection it
appears that your project is not entirely in compliance with the conditions of the certification. We
found that most the property along Emperor Blvd. has been developed, but the project plans for
the southern section have been changed considerably. It appears that the fill pad for the IBM
building may have encroached into wetland number 10. However, the Division's greatest concern
is with the construction activities along Stirrup Iron Creek. Sediment basins have been
constructed with their berms going right up to the stream banks, gravel check dams within the
relocated stream has blown out, allowing significant increases in downstream turbidity.
In order to bring your project into compliance with the 401 Water Quality Certification,
please provide this office with an updated plat showing the existing and proposed structures and
all proposed wetland and stream impacts on the project. It may be necessary to re-delineate
wetland number 10 in the field to determine if any filling has taken place. The stormwater pond
P.O. Box 29535, Raleigh, North Carolina 27626-0535
Telephone [phone] FAX # [phone]
An Equal Opportunity Allirrnalive Action Employer 50°/o recycled/10% post consumer paper

should be completed as soon as possible. Please provide us with a schedule for its completion
along with a signed operation and maintenance plan. By copy of this letter we are requesting that
Land Quality review this project for compliance with the sedimentation and erosion control plan.
Your cooperation in complying with the conditions of your 401 Water Quality
Certification is appreciated. Should you have any questions concerning this matter please feel free
to contact me at [phone] or Eric Fleek at [phone].
Sincerely,
Peter B. Colwell
Environmental Specialist
cc: Eric Fleek, DWQ Raleigh Regional Office
Eric Alsmeyer, USACOE Raleigh Field Office
John Holley, DLR Land Quality, Raleigh Field Office
John Dorney, DWQ Central Office
Kevin Martin, Soil and Environmental Consultants
Tile,
Imperialctr.93931
State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Environmental Management
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary.
A. Preston Howard, Jr., P.E., Director
January 25, 1994
Tri Properties Inc.
Attn: Harry Massey, Jr.
P.O. Box 19067
Raleigh, N.C. 27619
Dear Mr. Massey:
Subject: Proposed fill in Wetlands or Waters
Imperial Center development
Durham County
DEM Project # 93931
?EHNR
Upon review of your request for 401 Water Quality Certification to place
fill material in 2.88 acres of wetlands or waters which are tributary to
Stirrup Iron Creek for commericial development located at South of I-40, near
Wake County line in Durham County as described in your submittal dated 14
October & 9 December 1993, we have determined that the proposed fill can be
covered by General Water Quality Certification Numbers2671 & 2732. Copies of
the General Certifications are attached. These Certifications may be used in
qualifying for coverage under Corps of Engineers' Nationwide Permit Numbers 14
& 26.
Additional conditions are that
1.) final written approval for the stormwater plan must be
obtained from DEM and
2.) the shoreline of the detention pond (shown as "shallow
marsh" in the Envirotek application [5 August 1993])
shall be planted with emergent wetland plant species
and
3.) wetland area number 10 shall not be filled.
If this Certification is unacceptable to you, you have the right to an
adjudicatory hearing upon written request within thirty (30) days following
receipt of this Certification. This request must be in the form of a written
petition conforming to Chapter 150B of the North Carolina General Statutes and
filed with the Office of Administrative Hearings, P.O. Box 27447, Raleigh,
N.C. 27611-7447. Unless such demands are made, this Certification shall be
final and binding.
If you have any questions, please contact John Dorney at 919-733-3.786.
Sincerely,
I?? +P,,tn Howard, P.E.
93931.1tr t
Attachment
cc: Wilmington District Corps of Engineers
Corps of Engineers Raleigh Field Office
Raleigh DEM Regional Office
Mr. John Dorney
Central Files
Mary Frazier; Soil and Environmental Consultants
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post-consumer paper
State of North Carolina
Department of Environment,
Health and Natural Resources
Division of Environmental Management
James B. Hunt, Jr., Governor
Jonathan B. Howes, Secretary
A. Preston Howard, Jr., P.E„ Director
C)EHNR
December 6, 1993
Tri Properties Inc.
Attn: Henry Massey, Jr.
P.O. Box 19067
Raleigh, N.C. 27619
Project # 93931
Durham County
Dear Mr. Massey:
The Division of Environmental Management, Water Quality Section
has reviewed your plans for wetland fill for 4.51 acres of wetlands at
Imperial Center Property in Durham County for commercial development.
Based on this review, we have identified significant uses which would
be removed by this project. These uses are water storage and
pollutant removal. Furthermore, insufficient evidence is present in
our files to conclude that your project must be built as planned in
wetlands. Therefore, we are moving toward denial of your 401
Certification. Until we receive additional information, we are
requesting (by copy of this letter) that the U.S. Army Corps of
Engineers and/or the N.C. Division of Coastal Management place your
project on administrative hold.
Please provide us with information supporting your position that
your project must be constructed as planned and that you have no
practicable alternative to fill of these wetlands. Specifically can
you construct your development without filling the 2.7 acres on
wetlands #10,13 & 19? Any documentation such as maps and narrative
which you can supply to address upland alternatives may be helpful in
our review of your 401 Certification. Please respond within two weeks
of the date of this letter by sending a copy of this information to me
and one copy to our Mr. Karl Schaffer at the Raleigh Regional Office
at 3800 Barrett Drive, Raleigh, N.C. 27609.
93931.na
cc: Raleigh DEM Regional Office
Wilmington Office Corps of
Sincerely,
. L , VLLe--
Jo n R. orney
We lands and Techn cal
Engineers
Central Files
Eric Alsmeyer, COE Raleigh Field Office
Kevin Martin; Soil and Environmental Consultants
Review Group
P.O. Box 29535, Raleigh, North Carolina 27626-0535 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer 50% recycled/ 10% post-consumer paper
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
P.O. BOX 1890
WILMINGTON, NORTH CAROLINA 28402-1890
December 3, 1993
IN REPLY REFER TO
Regulatory Branch
Action ID. 199301842 and Nationwide Permit Numbers 14 (Road Crossing) and 26
(Headwaters and Isolated Waters)
Tri Properties, Inc.
c/o Mr. Kevin Martin
Soil and Environmental Consultants, Inc. 3
K'F(C f/3 V
3818 Bland Road
Raleigh, North Carolina 27609 Dear Mr. Martin:

Reference our letter dated July 22, 1993, confirming nationwide general
permit authorization of Tri Properties, Inc.'s proposed discharge of fill
material within waters of the United States, impacting a total of 0.475 acre
of wetlands and waters (0.175 for bank-to-bank road crossings and 0.30 for
buildings, parking, etc.), adjacent, and above the headwaters of, an unnamed
tributary to Stirrup Iron Creek, for construction of one temporary road, one
permanent road, and commercial development for the first phase of the Imperial
Center Property, east of N.C. 54 and south of Page Road, southeast of Durham,
Durham County, North Carolina. Reference also your application of October 29,
1993, for Department of the Army authorization for additional impacts to
waters of the United States, for the final stage of the project, and your
letter dated November 22, 1993, revising the application to delete additional
impacts to "Wetland 10," for total additional impacts to 2.98 acres (0.1 for
road crossings and 2.88 for buildings/parking/stormwater retention).
For the purposes of the U.S. Army Corps of Engineers' Regulatory Program,
Title 33, Code of Federal Regulations (CFR), Part 330.6, published in the
Federal Register on November 22, 1991, lists nationwide permits (NWP).
Authorization was provided, pursuant to Section 404 of the Clean Water Act,
for discharges of dredged or fill material into headwaters and isolated waters
provided:
a. The discharge does not cause the loss of more than 10 acres of waters
of the United States;
b. The permittee notifies the District Engineer if the discharge would
cause the loss of waters of the United States greater than one acre in
-2-
accordance with the "Notification" general condition. For discharges in
special aquatic sites, including wetlands, the notification must also include
a delineation of affected specific aquatic sites, including wetlands; and
c. The discharge, including all attendant features, both temporary and
permanent, is part of a single and complete project.
Authorization, pursuant to Section 10 of the Rivers and Harbors Act of 1899
and Section 404 of the Clean Water Act, was also provided for fills for roads
crossing waters of the United States (including wetlands and other special
aquatic sites) provided:
a. The width of the fill is limited to the minimum necessary for the
actual crossing;
b. The fill placed in waters of the United States is limited to a filled
area of no more than 1/3 acre. Furthermore, no more than a total of 200
linear feet of the fill for the roadway can occur in special aquatic sites,
including wetlands;
C. The crossing is culverted, bridged or otherwise designed to prevent
the restriction of, and to withstand, expected highflows and the movement of
aquatic organisms;
d. The crossing, including all attendant features, both temporary and
permanent, is part of a single and complete project for crossing of a water of
the United States; and
e. For fills in special aquatic sites, including wetlands, the permittee
notifies the District Engineer in accordance with the "Notification" general
condition.
Your revised project, impacting a total of 3.455 acres (3.18 under
NWP No. 26) is authorized by these NWPs provided it is accomplished in strict
accordance with the enclosed conditions and provided you receive a Section 401
water quality certification from the North Carolina Division of Environmental
Management. You should contact Mr. John Dorney, telephone [phone],
regarding water quality certification. These NWPs do not relieve you of the
responsibility to obtain other required State or local approvals.
This verification will be valid for 2 years from the date of this letter
unless the nationwide authorization is modified, reissued or revoked. Also,
this verification will remain valid for the 2 years if, during that period,
-3-
the NWP authorization is reissued without modification or the activity
complies with any subsequent modification of the NWP authorization. If during
the 2 years, the NWP authorization expires or is suspended or revoked, or is
modified, such that the activity would no longer comply with the terms and
conditions of the NWP, activities which have commenced (i.e., are under
construction) or are under contract to commence in reliance upon the NWP will
remain authorized provided the activity is completed within 12 months of the
date of the NWP's expiration, modification or revocation, unless discretionary
authority has been exercised on a case-by-case base to modify, suspend or
revoke the authorization.
Please note that this authorization is valid for the work described above
only, and impacts of subsequent projects on this property would have to be
considered cumulatively with these impacts, regardless of future subdivision
or ownership of the property. Questions or comments may be addressed to
Mr. Eric Rlsmeyer of my Raleigh Field Office regulatory staff, at telephone
[phone], extension 23.
Sincerely,
G. Wayne Wright
Chief, Regulatory Branch
Enclosure
Copy Furnished (without enclosure):
John Dorney
Water Quality Section
Division of Environmental Management
North Carolina Department of
Environment, Health and
Natural Resources
Post Office Box 29535
Raleigh, North Carolina 27626-0535
DEPARTMENT OF THE ARMY e t! ` "°" " J y
WILMINGTON DISTRICT, CORPS OF ENGINEERS
P.O. BOX 1890
WILMINGTON, NORTH CAROLINA 28402-1890
1fiiATER WETl OLITY?St` ;ls
IN REPLY REFER TO July 22, 1993.
t;? !?Y
Regulatory Branch
Action ID. 199301842 and Nationwide Permit Numbers 14 (Road Crossing)
and 26 (Headwaters and Isolated Waters)
Mr. Kevin Martin
Soil and Environmental Consultants, Inc.
3818 Bland Road
Raleigh, North Carolina 27609
Dear Mr. Martin:
Reference your application of February 23, 1993, submitted on behalf of
Tri Properties Inc., for Department of the Army authorization to discharge
fill material within waters of the United States, causing the loss of a total
of 0.475 acres of wetlands and waters (0.175 for bank-to-bank road crossings
and 0.30 for buildings, parking, etc.) adjacent to, and above the headwaters
of, an unnamed tributary to Stirrup Iron Creek, for construction of one
temporary road, one permanent road, and commercial development for the first
phase of development at the Imperial Center Property, east of NC 54 and south
of Page Road, southeast of Durham, a,,n,!ffiWm'iuntyNorth Carolina. Your
application indicates that application for additional jurisdictional impacts-
will be made when development plans are completed.
For the purposes of the Corps of Engineers' Regulatory Program,-Title 33,
Code of Federal Regulations (CFR); Part 330.6, published in the Federal
Register on November 22, 1991, lists nationwide permits. Authorization was-
provided, pursuant to Section 404 of the Clean Water Act, for discharges of
dredged or fill material into headwaters and isolated waters provided:
a. the discharge does not cause the loss of more than 10 acres of waters
of the United States;
b. the permittee notifies the District Engineer if the discharge would
cause the loss of waters of the United States greater than one acre in
accordance with the "Notification" general condition. For discharges in
special aquatic sites, including wetlands, the notification must also include
a delineation of affected specific aquatic sites,.including wetlands; and
c. the discharge, including all attendant features, both temporary and
permanent, is part of a single and complete project.
Authorization, pursuant to Section 10 of the Rivers and Harbors Act of 1899
and Section 404 of the Clean Water Act, was also provided for fills for roads
crossing waters of the United States (including wetlands and other special
aquatic sites) provided:

