Attachment_6_ORR_Roadside_Ecosystem_Improvements_and_Hazardous_Tree_Assessments.pdf

Roadside Ecosystem Improvement Assessment

OAK RIDGE RESERVATION

November 2014 TBC Solutions, Inc.

Oak Ridge National Laboratory Prepared for the Oak Ridge National Laboratory

Managed by UT-Battelle, for the U.S. Department of Energy under contract DE-AC05-00OR22725, subcontract 4000133367

DE-SOL-0008816

Attachment 6

DRAFT

Roadside Ecosystem Improvement Assessment, Oak Ridge Reservation

United States Department of Energy

Table of Contents

I. Executive summary

II. Background

III. Summary of assessment methodology

IV. Location and description of potential ecosystem enhancement areas observed in text and maps

V. Proposed alternative roadside ecosystem maintenance regime

VI. Summary Maps

I. Recommendations and Comments

II. References

I. Executive summary

The sections maintained as mostly close-cropped grasses by mowing along Bear Creek

Road, Bethel Valley Road, Bull Bluff Road, and Perimeter Road on the US Department of Energy’s (US DOE) Oak Ridge Reservation (ORR) represent a substantial area. The primary goal of roadside maintenance activities is to maintain safety and usability of the roadway. The attached project report presents a qualitative assessment of the roadside ecosystem that consists of as much as 90 acres of mowed area and a proposed alternative roadside ecosystem maintenance regime. The proposed alternative to the current mowing regime offers an opportunity to maintain the roadsides at the current level of safety and visibility while enhancing the roadside ecosystem and potentially reducing maintenance costs through reduced mowing quantity and frequency. It also offers a path forward toward having the roadside ecosystem be a self-sustaining native plant community.

II. Background

Several roads, with a total mileage close to eighteen miles and similar in appearance to a two-lane state highway, are present on the US Department of Energy’s (US DOE) Oak

Ridge Reservation (ORR). These roads are managed and maintained by the US DOE and its contractors and see motorist and bicycle use primarily by authorized users. The immediate roadside ecosystems of the roads appear to have been primarily maintained by often close mowing, frequently as far as 30 to 40 feet out from the actual paved travel area. TBC Solutions was tasked to conduct an on-the-ground assessment of approximately 17.5 miles of these US DOE maintained roadsides for opportunities to enhance the managed transition area between the road’s edge and the forest. Initially, it is anticipated that these opportunities would come through a change in mowing schedules consistent with motorist safe use of the roads. It is clear that the highest priority for managing this transition area is supplying safe transportation corridors with hazard-free safety clear zones, including low growing vegetation in the operational zone and open sight distances where necessary.

In preparing for the field work portion of this project, TBC Solutions found several references prepared by the US Department of Transportation, several state highway departments, and transportation research groups. These references provide a background of best practices and shared terminology among roadside maintenance professionals. A common approach used in them is the description of the area of the managed transition between the road’s edge and the unmanaged forest as a series of zones. Each of these zones has specific functions within the context of the road and a set of maintenance objectives prescribed to facilitate these functions in that zone.

The three zones vary in width and function and are termed Zone 1, Zone 2, and Zone 3 in order of their distance from the pavements edge. Zone 1 is in the immediate area of the pavement and typically has an aggregate surface that is kept free of vegetation for several feet out from the pavement’s edge. The general functions of Zone 1 include providing appropriate visibility of signage and entering roads, reducing roadside fire ignition potential, protecting pavement from plant root damage, and related functions.

Zone 2 extends from Zone 1 out to an area with minimal maintenance. It is typically maintained by mowing, with the area extending to drainage ditches often mowed several times a year and the area beyond the ditch mowed as dictated by safety, visual, and ecological concerns. The general functions of Zone 2 include providing drainage of water off of the road surface, providing safe lines of sight for traffic, a safe area for errant vehicles to recover control or reduce speed, and related functions.

Zone 3 extends from the more managed area of Zone 2 out to an area with no road associated maintenance aside from hazard tree removal. The vegetation in Zone 3 may be manipulated consistent with the functions of the zone, including identification and removal of hazard trees. The general functions of Zone 3 include hosting native plant communities, screening adjunct areas from the road, and enhancing roadside visual quality.

