On-site Mitigation Planning

The Natural Environment Engineering Group (NEEG) is a multi-discipline group of engineers that are involved in the planning, design, construction, monitoring, and remediation of on-site and/or adjacent wetland, buffer, stream, and conservation mitigation sites, statewide. These mitigation efforts are a result of unavoidable environmental impacts associated with roadway construction projects. The projects are used for compensatory mitigation to offset unavoidable environmental impacts pursuant with State and Federal Environmental Law and Guidelines. The mitigation projects are closely coordinated with several different internal Department Units, as well as State and Federal Environmental Regulatory Agencies, adjacent property owners, and the local citizens.

Planning

Once potential on-site mitigation areas are identified along, or adjacent to, the proposed roadway corridor in the Merger Process, the NEEG Supervisor is sent a request for input from the Natural Environment Unit's Indirect and Cumulative Impact (ICI) Group. This request will occur after the 4b Merger Meeting. The request should include a brief description of the project, along with the type of input that is requested for the project. Upon receipt of the request the NEEG Supervisor will assign the project to the appropriate staff within the group. The NEEG is responsible for providing input to the ICI Group involving site design constraints, construction issues, and post-construction monitoring activities.

Following the 4b Merger Meeting, the ICI Group, NEEG, and the Hydraulics Unit will coordinate to determine which potential sites should move forward and the method in which they will be investigated. This will be accomplished using one of the following methods: Hydraulics Unit "in-house", Hydraulics Unit "on-call" consultant, NEU "on-call" consultant, or Design Build.

Design

The NEEG is involved in establishing the design requirements for all wetland, stream, buffer, and conservation mitigation sites throughout the Department. Once the method for design is established, draft design plans are established in accordance with the following requirements. All plan sheets shall adhere to the NCDOT Highway Design Manual. The manual is located at the following website:http://www.doh.dot.state.nc.us/construction/ps/contracts/default.htm

Method of Task Completion

Upon identification of potential mitigation sites, the Hydraulics Unit, ICI Unit and the NEEG will decide how to accomplish the design task. One of the following methods is utilized to complete Design:

Hydraulics Unit "in-house"

The Hydraulics Unit will complete the design of the mitigation site utilizing the Design Requirements stated below. The NEEG will provide comments on the design.

Hydraulics Unit Consultant

The Hydraulics Unit will utilize one of their "on-call" consultants to complete the design of the mitigation site utilizing the Design Requirements stated below. The NEEG will provide assistance in the development of the scope, task list and cost estimate. The NEEG and ICI Group will also provide comments on the design.

Design Build

The NEEG and Hydraulics Unit will coordinate with the NCDOT Project Services Unit to develop a Scope of Work to be included in the Design Build Package. The NEEG and Hydraulics Unit will review the design completed by the Design Build firm (Design Build firm is chosen by the Project Services Unit).

NEU "in-house"

The NEEG will complete the design of the mitigation site with assistance from the Hydraulics Unit and ICI Group utilizing the Design Requirements stated below.

NEU Consultant

The NEEG will use one of its "on-call" consultants to complete the design. The Hydraulics Unit will assist in the development of the scope, task list, man-day estimate. The procedures for using the NEU consultants are established below.

Example Consultant - Design/Construction Over-sight Scope/Man-day Estimates:

The consultant through coordination with the NEEG will develop a scope of work and task list. Once the scope of work and task list is finalized the Consultant will prepare and submit a cost estimate to the appropriate contact person within the Natural Environment Unit (not directly to the NEEG project manager). The NEEG project manager will also prepare and submit a cost estimate to the appropriate contact person. The cost estimates must compare within 10%. If the cost estimates are not within 10%, the NEEG project manager must negotiate with the Consultant to bring the two cost estimates within 10%.

Example of Scope of Work for Wetland Mitigation

Example of Scope of Work for Stream Mitigation

Example of Man-day Estimate for Wetland Mitigation

Example of Man-day Estimate for Stream Mitigation

Design Requirements

Upon selection of the Method of Task Completion, the NEEG and the Hydraulics Unit must determine how to incorporate the design into the Roadway Project. Depending on the size of the mitigation sites, the design can be included as part of the Roadway Plan Sheets or the design can be completed as a separate set of plans that will be attached to the Roadway Plan Sheets. The method of incorporating the design needs to be addressed before a consultant is chosen. Either method selected will require coordination with Roadway Design to ensure the design SP's and quantities are included in the Roadway Plans. At a minimum, the following design requirements should be included in the design for the specific type of mitigation.