I',
-2-

a. The width of the fill is limited to the minimum necessary for the
actual crossing;
b. The fill placed in waters of the United States is limited to a filled
area of no more than one-third acre. Furthermore, no more than a total of 200
linear feet of the fill for the roadway can occur in special aquatic sites,
including wetlands;
C. The crossing is culverted, bridged or otherwise designed to prevent
the restriction of, and to withstand, expected highflows and the movement of
aquatic organisms;
d. The crossing, including all attendant features, both temporary and
permanent, is part of a single and complete project for crossing of a water of
the United States; and
e. For fills in special aquatic sites, including wetlands, the permittee
notifies the District Engineer in accordance with the "Notification" general
condition.
Your work is authorized by this nationwide permit provided it is
accomplished in strict accordance with the enclosed conditions and provided
you receive a section 401 water quality certification from the North Carolina
Division of Environmental Management. This nationwide permit does not relieve
you of the responsibility to obtain other required State or local approval.
This verification will be valid for two years from the date of this letter
unless the nationwide authorization is modified, reissued or revoked. Also,
this verification will remain valid for the two years if, during that period,
the nationwide permit authorization is reissued without.modification or the
activity complies with any subsequent modification of the nationwide permit
authorization. If during the two years, the nationwide permit authorization
expires or is suspended or revoked, or is modified, such that the activity
would no longer comply with the terms and conditions of the nationwide permit,
activities which have commenced (i.e., are under construction) or are under
contract to commence in reliance upon the nationwide permit will remain
authorized provided the activity is completed within twelve months of the date
of the nationwide permit's expiration, modification or revocation, unless
discretionary authority has been exercised on a case-by-case base to modify,
suspend or revoke the authorization.
-3-
Please note that this authorization is valid for the work described above
only, and impacts of subsequent projects on this property would have to be
considered cumulatively with these impacts, regardless of future subdivision
or ownership of the property. Questions or comments may be addressed to Mr.
Eric Alsmeyer, Raleigh Regulatory Field Office, at telephone [phone],
extension 23.
Sincerely,
G. Wayne Wright
Chief, Regulatory Branch
Enclosure
Copy Furnished (without enclosure):
Ir 'Tohn Dorney
Water Quality Section
Division of. Environmental Management
North Carolina Department of
Environment, Health and
Natural Resources
Post Office Box 27687
Raleigh, North Carolina 27611-768.7
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Soil & Environmental Consultants, Inc.
223 la lane %ad ¦ Raleigh, North Carolina 27609 ¦ {943} 96 1?-0 Fax #49?''96=tT2
OUR NEW ADDRESS:
244 West Milibrook Rd
Raleigh, NC 27609
Ph. 919-846-5900 Fax [phone] December 9, 1993
NRCD - DEM D 10 V t5
Attn: Mr. John Dorney
PO Box 29535 wa _J?
Raleigh, NC 27626 DEC 2221 F
Dear Mr. Dorney : WETLANDS GROUP
WATER QUALITY SECTION _
.The purpose of this letter is to,request a modification to our
October 14, 1993 application for Section 401-certification for the
Imperial Center Property, in Durham County, North Carolina.
Under the modification, the area labeled wetland 10 will not be
impacted, aside from the area previously permitted under.
Nationwide Permit 14 for a road.crossing. We are eliminating the
impacts to wetland 10 so that the remainder of the application can
be processed and approved.
F ication will reduce the area to be impacted under NW 26
res, reducing the area of total impact from 4.41 acres
res The area to be impacted under NW 14 will remain
he t 0.10 acres. From a water quality standpoint, we are
not tly proposing a revision in the pond's size; it will
still be sized as.if this area were being developed.
Please note that we may have to submit another permit application,
since we are not certain as of yet whether the plans can be
modified enough to completely avoid wetland 10. Envirotek is also
in the process of trying to redesign the project to see if wetland
impacts can be minimized any further. We have. chosen this option,
even though we feel impacts have been minimized and avoided, setae
can rethinkthe layout, determine if impacts can be avoided and/or
minimized further to wetland 10, prepare more detailed
justifications for the impacts, or a do combination of these
options.
Please contact me if you have questions or require additional
information. We will inform you whether or not another
application will be forthcoming as soon as the plan modifications
and/or review are complete. A copy of this letter has already

Soil/Site Evaluation ¦ Mapping and Physical Analysis ¦ Wetlands Mapping and Mitigation ¦ Environmental Audits
On-Site Waste Treatment Systems, Evaluation and Design
been sent to the U.S. Army Corps.
Sincerely,
Kevin C. Martin,
President
cc: David Franklin, US Army Corps
Karl Shaffer, DEM
N.C. Cultural Resources
US Fish & Wildlife Service
National Marine Fisheries Service
David Lasley, Envirotek
1

IMPERIAL CENTER
DURHAM, NORTH CAROLINA
WETLAND FILL PERMIT
I I Introduction

t

This report has been prepared to address restrictions which have been placed upon Imperial
Center by the State of North Carolina regarding expansion of development into wetland
areas. Preparation of this report, along with its findings and recommendations, has been
a collaborative effort between Envirotek and our wetlands consultant, Kevin Martin with
SEC, Inc.
It is our goal, through adoption of the concepts presented in this report by the agencies
involved, to obtain a permit from the U.S. Army Corps of Engineers to fill wetland areas
within several undeveloped portions of the project, a projected impact of approximately 5.7
acres of the total 9.4 acres of wetlands remaining.
Project History
Imperial Center, located adjacent to Research Triangle Park in Durham, North Carolina,
is a 425 acre mixed commercial, office and industrial use development. Since its inception
in 1983, Imperial Center has developed 180 acres, (approximately 92 acres of impervious
area) or 42 percent of the total project.
Approximately 310 acres of the total 425-acre project drains through a single creek which
traverses the property. For the most part, the site's most valuable wetlands parallel this
creek, with several smaller fingers extending from it to upland areas.
Concept

1

Imperial Center proposes to maintain a corridor of vegetated buffer along the major creek
and enhance the creeks water quality capability by constructing an on-line permanent pool
pond. The pond will be located just upstream from where the creek leaves the project.
Review of the current Master Plan prepared for Imperial Center indicates that there is
approximately 120 acres of impervious development remaining within those areas presently
under their control. The pond will be sized initially to support approximately 90 acres of
planned impervious development. Expansion of the pond at a later date will support the
remaining balance, approximately another 30 acres.
It is our recommendation to preserve and enhance the main creek rather than develop the
project around the isolated fingers which feed it.
ICEN93 Imperial Center Engineering 1993 5 August 1993
Wetland Fill Permit GMP:eyb Page 1
-,°?;
s.JauuDId lsjoau16uo 's}09}140M
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Ivioadwi.

I I I Approval Process
Envirotek, Inc. along with its consultant, SEC, Inc., seeks an approval design process which
reflects the concept outlined above. We would like to obtain approval of the . concept
through circulation of this report with supportive exhibits. After input by the various
agencies involved, we would like to obtain approval of the detailed design and phased
construction. New development will be monitored via a bi-annual report, published to track
changing levels of impervious cover until the pond construction and expansion is complete.

1

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o ICEN93 Imperial enter Engineering 1993 5 August 1993
1 i Wetland Fill Permit GMP:eyb Page 2

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IMIDEMAL
CENTER
IRV

Wetland Fill Permit Exhibits
ENVIROTEK, INC.
1111 OBERLIN ROAD
RALEIGH, N.C. 27605
architects, engineers, planners

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1
EXHIBITS LIST
Exhibit No.
1
2
3
4
5
6
7
8
o I EN93 Imperial Center Engineering 1993 MP:pal 2 August 1993
Wetland Fill Permit Page 1
11
Water Quality Plan Flow Chart
Wet Pond Locations
Concept-Permanent Pool
Typical Pond Section
Calculations
Overall Drainage Area
Drainage Area
Impervious Cover Analysis

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1
H

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Obtain Necessary
Approvals
Renew Corps Permit
6 Mo. Prior to
Expiration Date
(If Necessary)
Until Wetlands
Have Been Filled
Prior To Impacting Further
Wetland Areas: Construct
Pond (Phase 1)
Prior To Exceeding
90 Ac. of Impervious
Cover Within Imperial
Center: Expand Pond
(Phase II)
Monitor Imperial Center
Construction - Issue BI-Annual
Report to NCDEM-Water Quality
Project
Complete

Water Quality Plan
Flow Chart
IMPERIAL CENTER
Prepared by
ENVIROTEK, INC.
Job Code : ICEN93
Date :2 AUGUST 1993
EXHIBIT 1
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CONCEPT
PERMANENT POOL
POND
North
0• 100' 200'
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IMPERIAL CENTER
Prepared By
ENVIROTEK, INC.
Job Code: ICEN93
Date: 2 AUGUST 1993
EXHIBIT NO. 3

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Typical Pond
Section
IMPERIAL CENTER
Prepared By
ENVIROTEK, INC.
Job Code: ICEN93
Date- 2 AUGUST 1993
EXHIBIT NO. 4

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D

CALCULATIONS
DESIGN FOR WATER QUALITY CONTROL
A. PERMANENT POOL - OVERALL
1. DRAINAGE AREA
TOTAL DRAINAGE AREA TO OUTLET OF EAST POND = 475 AC
(SEE EXHIBIT NOS. 6 & 7)
2. AVERAGE PERMANENT POOL DEPTH:
WE WILL USE 5.5'
3. ANTICIPATED POST-DEVELOPMENT LEVELS OF IMPERVIOUS COVER:
EXHIBIT NO. 8 LISTS FUTURE SITES WITHIN IMPERIAL CENTER. A
CALCULATED PERCENTAGE OF IMPERVIOUS COVER IS ALSO LISTED. WE
WILL USE 25%.
4. FOR 85% POLLUTANT REMOVAL EFFICIENCY SA/DA RATIO = 0.78
(NCDNRCD, DEM, 8/28/87 - DRAFT)
5. REQUIRED SURFACE AREA:
SAfeq = .0078 x 475 AC. = 3.7 AC.
B. TEMPORARY WATER QUALITY POOL - OVERALL
RV (RUNOFF VOLUME) = r * A/12 AC.-FT.
r = STORM RUNOFF (in.)
A = WATERSHED AREA TREATED
(T.R. SCHUELER, "CONTROLLING URBAN RUNOFF," 1987)
r= p*Rv
p = 1 in. (STORM RAINFALL)
Rv = RUNOFF COEFFICIENT (T.R. SCHUELER, 1987)
Rv = 0.05 + 0.009 (1)
I = PERCENT OF IMPERVIOUSNESS
Rv = 0.05 + 0.009 (25) _ .275
r = 1 in. *.275 = .275 IN.
A = 245 AC (425 AC - 180 AC)
Rv _ .275 in. * 245 AC * 1 ft./12 in. = 5.62 AC.-FT.
APPROXIMATE WATER QUALITY POOL DEPTH:
DEPTH = RV/SAreq.
5.62 AC.-FT. = 1.51 FT.
3.7 AC.
C. APPROXIMATE SEDIMENT STORAGE POOL - OVERALL
L = (P*PI*Rv/12)*C*A*2.72 (SCHUELER, 1987)
P = 42 in/yr (NCDNRCD, DEM)
PI= 0.9 (SCHUELER, 1987)
Rv= .275 (SEE ABOVE)
C = 350 mg/1 (SCHUELER, 1987)
A = 245 AC
L= 202045 LB/YR
Exhibit 5
I EN93 Imperial Center Engineering 1993 MP:pal 2 August 1993
Wetland Fill Permit Page 1
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CALCULATIONS (Continued)
ASSUMING 1 TON OF SEDIMENT IS APPROXIMATELY 1CY & A DESIGN LIFE OF 20
YEARS
SEDIMENT VOLUMEreq = 2020 CY
D. CONCEPT DESIGN
PHASE I (FOR CONCEPT SKETCH SEE EXHIBIT NOS. 3 & 4)
a) DESIGN CRITERIA
• BUILD POND FIRST AT LOWEST POINT IN BASIN.
• AVOID IMPACTING EXISTING WETLAND AREA LOCATED SOUTH OF
"COMMERCE CENTER".
b) PERMANENT POOL
1) DRAINAGE AREA = 475 AC.±
(SEE EXHIBIT NOS. 6 & 7)
2) AVERAGE PERMANENT POOL DEPTH:
WE WILL USE 55
3) AREA OF IMPERVIOUS COVER: 90 AC.
% IMPERVIOUS COVER = 90 AC/475 AC x 100 = 18.95
4) FOR 85% POLLUTANT REMOVAL EFFICIENCY
SA/DA = 0.623%
(NCDNRCD, DEM, 8/28/87 - DRAFT)
5) REQUIRED SURFACE AREA:
SAre = 0.00623 x 475 AC = 2.96 AC
C) TEMPORARY WATER QUALITY POOL
RV = r * A/12 AC-FT (SECTION B.)
RV = p * Rv * A/12 AC-FT (SECTION B.)
Rv = 0.05 + 0.009 (18.95) = .221 (SECTION B.)
RV = 1 in. * .221 * 245 AC/12 = 4.51 AC-FT
APPROXIMATE WATER QUALITY POOL DEPTH:
DEPTH = 4.51 AC-FT = 1.52 FT
2.96 AC
d) APPROXIMATE SEDIMENT STORAGE POOL
L= (P*Pi*Rv /12) * C * A * 2.72 (SECTION C.)
L = (42 *.9 *.221/12) * 350 * 245 * 2.72
Exhibit 5
I EN93 Imperial Center Engineering 1993 MP:pal 2 August 1993
Wetland Fill Permit Page 2
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CALCULATIONS (Continued)
L = 162,370 LB/YR
ASSUMING 1 TON OF SEDIMENT IS APPROXIMATELY 1 CY AND A
DESIGN LIFE OF 20 YEARS
SEDIMENT VOLUMEreq = 1624 CY
2. PHASE II (FOR CONCEPT SKETCH SEE EXHIBIT NOS. 3 & 4)
a) DESIGN CRITERIA
• EXPAND EAST POND TO MAXIMUM SURFACE AREA AVAILABLE BY
RELOCATING A PORTION OF THE EXISTING SANITARY SEWER AND
FORCEMAIN.
• EXPANSION MUST AVOID "NORTHERN TELECOM" PARCEL TO NORTH.
THIS PARCEL IS DEVELOPED AND IS NOT CONTROLLED BY IMPERIAL
CENTER.
• AVOID IMPACTING EXISTING WETLAND AREA LOCATED SOUTH OF
"COMMERCE CENTER".
b) PERMANENT POOL
1. PRELIMINARY GRADING OF THE EXPANDED POND INDICATES AN
AVAILABLE PERMANENT POOL SURFACE AREA OF APPROXIMATELY
3.75 AC TOTAL.
2. DRAINAGE AREA REMAINS SAME (475 ACS
(SEE EXHIBIT NOS. 6 & 7)
3. AVERAGE PERMANENT POOL DEPTH WILL BE MAINTAINED WITHIN
EXPANDED AREA.
(WE WILL USE 55)
4. SA/DA = 3.75 AC/475 AC = .0079
5. FOR 85% POLLUTANT REMOVAL EFFICIENCY THE CORRESPONDING
LEVEL OF IMPERVIOUS COVER IS 25.39%.
{NCDNRCD, DEM, 8/28/87) - DRAFT)
6. MAXIMUM IMPERVIOUS ACREAGE TREATED = .2539 * 475 AC = 120.6
AC
OR
AN ADDITIONAL 30.6 AC OF IMPERVIOUS DEVELOPMENT
C) TEMPORARY WATER QUALITY POOL
RV = r * A/12 AC-FT (SECTION B.)
RV = p * R„ * A/12 AC-FT (SECTION B.)
Rv = 0.05 + 0.009 (25.39) = .279 (SECTION B.)
Exhibit 5
I EN93 Imperial Center Engineering 1993 GMP:pal 2 August 1993
Wetland Fill Permit Page 3
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CALCULATIONS (Continued)
RV = 1 IN. *.279 * 245 AC/12 = 5.7 AC-FT
APPROXIMATE WATER QUALITY POOL DEPTH:
DEPTH = 5.7 AC-FT = 1.52 FT
3.75 AC
d) APPROXIMATE SEDIMENT STORAGE POOL
L= (P*P•*RV/12)*C*A*2.72(SECTION C.)
L = (42 -.6 -.279/12) * 245 * 310 * 2.72
L = 204,980 LB/YR
ASSUMING 1 TON OF SEDIMENT IS APPROXIMATELY 1 CY AND A
DESIGN LIFE OF 20 YEARS
SEDIMENT VOLUMEfeq = 2050 CY
?••N,6Nq //* '
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M
o I EN93 Imperial Center Engineering 1993 GMP:pal 2 August 1993
Fu I Wetland Fill Permit Page 4

