ANC_Tree_Preservation_Specifications_-_UPDATE_Nov-2020.pdf

Revised 11-24-2020

TREE PRESERVATION

PROCEDURES AND SPECIFICATIONS

ARLINGTON NATIONAL CEMETERY

1. Prior to allowing any vehicle or construction equipment to enter the site, the

Construction Foreman and Project Arborist (also foreman of company doing actual tree work if different from Project Arborist) is to meet the Cemetery Urban Forester (Urban Forester) or Horticulture representative to mark the location of the limits of clearing/tree preservation fencing, erosion control fabric, root pruning line (where required), access routes, storage areas, and parking areas. The location of the LIMITS OF CLEARING/TREE PRESERVATION FENCING is to be installed in accordance with the approved plan, and field located from existing benchmarks, landmarks, and stakeout survey markers. All work procedures and tree preservation measures are to be discussed at this time.

2. Trees to be removed shall be clearly marked and approved by the Cemetery

Urban Forester prior to demolition or entry of any equipment on site.

3. Tree preservation fencing shall be the following:

Six (6) foot high chain link fence attached to one and five eights (1 5/8) inch outside diameter pipe with eleven (11) gauge mesh in a two (2) inch diamond pattern. The posts shall be driven into the ground a minimum of two (2) feet. If on hardscape, standard fence footings shall be used.

The fencing type noted above shall be flagged with brightly colored surveyor ribbon to improve its visibility.

The Project Contractor must maintain fencing in place throughout construction.

In the event fencing must be temporarily removed for any reason, contact must be made first with the Urban Forester at 703-695-3588. The Urban Forester must grant approval before any tree preservation fencing is removed, even temporarily.

4. Erosion and sediment control fencing shall be placed on the inside (toward construction) from the tree preservation fencing and any root-pruning trenches.

Erosion control devices such as silt fencing, debris basins, and water diversion structures shall be installed to prevent siltation and/or erosion within the tree protection zone.

5. Tree Removal and Protection:

a. The Urban Forester shall be notified a minimum of three (3) days in advance of commencing any form of tree work. Call 703-695-3588 for an appointment.

b. Trees that must be removed shall be identified by the Urban Forester.

c. Trees shall be felled so as to fall away from tree protection zones and to avoid the pulling and breaking of roots of trees to remain. If roots are entwined, the Urban Forester may require first severing the major woody root mass before extracting the trees. This may be accomplished by cutting through the roots by hand, with a vibrating knife, rock saw, and narrow trencher with sharp blades, or other approved root-pruning equipment.

d. Trees being cut within the tree preservation zone shall be cut near ground level and the stumps ground out with a walk-behind grinding machine.

Stumps may also be left high, and extracted with a backhoe or other equipment, if first approved by the Urban Forester.

e. All downed brush and trees shall be removed from the tree protection zone either by hand or with equipment sitting outside the tree protection zone.

Extraction shall occur by lifting the material out, not by skidding it across the ground.

f. Structures and underground features to be removed within the tree protection zone shall be removed using the smallest equipment possible operating from outside the tree protection zone.

g. Any damage to trees due to demolition activities shall be reported to the Urban Forester immediately.

h. If temporary haul or access roads must pass over the root area of trees to be retained, the Project Contractor must install a roadbed of at least 10 inches of mulch or wood chips shall be created to protect the soil from compaction. The chips or mulch to be covered with a hard, flat surface, such as plywood, Alturnamats, etc. The roadbed material shall be replenished as necessary to maintain a 10-inch depth. The Urban Forester must approve the use of any such temporary road in the tree protection area.

6. Pruning & Other Preservation Measures Specifications:

a. The Urban Forester shall be notified a minimum of three (3) days in advance of commencing any form of tree work. Call 703-695-3588 for an appointment.

b. Root pruning, where required, shall be performed by the Cemetery Tree Care Contractor at the direction of the Urban Forester. In the event that the work must be performed by the Project Tree Contractor, the work will be performed to the following specifications: Trenches shall be made mechanically with a narrow trencher with sharp blades. Alternately, a trench may be created using a supersonic air tool (ex. Air Spade) to avoid mechanically damaging existing tree roots. Once a trench is opened up, approximately 18-24” in depth and 4” wide all exposed roots will be hand pruned so that the clean-cut ends can regenerate.

The tree preservation fencing shall be placed 6-12” outside the root-pruning trench (construction side of the trench). The erosion and sediment fencing shall be placed outside the tree preservation fencing (construction side of the fence).

c. Where temporary clearance is needed for access, branches shall be tied back to hold them out of the clearance zone. The Urban Forester must approve such tying, and may direct the Cemetery Tree Care Contractor to conduct this work.

d. Where tree limbs must be removed for access or clearance, The Urban Forester must approve such pruning, and may direct the Cemetery Tree Care Contractor to conduct this work.

e. Pruning shall not be performed during periods of flight of adult boring insects because fresh wounds attract pests. Pruning shall be performed only when the danger of infestation is past.

f. All work to be performed by a Project Tree Contractor must be in accordance with the direction of the Project Certified Arborist and the Cemetery Urban Forester, and in accordance with American National Standards Institute (ANSI) Standard Practices for Trees, Shrubs, and Other Woody Plan Maintenance ANSI A300, and adhere to the most recent edition of ANSI Z133.1.

g. It may also be necessary to fertilize, aerate, or otherwise treat the “trees to be saved” as required by the Urban Forester, following a meeting with the project Certified Arborist and approval of the Tree Preservation Plan. Trees to be treated will be identified by the Urban Forester and treated post construction, once all vehicles, equipment, and materials have been removed from the site.