The figure on the next page, derived from similar figures in the references mentioned above, illustrates the three zones from pavement edge to the unmaintained area.

III. Summary of assessment methodology

TBC Solutions personnel performed a field assessment on foot of selected portions of four US DOE maintained roads on the ORR between August 20 and September 13, 2014. The roads assessed were:

Bear Creek Road from the US DOE reservation boundary at the western edge of the

Central Training Facility along West Bear Creek Road to the West Portal on East

Bear Creek Road. This is a distance of about 6.5 miles.

Bethel Valley Road, from State Route 95 to Scarboro Road on the north side of

Bethel Valley Road and to the west edge of the Bethel Valley Industrial Park property on the south side. The area on either side of the road between First Street and East

Plant Road, on the ORNL campus area was not assessed. This is a distance of about 6 miles.

Bull Bluff Road, from Pumphouse Road to a locked gate at the west end of the Clark

Center Park Swimming Area. This is a distance of about 2.5 miles.

Perimeter Road, from its intersection with State Route 58 and State Route 327. This is a distance of about 2.8 miles.

The field assessment consisted of a traverse by walking both sides of all these roads to observe natural communities present, apparent maintenance regime, width of roadside area to drainage ditch if any, total width of maintained roadside area, and general presence of exotic and invasive plant species. This assessment was qualitative in nature.

IV. Location and description of potential ecosystem enhancement areas observed in text and maps

The ORR’s potential roadside ecosystem enhancement areas lie along the four roads assessed. It is estimated that between 60 and 90 acres are maintained by relatively frequent mowing of the roadside ecosystem for these four roads. It could well be more, for in many areas the roads appear to have been mowed several times a year as much as 40 feet away from the pavement’s edge. Much of the mowed area is occupied by tall fescue (Schedonorus arundinaceus) dominated plant communities. Where lawn or pasture is desired, tall fescue serves the purpose. However, with an aim to have native plant communities dominant, tall fescue is not a good choice. Many other species, native and exotic, are present along these four ORR roads and with time and an altered mowing regime are likely to become more prominent in the roadside plant communities.

The map below depicts these mowed areas, as they lie along both sides of all four of these roads. Altering the roadside maintenance regime offers an opportunity to maintain safety and visual clearance along these roads while enhancing the roadside ecosystem, improving water quality, and possibly reducing the cost of roadside maintenance through reducing the amount and frequency of roadside mowing.

V. Proposed alternative roadside ecosystem maintenance regime

Consistent with the zone system discussed in the Background section, the proposed roadside ecosystem maintenance regime is arranged by zone. It is proposed that this system be initiated into use next spring and tested for three years to evaluate its safety, effectiveness, and enhancement of the roadside ecosystem.

Zone 1 (immediate shoulder area, typically with an aggregate surface)

This area and the paved areas should be kept free of vegetation of all kinds through the use of herbicide. Glyphosate is frequently a good choice for this type of use and aquatically labeled glyphosates are available as well. Herbicide choice would depend upon a number of factors, including plants treated, proximity to aquatic areas, and other considerations. The width of this zone from pavement edge to Zone 2 is commonly three feet. On the approximately 17.6 miles of roads assessed, a three foot wide strip kept free of vegetation would result in nearly 13 acres eliminated from the mowing schedule. Benefits of maintaining the Zone 1 in this manner include:

Providing for improved surface drainage off the pavement;

Reducing fire potential from cigarettes and other potential ignition sources;

Providing for visibility and maintenance of roadside hardware and signage in this zone;

Preventing pavement breakup by invasive plants;

Contributing to maintaining adequate sight distance for passing, stopping and at intersections; and

Preventing the buildup of wind-blown debris, snow, and winter sand at the pavement edge.

Zone 2 (regularly maintained area)

The goal for this area between Zone 1 and Zone 3 is to eventually have it occupied with a sustainable community of native vegetation. It is divided into two areas, Zone

2a and Zone 2b. Zone 2a is the typically 6 to 12 foot area bounded by the Zone 1 vegetation free area and the far side of the roadside drainage ditch, if present. It

Paved Area

Zone 1 Vegetation

Free should be mowed three times of year in order to maintain the adequate sight distances for motorists and to ensure the hydraulic function of the drainage ditch.