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DRAINAGE
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ii/EXISTING
PROPOSED -

OVERALL
DRAINAGE

-?-' AREA

IMPERIAL CENTER

. Prepared by
?,
*ti ENVIROTEK, INC.
On Sn. Dmin.pe Area W?B-Jn
. DnWUq. Seel" when (310 Ac:t)
Dime To b wo" C~
® Drainer A os Whhln bnp-w
Cent. Whkh (),sins OR SIN. (115 Acs)
Off Sk. Dnun.p. An. Whhbn
w.mD,.wr s..in whirl, (165 Acs)
O mina To bnp.A.l C.M.,
DRAINAGE DIVIDES REFLECT EXISTING
OR PROPOSED DRAINAGE PATTERNS

0' Soo' loo* I,& .
Job Code : ICEN93
Date :. 30 AUGUST 1993
EXHIBIT NO. 6
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0. 2000' 4000'
DRAINAGE AREA
IMPERIAL CENTER
Prepared By
ENVIROTEK, INC.
Job Code: ICEN93
Date: 2 AUGUST 1993

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IMPERIAL CENTER (continued)
PLANNED IMPERVIOUS COVER (continued)**

Description Planned
Building
Area (sf) Planned
Parking
& Street
Area
(Ac)
Royal Center* 74,800 4.11
Lot #S43 74,000 1.65
Lot #S44 60,000 0.74

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IMPERIAL CENTER (continued)
PLANNED IMPERVIOUS COVER (continued)**

Description
Planned
Building
Area (sf) Planned
Parking
& Street
Area
(Ac)
Lot #S15 92,000 1.45
Lot #S13 106,000 5.87
Lot #S10 30,000 1.08
Lot #S8 97,200 1.13
Lot #S7 132,000 1.10
Lot #S6 20,000 1.84
Lot #613 20,000 1.72
Lot C-17 12,000 1.30
Lot C-16 6,800 0.78
Lot C-14 20,000 2.12
Lot C-8 122,800 1.33
Lot C-3 79,200 0.91
Lot C-2 0 0.18
Total Planned Building Area = 48.77 AC.
Total Planned Parking & Street Area = 69.03 AC.
Total Planned Impervious Area = 117.8 AC.
Proposed Percent Impervious Cover Within Drainage Basin = 24.8
(117.8 AC/475 AC, Use 25%)
* Reflects Remaining Portion to be Built
"Based upon Imperial Center Master Plan
NOTE: The above areas are based on general layouts with areas developed by
planimeter. The areas are not surveyed.
EXHIBIT 8
imperial en er ngineenng 199.3 :pa August
Wetland Fill Permit Page 2
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W,
WETLAND FILL PLAN
IMPERIAL CENTER
DURHAM, NORTH CAROLINA
PROJECT SPECIFICATIONS
JOB CODE: ICWFF
DATE: 10 MARCH, 1997
ENVIROTEK INC
1111 OBERLIN ROAD
RALEIGH NC 27605 USA
architects engineers planners
TELEPHONE [phone]
TELEFAX 919 839 2255
R-
IMPERIAL CENTER
WETLAND FILL PLAN
DURHAM, NORTH CAROLINA
TABLE OF CONTENTS
PAGE
PROJECT SPECIAL PROVISIONS 2
PROJECT SCHEDULE 3
PROPOSAL 4
DIVISION 02 SITE WORK
SECTION 02/110 SITE CLEARING 9
SECTION 02/200 EARTHWORK 11
SECTION 02/720 STORM SEWERS 16
APPENDIX "A' WETLAND BOUNDARY POINT COORDINATE LIST
APPENDIX "B" NDS GRATES, BASINS AND RISERS
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 2
PROJECT SPECIAL PROVISIONS
TIME
TIME IS THE ESSENCE OF THIS CONTRACT. ALL WORK ON THIS PROJECT
MUST BE COMPLETE BY 30 SEPTEMBER 1997. CONTRACTORS SHALL SUBMIT
COMPLETED PROJECT SCHEDULES WITH THEIR PROPOSALS. THE
CONSTRUCTION ORDER OF THE WETLAND AREAS TO BE FILLED SHALL BE
AT THE DISCRETION OF THE CONTRACTOR PROVIDED HE DEMONSTRATES,
BY SUBMITTING A REVISED SCHEDULE, THAT ALL WORK WILL BE
COMPLETE BY 30 SEPTEMBER 1997.
SCOPE
The work to be completed under this contract is shown on drawing Nos. ENGR-0 through
ENGR-11 dated 10 March 1997 by Envirotek, Inc. It is the Owner's intention to have all
work shown on the plans completed under this contract by 30 September 1997. However,
the Owner reserves the right to delete portions of the work from the contract for his
convenience and at his sole discretion. The Owner may elect to have portions of the work
shown on these plans completed in conjunction with other projects currently or proposed
for construction at Imperial Center.
FORM OF CONTRACT
The Owner will execute a Lump Sum Contract (AIA Document No. A101) with the
Contractor who submits the proposal in the best interest of the Owner. The proposal is
itemized for the purpose of providing an equitable basis for processing pay requests. The
breakdown and the unit price schedule will also be the basis for either increasing or
decreasing the Contract Sum due to increases or decreases in the scope of the work.

ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 3
PROJECT SCHEDULE
Proposal Packages Available 14 March 1997
Pre-Proposal Meeting 27 March 1997
Proposals Due to Owner 28 March 1997
Owner Selects Contractor 4 April 1997
Contract Signed by Contractor 11 April 1997
Contract Signed by Owner 18 April 1997
Site Available for Construction 19 April 1997
CONSTRUCTION SCHEDULE.
(TO BE COMPLETED BY CONTRACTOR)
BEGIN COMPLETE
Borrow Area No. 1
Wetland Area #1
Wetland Area #6
Wetland Area #8
Wetland Area #9
Wetland Area #10B
Wetland Area #13
Wetland Area #15,16,17
Wetland Area #20
Wetland Area #22
Project Completion
ICWFF SPECIFICATIONS (Draft)
PROPOSAL
WETLAND AREA #1
Erosion Control
Clearing and Grubbing
(including haul road)
Grading and Filling
Seeding
AREA #1 SUBTOTAL.
WETLAND AREA #6
Erosion Control
Grading and Filling
30" RCP
42" RCP
Storm MH/JB
Riprap Apron
Seeding
AREA #6 SUBTOTAL:
WETLAND AREA #8
Erosion Control
Clearing and Grubbing
Grading and Filling
72" C.M.P.
Class I Riprap
Seeding
AREA #8 SUBTOTAL:
Unit Price
1 L.S. $ $
1 L.S. $ $
12 March 1997 Page 4
Amount
1 L.S. $ $
1 L.S. $ $
Unit Price Amount
ii-S. $ $
1 L.S. $ $
242 L.F. $ $
560 L.F. $ $
2 ea. $ $
1 L.S. $ $
1 L.S. $ $

Unit Price Amount
1 L.S. $ $
1 L.S. $ $
1 L.S. $ $
290 L.F. $ $
1 L.S. $ $
1 L.S. $ $

ICWFF SPECIFICATIONS (Draft)
PROPOSAL (continued)
.WETLAND AREA #9
Erosion Control
Grading and Filling
8" Solid P.E. Pipe
4" Perforated Trench Drain
18" P.E. Drain Basin
Seeding
AREA #9 SUBTOTAL:
WETLAND AREA #10B
Erosion Control
Grading and Filling
Seeding
AREA #10B SUBTOTAL:
WETLAND AREA #13
Erosion Control
Clearing and Grubbing
Grading and Filling
Storm MH/JB
Raised Top Catch Basin
36" RCP
24" P.E. Pipe
Seeding
AREA #13 SUBTOTAL:
12 March 1997 Page 5
Unit Price Amount
1 L.S. $ $
1 L.S. $ $
360 L.F. $ $
200 L.F. $ $
4 ea. $ $
1 L.S. $ $
T
Unit Price Amount
1 L.S. $ $
1 L.S. $ $
1 L.S. $ $
Q
Unit Price Amount
1 L.S. $ $
1 L.S. $ $
1 L.S. $ $
2 ea. $ $
2 ea. $ $
240 L.F. $ $
570 L.F. $ $
1 L.S. $ $

ICWFF SPECIFICATIONS (Draft)
PROPOSAL (continued)
WETLAND AREA Ws 15.16 and 17
Erosion Control 1 L.S.
Clearing and Grubbing 1 L.S.
Grading and Filling 1 L.S.
18" RCP 65 L.F.
Class "B" Riprap 1 L.S.
Class 1 Riprap 1 L.S.
Seeding 1 L.S.
AREA #15,16 and 17 SUBTOTAL:
WETLAND AREA #20
Erosion Control
Clearing and Grubbing
Grading and Filling
Storm NIH/JB
36" F.E.S.
36" RCP
Seeding
AREA #20 SUBTOTAL:
12 March 1997 Page 6
Unit Price Amount

Unit Price Amount
1 L.S. $ $
1 L.S. $ $
1 L.S. $ $
2 ea. $ $
1 ea. $ $
794 L.F. $ $
1 L.S. $ $

