Creative Applications: Impact Posts in the Landscape by Ron Maltin Often compared to plastic lumber-- which is produced from recycled, high-density polyethylene plastics-- environmentally friendly Impact Posts are made from synthetic materials that contain significant, recycled fibre content. More and more, Landscape Architects are recognizing the many applications that these posts have in various landscape environments, including terracing/edging, retaining walls, planter boxes, sign posts, and curbing. Technology created by Winnipeg, Manitoba-based XPotential Products has resulted in a 6"x 6"x 8' square post used in place of treated lumber and railroad ties for area fencing and perimeter delineation. Retaining walls, raised flower and vegetable beds, and environmentally sensitive areas that may have adverse effects from "treated lumber leachates," are other venues for these posts. One of the most unique applications is illustrated by the Town of Cut Knife, Saskatchewan. Cut Knife has long been known for its beautiful tree-lined approach to the town, which ends in a 3-block boulevard of trees on the main street. The boulevard was re-planted with new trees and shrubs in 1995, and the soil covered with tree bark chips. There had never been a curb around it, and the use of bark chips made this necessary-- not just to improve the finish, but to keep the chips in place. Needing 2,700 feet of curbing, the city council looked at several options. Concrete curb and gutter were far too expensive; and the cold-mix base was not strong enough for asphalt. Used railway ties were quite inexpensive, but would not achieve the required look. The city council wanted something inexpensive yet durable with an aesthetic finish. Impact posts were easily installed by town employees in just a few days. "The street has never looked so neat, and there have been many favorable comments from both residents and visitors," explains Dick Emanuel, Town Administrator. Later, after one of the most severe prairie winters the town had faced, the Impact Posts were put to a real test thanks to the winter road maintenance program. The street on which the posts were installed is the main access to town, and received plenty of attention from the snow removal crew. The Impact Posts have "passed with flying colors... and look as good as the day they were installed," remarks Emanuel. For city planners, this material also provides a cost effective alternative to fragile but bulky concrete bumper stops. A virtually indestructible curb stop has been developed using the same recycled materials from old cars and trucks. Add in the plastics that are reclaimed from household and post consumer sources, and the family wagon can be literally parked against "your father's Oldsmobile." Ongoing field tests have been conducted by the City of Winnipeg since 1995. Winnipeg's severe temperature range of -40F to +100F has very damaging effects on concrete curbs. As one industry pundit puts it, "If it lasts for one year in Winnipeg, it should last forever anywhere else." In conclusion, Doug Thiessen, Supervisor of Business Operations, Winnipeg Civic Buildings Department raves, "A landscape material of this nature, with its positive environmental attributes, overall aesthetics, durability and cost effectiveness, certainly gave us the opportunity to allow the curbs their place in the bidding process." lasn