Treatment shall consist of deep-root liquid fertilizer and/or bio-stimulant application by soil injection, soil drench, or surface application of granular material as determined by the Urban Forester.

h. ‘Selective clearing’ in wooded areas will be allowed only under the direction of the Urban Forester. Trees to be removed will be felled by hand so that minimal damage is done to “trees to be saved”.

i. No vehicles or storage of materials of any kind will be allowed inside the limits of clearing. No storage of material or debris will be allowed within the “tree preservation area”. No burning will be allowed on site.

7. Construction Specifications:

a. Supplemental water shall be supplied to trees being preserved when natural rainfall is less than 1” a week, from early spring until the ground freezes in the fall. Irrigation should be designed to wet the soil to a depth of 2-3 feet.

Lacking a source of water early on the construction site, this may be accomplished by constructing a 6” berm around the tree protection zone and filling the basin with a water truck or by injecting the soil using a pressure system form of a truck mounted water tank. Shallow frequent watering should be avoided

c. Where construction traffic must occur in the area of tree roots, it shall be necessary to apply the following procedure: cover undisturbed soil with 10-15 inches wood chips and topped with chain link fence pulled taught and anchored or topped with 5/8 to 3/4 inch plywood with non-skid surface.

d. Before grading, pad preparation, or excavation for foundations, footings, walls, or trenching, relevant trees shall be root pruned 1 foot outside the tree protection zone. This work shall be performed by the Cemetery Tree Care Contractor at the direction of the Urban Forester. In the event that the work must be performed by the Project Tree Contractor, the work will be performed to the following specifications: Cut all roots cleanly to a depth of 24 inches to the maximum depth of root penetration, (usually 3 feet). Roots shall be cut by manually digging a trench and cutting exposed roots with a saw, vibrating knife, rock saw, narrow trencher with sharp blades, or other approved root-pruning equipment. Alternately, a trench may be created using a supersonic air tool (ex. Air Spade) to avoid mechanically damaging existing tree roots.

Pruned roots shall be promptly covered with soil.

e. Any roots damaged during grading or construction shall be exposed to sound tissue and cut cleanly with a saw and promptly covered with moist soil.

f. Spoil from trenches or other excavations shall not be placed within the tree protection zone, either temporarily or permanently. Soil stockpiles should be placed only in previously designated areas. No vehicles or construction equipment shall be parked in the tree protection zone.

g. No burn piles or debris pits shall be placed within the tree protection zone. No ashes, debris or garbage may be dumped or buried within the tree protection zone. No materials of any kind shall be stored in the tree protection zone.

h. Maintain fire-safe areas around fenced areas. Also, no heat sources, flames, ignition sources, or smoking is allowed near mulch around trees.

i. A copy of the approved plan and TREE PRESERVATION PROCEDURES AND SPECIFICATIONS must be maintained on site at all times.

j. All underground utilities and drain or irrigation lines shall be routed outside the tree protection zone. If lines must traverse the protection area, they shall be tunneled or bored under the tree(s) with the approval of the Urban Forester.

k. The Cemetery Tree Care Contractor must perform additional tree pruning required for clearance during construction under the direction of the Urban Forester. Construction workers shall not be allowed to prune trees.

l. Any herbicides placed under paving materials must be safe for use around trees and labeled for that use. Any pesticides used on site must be tree-safe and not easily transported by water.

m. If injury should occur to any tree during construction, it should be treated as soon as possible under the direction of the Urban Forester.

n. The Urban Forester must monitor any grading, construction, demolition, or other work that is expected to encounter tree roots.

o. At the completion of construction (all equipment removed from site), notify the Urban Forester for an inspection before removing the tree preservation fencing. At this time, all trees will be inspected and any repairs needed will be stipulated by the Urban Forester and promptly made by the Project Contractor.

8. The planting of the new tree(s) specified on the plan shall take place after the completion of construction. The Urban Forester must inspect the trees prior to planting and also inspect the placement and installation of the tree(s). All products and workmanship related to the planting of the tree(s) must be in accordance with the Tree Planting Specifications. The Project Contractor/Owner must present the Cemetery with a copy of a one-year guarantee from the Landscape Contractor for the newly planted tree(s). The tree(s) will need to be thriving and in good condition one year from the date of planting or will need to be replaced.

If you have questions on any of the “procedures” or specifications” noted above or concerns that may arise during construction, please contact the Urban Forester at

(703) 695-3588.