ICWFF SPECIFICATIONS (Draft)
PROPOSAL (continued)
WETLAND AREA #22
Erosion Control
Clearing and Grubbing
Grading and Filling
Storm MH/JB
Raised Top Catch Basin
36" RCP
Tap Exist CI
Seeding
AREA #22 SUBTOTAL:
BORROW AREA #1
12 March 1997 Page 7
Unit Price Amount
1 L.S. $ $
1 L.S. $ $
1 L.S. $ $
2 ea. $ $
1 ea. $ $
576 L.F. $ $
1 ea. $ $
1 L.S. $ $
0
Erosion Control 1 L.S.
Install Temporary 36" CMP 1 L.S.
Remove Temporary 36" CMP 1 L.S.
Seeding 1 L.S.
BORROW AREA #1 SUBTOTAL:
Unit Price Amount

e

ICWFF SPECIFICATIONS (Draft)
PROPOSAL (continued)
SUMMARY
Subtotal Amount
Wetland Area #1 $
Wetland Area #6 $
Wetland Area #8 $
Wetland Area #9 $
Wetland Area #10B $
Wetland Area #13 $
Wetland Area #15, 16 & 17 $
Wetland Area #20 $
Wetland Area #22 $
Borrow Area #1
Total Lump Sum Proposal: $
UNIT PRICE SCHEDULE
(see Project Special Provision)
Unit Price
Clearing and Grubbing 1 Acre $
Overexcavation 1 C.Y. $
Placing Fill Material 1 C.Y. $
Gravel Construction Entrance 1 L.S. $
Silt Fence 1 L.F. $
Diversion Ditch 1 L.F. $
Class I Riprap 1 Ton $
Class B Riprap 1 Ton $
Stabilization Stone (No. 57) 1 Ton $
12 March 1997 Page 8
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 9
DIVISION 02 STTEWORK
Section 02/110 Site Clearing
A. General
1. Related Documents: Drawings and general provisions of Contract, including
General and Supplementary Conditions and Division 1 Specification Sections, apply
to this Section.
2. Summary
This Section includes the following:
a. Protection of existing trees.
b. Removal of trees and other vegetation.
c. Topsoil stripping.
d. Clearing and grubbing.
e. Removing above-grade improvements.
L Removing below-grade improvements.
3. Project Conditions
a. Traffic: Conduct site clearing operations to ensure minimum interference with
roads, streets, walks, and other adjacent occupied or used facilities. Do not
close or obstruct streets, walks or other occupied or used facilities without
permission from authorities having jurisdiction.
b. Protection of Existing Improvements: Provide protection necessary to prevent
damage to existing improvements indicated to remain in place.
(1) Protect improvements on adjoining properties and on Owner's property.
(2) Restore damaged improvements to their original condition, as acceptable
to property owners.
(3) Protection of Existing Trees and Vegetation: Protect existing trees and
other vegetation indicated to remain in place, against unnecessary cutting,
breaking or skinning of roots, skinning or bruising of bark, smothering of
trees by stockpiling construction materials or excavated materials within
drip line, excess foot or vehicular traffic, or parking of vehicles within drip
line. Provide temporary tree protection fencing to protect trees and
vegetation to be left standing as shown on the plans.
B. Products (Not Applicable)
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 10
DIVISION 02 STTEWORK (continued)
Section 02/110 Site Clearing (continued)
C. Execution
1. Site Clearing
a. General: Remove trees, shrubs, grass and other vegetation, improvements, or
obstructions as required to permit installation of new construction. Remove
similar items elsewhere on site or premises as specifically indicated. "Removal"
includes digging out and off-site disposing of stumps and roots.
b. Topsoil: Topsoil is defined as friable clay loam surface soil found in a depth of
not less than 4 inches. Satisfactory topsoil is reasonably free of subsoil, clay
lumps, stones, and other objects over 2 inches in diameter, and without weeds,
roots, and other objectionable material.
(1) Strip topsoil to whatever depths encountered in a manner to prevent
intermingling with underlying subsoil.
(2) Where existing trees are indicated to remain, leave topsoil in place within
drip lines and/or within designated tree protection limits as shown on the
plans to prevent damage to the root system.
(3) Stockpile topsoil in storage piles to provide free drainage.
(4) Dispose of unsuitable or excess topsoil in the same manner as specified
for disposed of waste material.
c. Clearing and Grubbing: Clear site of trees, shrubs and other vegetation, except
for those indicated to be left standing. Fill depressions caused by clearing and
grubbing with suitable fill material as specified under "Earthwork, Backfill and
Fill".
d. Removal of Improvements: Remove existing above-grade and below-grade
improvements as indicated and as necessary to facilitate new construction.
e. Sawcut existing asphalt and/or concrete pavement to the limits shown on the
plans prior to removal of pavement shown as 'TO BE REMOVED". Sawcut
full depth if pavement is less than 4" thick; sawcut to 4" depth or one-half of
pavement depth, whichever is greater if pavement is thicker than 4". Remove
existing pavement leaving a clean, straightedge to build to.
2. Disposal Of Waste Materials
a. Burning on Owner's Property: Burning will not be permitted on Owners
property.
b. Removal from Owner's Property: Remove trees, shrubs, stumps and other waste
materials from Owner's property.
c. Spread excess topsoil and unsuitable material in on-site areas designated on the
plans.
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 11
DIVISION 02 SITEWORK (continued)
Section 02/200 Earthwork
A. General
1. Related Documents: Drawings and general provisions of Contract, including
General and Supplementary Conditions and Division 1 Specification Sections, apply
to this Section.
2. Requirements of the State of North Carolina Soil Erosion and Sedimentation
Control Law and the Durham County Guidelines For Land Disturbing Activities
apply to this section.
3. Excavation is unclassified; see Part B.3-Definitions.
B. Summary
1. This Section includes the following:
a. Excavating and backfilling.
b. Final Grading, together with placement and preparation of topsoil for lawns
and planting, is specified in Division 2 Section, "Landscape Work."
2. Definitions
a. Excavation consists of removal of material encountered to elevations indicated
and subsequent disposal of materials removed.
b. Unauthorized excavation consists of removal of materials beyond indicated
elevations or dimensions without specific direction of Architect/Soils Engineer.
Unauthorized excavation, as well as remedial work directed by Architect/Soils
Engineer, shall be at Contractor's expense.
c. Additional Unsuitable Excavation: When excavation has reached required
elevations, notify Architect/Soils Engineer, who will make an inspection of
conditions. If Architect/Soils Engineer determines that materials at required
elevations are unsuitable, continue excavation until suitable bearing materials
are encountered and replace excavated material as directed by Architect/Soils
Engineer. The Contract Sum will not be adjusted for removal and replacement
of unsuitable bearing material.
3. Test Reports
a. Test reports will be paid for by the Owner unless otherwise specified. The
following test reports shall be sent directly to the Owner from the testing
services, with copy to Contractor:
b. Test reports on borrow material.
c. Verification of suitability of each subgrade material, in accordance with
specified requirements.
d. Field reports; in-place soil density tests.
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 12
DIVISION 02 SITEWORK (continued)
Section 02/200 Earthwork (continued)
e. One optimum moisture-maximum density curve for each type of soil
encountered.
4. Quality Assurance
a. Codes and Standards: Perform excavation work in compliance with applicable
requirements of authorities having jurisdiction.
b. Testing and Inspection Service: Owner will employ and pay for a qualified
independent geotechnical testing and inspection laboratory to perform soil
testing and inspection service during earthwork operations.
5. Project Conditions
a. Site Information: No geotechnical studies have been prepared for this project.
b. Existing Utilities: Locate and verify depth of existing underground utilities in
areas of excavation work. If utilities are indicated to remain in place, provide
adequate means of support and protection during earthwork operations.
(1) Should uncharted, or incorrectly charted, piping or other utilities be
encountered during excavation, consult utility owner immediately for
directions. Cooperate with Owner and utility companies in keeping
respective services and facilities in operation. Repair damaged utilities to
satisfaction of utility owner.
(2) Demolish and completely remove from site existing underground utilities
indicated to be removed. Coordinate with utility companies for shutoff of
services if lines are active.
c. Use of Explosives: Use of explosives is not permitted.
d. Protection of Persons and Property: Barricade open excavations occurring as
part of this work and post with warning lights. Provide shoring and bracing as
necessary to protect existing buildings, streets, walkways, utilities and other
improvements against loss of ground or caving embankments and in compliance
with OSHA requirements.
C. Products
1. Soil Materials
a. Satisfactory Soil Materials: ASTM D 2487 soil classification groups GC, GW,
GP, SC, SW, SP, MI., CL, and SM; free of rock or gravel larger than 2 inches
in any dimension, debris, waste, frozen materials, vegetation and other
deleterious matter. The soils engineer shall make the final determinations as
to the suitability of the soil.
b. Unsatisfactory soil materials are defined as those soils containing organic or
other deleterious material, excessive moisture, large rocks or lumps and soil
material containing graphite. The Soils Engineer shall make the final
determinations as to the suitability of the soil. Unsatisfactory Soil Materials:
ASTM D 2487 soil classification groups MH, OL, OH, and PT.
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 13
DIVISION 02 STTEWORK (continued)
Section 02/200 Earthwork (continued)
c. Backfill and Fill Materials: Satisfactory soil materials free of clay, rock or
gravel larger than 2 inches in any dimension, debris, waste, frozen materials,
vegetation and other deleterious matter. The Soils Engineer shall make the
final determination on the suitability of fill material.
D. Execution
1. Stability Of Excavations
a. General: Comply with local codes, ordinances, and requirements of agencies
having jurisdiction. All shoring shall comply with OSHA requirements.
b. Slope sides of excavations to comply with local codes, ordinances, and
requirements of agencies having jurisdiction. Shore and brace where sloping
is not possible because of space restrictions or stability of material excavated.
Maintain sides and slopes of excavations in safe condition until completion of
backfilling.
c. Shoring and Bracing: Provide materials for shoring and bracing, such as sheet
piling, uprights, stringers, and cross braces, in good serviceable condition.
Maintain shoring and bracing in excavations regardless of time period
excavations will be open. Extend shoring and bracing as excavation progresses.
d. Temporary side slopes for the new construction shall be constructed in
accordance with OSHA regulations. Virgin soils should stand for short periods
of time at slope angles of at least 1H: 1V, however, the individual cut slopes will
have to be inspected on an individual basis in order to confirm that a slope of
this angle will comply with OSHA regulations. Permanent slopes shall be
constructed at angles of not steeper than 2H:1 V except as previously
recommended where flatter slopes should be used if topsoil is the embankment
fill material.
2. Dewatering: Prevent surface water and subsurface or ground water from flowing
into excavations and from flooding project site and surrounding area.
3. Storage Of Excavated Materials: Stockpile excavated materials acceptable for
backfill and fill where directed. Place, grade, and shape stockpiles for proper
drainage.
4. Backfill and fill
a. General: Place soil material in layers to required elevations using materials
specified in Part C.1 of this Section.
(1) Use satisfactory excavated or borrow material.
(2) Under piping and conduit and equipment, use subbase materials where
required over rock bearing surface and for correction of unauthorized
excavation. Shape excavation bottom to fit bottom 90 degrees of cylinder.
b. Backfill excavations as promptly as work permits.
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 14
DIVISION 02 SITEWORK (continued)
Section 02/200 Earthwork (continued)
5. Placement And Compaction
a. Ground Surface Preparation: Remove vegetation, debris, unsatisfactory soil
materials, obstructions, and deleterious materials from ground surface prior to
placement of fills.
Plow strip, or break up sloped surfaces steeper than 1 vertical to 4 horizontal
so that fill material will bond with existing surface.
b. Control soil and fill compaction, providing minimum percentage of density
specified for each area classification indicated below. Correct improperly
compacted areas or lifts as directed by the Soils Engineer if soil density tests
indicate inadequate compaction.
c. All excavation, filling, and compaction operations shall be observed by the Soil
Engineer.
(1) Remove all unsuitable and deleterious material encountered in the field
from the project sites indicated on the plans (as directed by the Soils
Engineer). Waste areas are shown on the plans.
(2) All areas of fill (prior to fill operations) shall be tested for compaction by
the Soils Engineer.
(3) Imported fill from borrow pits must be material similar in content to
native material. All imported fill material must be tested and have the
approval of the Soils Engineer.
(4) Fill shall be deposited in eight (8) inches loose layers maximum. All fill
shall be compacted to a minimum of 95% of maximum density at
optimum moisture content ± 2% as determined by ASTM D-698.
(5) Fill density and soil bearing capacity tests shall be performed by Soils
Engineer.
(6) When wet excavation is encountered, the excavated area shall be
dewatered and kept free of water. All saturated material shall be
removed.
(7) Upon completion of the work of this section, immediately remove all
debris from the site and waste excess earth materials on the site.
6. Grading
a. General: Uniformly grade areas within limits of grading under this section,
including adjacent transition areas. Smooth finished surface within specified
tolerances, compact with uniform levels or slopes between points where
elevations are indicated or between such points and existing grades.
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 15
DIVISION 02 SITEWORK (continued)
Section 02/200 Earthwork (continued)
7. Field Quality Control
a. Quality Control Testing During Construction: Allow testing service to inspect
and approve each fill layer before further backfill or construction work is
performed.
b. Coordinate with geotechnical testing laboratory for testing of fill areas and
trench back fill as work progresses.
8. Erosion Control
a. General: Work included shall comply with the following:
(1) Approved soil erosion plan sequence and details. See Site Drawings.
(2) Requirements of the State of North Carolina Soil Erosion and
Sedimentation Control Law and Durham County Ordinances.
b. Products: All materials required for proper execution of this work shall be
furnished by the Contractor.
c. Execution:
(1) All work on this project shall be performed in a manner which will cause
a minimum of soil erosion, and shall be in accordance with the Soil
Erosion Control Plan. The Contractor shall perform such erosion control
work, temporary or permanent, to satisfactorily minimize erosion resulting
from his operations.
(2) If grading operations are suspended for any reason whatsoever, partially
completed cut and fill slopes shall be brought to the required slope and
the work of seeding and mulching or other required erosion control
operations shall be performed.
(3) The approved soil erosion plan including required sedimentation devices,
structures, construction sequence and seeding specifications shall be
adhered to and maintained to comply with the requirements of Durham
County Guidelines For Land Disturbing Activities and the North Carolina
Soil Erosion and Sedimentation Control Ordinances.
9. Maintenance
a. Protection of Graded Areas: Protect newly graded areas from traffic and
erosion. Keep free of trash and debris.
b. Repair and reestablish grades in settled, eroded, and rutted areas to specified
tolerances.
10. Disposal Of Excess And Waste Materials: Removal from Owner's Property:
Remove waste materials, including trash and debris, and dispose of off Owner's
property. Waste areas for disposing of unsuitable excavated material are shown on
the plans.
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 16
DIVISION 02 SITEWORK (continued)
Section 02/720 Storm Sewers
A. General
1. Related Documents: Drawings and general provisions of Contract, including
General and Supplementary Conditions and other Division 1 Specification Sections,
apply to this Section.
2. Summary: This Section includes storm sewerage system piping and appurtenances
to the point of discharge or connection to existing storm sewer.
3. Submittals
a. General: Submit the following in accordance with Conditions of Contract and
Division 1 Specification Sections.
b. Product data for drainage piping specialties.
c. Shop drawings for precast concrete storm drainage manholes and catch basins,
including frames, covers, and grates.
4. Project Conditions: Verify that storm sewerage system piping may be installed in
compliance with original design and referenced standards.
5. Sequencing And Scheduling
a. Coordinate connection to public storm sewer with the City of Durham.
B. Products
1. Pipe And Fittings
a. General: Provide pipe and pipe fitting materials compatible with each other.
Where more than one type of materials or products is indicated, selection is
Installer's option.
b. PVC (Polyvinyl Chloride) Sewer Pipe and Fittings: ASTM D1785, PVC pipe,
schedule 40.
c. Reinforced Concrete Sewer Pipe and Fittings: ASTM C 76, Class III, Wall B,
for mastic joints.
d. Non-reinforced Concrete Sewer Pipe and Fittings: ASTM C 14, Class 2, for
mastic joints.
e. Corrugated plastic pipe (HDPE) with smooth core interior ASTM F-405-"S"
(8") and ASTM F667-"S" (24").
f. Corrugated plastic pipe (HDPE) with corrugated wall ASTM F-405-"C" (4")
with knitted polyester sock filter.
g. Soil tight split coupler per ASTM F-405 for HDPE corrugated plastic pipe.
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 17
DIVISION 02 SITEWORK (continued)
Section 02/720 Storm Sewers (continued)
2. Manholes
a. Precast Concrete Manholes: ASTM C 478, precast reinforced concrete, of
depth indicated.
b. Brick Manholes: Brick and mortar, of depth indicated.
c. Cast-in-Place Manholes: Reinforced concrete of dimensions and with
appurtenances indicated.
(1) Bottom, Walls, and Top: Reinforced concrete.
(2) Channel and Bench: Concrete.
(3) Steps: Cast into sidewall at 12- to 16-inch intervals.
d. Manhole Steps: 12 inch wide cast iron, galvanized steel or steel encased in
corrosion resistant material (rubber or plastic).
e. Manhole Frames and Covers: Heavy-duty traffic bearing, cast iron, 24-inch
inside diameter by 7- to 9-inch riser with 4-inch minimum width flange, and
