Level-3-Turf-Protection-Planning-Guide-Primer

Level 3 Guidelines

Summary: Level 3 areas, in addition to Level 2 allow:

• Larger equipment with smooth, wide turf tire, with ground pressure less than 7 psi allowed to drive directly on turf. This includes tractors 45 hp and less and forklifts.
• Tractor trailers allowed with protective flooring and proper traffic dispersal (a route in and out may only be used once by a tractor trailer).
• Aluminum roll out flooring allowed for 4 hours a day before 10 am and after 4 pm.

Turf Area Protective Decking Guidelines

For the protection of the park’s resources, the National Park Service must institute management practices to limit damage to the turf.

Temporary covering of turf substantially reduces wear injury by protecting the plant from tearing and abrasion due to traffic. Temporary covering helps reduce soil compaction although it is not eliminated. Set up for events are encouraged to be configured to avoid concentrating foot traffic and the need for protective decking. The area between the stage and front of house will require decking for pedestrians.

Efforts will be made to maximize the amount of pedestrian flooring used.

Acceptable Drivable Turf Decking Systems: There are conditions that warrant a solid back such as some soft soil conditions, temporary cover for equipment access, or hot weather. In this case MatraxHD, ArmorDeck 3, RGT Panel Flat back, or equal is acceptable; but plywood is not ever an acceptable material.

Acceptable Pedestrian Turf Decking Systems: Products such as Terraplas, ArmorDeck 1, Supa Trac Translucent, Clear Road, GroundShieldz, RGT Panel Pedestrian, and Matrax LD.

These are ADA-compliant, interlocking mats that are translucent to allow UV light to pass through or provide light to the grass below. These types of materials are considered leading turf protection systems for stadia and other venues such as public parks, racecourses, and private events and are used for walkways, exhibitions, show stands and hospitality areas. An approved equal to these would be translucent in color, flat backed, and would lock together with adjoining pieces. These products are quick and easy to fit; allows passage of air, light, and water; perform to high public safety standards; and protect turf from large crowds and structures. Time restrictions noted below.

While temporary turf decking helps prevent some damage if used for a short period of time, covering the turfgrass still results in additional stressors such as reduced airflow, restricted moisture infiltration, heat buildup, and reduced light, so seasonally adjusted turf cover time limits are needed.

 

Flooring shall follow the guidelines below:

• Comprised of single-sided or double sided high density translucent polypropylene. Dirty panels will not be accepted, as translucence is limited by this.
• Not result in turf damage during installation or removal.
• The cavity back (if specified) must have appropriate clearance above crown of grass (not compress the turf, approximately 1.75” to 2.25”); this depends on the time of year and ground conditions.
• Cavity back must have holes for air, light, and water to permeate the product.
• No fabric or other obstructions to turf decking covering holes or blocking light will be allowed below the protective decking.
• Carpet may be allowed on top of the decking with seasonally defined time restrictions (see inserted box above)
• Plywood is never an acceptable temporary covering. Plywood blocks nearly all irradiance, thereby shutting down the photosynthetic process within the turfgrass plants. This results in unacceptable decline of turfgrass health.
• Aluminum roll out flooring allowed for 4 hours a day before 10 am and after 4 pm.
• Installation after five (5) pm and working through the night to minimize turf coverage time and meet these guidelines is permitted with approval from the Superintendent’s office.
  • Permittee will be responsible for paying personnel overtime charges related to the assignment of National Park Service employees and US Park Police for monitoring set-up and take down construction or security beyond an eight hour shift or on weekends in association with the special event.
• Vehicles- allowed for set up at the discretion of permit specialist and turf management specialist with the submission of a vehicle plan.
  • Approved vehicles driving on approved decking is allowed.
  • One vehicle allowed delivering and removing a stage that weighs no more than 9990 lbs.
  • Dumpster installation and removal.
• Crane for installing and removing items are permitted on hardscape.
  • Outriggers should be situated on hardscape when possible while avoiding edges and avoiding irrigation.
  • Protect turf and hardscape with four layers of Enkamat and two layers of plywood (3/4”) under each outrigger.
  • 60 ton crane is the maximum allowed.
• Approved turf vehicles (golf cart size (800 lbs) or similar) with turf tires (smooth tread and ground pressure of less than 4 psi) are allowed to drive on turf without decking (except Washington Monument grounds).
• 6,000 lbs or less Forklifts and Telehandlers, articulating with flotation tires.
• Limited number of approved turf vehicles weighing less than 800 lbs with turf tires (smooth tread and a psi of less than 15) are allowed to drive on turf without decking.
  • A limited number of tractors and forklifts with smooth, wide turf or flotation tire with a tire pressure of less than 20 psi on larger equipment allowed to drive directly on turf.
  • Tractor trailers allowed with protective flooring and proper traffic dispersal (a route in and out may only be used once by a tractor trailer).

Products proposed must be approved by the NPS Turf Specialist and affirmed through the permitting process (planning, writing) by
the Permit Specialist.