Wetland, Buffer, and Conservation Mitigation Sites

Plan

Base line survey data Existing ditches (if applicable) Existing streams (if applicable) Existing wetland boundaries (if applicable) Proposed swales or channel blocks (if applicable) Property boundary- Proposed slope stake lines Target elevation for wetland site

Typicals

Typical section showing existing ground and proposed grade Typical section of swales (if applicable)

Cross Sections

Cross Sections at intervals specified by the NEEG

Details & Special Provisions

Use applicable standard details and special provisions that have been developed by the Hydraulics Unit and NEU. Standard details are available in the Hydraulics Unit Microstation Workspace. Special Provisions are available at the following website: (website currently under construction)

Miscellaneous

Reforestation Plans and Specifications Erosion Control Plans and Specifications

Stream Mitigation and Stream Relocation Sites

Profile

Thalweg profile Grade control structure locations and elevations Appropriate Riffle/pool sequence as referenced in morphological table Scale

Plan

Proposed stream alignment Existing stream alignment Structure locations Slope stake lines (stream and floodplain, if applicable) Stationing on stream sections Property boundary

Typicals

Typical riffle and pool sections, with depths and widths (bankfull channel depth, bankfull width, bottom of channel width, and side slopes, floodplain dimensions) Typical structure placement relative to channel geometry

Cross-sections

Cross-sections of new channel

Details and Special Provisions

Use applicable standard details and special provisions that have been developed by the Hydraulics Unit and NEU. Standard details are available in the Hydraulics Unit Microstation Workspace. Special Provisions are available at the following website: (website currently under construction)

Morphological Table

Include morph table in plans

Curve data

Curve data to stake out channel section (coordinates on head and tail of riffle, radius length, angle, etc)

Miscellaneous

Reforestation Plans and Specifications. Erosion Control Plans and Specifications

Upon completion of the draft design plans, the Hydraulics Unit, ICI Unit, and NEEG will review the proposed design and provide written comments to the established method of design. This review will take place prior to the 4c Merger Meeting. Revisions will be incorporated in the design plans for inclusion at the 4c Merger Meeting. The NEEG will work with the ICI Group to complete the draft Mitigation Plan for the proposed mitigation. A consultation will be held with the Roadside Environmental Unit to coordinate all vegetation issues included in the mitigation plan.

The draft mitigation design and draft mitigation plan will be presented by the Hydraulics Unit at the 4c Merger Meeting. The ICI Group and NEEG will also attend the 4c Merger Meeting.

After the 4c Merger Meeting, the regulatory agencies have the option of reviewing the proposed designs in the field as the final plans are prepared.

Preliminary Engineers Estimate (60% Design)

Upon completion of the Draft Mitigation Design, the Consultant shall provide the NEEG with preliminary quantities. The NEEG will be responsible for developing a preliminary engineer's estimate to ensure appropriate funding is available for construction of the mitigation site.

Example of Preliminary Engineer's Estimate

Funding Request

Upon completion of the preliminary engineer's estimate, the NEEG shall submit a request for funding to the Program Development Branch. If it is determined that State Forces will perform the construction, the funding request must contain detailed information to justify the use of State Forces versus contract construction.

Example of Funding Request for Contract Construction

Example of Funding Request for Contract Construction

Example of Funding Request for State Forces Construction

Upon completion of the final design plans, the NEEG will be responsible for verifying quantities, and coordinating with the Roadway Design Unit to ensure that the appropriate special provisions and individual bid items for the mitigation sites are included in the bid contract document. All erosion control design plans, special provisions, reforestation plans, and planting details will be developed and included in the final roadway plan set by the Roadside Environmental Unit.

Wetland Design Plan

Example of Wetland Design Plans (link to example is currently under construction)

Stream Design Plan

Example of Stream Design Plans (link to example is currently under construction)

Final Engineer's Estimate

Upon Completion of the final plans, the NEEU will develop a Final Engineer's Estimate based on the final quantities. This estimate will be used to compare bids received from contractors.

Example of Final Engineer's Estimate

Construction

The construction of the mitigation sties is accomplished as a part of the overall TIP roadway project, in most cases. These construction contracts are administered by each of the Division Offices across the state. The NEEG provides assistance to the Construction and Maintenance personnel during the construction phase of wetland, stream, buffer, and conservation mitigation sites. This includes periodic site visits during construction of the sites. Staff is available to ensure that the approved design plans and details are installed to specification and that there is a clear understanding of the goals of the project.