26-inch-diameter cover, indented top design, with lettering "STORM SEWER"
cast into cover.
3. Catch Basins
a. Precast Concrete Catch Basins: ASTM C 478 or ASTM C 858, precast
reinforced concrete, of depth indicated. Sections shall have provision for
rubber gasket joints. Base section slab shall have minimum thickness of 6
inches, riser sections shall have minimum thickness of 4 inches and be 48 inches
inside diameter, and top section and grade rings shall match 24-inch frame and
grate, unless otherwise indicated.
b. Brick Catch Basins: Brick and mortar, of depth indicated. Wall thickness shall
be 8 inches minimum, and inside diameter shall be 48 inches with tapered top
for a 24-inch frame and grate, unless otherwise indicated. Thickness of section
of wall deeper than 8 feet shall be 12 inches minimum.
c. Cast-in-Place Catch Basins: Reinforced concrete of dimensions and with
appurtenances indicated.
(1) Bottom, Walls, and Top: Reinforced concrete.
(2) Channel and Bench: Concrete.
d. Catch Basin Steps: 12 inch wide cast iron, galvanized steel or steel encased in
corrosion resistant material (rubber or plastic).
e. Catch Basin Frames and Grates: ASTM A 536 Grade 60-40-18, heavy-duty,
ductile iron, 24-inch inside diameter by 7- to 9-inch riser with 4-inch minimum
width flange, and 26-inch-diameter flat grate having small square or short
slotted drainage openings.
L Curb Inlets: Precast concrete, brick, or other materials, of dimensions
conforming to utility standards.
g. 18" PE catch basin: NDS Grates basins and risers (or Owner approved equal) -
cut sheets are attached. (Appendix "B")
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 18
DIVISION 02 SITEWORK (continued)
Section 02/720 Storm Sewers (continued)
4. Concrete And Reinforcement
a. Concrete: Portland cement mix, 3,000 psi.
b. Reinforcement: Steel conforming to the following:
(1) Fabric: ASTM A 185, welded wire fabric, plain.
(2) Reinforcement Bars: ASTM A 615, Grade 60, deformed.
C. Execution
1. Preparation Of Foundation For Buried Storm Sewerage Systems
a. Grade trench bottom to provide a smooth, firm, stable, and rock-free
foundation, throughout the length of the pipe.
b. Remove unstable, soft, and unsuitable materials at the surface upon which
pipes are to be laid, and backfill with clean sand, pea gravel or crushed stone
(100% passing 1-1/2" sieve and 0-5% passing a No. 50 sieve) to indicated level.
Clean native material to subgrade of pipe.
2. Pipe Applications For Underground Storm Sewers
a. Pipe sizes 12 inches and Larger: Reinforced concrete sewer pipe and fittings.
b. Pipe sizes smaller than 12 inches: PVC sewer pipe or non-reinforced concrete
sewer pipe.
c. HDPE corrugated plastic pipe: at locations shown on plans.
3. Installation, General
a. General Locations and Arrangements: Drawings (plans and details) indicate
the general location and arrangement of the underground storm sewerage
system piping. Location and arrangement of piping layout take into account
many design considerations. Install the piping as indicated, to the extent
practical.
b. Install piping pitched down in direction of flow, at minimum slope of 1 percent,
except where indicated otherwise.
c. Extend storm sewerage system piping to connect to building storm drains, of
sizes and in locations indicated.
4. Pipe And Tube Joint Construction And Installation
a. Join concrete pipe and fittings with mastic in accordance with applicable
provisions of ACPA "Concrete Pipe Installation Manual."
b. Join CCP in accordance with manufacturers published recommendations.
5. Manholes
a. General: Install manholes complete with accessories as indicated. Form
continuous concrete or split pipe section channel and benches between inlets
and outlet. Set tops of frames and covers flush with finish surface where
manholes occur in pavements. Elsewhere, set tops 6 inches (min.) above finish
surface, unless otherwise indicated.
ICWFF SPECIFICATIONS (Draft) 12 March 1997 Page 19
DIVISION 02 SITEWORK (continued)
Section 02/720 Storm Sewers (continued)
b. Construct brick manholes as indicated.
c. Construct cast-in-place manholes as indicated.
d. Apply bituminous mastic coating at joints of sections.
6. Catch Basins
a. Construct catch basins to sizes and shapes indicated.
b. Set frames and grates to elevations indicated.
7. Field Quality Control
a. Testing: Perform testing of completed piping in accordance with local
authorities having jurisdiction.
b. Cleaning: Clear interior of piping and structures of dirt and other superfluous
material as work progresses. Maintain swab or drag in piping and pull past
each joint as it is completed.
c. Interior Inspection: Inspect piping to determine whether line displacement or
other damage has occurred.
ICWFF SPECIFICATTONS (Draft) 12 March 1997 Page 20
APPENDIX "A"
WETLAND BOUNDARY
POINT COORDINATE LIST
BY
KEN CLOSE, INC.
Imperial Center ICWFF
Wetland Boundary Point Coordinate List
10 March 1997
Pt. No. Northing Easting Pt. No. Northing Easting
1 771168.9877 2047414.443 51 771247.3031 2046703.589
2 771161.1337 2047394.193 52 771215.9382 2046698.94
3 771145.3501 2047380.071 53 771195.3302 2046666.593
4 771108.8906 2047327.6 54 771213.8284 2046658.681
5 771084.8649 2047283.197 55 771231.4517 2046664.389
6 771034.4291 2047220.996 56 771278.5506 2046708.69
7 770971.6625 2047184.815 57 771343.151 2046756.036
8 770933.5389 2047142.462 58 771375.6967 2046842.606
9 770899.7241 2047114.637 59 771395.4219 2046849.973
10 770882.3245 2047095.046 60 771401.7303 2046877.648
11 770867.2191 2047051.319 61 771439.5189 2046915.867
12 770856.7256 2047059.188 62 771452.3028 2046940.884
13 770851.8212 2047078.664 63 771502.4006 2046980.965
14 770879.388 2047125.082 64 771556.9671 2047012.783
15 770915.0447 2047151.587 65 771592.8585 2047037.453
16 770961.9528 2047189.176 66 771631.5905 2047053.198
17 771010.3462 2047214.638 67 771675.2025 2047094.819
18 771031.9898 2047234.624 68 771698.6417 2047115.997
19 771075.2564 2047282.303 69 771716.9995 2047154.168
20 771106.8195 2047336.015 70 771754.0534 2047131.048
21 771143.5817 2047388.243 71 771770.5026 2047095.944
22 771160.9006 2047398.917 72 771826.8381 2047043.729
23 771164.3455 2047426.199 73 771863.0641 2046981.67
24 771485.5011 2047417.498 74 771885.1952 2046927.019
25 771495.2664 2047389.639 75 771896.9196 2046914.539
26 771540.3433 2047343.759 76 771875.126 2046872.921
26 771902.1569 2045833.731 77 771907.1079 2046837.215
27 771543.676 2047285.983 78 771960.6239 2046789.681
27 772081.7336 2045811.495 79 771996.4565 2046737.406
28 771613.8298 2047232.379 80 771997.3723 2046718.809
28 772224.0379 2045839.615 81 771959.8961 2046706.124
28 772224.0379 2045839.615 82 771937.8774 2046622.261
29 771613.0079 2047207.208 83 771910.6486 2046556.13
30 771628.0722 2047195.09 84 771931.0385 2046516.032
31 771635.8712 2047175.204 85 771935.0247 2046483.11
32 771647.537 2047172.001 86 771976.494 2046452.972
33 771637.3769 2047209.103 87 771972.025 2046413.123
34 771620.7663 2047228.208 88 772001.2032 2046399.467
35 771687.1967 2047204.705 89 772025.3397 2046397.705
36 771680.3646 2047183.766 90 772032.0552 2046370.592
37 771677.3572 2047146.42 91 772037.7164 2046361.867
38 771656.4084 2047105.926 92 772024.0135 2046343.202
39 771601.7476 2047069.02 93 771998.896 2046314.904
40 771553.4198 2047026.24 94 771938.8411 2046273.476
41 771510.5199 2047004.38 95 771906.2864 2046240.558
42 771465.8011 2046965.692 96 771883.4082 2046233.195
43 771430.6894 2046919.83 97 771845.0311 2046192.267
44 771384.4395 2046879.561 98 771816.2579 2046166.598
45 771379.8244 2046853.356 99 771786.218 2046171.179
46 771366.3037 2046843.205 100 771766.9937 2046141.991
47 771351.1937 2046816.046 101 771737.4925 2046121.67
48 771336.6309 2046777.762 102 771701.3348 2046096.137
49 771317.7832 2046753.86 103 771680.2554 2046082.305
50 771275.7578 2046722.809 104 771660.8977 2046046.448
Page 1
Imperial Center ICWFF
Wetland Boundary Point Coordinate List
10 March 1997
Pt. No. Northing Easting Pt. No. Northing Easting
105 771625.6035 2045991.506 158 772149.4842 2046686.645
106 771586.6361 2045948.96 159 772089.8148 2046671.114
107 771446.2847 2045886.965 160 772058.5381 2046660.565
107 771482.8547 2045913.488 161 772014.9878 2046672.956
108 771360.2716 2045852.673 162 772015.7031 2046696.994
109 771317.6352 2045815.125 163 772018.7261 2046741.916
1.10 771320.7896 2045796.593 164 771954.4442 2046824.57
111 771398.1197 2045854.136 165 771904.6364 2046883.36
112 771491.8823 2045886.079 166 771921.7409 2046926.416
113 771548.2279 2045902.384 167 771890.8425 2046957.898
114 771616.5716 2045930.774 168 771885.1697 2047008.447
115 771659.4369 2045985.069 169 771844.2797 2047058.144
116 771694.9018 2046024.331 170 771781.755 2047140.875
117 771739.479 2046067.439 171 771861.7574 2047135.316
118 771780.3726 2046121.825 172 771887.6182 2047152.286
119 771828.7172 2046166.308 173 771923.6532 2047162.054.
120 771871.6264 2046187.317 174 771969.2171 2047153.291
121 771912.8149 2046233.085 175 772011.7687 2047131.21
122 771944.4683 2046268.373 176 772010.2033 2047149.016
123 772000.3836 2046306.552 177 771964.6344 2047171.935
124 772045.5379 2046351.667 178 771913.2087 2047173.451
125 772045.3956 2046367.398 179 771848.7979 2047152.896
126 772097.2427 2046358.363 180 771819.0926 2047163.712
127 772100.5008 2046316.289 181 771759.7578 2047154.419
128 772082.9321 2046289.171 182 771621.9923 2047249.975
129 772059.8485 2046257.643 183 771576.1212 2047294.723
130 772065.5872 2046220.302 184 771571.4236 2047341.816
131 772126.6061 2046180.867 185 771554.2511 2047370.605
132 772196.0926 2046188.87 186 771528.2454 2047377.262
133 772134.7496 2046093.958 187 771509.1405 2047438.167
134 772192.6219 2045963.838 300 770557.1933 2045382.665
135 772206.7651 2046001.134 301 770589.8677 2045379.234
136 772162.2698 2046088.458 302 770619.107 2045380.12
137 772205.7575 2046162.013 304 770658.3284 2045365.335
138 772209.7218 2046208.71 305 770658.0665 2045372.067
139 772133.2669 2046202.829 306 770605.7723 2045390.295
140 772081.1315 2046239.319 307 770577.6258 2045392.413
141 772117.7283 2046293.342 308 770559.1874 2045403.11
142 772117.5264 2046373.109 400 772244.7602 2045022.69
143 772060.9607 2046384.284 401 772248.1534 2044981.87
144 772038.2804 2046418.144 402 772253.5837 2044951.648
145 771997.713 2046426.48 403 772230.418 2044897.446
146 771992.5489 2046469.185 404 772184.0964 2044830.907
147 771955.8261 2046500.161 405 772143.331 2044808.239
148 771929.7178 2046561.092 406 772089.0816 2044812.647
149 771961.1976 2046633.201 407 772037.5925 2044805.152
150 771963.5856 2046663.209 408 771996.3124 2044791.947
151 771976.7102 2046684.381 409 771953.4095 2044791.23
152 771993.5089 2046681.591 410 771898.4891 2044811.232
153 772009.312 2046658.505 411 771852.8743 2044810.007
154 772011.3413 2046647.302 412 771775.1869 2044779.598
155 772142.4298 2046664.396 413 771746.8154 2044772.137
156 772192.6681 2046667.021 414 771732.4858 2044774.514
157 772199.0116 2046693.383 415 771592.562 2044795.228
Page 2
Imperial Center ICWFF
Wetland Boundary Point Coordinate List
10 March 1997
Pt. No. Northing Easting Pt. No. Northing Easting
416 771535.3911 2044786.134 464 772410.6756 2044967.308
416 771535.6091 2044787.59 465 772424.8361 2044902.669
418 771479.4708 2044797.028 466 772450.3655 2044829.339
419 771392.1514 2044805.651 467 772443.2732 2044762.548
420 771314.071 2044787.405 468 772463.0139 2044700.07
421 771257.751 2044771.669 469 772489.9018 2044647.207
422 771206.4553 2044765.264 470 772501.929 2044592.963
423 771161.8812 2044724.625 471 772486.3301 2044544.14
424 771142.1479 2044702.478 471 771972.2292 2044107.566
425 771096.0067 2044689.435 472 772497.2815 2044457.227
426 771034.5725 2044683.55 473 772496.4621 2044403.218
427 770966.167 2044684.984 474 772502.43 2044347.726
428 770945.3495 2044687.436 475 772514.5579 2044275.715
429 770886.9529 2044694.534 476 772524.5865 2044216.809
430 770946.6071 2044676.152 477 772516.3185 2044202.146
431 771018.0198 2044666.212 478 772472.4895 2044194.938
432 771081.54 2044662.084 479 772435.6325 2044204.039
433 771104.7609 2044649.558 480 772402.2733 2044204.028
434 771119.8328 2044631.11 481 772375.1212 2044188.775
435 771109.775 2044586.76 482 772315.2922 2044202.175
436 771123.7469 2044550.083 483 772242.0791 2044206.327
437 771133.5349 2044550.532 484 772200.5183 2044216.247
438 771137.9017 2044586.726 485 772111.463 2044244.128
439 771150.158 2044641.352 486 772142.1115 2044217.63
440 771165.0086 2044676.512 487 772207.4724 2044208.125
441 771258.7746 2044720.307 488 772247.4171 2044196.553
442 771367.4198 2044738.472 489 772309.523 2044196.209
443 771463.0557 2044743.021 490 772365.6453 2044180.506
444 771564.5733 2044727.984 491 772421.8342 2044173.889
445 771678.7713 2044728.652 492 772472.5151 2044185.353
446 771756.8153 2044755.185 493 772535.2959 2044192.089
447 771820.2145 2044757.357 494 772533.2627 2044148.199
447 772224.3678 2044052.507 495 772531.9869 2044108.408
448 771880.5209 2044732.36 496 772576.2624 2044113.561
448 771922.5704 2044081.997 497 772564.5886 2044174.487
449 771946.8618 2044744.048 498 772548.0217 2044252.515
449 771822.9625 2044092.107 499 772531.8228 2044335.403
450 771994.5979 2044757.935 500 772534.3382 2044412.931
450 770903.2695 2044291.426 501 772505.0977 2044516.836
451 772061.5677 2044787.201 502 772650.8241 2044437.901
451 772211.2898 2045839.375 503 772714.0118 2044405.275
451 772211.2898 2045839.375 504 772717.0045 2044442.501
452 772114.9808 2044789.783 505 772604.725 2044502.784
453 772155.5612 2044790.792 506 772520.9863 2044543.616
454 772185.6525 2044814.479 507 772519.0844 2044634.66
455 772250.5191 2044885.674 508 772492.2798 2044691.301
456 772286.0439 2044897.79 509 772509.4694 2044712.934
457 772309.4469 2044909.706 510 772562.2716 2044728.497
458 772313.3386 2044943.696 511 772658.7094 2044775.609
459 772337.2368 2044973.5 512 772706.1681 2044802.779
460 772357.4932 2045007.656 513 772691.7197 2044833.421
461 772372.9533 2045031.62 514 772563.0261 2044764.102
462 772399.3344 2045031.513 515 772510.2029 2044739.355
463 772401.4998 2045016.157 516 772479.4236 2044737.12
Page 3
Imperial Center ICWFF
Wetland Boundary Point Coordinate List
10 March 1997
Pt. No. Northing Easting Pt. No. Northing Easting
517 772460.9856 2044776.181 652 772705.8319 2048358.975
518 772455.3339 2044863.378 653 772733.2609 2048399.43
519 772452.5886 2044898.136 654 772741.0885 2048437.697
520 772447.9692 2044940.848 655 772664.5678 2048619.161
521 772450.3193 2044976.48 656 772637.2409 2048659.149
522 772443.0566 2045026.136 657 772617.0638 2048689.207
523 772435.9478 2045055.399 658 772574.3937 2048826.112
600 775826.7166 2044355.93 659 772498.4232 2048785.577
601 773795.4415 2046816.895 661 772577.2625 2048670.38
602 773779.3923 2046809.923 663 772640.1471 2048580.277
603 773732.5732 2046794.711 665 772588.2099 2048625.204
604 773763.7577 2046696.324 700 773512.4907 2048680.047
605 773771.9014 2046671.246 _ 701 773519.613 2048638.135
606 773799.234 2046669.644 702 773531.5141 2048604.977
607 773798.3173 2046658.035 703 773554.6072 2048546.953
608 773756.7019 2046668.929 704 773570.4956 2048497
609 773714.4333 2046766.738 705 773563.7368 2048463.46
610 773689.7171 2046883.502 706 773557.1531 2048399.991
611 773703.7229 2046911.849 707 773567.8894 2048401.349
612 773676.6508 2046990.394 708 773575.653 2048465.293
613 773631.6693 2047073.992 709 773580.4165 2048500.502
614 773595.115 2047146.403 710 773564.7472 2048560.623
615 773544.3118 2047213.905 711 773546.9732 2048603.678
616 773523.9403 2047284.564 712 773548.3854 2048656.816
617 773452.8607 2047304.792 713 773549.1278 2048698.262
618 773692.1121 2047506.39 714 774086.6203 2048442.144
619 773734.1883 2047502.464 715 774069.7629 2048504.447
620 773768.5653 2047486.58 716 774041.6986 2048516.749
621 773816.6454 2047481.969 717 774020.7063 2048535.241
622 773876.6829 2047478.408 718 774032.1926 2048562.952
623 773937.5702 2047478.401 719 774024.1201 2048669.421
624 773850.9329 2047470.462 720 774016.9506 2048691.81
625 773817.2713 2047474.251 721 773980.2201 2048713.798
626 773747.2543 2047458.475 722 774030.4556 2048686.032
627 773678.3568 2047460.415 723 774074.183 2048621.958
628 773629.9886 2047422.602 724 774091.0641 2048548.601
629 773605.2962 2047399.545 725 774104.5213 2048517.774
630 773581.4642 2047402.015 726 774182.4797 2048435.428
631 773493.9995 2047340.195 727 774167.5083 2048427.093
632 773512.4554 2047314.915 728 774093.3695 2048512.059
633 773576.2986 2047253.294 729 774079.184 2048521.155
634 773596.2581 2047189.522 730 774105.1095 2048438.18
635 773609.5449 2047135.041 800 775078.955 2047384.75
636 773637.7119 2047083.189 801 775111.6307 2047340.638
637 773682.1358 2047003.492 802 775155.6995 2047329.24
638 773719.8283 2046915.894 803 775213.1495 2047282.113
639 772904.8069 2046796.846 804 775259.796 2047282.733
640 772947.5207 2046804.176 805 775329.2441 2047239.346
641 773009.518 2046801.534 806 775351.5535 2047214.611
642 773016.8258 2046790.339 807 775379.7574 2047210.833
643 772959.3244 2046769.295 808 775420.5729 2047147.089
644 772898.4455 2046766.224 809 775415.3426 2047117.54
650 772723.6799 2048417.326 810 775441.7034 2047060.369
651 772692.246 2048370.064 811 775454.7558 2047022.977
Page 4
Imperial Center ICWFF
Wetland Boundary Point Coordinate List
Pt. No. Northing Easting Pt. No.
812 775483.739 2047007.112 908
813 775433.0184 2047001.914 909
814 775391.6784 2046992.67 910
815 775356.6526 2046986.454 911
816 775269.1 2046977.26 912
817 775211.5162 2046971.211 913
818 775147.9158 2046964.366 914
819 775149.2929 2046957.033 915
820 775202.0741 2046962.101 916
821 775251.1531 2046965.426 917
822 775305.7964 2046964.011 1197
823 775320.8879 2046974.41 1198
824 775346.8155 2046979.053
825 775358.437 2046965.754
826 775431.0957 2046990.568
827 775489.5409 2046998.348
828 775537.1683 2046990.959
829 775559.0538 2046999.814
830 775497.0655 2047008.296
831 775465.1685 2047036.02
832 775448.3549 2047073.285
833 775435.0761 2047068.6
834 775435.6807 2047131.846
835 775429.0757 2047159.543
836 775386.6403 2047223.014
837 775343.6857 2047244.389
838 775281.5265 2047291.363
839 775206.5587 2047307.456
840 775155.6194 2047341.335
841 775122.2434 2047354.534
842 775085.5321 2047388.693
850 775020.3542 2046486.843
851 775049.1621 2046469.854
852 775099.9204 2046485.277
853 775191.6755. 2046524.982
855 775309.4237 2046575.235
856 775354.0591 2046600.219
857 775360.796 2046589.623
858 775282.2048 2046551.053
859 775269.2522 2046529.196
860 775167.5192 2046498.241
861 775116.3548 2046467.528
862 775058.8401 2046453.207
863 775029.5334 2046442.339
864 775028.1873 2046459.069
865 775024.2882 2046474.133
900 775754.4674 2046728.075
901 775793.2832 2046807.984
902 775772.5699 2046857.694
903 775792.8083 2046898.21
904 775785.979 2046910.749
905 775851.2866 2046934.972
906 775886.1049 2046976.147
907 775865.3213 2046985.163
Page 5
10 March 1997
Northing Easting
775818.7767 2046943.526
775793.3259 2046929.215
775757.7904 2046938.401
775755.6465 2046925.861
775770.0514 2046920.325
775778.7568 2046889.113
775756.4414 2046869.364
775772.4909 2046821.109
775774.6599 2046801.459
775740.771 2046736.738
771828.5159 2044146.826
771928.0216 2044136.727
ICWFF SPECIFICAITONS (Draft) 12 March 1997 Page 21
APPENDIX "B"
CUT SHEETS
GRATES, BASINS AND RISERS
(NDS)