Mowing height should be set at four (4) inches above the ground to better foster use of the roadside zone by insects and birds with periodic supervisor verification that the correct mower height is set. Scalping (shown on the ground as patches of bare soil) should be minimized in order to not degrade water quality due to having exposed soil. If feasible, given sight lines, slopes greater than 3:1 or 33% should not be mowed. This can be managed by marking the steeper no mow areas or have slope indicator devices attached to each tractor/machine that is used for mowing.

Zone 2b is the remainder of the Zone 2 and, if natural vegetation does not negatively affect visual clearance, it should be mowed every two to four years with the objective of keeping trees and other native woody perennials smaller than one-inch in diameter six inches above the ground.

The suggested timing of these three mowings in Zone 2a is as follows:

First Mowing; to occur between Memorial Day and June 15 to keep height of annual vegetation maintained;

Second Mowing; to occur between July 15 and Labor Day as needed to correct sight distance and visual obstruction problems wherever they occur.

Sight distance may have to be corrected more than once. This is also the time to complete mowing of Zone 2b areas receiving a periodic mowing.

Third and final Mowing; to occur after Labor Day and before potential snowfall as needed.

Benefits of maintaining the Zone 2 in this manner include:

Maintaining design width for errant vehicle recovery;

Providing sight distance for passing, stopping, at interchanges and at intersections as needed;

Maintaining the hydraulic capacity of ditches;

Zone 2a Mow 3 times a year

Zone 2b Mow every 2-4 years

Low Growing Vegetation

Taller Annuals and Perennials

Eliminating vegetative obstructions in the roadside zone (trees and woody perennials with a trunk diameter of 1" or more);

Controlling invasive species;

Reduce and then prevent soil erosion;

Providing wildlife habitat where compatible with roadway traffic;

Accommodating underground utilities; and

Enhancing visual quality.

Zone 3 (minimally maintained area)

The goal for this area outside of Zone 2 is to generally maintain it as natural forest in which potential hazard trees are minimized and invasive species are not present. No regular on the ground maintenance activities would take place in this zone. It serves as a transition zone between Zone 2 and areas outside of the roadside’s influence. Benefits of maintaining the Zone 3 in this manner include:

Promoting natural self-sustaining plant communities;

Blending and/or screening adjacent surroundings to meet other goals and objectives;

Eliminating hazard trees that may fall into the travel area or cause excessive shade (ice and frost potential) on the pavement;

Maintaining and enhancing visual quality;

Preserving wetlands and wildlife habitat;

Accommodating utilities, if needed; and

Encouraging native plants and wildflowers.

An example of a reduced maintenance mowing regime is portions of the area along the Perimeter

Road running along the north and west perimeter of the K-25 built up area. The photograph at right, taken during September 2014, depicts an approximate vehicle width area (Zone 1 and a portion of Zone 2 in the earlier discussion) mowed beside the pavement with the native vegetation permitted to grow about waist high in the remainder of the roadside zone. This provides both good line of sight along the road and a relatively unmowed area in which elements of the native plant communities can grow.

VI. Summary Maps The maps in this section depict the portions of the roadsides traversed in the course of this project in alphabetical order.

I. Recommendations and Comments

1. Keep in mind that this assessment represents a description of the proposed alternative roadside ecosystem maintenance regime and that execution by staff or contractors should be accomplished using a prescription dictating appropriate specific practices, materials, and operational schedules.

2. Establish a program of vegetation sampling in the roadside ecosystem zone for Zone 2a and Zone 2b that would provide a source of quantitative vegetation community data and foster the development of a map of vegetation communities along the four roads.

3. Continue the program of treating or removing invasive exotic plant species in the roadside ecosystem to encourage native plant occupation and limit the availability of invasive exotic seeds that could colonize roadside areas.

II. References

Doran, Michael, 2014. Personal communication with Michal Doran of the Tennessee

Department of Transportation’s Maintenance Contracts Office. September 10, 2014.

Transportation Research Board, 2005, Integrated Roadside Vegetation Management: A Synthesis of Highway Practice (NCHRP Synthesis, 341), Transportation Research Board, Washington, D.C.

US Department of Transportation, Federal Highway Administration, 2008, Vegetation Control for Safety: A Guide for Local Highway and Street Maintenance Personnel, Publication No. FHWA-SA-07-018, FHWA.

