For the purposes of the Washington state public works law, chapter 39.12 RCW, landscape construction involves the beautification of a plot of land by changing its natural features through the addition or modification of lawns, trees, bushes, etc.

(1) Landscape construction includes:

• Constructing or maintaining lawns, yards, gardens or other landscaped surfaces.

• Mixing and spreading mulches, ground covers, soil amendments, decorative bark or decorative rock.

• Seeding, sodding or hydroseeding.

• Applying chemicals or fertilizers.

• Planting trees, shrubs or plants.

• Installing, servicing or repairing above ground lawn or landscape sprinkler systems.

• Installing, servicing or repairing underground lawn or landscape sprinkler systems to a maximum depth of three feet below finish grade.

• Assembling or placing premanufactured trellis work, play equipment, benches or picnic tables.

• Constructing rock walls to a maximum height of four feet.

• Land clearing.

• Spreading top soil to a maximum depth of six inches below finish grade.

• Trenching to a maximum depth of three feet below finish grade.

• Installing french drains or other subsurface water collection systems to a maximum depth of three feet below finish grade.

• Hauling top soil, plants or other landscaping materials in trucks with only one rear axle.

(2) Landscape construction does not include:

• Any activity or task (including those mentioned above) when performed preparatory to any nonlandscaping construction work.

• Constructing roads, footpaths, trails or rock walls more than four feet high.

• Custom fabrication of trellis work, play equipment, benches or picnic tables.

• Constructing restrooms, shelters or similar structures.

• Installing sewer systems, storm sewer systems, catch basins, vaults or drainage systems for impervious surfaces (such as parking lots).

• Installing drainage systems or underground sprinkler systems more than three feet below final grade.

• Land clearing, dozing, grading, excavating or hauling except as permitted above.

• Tree falling or bucking.

• Subgrade preparation.

• The use of power equipment with more than ninety horsepower.

• The use of trucks with more than one rear axle except hydroseeders.

• Demolition of structures.

• Asphalt or concrete work except incidental anchorage for play equipment, benches or picnic tables.

• Welding.

• Installing agricultural irrigation systems.

• Encapsulation of landfills.