-= DESCRIPTION PART NO. PKG.QTY. COLOR
,e„r 18" Square Grate 1810 4 Grey
1811 4 Black
1812 4 Green
1e 7r U th 18" 18" Basin Series
- ? ? se wi x
Specification: NDS #1810, #1811, #1812, 18" Structural
Foam Polyethylene Grate with UV Inhibitor. Open surface
area 104 sq. in.
18" x 18" GAL VANIZED STEEL GRATE
DESCRIPTION PART NO. PKG.QTY. COLOR
1, ,,,r _ 18"_Square Grate 1815 2- , , z Galvanise
::- 09? Use with 18- x 18 Basin Series.
L PM-
S -
1. 1.
Specification: NDS #1815, 18" x 18" heavy duty
Galvanized Steel Bar Grate. Open surface area 291.0 sq. in.
Specification: NDS #1800, #1804,18" x 18" Modular Catch
Basin with locking tabs.
1e

1
19 1/I•
,e +re•
I
er
Assembly Required. Includes 4 pcs. # 1822 and 1 pc. # 1828.
*Use #1800 and #1804 with #1206, #1243, #1244, #1245, #1266, or #1888
Universal Outlets (See page 17).
NOTE: Use Roof Tar or Silicone to seal joints.

Specification: NDS #1816, 6" Riser for 18" Catch Basin.