US Department of Transportation, Federal Highway Administration, 2013, Vegetation Management, an Ecoregion Approach, Publication No. FHWA-HEP-13-043, FHWA.

Draft Roadside Hazard Tree Assessment, Oak Ridge Reservation

Roadside Hazard Tree Assessment

OAK RIDGE RESERVATION

November 2014 TBC Solutions, Inc.

Oak Ridge National Laboratory Prepared for the Oak Ridge National Laboratory

Managed by UT-Battelle, for the U.S. Department of Energy under contract DE-AC05-00OR22725, subcontract 4000133367

Table of Contents

I. EXECUTIVE SUMMARY

II. BACKGROUND

III. SUMMARY OF METHODOLOGY

IV. RESULTS OF ASSESSMENT

V. INDIVIDUAL ROAD MAPS AND A SUMMARY MAP

VI. RECOMMENDATIONS AND COMMENTS

VII. REFERENCES

I. EXECUTIVE SUMMARY

The immediate roadside and adjoining forested areas along Bear Creek Road, Bethel

Valley Road, Bull Bluff Road, and Perimeter Road on the US Department of Energy’s

(US DOE) Oak Ridge Reservation (ORR) were traversed to identify trees that may present a potential hazard to the paved area of these roads. Both sides of approximately

17.8 miles of road were walked during this project and 177 potential hazard trees were identified and data collected about each of them. The potential hazard trees were assessed as presenting an imminent or likely risk of failure. Recommendations were made regarding the mitigation of these hazards through removal or felling of the identified trees. In addition, the location of approximately 350 ash trees along these roads was also collected with project data for future use by ORR Natural Resources staff.

II. BACKGROUND

Trees along a roadside may present risk to road users should they fail and fall into the roadway itself. This risk can be assessed as the combination of the condition of an individual tree and the tree’s proximity to the roadway. Tree condition risk stems from the presence of dead or dying trees, dead parts of live trees, or unstable live trees (due to structural defects or other factors) that when they fall are within striking distance of the paved area of a roadway (i.e. between the white lines at road’s edge).

Tree failure can result from the interaction of defects, weather factors, ice or snow loading and/or exposure to ordinary wind and weather conditions. Defects are flaws in a tree that reduce its structural strength. Trees may have single or multiple defects which may or may not be detectable. The potential risk that hazard trees are present is based on a judgment of where and when they may fail and fall. For the purposes of this project, trees were assessed either as being at imminent risk of failure or as likely to fail and in doing so place portions of the tree within the paved area of the road. Imminent failure means generally that the tree is dead, often losing bark, and could fail at any time. Trees judged to be likely to fail, with the exception of eastern red cedars, were deemed to have potential structural defects that could contribute to failure in the next six months or so. These trees should be examined and a decision made about their removal. Trees can fall in any direction, but generally fall downhill and in the direction of a lean they currently have. Many factors contribute to trees failing and falling when subject to unusual weather conditions, such as the winds and rain of winter and spring that have a large influence on failure. This assessment was undertaken with an effort to identify trees with an imminent or likely potential to fail, where that failure would place trees or large portions of trees within the roadway on selected portions of Bear Creek

Road, Bethel Valley Road, Bulls Bluff Road, and Perimeter Road on the US Department of Energy’s (US DOE) Oak Ridge Reservation (ORR).

III. SUMMARY OF METHODOLOGY

TBC Solutions personnel performed a field assessment on foot of selected portions of four US DOE maintained roads on the ORR between August 20 and September 13, 2014. The roads assessed were:

Bear Creek Road from the US DOE reservation boundary at the western edge of the

Central Training Facility along West Bear Creek Road to the West Portal on East

Bear Creek Road. This is a distance of about 6.5 miles.

Bethel Valley Road, from State Route 95 to Scarboro Road on the north side of

Bethel Valley Road and to the west edge of the Bethel Valley Industrial Park property on the south side. The area on either side of the road between First Street and East

Plant Road, on the ORNL campus area was not assessed. This is a distance of about 6 miles.

Bull Bluff Road, from Pumphouse Road to a locked gate at the west end of the Clark

Center Park Swimming Area. This is a distance of about 2.5 miles.