NEEG project manager is responsible for making alterations and field adjustments as designs are implemented. This includes close coordination with the Division, Contractors, State and Federal Environmental Regulatory agencies.

Planting

Planting for on-site wetland, stream, buffer, and conservation sites will be included as part of the overall TIP roadway construction project contract. The details, specifications, and pay items are included as a part of the Erosion Control Plan provided by the Roadside Environmental Unit (REU). Planting installation is administered through the Division with input from the REU.

Monitoring Gauge Installation

The NEEG is responsible for purchasing and installing monitoring gauges on the mitigation sites. This includes groundwater gauges, rain gauges and/or surface water gauges. These monitoring gauges are used in order to document alterations in hydrology on mitigation sites. Gauges are installed in accordance with the approved mitigation plan for each site. Each gauge is installed according to the detail below. After installation, each gauge is located using GPS for inclusion in the as-built report.

Monitoring Gauge Installation Detail

Section 7.3.c Vegetation Sample Plot Installation

The NEEG is responsible for coordinating the installation of the vegetation sample plot locations with the REU. The REU installs 50 feet by 50 feet (0.05 Ac.) vegetation plots throughout mitigation sites that are planted in order to ensure adequate plant survival in order to meet regulatory permit requirements. At planting, plots are established and initial plant counts are obtained in each sample plot. This provides the baseline for subsequent monitoring periods throughout the monitoring process. Each vegetation sample plot is located using GPS and provided to the NEEG for inclusion in the as-built report.

As-Built Package

Upon successful completion of site construction, the NEEG coordinates the completion of the as-built package for each mitigation site that is forwarded to the state and federal regulatory agencies, in order to meet permit requirements. The following information is required in the as-built package:

Wetlands, Buffer, & Conservation Mitigation

Complete set of Design Plans documenting any and all modifications, including reforestation sheets and planting details for the project. Complete map depicting monitoring gauge locations, vegetation plot locations and photograph locations.

Stream Mitigation

Complete set of Design Plans documenting any and all modifications, including reforestation sheets and planting details for the project. Complete map depicting monitoring locations, including cross sections (elevations), profile (elevations), and pebble count information. Complete map depicting monitoring gauge locations, vegetation plot locations and photograph locations.

Monitoring

The NEEG is responsible for coordinating all monitoring activities for wetland, stream, buffer, and conservation mitigation sites statewide. This includes collecting field data from both the hydraulics and vegetation perspective. This data is collected throughout the growing season according to the mitigation plan for each individual site and is reported via the annual monitoring report. Each monitoring report is submitted at the end of the growing season to state and federal environmental regulatory agencies in order to comply with roadway/bridge project permit requirements.

Method of Task Completion

In-house Monitoring
The NEEG, through coordination with the REU, will complete the monitoring requirements for vegetation monitoring, gauge installation, data collection, and report compilation. Once REU completes the vegetation monitoring reports, REU will submit to the NEEG to be compiled with the recorded gauge data into the monitoring report.

Consultant Monitoring - Scope/Man-day Estimates:
The consultant, through coordination with NEEG and/or REU, will develop a scope of work and task list for vegetation monitoring, gauge installation, monthly gauge download, and report compilation. Once the scope of work and task list is finalized the Consultant will prepare and submit a cost estimate to the appropriate contact person within the Natural Environment Unit (not directly to the NEEG). The NEEG project manager will also prepare and submit a cost estimate to the appropriate contact person. The cost estimates must compare within 10%. If the cost estimates are not within 10%, the NEEG must negotiate with the Consultant to bring the two cost estimates within 10%.

Example of Scope of Work for Consultant Monitoring

Example of Man-day Estimate for Consultant Monitoring

Monitoring Requirements for Wetland, Buffer, & Conservation Mitigation Sites:

Hydrology
The NEEG is responsible for data collection of hydraulic monitoring gauges at each site on a monthly basis. This data is analyzed monthly to ensure completeness and accuracy. Wetland hydrology is defined as groundwater within 12 inches of the surface for 29 consecutive days during the growing season (12.5 percent of the growing season). The growing season is dependent upon the region of North Carolina that the site is located. The growing season can be determined by referencing Soil Survey book produced by the Natural Resources Conservation Service. Rainfall data for the given monitoring year is also obtained from the closest National Oceanic and Atmospheric Administration gauge station and analyzed as to whether or not the year was deemed as a normal year. The gauge data is then compared to the rainfall data to determine whether or not the site has met the success criteria stated in the mitigation plan.