DESCRIPTION PART NO. PKG.QTY. COLOR
Two Opening Basin* 1800 1 Black " .'
Assembly Required. Includes 2 pc. - # 1820, # 1822, 1 pc. # 1828
Four Opening Basin* 1804 1 Black ::
DESCRIPTION PART NO. PKG.QTY. COLOR
6" Extension 1816 1 Black
Riser package includes 4 sides.
DESCRIPTION

PART NO. PKG.QTY. COLOR
Frame to Adapt 18" x 18" 1840
Grate to Concrete
Catch Basin
4 Black ,
Specification: NDS #1840, 18" x 18" Frame.
zSWIO
INNER R1W
..
3700
z ?
INNER
?z1
Specification: NDS #1245 3" and 4" Offset Universal
e VP 10
INNER RING
i
0VMR FWM
0r
?z iene•
I
Specification: NDS #1266, 6" Universal Outlet.
4D
o e
I?
3" & 4" Universal Outlet* 1243 20 Black
Fits 3' and 4" Corrugated Pipe and 4" Sewer and Drain Pipe.
3" & 4" Universal Outlet* 1244 20 Black
Fits 3" and 4" Corrugated Pipe and 3" and 4" Sewer and Drain
Pipe.
* Use with 9'x 9', 12"x 12" and 18'x 18" Catch Basin Series and
#930, # 1230 and # 1830 Adapters.
DESCRIPTION PART NO. PKG.QTY. COLOR
3" & 4"..Offset Universal Outlet 1245 ` v. 20 Black
Fits 3' and 4' Corrugated Pipe and 4' Sewer and Drain Pipe.
Y?
Allows for Adjusting Inlet Height.
Use with 9'x 9", 12'x 12" and 18'x 18" Catch Basin Series.
DESCRIPTION PART NO. PKG.QTY. COLOR
6" Universal Outlet 1266 20 Black '
Fits 6' Sewer and Drain Pipe and 6" Corrugated Pipe.
Use with 9'x 9, 12"x 12" and 18'x 18" Catch Basin Series and
#930, # 1230 and # 1830 Adapters.
DESCRIPTION PART NO. PKG.QTY. COLOR
8" Universal Outlet 1888 .8 Black
Fits 8' Corrugated, and 8' Sewer and Drain Pipe. r
Use with 18'x 18' basin series only.
Universal Outlet Reducer Ring 1890 8 Black
Required on # 1821 Basin Side to adapt to # 1206, # 1243, # 1244,
# 1245, or # 1266 Universal Outlets.
DESCRIPTION PART NO. PKG.QTY. COLOR
Universal Plug 1206 20 Black
Use with 9'x 9, 12"x 12" and 18'x 18" Catch Basin Series.
I

Specification: NDS #1206, Universal Plug.
?z1
Specification: NDS #1243 or #1244, 3" and 4" Universal
Outlet.
Specification: NDS #1888, 8" Universal Outlet.
E 8 July
ICWQPI
w o Page 1
z
z @ Mr. Peter Colwell
a State of North Carolina

J 0
DEHNR
Division of Water Quality
w P.O. Box 29535
' Raleigh, NC 27626-0535
N
N N Reference: Imperial Center Wetland Fill Plan and Water Quality Pond
a
M
w
Im
P

Dear Mr. Colwell:
W
P
Z ,0 We are, as discussed by telephone Monday, forwarding the current construction plans for the
Water Quality Pond and the Wetland Fill Plan to address the concerns in your letter of 7
Z April 1997. The cover sheet on the Wetland Fill Plan reflects the current status of
w development at Imperial Center.
N
M
We are also forwarding a copy of the "Wetland Mitigation Plan" dated 25 March 1997 and
a prepared by Soil & Environmental Consultants. I was recently informed this plan had not
N C been forwarded to DWQ. We are, under separate cover, forwarding this to Mr. Dorney for
0 his files. The "holes" in this document will be filled in as the information becomes available.
w The Owners are currently obtaining plant material and installation prices from contractors
qualified in the wetland planting area. Physical construction of the Water Quality Pond is
- o substantially complete; filling of the wetlands is scheduled to be complete by 1 November
N 1997; planting the wetland mitigation area will be accomplished in the Fall of 1997 and the

a _
Spring of 1998.