Perimeter Road, from its intersection with State Route 58 and State Route 327. This is a distance of about 2.8 miles.

The field assessment consisted of a traverse by walking both sides of all these roads to observe trees with an imminent or likely potential to fail, including those seen to have the following defects and/or conditions:

Growing on Altered Grades/Drainage Patterns;

Canker Faces;

Dead;

Decay Visible;

Fungal Fruiting Bodies;

Insect Frass Or Bore Holes;

Leans Unnaturally;

Lightning Damage;

Limbs Poorly Attached;

Mechanical Damage;

Necrotic Or Chlorotic Appearance;

Root Plate Deformation;

Roots Undermined Or Heaving;

Sap Seeping Or Bark Stains;

Scars Or Sunscald;

Sloughing Bark;

Soil Saturated; and

Splits Or Cracks In The Trunk Or Branches.

In addition to this information, data about each tree judged to be either imminent or likely to fail was collected to include:

Species of tree when identifiable, using the US Department of Agriculture symbol code for each species (USDA, 2014). Species data was recorded using a custom

TBC Solutions two-digit species code with the list below serving as a crosswalk between that code and each tree’s symbol, common name, and Latin name by genus and species:

2-code PLANTS Symbol Common Name Latin Name

31 QUAL White Oak Quercus alba

32 QUMO4 Chestnut Oak Quercus montana

33 QURU Northern Red Oak Quercus rubra

34 QUFA Southern Red Oak Quercus falcata

35 QUVE Black Oak Quercus velutina

36 QUCO2 Scarlet Oak Quercus coccinea

61 PIST Eastern White Pine Pinus strobus

62 PITA Loblolly Pine Pinus taeda

63 PIEC2 Shortleaf Pine Pinus echinata

64 PIVI2 Virginia Pine Pinus virginiana

65 JUVI Red Cedar Juniperus virginiana

71 LITU Yellow Poplar Liriodendron tulipifera

72 FAGR Beech Fagus grandifolia

73 CARYA Hickory Carya spp.

74 ACRU Red Maple Acer rubrum

75 ACSA3 Sugar Maple Acer saccharum

91 LIST Sweet Gum Liquidambar styraciflua

92 NYSY Black Gum Nyssa sylvatica

93 FRAM2 Ash Fraxinus americana

94 PRSE2 Black Cherry Prunus serotina

95 AEFL Buckeye Aesculus flava

99 OTHR Other Other Species

99 ROPS Black Locust Robinia pseudoacacia

99 MADO Apple Malus domestica http://plants.usda.gov/java/profile?symbol=QUFA

Tree diameter at breast height, in two inch increments from 2 to 40 inches;

Tree height, in ten foot increments from 10 to 100 plus feet tall;

Approximate proximity of tree to paved travel area, in 10 foot increments from 10 to

50 feet;

Bearing of tree lean, in 45 degree increments from 0 to 315 degrees;

Angle of tree lean, in 5 degree increments from 5 to 30 degrees;

Ground slope at base of tree, in 5 degree increments from 5 to 45 degrees;

Suggested remediation method, with chainsaw indicating the tree seemed able to be felled in an ordinary way by a skilled operator, equipment indicating that heavy equipment may be required for a skilled chainsaw operator to safely fell the tree, and difficult meaning that felling the tree with a skilled operator and equipment appeared to pose more than ordinary felling challenges;

The road where the tree is located;

The aspect or side of the road that the tree was observed on, generally being either north or south; and

The seeming timing of tree failure, either imminent or likely.

This data collected and the trees approximate location were recorded using a Trimble

GeoXH geographic position system equipped device.

After tree data was collected each tree was marked with a dot of orange tree marking paint at the low part of the tree facing the road as inconspicuously as possible and marked with an orange paint mark on the backside of the tree, with respect to the road.

IV. RESULTS OF ASSESSMENT

A total of 177 trees were observed to potentially present a hazard of failing and falling within the paved travel area of those portions of Bear Creek Road, Bethel Valley Road, Bull Bluff Road, and Perimeter Road that were assessed. Of these, a total of 177 trees were observed to be at either imminent risk of failure or likely to fail within the next six months or so. The table below displays this information by road.