Vegetation
The REU is responsible for performing the vegetation monitoring according to the mitigation plan on an annual basis. REU performs stem counts within each of the vegetation plots that are established immediately following construction of the mitigation project. The 50 x 50 vegetation plots are randomly located throughout the site to ensure that unbiased results are produced. The number of plots on the site is determined by taking a two- percent sample of the total acreage. The vegetation data is forwarded to the NEEG at the end of the growing season for inclusion in the annual monitoring report. Photographs are also taken on an annual basis at the same photo point location to visually show the success of the site from the beginning to the end of the required monitoring period.

Annual Monitoring Report Format

	Title Page
	Executive Summary
1.0	Site History
	Timeline of Construction
2.0	Hydrology
	30-70 Historical Rainfall Data
3.0	Vegetation Data
4.0	Conclusions
Appendix A	Gauge Data
Appendix B	Site Photos

Example:Annual Wetland Mitigation Monitoring Report

Monitoring Requirements for Stream Mitigation Sites:

The NEEG is responsible for coordinating with the REU to complete the monitoring of all permitted stream restoration and relocation sites as required. The level of stream monitoring is dependent upon the type of restoration that is planned for the site. REU is responsible for completing the stream channel monitoring in-house or by tasking a consultant to complete the monitoring. This monitoring is done in accordance with the "US Army Corps of Engineer Stream Mitigation Guidelines, April 2003" and typically requires a monitoring period of one to five years. The purpose of monitoring is to determine whether or not the specific objectives of the project have been met and to what degree of success a mitigation project has achieved in providing proper channel function and increased habitat quality per the mitigation plan.

Channel Stability

Full Channel Analysis Stream Monitoring
This type of stream monitoring involves surveying a reach of the restored or enhanced channel to determine success. This is typically done when a Level I Restoration or Enhancement project is completed. The channel will normally be surveyed every year or every other year depending on the permit conditions for five years. The data collected from the site is then compiled into the monitoring report and submitted each year throughout the monitoring period. The main components of the full channel analysis are as follows:

Cross Sections
Cross section data provides a majority of the morphological parameters required for stream classification. Bankfull cross sectional area, bankfull width, mean and max bankfull depth, width/depth ratio, and entrenchment ratio are determined from the cross sectional survey (Wildland Hydrology, 2002).

Profile
The longitudinal profile characterizes average stream slopes and depths of riffles, pools, runs, glides, rapids, and step pools. Longitudinal profile is an important component of stream monitoring in that it is used to determine the average water slope which in turn is used for delineating stream types. In addition, the longitudinal profile can be used to obtain maximum depth of individual bed features as well as bed feature spacing (Wildland Hydrology, 2002).

Pebble Count
The pebble count characterizes the bed material present through a given reach. This information is used during design to determine the stream type and for use in the hydraulic calculations that are used to determine velocity. During the monitoring process this information is used to see how closely the newly designed channel substrate material mimics the reference stream.

Example: Annual Stream Mitigation Full Channel Analysis Monitoring Report

Visual Quarterly/Biannual Stream Monitoring

Quarterly or biannual visual monitoring may be done on some projects per permit requirements in lieu of the full channel monitoring described above. Typically, this type of monitoring protocol is used on smaller streams and is dependent on the level of restoration that is done. While the biannual monitoring is similar to full channel analysis in that the monitoring period is typically five years in length, the quarterly monitoring is normally done for only one to two years. Both types of visual monitoring require that photo points be established such that an upstream and downstream shot of each structure are taken as well as the stability of the stream banks photographed. This allows for an evaluation over time by the regulatory agency personnel in order to determine site success.

Example:Annual Stream Mitigation Quarterly/Biannual Monitoring Report

Remediation

The NEEG is responsible for coordinating all remediation activities for Wetland, Stream, Buffer, and Conservation Mitigation sites statewide. This includes investigating and analyzing problem areas on sites based on annual monitoring data and visual inspection. The NEEG is responsible for coordinating the development of design plans, coordinating the procurement of any necessary state and federal environmental permits, acquiring construction funding, and implementing the proposed solutions.

Investigation/Analysis

Remediation activities are usually required based on failure of any areas within a site to meet the required success criteria. Common occurrences that require remediation include failure to meet hydrologic success, failure to meet vegetation success, excessive erosion problems, and/or stream instability problems. Close coordination with state and federal environmental regulatory agencies is necessary to determine if the site requires remedial action. While an in-house assessment is usually sufficient, a consultant analysis can be used if the problem involves a more in-depth study.