 

Time Limits for Protective Decking
Total turf coverage time including set up: November 15 to March 14: 10 days
March 15 to May 14: 5 days
May 15 to September 14: 3 days
September 15 to November 14: 5 days

Time Limits for Blocking Light (i.e. tents, stages)
November 15 to March 14: 5 days
March 15 to May 14: 3 days
May 15 to September 14: 2 days
September 15 to November 14: 3 days

Carpets above the decking with seasonally defined time limits.
May 15 to September 14 carpet allowed from 5 pm to 6 am.
September 15 to May 14 carpet allowed for 24 hours.

LED Flooring
The use of flooring with internal lighting can be used to avoid the blocking of light and carpet limitations.

 

Tents or Other Temporary Structures on Turf Areas

Permittee shall provide drawings for all structures (including foundation/anchoring systems) over 500 square feet in area. Drawings are also required where the total combined area of connected individual structures exceeds 500 square feet. Structures shall be considered connected if they are within 5-feet of each other, share a common foundation/anchor, share a common utility, or are connected by any other means. Temporary walkways shall not be considered when evaluating if structures are connected.

If tents or other temporary structures are placed on the turf, they must follow the guidelines below:

• In event areas where there are underground utilities or designated no stake zones, water filled ballast tanks or concrete blocks will be used on the turf with proper protection decking and seasonal time restrictions. This is to help minimize compaction of the turf by the weight of the ballasts. This also allows maximum access of air, sunlight, and water to the turfgrass.
• Water from tanks may not be dumped on park grounds or storm drains.
• Any approved staking cannot take place without a National Park Service official present.
• Permittee to hire a private utility marking company for stakes deeper than 18”.
• Flooring not automatically required under tents. This will be based on programming inside the tent and the determination of the permitting process of the possibility of turf or soil damage. Programing that will result in concentrations of 1 person per 5 square feet will require flooring, typically this would happen with cuing lines, concert seating arrangements, or front of stage.
• Tent walls will be put on at the last possible moment before the event. This will allow for air circulation and light penetration for turf health. Please refer to the preceding table for guidance on time requirements for blocking light.
• All screws, fasteners, and ties should be policed during the build and retained during the removal. They should be made of a non-aluminum or non-plastic material. Cleanup with a magnetic sweeper is required to ensure all fasteners and screws are retrieved.
• Steel, lumber, vinyl, and other construction materials, etc. should not be left on the turfgrass for a prolonged period of time (more than 4 hours).

Temporary Stages on Turf

The park has many locations where stages can be set up on hardscape. However, stages with proper turf protection can be set up in certain turf areas if approved by the NPS in the permit conditions. The stage must be arranged so that as much turf can be protected as possible, this is accomplished by utilizing hardscape areas. Plywood, because of its ability to be modified to the proper size, is allowable for protection of turf from screw jacks or ballasts. Event planners should plan on some turf replacement with thick cut sod where the plywood is used.

• Protective decking will be installed under the stage if 3’ or more above the ground.

• All structures must minimize all points that come in contact with the turf grass, structures on the turf should be on a riser with as few points as possible touching the turf, if not on the protective decking, these points should have Enkamat and plywood pads underneath as outlined:
  • Each screw jack should have a 16”x16”wooden pad (3/4” plywood) and two layers of Enkamat 18”x18”.
• Scheduling of set up should include efforts to hold off stage skirting installation until last possible moment and removed immediately after the event. This will allow for maximum light penetration and airflow.
• Ballasts damage should be mitigated with four layers of Enkamat and two layers of plywood (3/4”) weight distributed in a way as to provide less than 4 psi of ground pressure. Cost recovery estimates should include sodding these areas with thick cut sod.
• Grounding rods are permitted in areas outside the “No Stake” zones (maps at the end of this chapter). The permittee must hire a private utility locating company to determine if an area is safe for this. Permittee must provide the NPS with a copy of the utility report.
• All cables (power, audio, etc) shall be encased in Yellow Jacket wire trough (or approved equal).
  • Where a wire path crosses a known road or trail, ADA compliant Yellow jacket or approved equal must be used.
  • The trough, where it crosses turf must be place on approved decking (level 1) or 2 layers of Enkamat.
  • Yellow Jacket on turf will need to be moved daily so that no area of turf is under it for more than 24 hours.
  • Areas not requiring Yellow Jacket Trough but on the turf, the cable shall be laid on two layers of Enkamat and moved every 24 hours.
  • In a stage situation, cables should be flown over the steel, tied to stage or structure under the stage, and the mix position and not allowed to touch any grass area.
• Tear-down of the stage and structures should begin immediately following the load out of show productions. Unless conditions due to weather would cause tear down operations to damage the turf.
• An industrial magnet will be used over the entire area to recover screws, fasteners, etc.
• The turf manager will inspect the area for damage after the event in order to determine the extent of turf that will need to be replaced by sod.