Road

Miles

Assessed

Imminent

Trees

Likely

Trees

Total

Trees

Hazard Trees per

Road Mile

Bear Creek Road 6.5 25 60 85 13.1

Bethel Valley Road 6 29 19 48 8.0

Bull Bluff Road 2.5 21 13 34 13.6

Perimeter Road 2.8 8 2 10 3.6

17.8 83 94 177 9.9

A number of tree species were identified as hazard trees. Due to the decayed and bark-less condition of many of the dead trees, the exact species of 62 of the 177 hazard trees was not determinable. The graphic below depicts each species by number of potential hazard trees identified.

Number of Trees By Species DRAFT

The height of the hazard trees ranged from an estimated 20 to 90 feet tall. These trees ranged from 10 to 50 feet away from the nearby road pavement. The average difference between tree height and proximity to the paved area was about 20 feet. This means that if these trees were to fall in the direction of the nearby road, they would likely obscure at least one full lane width, if not the entire road.

The data collected during the course of this assessment is available in the form of .dbf files that are provided as a portion of the ArcView files submitted with this report.

As the roadside traversing progressed, field personnel noted that there were many ash trees present (mostly white ash= Fraxinus americana with a sprinkling of green ash =

Fraxinus pennsylvanica) along these roadways. To add value to TBC Solutions services and aid ORR Natural Resources staff in the future, the approximate location of single ash trees and in some cases multiple ash trees were recorded from the roads edge. No individual tree data was recorded, merely the tree’s presence near the road. Ash as a species is currently under attack in east Tennessee by the insect known as Emerald Ash

Borer (Agrilus planipennis). Ash was the most numerous potential hazard tree identified to species. Ash trees observed along these roads were between 50% and 70% symptomatic of being under Emerald Ash Borer attack. It is reasonable to presume that over the next three to five years virtually all of the ash trees on the ORR will be under attack by the Emerald Ash Borer and many of them will have succumbed. Although effective treatments exist for individual ash trees it is not generally thought feasible to treat forest dwelling trees for this insect.

The table below provides a summary of ash trees observed, listed by road.

Road Miles Ash Trees Noted Percent Multiple Ash Recorded

Ash Trees per Road Mile

Bear Creek Road 5.9 43 14.0% 7

Bethel Valley Road 6 152 28.3% 25

Bull Bluff Road 2.5 44 20.5% 18

Perimeter Road 2.8 72 6.9% 26

17.2 311

The map below indicates generally where ash trees were located.

V. INDIVIDUAL ROAD MAPS AND A SUMMARY MAP

VI. RECOMMENDATIONS AND COMMENTS

The forests along these roads are generally in good condition and are quite variable in the age of dominant trees. The following recommendations are provided for consideration:

It is recommended that felling and removal be planned and executed to mitigate the potential hazard presented by the trees identified as presenting an imminent risk of failure.

It is recommended that all trees identified as representing a likely risk of failure be mitigated by removal, if judged appropriate, or that individual trees receive more frequent inspections to monitor changes in condition.

It is recommended that a plan be drafted to mitigate the hazard that dying ash trees will present to roads, utilities, fences, and facilities as most all ash trees will succumb to Emerald Ash Borer attack over the next few years, if not sooner. Ash trees are reported to dry rapidly after death and be subject to catastrophic structural failure and thus damage to nearby manmade objects in a short period of time compared to other hardwood species.

In particular, it is recommended that Y-12 related security fences and boundaries that have ash trees in proximity to them be identified and that the risk they present to boundaries be mitigated in order to maintain their integrity. Ash is especially prevalent along Old Bethel Valley Road.

It is recommended that large mature southern yellow pines along and within fifty or so feet of Bull Bluff Road be marked and inventoried to be removed via a timber sale or other similar mechanism. While these large trees are generally healthy they are of a size and age that they present the ability to block Bull Bluff Road should they fall.

It is recommended that an annual “windshield cruise” of these roads be conducted lasting a day or so to search for potential hazard trees and that a more detailed survey be conducted on approximately five year intervals.

VII. REFERENCES

USDA, NRCS. 2014. The PLANTS Database (http://plants.usda.gov, 29 September 2014). National Plant Data Team, Greensboro, NC 27401-4901 USA.

http://plants.usda.gov/