Site Plans

Once the analysis is complete, a detailed summary of all proposed remediation activities is developed. Site plans are then developed to convey this information. The level of documentation can range from simple schematics to detailed site plans and provisions. The level of detail is based upon the magnitude of the proposed remediation. The design requirements used to prepare site plans are the same as those outlined in Section 7.2.Depending on the extent of the remediation work, all of the outlined design requirements may not be needed. The NEEG is responsible for determining the appropriate information that is required in the site plans. Site plans are generally prepared utilizing two different methods: ONE "in-house" or ONE Consultant.

Method of Task Completion

ONE "in-house"

The NEEG will complete the site assessment and design of the site plans with input from the Hydraulics Unit and ICI Unit utilizing the Design Requirements stated in Section 7.2.

ONE Consultant

The consultant, through coordination with the NEEG, will develop a scope of work and task list for site remedial assessment, site plan design, and construction oversight. Once the scope of work and task list is finalized, the Consultant will prepare and submit a cost estimate to the appropriate contact person within the NEEG. The NEEG will also prepare and submit a cost estimate. The cost estimates must be within 10% in order to issue a Notice to Proceed. If the cost estimates are not within 10%, the NEEG must negotiate with the Consultant to get the cost estimate within 10% or revise the task list in the scope of work.

Example of Scope of Work for Mitigation Site Assessment

Example of Man-day Estimate for Mitigation Site Assessment

Example of Scope of Work for Mitigation Site Plan Development

Example of Man-day Estimate for Mitigation Site Plan Development

Funding/Design/Construction

Once 60% design plans are complete, a list of quantities is developed for the proposed remediation. A construction estimate is then developed based on the 60% design plans. The method of construction must be determined in conjunction with the preparation of the estimate, through close coordination with the Division, so that the appropriate funding can be secured for implementation of remedial activities. There are generally two options available for construction activities related to remediation: State Forces or Purchase Order Contract. Design plans are needed either option.

Method of Task Completion

State Forces Construction

At the 60% design phase, it is determined if state forces will be utilized to perform remediation on the mitigation site and two line item estimates are prepared. One shows state forces performing the work and the other shows the project being accomplished through a P.O. Contract. Finally, a Funding Request is prepared in order to justify the use of state forces and submitted to the Project Management Unit with the two line item estimates.

Example of Funding Request for State Forces Construction

Example of Estimate for State Forces Construction

Upon completion of the final site plans, the NEEG will be responsible for verifying quantities and coordinating with Division personnel to insure that the appropriate site plans and special provisions are available. Any necessary erosion control design plans, special provisions, reforestation plans, and planting details will be developed and included in the final site plan by the Roadside Environmental Unit.

Purchase Order Contract Construction

At the 60% design phase, it is determined if the remediation work will be performed by P.O. Contract. A line item estimate is prepared based on the quantities taken from the 60% design plans. A Funding Request is prepared and submitted to the Project Management Unit with the line item estimate.

Example of Funding Request for Contract Construction

Example of Estimate for Contract Construction

Upon completion of the final site plans, the NEEG will develop a Final Engineer's Estimate based on the final quantities. This estimate will be used to compare bids received by the Division from potential contractors. The NEEG will be responsible for verifying quantities and coordinating with the Division Design Construction Engineer to insure that the appropriate special provisions and individual bid items are included in the bid contract document. Any necessary erosion control design plans, special provisions, reforestation plans, and planting details will be developed and included in the final site plan by the Roadside Environmental Unit.

Example of Final Engineer's Estimate for Contract Construction

Remedial Construction

Once remedial construction begins, the NEEG provides assistance to the Department's Construction and Maintenance personnel during the remediation construction phase of wetland, stream, buffer, and conservation mitigation sites. This includes periodic site visits during construction of the sites. Staff is available to ensure that the approved design plans and details are installed within the specifications and that there is a clear understanding of the goals of the project.

NEEG staff is responsible for making alterations and field adjustments as designs are implemented. This includes close coordination with the Division, State and Federal Environmental Regulatory agencies.

Additional Information

If additional planting, vegetation sample plots, and monitoring gauges are required due to the remedial work, the NEEG will be responsible for coordinating these activities in accordance with Section 7.3 Construction.

In addition, a remediation as-built plan is required in accordance with Section 7.3-Construction that fully documents work complete on the mitigation site. Upon successful completion of site construction, the NEEG coordinates the completion of the as-built package for each mitigation site that is forwarded to the state and federal regulatory agencies, in order to meet the permit requirements.