Q 0
o
You also indicated a concern over construction of the IBM customer fulfillment center
s adjacent to Wetland Area #10. We have enclosed a copy of the site plan, with the wetlands
o limits delineated, to address your concern in this area.
z
s
We trust this answers your concerns. Please call me at 832-6658 if you have any questions.
o Incidently, you should address future correspondence to TriProperties to David Davenport's
attention.
0
Sincerely,
0
Ed Sconfienza, P.E.
Enclosures
EFS:s1s
w cc: David Davenport/TriProperties
ME'U Chris Huysman/Soil & Environmental Consultants
¦RrE
EME
?a
IMPERIAL CENTER STORMWATER LAKE
WETLAND MITIGATION PLAN
DURHAM, DURHAM COUNTY,
NORTH CAROLINA
SUBMITTED IN COMPLIANCE
WITH A CONDITION OF THE
401 WATER QUALITY CERTIFICATION
PREPARED FOR:
Tri Properties, Inc.
1009 Slater Road, Suite 110
Durham, NC 27705
PREPARED BY:
Mike Ortosky - Soil Scientist
Chris Huysman - Biologist
Soil and Environmental Consultants, Inc.
Job Number: 2699
3/25/97
of
A
IMPERIAL CENTER
WETLAND MITIGATION PLAN
EXECUTIVE SUMMARY:
INTRODUCTION:
IMPACT SITE:
MITIGATION SITE:
REFERENCE ECOSYSTEM:
MITIGATION GOALS:
SUCCESS CRITERIA:
COMPONENTS OF THE MITIGATION SITE:
MITIGATION SEQUENCE:
MONITORING AND MANAGEMENT:
Appendix 1: Planting Plan and Specifications
Appendix 2: Proposed Potential Sources for Plant Material
Appendix 3: Proposed Seed Mixture for Stabilization
Appendix 4: List of Plan Authors and References
Map 1: Site Vicinity Map
Map 2: Mitigation Site Map
Attachment 1: As-built Plans
Attachment 2: Pre-construction Meeting Log for Imperial Center
1
Soil and Environmental Consultants, Inc.
Job Number: 2699
3/25/97
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w
HAPERIAL CENTER
WETLAND MITIGATION PLAN
EXECUTIVE SUNPAARY:
Soil and Environmental Consultants, Inc. (S&EC), in conjunction with Tri Properties, Inc.
and Envirotek, Inc. (clients), has developed this mitigation plan to satisfy a NC Division of
Water Quality (DWQ) requirement for issuance of a 401 Water Quality Certification for
the Imperial Center in Durham, NC. The impacted wetlands and wetland mitigation sites
are located within the Stirrup Iron Creek drainage basin; as shown on Map 1: Site Vicinity
Map ( USGS topo). Water quality protection will be afforded by the establishment of a
vegetated littoral bench on the stormwater pond. The success and progress of the project
will be quantified over a period of five years with reports periodically furnished to DWQ
and the Army Corps of Engineers (COE). Mitigation success will be measured in terms of
herbaceous coverage and woody plant survival. Plant material that is to be added to the
site will be suited for the soils and final hydrology and will be derived from local sources.
Hydrology at the mitigation site will be provided by maintenance of normal pool elevation
within the stormwater pond. The proposed mitigation satisfies a 401 Water Quality
Certification Condition placed on the project in 1994. No endangered species,
archeological resources, or hazardous waste sites will be impacted by this effort.
INTRODUCTION:
This mitigation plan describes the impact sites and the resulting mitigation sites as well as
the reference ecosystems used in planning the mitigation activities. Mitigation goals and
success criteria are discussed as guidance to the development of the mitigation plan. The
components of the proposed mitigation site (vegetation, soils, hydrology) are described as
interrelated components of the overall plan. A mitigation sequence is offered as guidance
in scheduling and installation of the mitigation components. Finally, monitoring and
management of the mitigation site are discussed as a means of assuring the long-term
success of the project.
RAPACT SITE:
The impact sites are headwaters forested areas and freshwater marsh types. Wetland
vegetation at the impact site consists of the species listed below which are found within
jurisdictional areas. Soils, in wetland areas, were determined to be poorly drained
Wehadkee Soils.
VEGETATION WITHIN THE IlVIPACT SITE*
Acer rubrum red maple fac
Acer negundo box-elder facw
2
Soil and Environmental Consultants, Inc.
Job Number: 2699
3/25/97
UAPERIAL CENTER
WETLAND UMGATION PLAN
Alnus serrulata tag alder facw+
Betula nigra river birch facw
Boehmeria cylindrica false nettle facw+
Carex spp. Sedge facw(+)
Cornus amomum silky dogwood facw+
Corylus cornuta beaked hazel-nut facu
Eleocharis spp. Spikerush facw or greater
Eulalia viminea microstigium fac+
Eupatoriadulphus spp. Joe-pye weed fac or greater
Ilex opaca American holly fac
Impatiens capensis jewel weed facw
Juncus effusus soft rush facw+
Ligustrum sinence Chinese privet fac
Lindera benzion spice bush facw
Liquidambar styraciflua sweet gum fac+
Liriodendron tulipifera tulip poplar fac
Ludwigia spp. Box-seed obl
Nyssa sylvatica black gum fac
Platanus occidentalis sycamore facw-
Pluchea foetida stink-weed obl
Quercus phellos wiflow oak facw-
Salix nigra black willow obl
Sambucus canadense American elder facw-
Woodwardia areolata netted chain fern obl
*These species occur at the impact site and likely will regenerate
at the mitigation site as volunteers.
MITIGATION SITE:
The proposed pond will be excavated in non-wetland floodplain alluvium and to a limited
extent, within the toeslopes of the adjacent uplands. Impacts to jurisdictional channels are
required for the construction of the pond. The pond is to be constructed in accordance
with accepted stormwater pond design criteria. Portions of the proposed pond may be
excavated to depths below soil material. This will affect the amount of topsoil fill required
in those areas. The limits of these areas will not be fully known until they have been
excavated.
REFERENCE ECOSYSTEM:
The reference ecosystems are fresh water marsh and pond headwater areas types typical of
impoundments in the region. The reference ecosystems are suitable for illustrating
3
Soil and Environmental Consultants, Inc.
Job Number. 2699
3/25/97
11"ERIAL CENTER
WETLAND MITIGATION PLAN
regional native plant community reactions to saturation and inundation in a man made
feature. The reference ecosystems were selected based on their similarities with the design
concept and their proximity within the local Piedmont landscapes.
MITIGATION GOALS:
1) A self-sustaining littoral wetland and aquatic plant community within a formerly
non-wetland site.
2) Functional value as associated with similar wetland communities.
3) Spatial extent commensurate with mitigation requirements and aesthetic value.
SUCCESS CRITERIA:
Spatial success will be realized when 75% herbaceous coverage is attained within the
mitigation site and 75 % of woody wetland plants have survived for three years. The
herbaceous cover must be comprised of at least three of the introduced or volunteer
species. The estimated schedule for achieving 75% coverage is by the third growing
season, however, the site will be monitored until success is achieved. Woody plant
survival is defined as the percent of material alive based on the planting spacing (i.e. 2' x
2'- forbes spp. and 6'x 6' -shrub spp.), or volunteers within that area. At least 50% of the
vegetation must be FACW or OBL.
If after the second growing season coverage is significantly lower than what is expected in
a normal progression necessary to reach 75% by the end of the third season (<1/3
coverage), a plan to rectify the situation will be prepared and submitted to the client and
DWQ within 30 days of inspection.
Functional success of the mitigation project will be assumed upon achievement of the
spatial criteria. Enhancement of bank stabilization, flow control, pollutant removal,
wildlife habitat, and educational and aesthetic aspects of the site may be assumed through
successful re-vegetation with wetland plants. Additionally, the functional value as a
dispersal corridor may be assumed once the plant community interfaces with adjacent
native plant communities.
4
Soil and Environmental Consultants, Inc.
Job Number: 2699
3/25/97
MTERIAL CENTER
WETLAND MITIGATION PLAN
COMPONENTS OF THE MITIGATION SITE:
Vegetation
Plant material will be added to the littoral bench after completion of grading and during
the next appropriate growing season. Proposed plant material is described in Appendix I,
PlantingPlans and Specifications . Plant material will be appropriate for a littoral edge
community. Volunteer plants will also invade the littoral edge over time from propagules
in the existing and imported soil and from off-site sources (animals, inflowing water, wind,
etc.).
Soils
Soil in the reference ecosystem have been identified as the Wehadkee Soil Series by on-
site evaluation. Upon completion of rough grading, the mitigation site (littoral bench) will
be composed of existing alluvial soils, areas graded to non-soil, and fill material from the
adjacent areas. Some areas will undoubtedly be unsuitable for planting due to poor
physical and fertility conditions. Some of the existing alluvial topsoil at the pond site
and/or the topsoil from the impacted wetland sites will be stockpiled for use where
unsuitable areas result from grading. Where unsuitable material is encountered in the
mitigation area, the site will be over-excavated by 6" (0.5') and the stockpiled material
will be used to bring the littoral bench up to final grade during fine-grading. Soil
amendments are discussed in Appendix I, Planting Plans and Specifications.
Hydrology
Hydrology (a saturated and inundated soil condition on the littoral bench soils) at the
mitigation site will be established after completion and filling of the stormwater pond.
Normal pool elevation will flood the littoral bench from 0" to 12" in depth. Normal pool
will be maintained by inflow from Stirrup Iron Creek and runoff from adjacent landscapes.
During storm events, water elevation will rise for short periods as the outlet device detains
the excess flow. The stormwater outflow will be regulated by a low flow device which
releases the excess water over time, preventing high peak flows downstream. Pollutant-
containing stormwater will be detained in the pond during that time and the detention
effect of the pond and the plant community of the littoral bench will act in combination to
reduce the pollutant load.
MITIGATION SEQUENCE:
Erosion Control-
5
Soil and Environmental Consultants, Inc.
Job Number: 2699
3/25/97
IMPERIAL CENTER
WETLAND MITIGATION PLAN
The pond installer will erect the appropriate erosion control devices in all necessary areas
so as to avoid excessive siltation within the construction area and shall be responsible for
securing all needed land clearing permits.
Pre-construction meeting-
Pre-construction / planting meeting with the installer, Client representative, designer
(S&EC), and DWQ to review the plan and confirm the roles of all involved parties. A
log of this meeting will be appended to this plan (See Attachment 5: Pre-construction
Meeting Log or ...).
Pond Installation -
The stormwater detention pond will be constructed according to approved detention pond
design criteria. The littoral bench shall be constructed according to the grading plan and
soil criteria as described in the Components of the Mitigation Site section.
Plantings-
Upon completion of grading, plant littoral bench with either stabilization plantings or, if
the season is appropriate, plant permanent plantings (spring - herbaceous marsh plants and
shrub/tree species or fall - shrub/tree species) per planting plans and specifications.
As-built Plan -
The designer will prepare a general as-built plan for the site after site preparation and
planting which shows relative elevations within site, establishes reference elevations, and
locates areas to be monitored during the evaluation period.
Project Evaluation -
Following initial plantings the monitoring and maintenance phase begins as described in
the following section.
MONITORING AND MANAGEMENT:
Tri Properties will be responsible for all financial aspects of the project and the long-term
maintenance of the mitigation site (after the fifth growing season). The installer and / or
designer will be responsible for reporting on and assisting with the monitoring,
maintenance, and management of this site until success criteria are met. Evaluation
reports drafted by the designer will be furnished to the clients, DWQ and COE. Reports
will contain data pertaining to percent herbaceous coverage and plant survival, and a
6
Soil and Environmental Consultants, Inc.
Job Number: 2699
3/25/97
P PERIAL CENTER
WETLAND MITIGATION PLAN
narrative of management activities and general project condition. A final report will be
prepared upon the completion of the monitoring period or until success criteria are met.
Should an unanticipated catastrophic event destroy the mitigation site within the
monitoring period a contingency plan will be drafted.
Monitoring and evaluation of site will include:
Site inspections, by S&EC and client, during the installation and monitoring of the
mitigation site to identify potential depredation and degradation sources; if any are
identified, a plan to rectify the problem(s) will be appended .
Final inspection after all site work is complete, preparation of appropriate
completion 'of work statement, preparation of a brief as-built report, sketch plan,
and documentary photos and submission of that report to DWQ for
review within 60 days of completion.
Location of mitigation sites (planted material) such that it can be differentiated
from native succession.
Site inspection early in first growing season.
Site inspection at end of first growing season and preparation of letter of
evaluation, documentary photos, and suggested treatment of any failed areas
and submission to DWQ within 30 days of inspection.
Site inspection during late growing season of second and third years with
documentary photos and letter of evaluation at end of third growing season (to
DWQ within 30 days of inspection).
Management and maintenance of the site will focus on establishment and protection of the
wetland and will consist of the following:
Removal of undesirable sprouting woody vegetation (by hand-taking rootstock if
possible) within the systems. To be done in late August -
September of the growing seasons.
Re-planting of any bare or sparse spots during season appropriate to plant species
as necessary to achieve success.
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Job Number: 2699
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BeERIAL CENTER
WETLAND MITIGATION PLAN
Maintaining ground cover and sediment control devices on all up-slope uplands to
prevent sedimentation within the mitigation area.
Removal and control of any potentially degrading factors such as destructive
wildlife, humans, domestic animals, and debris.
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Job Number: 2699
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INTERIAL CENTER
WETLAND MITIGATION PLAN
Appendix 1: Planting Plan and Specifications
The mitigation site will be planted with the appropriate species at the start of a growing
season. A preliminary listing of species is found below; additional species may be selected
after site preparation and site equilibrium and will be noted in the As-built Plan: Tri
Properties Mitigation Plan (Attachment 4:). If the season is not appropriate for
installation of permanent plantings, the site will be stabilized with a readily available
temporary cover (Appendix 4: Proposed Seed Mixture for Stabilization). The planting
plan is subject to change upon completion of site preparation, all changes will be noted in
subsequent reports and the as-built plans.
The site will be prepared accordingly and be planted as described below and with all
appropriate soil amendments.
Littoral Bench / Marsh Areas:
Water Depth Range 011- 12"
Juncus effusus
Typha angustifolia
Scirpus cyperinus
Pontederia cordata
Iris versicolor
Iris pseudocorus
Cephalanthus occidentalis
Taxodium distichum
Magnolia virginia
All marsh / emergent plants will be planted on a 2'x2' spacing. Shrub and tree species will
be planted on a 6'x6' spacing. Refer to accompanying sample planting plans for typical
arrangement.
Plant Material Specifications (Adapted from Garbisch, 1995)
Balled and Bagged (Woody Plants):
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Job Number: 2699
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The size of the earthen ball shall be at least as large as specified in the American Standard
for Nursery Stock (1980). Where plants are to be planted in soils that will be saturated
most of the growing season, the bagged root ball shall have a surface diameter that is at
least 1/2 the diameter of the un-pruned drip-line and a depth that is at least 8" per 5' of
tree/shrub height.
If not planted immediately upon delivery to the job site, plants shall be stored in shade and
root balls kept moist through periodic watering until the time of planting.
If growing, the plants shall appear healthy with no leaf spots, leaf damage, leaf
discoloration, chlorosis, leaf wilting or curling, or evidence of insects on the leaves.
Container (Woody and Herbaceous Plants):
The soil within the root ball shall be at field capacity (1/3 atmosphere) or wetter upon
delivery to the job site. Any wilted, dry and/or light weight plants shall be rejected. If not
planted immediately upon delivery to the job site, plants shall be stored in shade and root
balls kept moist through periodic watering until the time of planting.
The container size shall be at least as large as specified. Plants shall not necessarily be
rejected when supplied in containers larger than specified. However, the soil/root masses
shall be the size of the specified container size. If the soil/root masses are substantially
smaller than the specified container size and loose soil exists on the sides and bottom of
the containers, indicating that plants have not been in specified containers long enough to
root into surrounding soil, the plants shall be rejected.
If growing, the plants shall appear healthy with no leaf spots, leaf damage, leaf
discoloration, chlorosis, leaf wilting or curling, or evidence of insects on the leaves.
For trees and shrubs, where spiraling woody roots exist on the outside of the soil/root
mass upon the removal of the plants from the containers, the landscape contractor shall
separate (cutting where necessary) and spread them out (frazzle) prior to planting.
Fiber or Peat Pot (Herbaceous Plants):
If not planted immediately upon delivery to the job site, plants shall be stored in shade and
root masses kept moist through periodic watering until the time of planting.
The plants shall be well-rooted through the sides and bottoms of the pots and firmly
contained therein.
If the plants may be easily removed from the pots by holding the upper portion of the plant
and gently pulling on the pots, the plants shall be rejected.
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Job Number: 2699
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HAPERIAL CENTER
WETLAND MITIGATION PLAN
If growing, the plants shall appear healthy with no leaf spots, leaf damage, leaf
discoloration, chlorosis, leaf wilting or curling, or evidence of insects on the leaves.
The pot size shall be at least as large as specified. Plants shall not necessarily be rejected
when supplied in pots larger than specified.
The number of plants or stems (culms) per port as specified shall be present at the
minimum, and on the average, or the plants shall be rejected.
Dormant Propagule (Herbaceous Plants):
If not planted immediately upon delivery to the job site, the dormant propagules shall be
stored out of direct exposure to the sun and wind and they shall be protected by covering
with straw, peat moss, compost, or other suitable materials and shall be kept moist,
through periodic watering, until the time of planting.
The bodies and shoots associated with the propagules shall have turgor or be rigid to the
touch. If the bodies and/or shoots associated with the propagules are soft or mushy, or
appear rotten or decomposed, the plant materials shall be rejected. Rhizome (stolon)
sections shall provide a minimum of two shoots per section. Or: Rhizome (stolon)
sections containing at least a terminal shoot shall be a minimum of four inches (4") in
length (in order to ensure sufficient stored energy to support the new growth). Rhizome
sections containing shoots that are soft or mushy or otherwise appear rotten shall not be
accepted.
Plug (Herbaceous Plants. Woody Seedlings, or Rooted Cuttings):
If not planted immediately upon delivery to the job site, the plugs whether in or out of
their growing units shall be stored out of direct exposure to the sun and wind and
maintained moist through periodic watering until the time of planting. If the plugs are not
contained in their growing units upon delivery and will not be planted immediately, they
should be treated as above and their root masses shall be protected by straw or other
suitable materials and maintained moist, through periodic watering, until planting time.
Plugs shall have solid soil/root masses with the soil in place. Roots shall appear clean and
white in coloration.
If growing, the plants shall appear healthy with no leaf spots, leaf damage, leaf
discoloration, chlorosis, leaf wilting or curling, or evidence of insects on the leaves.
If dormant (herbaceous), new healthy shoots shall be apparent. Plugs containing shoots
that are soft or mushy or otherwise appear rotten shall not be accepted.
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If dormant (woody), stems shall be pliable and exhibit light green to yellowish green
cambium. Plugs containing brittle stems and having unhealthy cambium shall not be
accepted.
Plugs (woody seedlings) shall have widths that are at least to the limb lines of the
seedlings and have depths that are at least one-fourth the heights of the seedlings.
Seed:
Shall be delivered in clean, unopened containers and labeled as to seed origin, purity,
germination percentage, and date of germination testing.
Fertilization
Herbaceous plantings:
Spring plantings - Use Osmocote 18-6-12, eight to nine month release fertilizer, to be
placed in hole at time of planting. For Dormant propagules, container/fiber pot, or plug
seedlings use about 15 grams (0.5 oz.) per planting.
Woody plantings:
Fall/Winter plantings - Use Osmocote 18-5-11, twelve to fourteen month release fertilizer,
to be placed in hole or in soil fill/amendment mix at planting. Use 30 grams (1 oz.) per 1
quart container, 90 grams (3 oz.) per 1 gallon container (30 grams per each additional
gallon). Use 15 grams (1 oz.) per un-rooted cutting for willow whips.
Soil Amendments:
Soil amendments are required only around tree and shrub plantings, with the exception of
significantly graded areas (where stockpiled wetland topsoil may be used). The
amendment used should be leaf or pine bark compost at rates of one part compost to one
part soil (from planting hole). Fertilizer should be mixed in with soil/amendment mix. No
surface mulch is required where plants are planted at or near original grade.
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Job Number: 2699
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A
IIAPERIAL CENTER
WETLAND MITIGATION PLAN
Appendix 2: Proposed Potential Sources for Plant Material
(additional sources may be proposed prior to installation, for approval by DWQ).
Herbaceous material:
Campbell's Greenhouse Carlton Campbell/Larry Hobbs
2816 Campbell Road
Raleigh, NC. 27606 919-851-1162
(also has team of experienced installers)
Shrub Material:
Campbell's Greenhouse
2816 Campbell Road
Raleigh, NC. 27606
Carlton Campbell/Larry Hobbs
919-851-1162
Fern Valley Farms
1624 Fern Valley Road
Yadkinville, NC. 27055
NC Forest Service Nurseries
Raleigh, NC.
Specimen ornamental species:
Campbell's Greenhouse
2816 Campbell Road
Raleigh, NC. 27606
Tom Clark
910-463-2412
Carlton Campbell/Larry Hobbs
919-851-1162
Niche Gardens .
1111 Dawson Road
Chapel Hill, NC. '27516
Woody tree species:
NC Forest Service Nurseries
Raleigh, NC.
Kim Hawkes
919-967-0078
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Job Number: 2699
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WETLAND MITIGATION PLAN
Appendix 3: Proposed Seed Mixture for Stabilization
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Job Number: 2699
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IMPERIAL CENTER
WETLAND MITIGATION PLAN
Appendix 4: List of Plan Authors and References
REFERENCES:
Garbish et al., Environmental Concern Inc., 1995. 210 West Chew Avenue. St,
Michaels, Maryland 21663
USACOE, Wetland Development and Restoration. 1993. Government Printing
Office. Washington, DC
PREPARED BY:
J. Michael Ortosky, Jr.
Licensed Soil Scientist
Soil and Environmental Consultants, Inc.
Christopher Huysman
Biologist and Wetland Scientist
Soil and Environmental Consultants, Inc.
Bob Zarzecki
Biologist
Soil and Environmental Consultants, Inc.
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Job Number: 2699
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WETLAND MITIGATION PLAN
Map 1: Site Vicinity Map
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Job Number: 2699
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IMPERIAL CENTER
WETLAND MITIGATION PLAN
Map I Mitigation Site Map
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Attachment 1: As-built Plans
To be attached upon completion.
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Job Number: 2699
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Attachment 2: Pre-construction Meeting Log for Imperial Center
Mitigation Designer's Representative Date
Client's Representative Date
Installer's Representative Date
Division of Water Quality Representative Date
NOTES:
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