Sustainable Restoration Strategies for Aggregate Pits in Ontario Jesse Long 15 th Annual A.D. Latornell Conservation Symposium November 19, 20, 21, 2008
The MAAP Program rehabilitates abandoned aggregate pits and quarries in areas of Ontario that are designated under the Aggregate Resources Act, and both conducts and funds rehabilitation research. MAAP is funded by a portion (1/2 cent per tonne) of the annual 11.5-cent/tonne licence fee paid by aggregate producers in Ontario. To date, over $4.6 million has been spent to make over 416 hectares of land safer, healthier and more productive, all at no cost to the landowner. Our view of successful rehabilitation now places a greater emphasis on the importance of ecological function and sustainable rehabilitation
Sustainability is a characteristic of a process or state that can be maintained at a certain level indefinitely. What do we mean when we say, Sustainable Rehabilitation? appropriate land use pits to prairies, quarries to alvars species selection climate tolerant native species ability to naturally develop without further interference no permanent man-made structures
Case Study: Project 07-11 Stephens Pit April 19, 2007; Existing conditions The Stephens Pit is a sand and gravel pit was deemed abandoned when the Aggregate Resources Act came into effect (1990). Very few native and non-native species have populated the pit due to steep slopes, the lack of organic material and erosion. The development of a natural habitat has been severely restricted leading to our goal of restoring the pit as a prairie habitat.
Seed Mixture: Prairie Circle Mix The seed mixture in the hydro-seeding was a shotgun approach that comprised of tree and shrub, grasses, wildflowers, sedges, aquatics and rushes seeds. Prairie Circle is an Ontario native plant species mix. Some species in the mix are, but not limited to: Tree and Shrub Grasses Wildflowers Sedges and Aquatics Staghorn Sumac Redtop Canada Anemone Water Platain Grey/ Red Osier Dogwood Big Bluestem Joe Pye Weed Fox Sedge Eastern Red Cedar Canada Wild Rye Black Eyed Susan Green Bulrush Indiangrass Wild Lupine Woolgrass Shotgun Approach: One of the main reasons for the selection of the Prairie Circle seed mix was the variety of species it incorporated into one mix. This Shotgun approach was used to give all species a level playing field and then to see which ones prevailed. The species that perform better, i.e. establish themselves in the harsh conditions, will be used on other abandoned pits with similar conditions.
The Stephens pit was completed over the course of a few months. This project turned potential safety hazards into a functioning part of an ecosystem. September 11, 2007; Annual cover crop established PROJECT AT A GLANCE PRAIRIE HABITAT OUTCOME: USING ONLY THE PARENT MATERIAL, ESTABLISH PRARIE HABITAT ON AN PIT. SERVICES: EARTHWORKS TREE PLANTING SIZE: 0.72 ha (1.78 acres) HYDRO-SEEDING MONITORING COST: $18,660.00 (w/o GST)
April 19, 2007 July 06, 2007 September 11, 2007
Case Study: Project 07-13 Scott Pit April 19, 2007; Existing conditions The Scott Pit is a former sand and gravel pit ideally positioned on a naturally occurring wetland that borders on an agricultural field. A two part solution has coined this pit as The pit with two faces. With the help and cooperation of the landowner, the project combined an agricultural end use and a wetland enhancement into one viable restoration initiative.
Page wire fencing with white pine and birch provided distinction between the two areas and protection against illegal dumping. Tracking of slopes increases micro-topography and allows for better adhesion of seed to soil surface November 08, 2007 Tracking the slope PROJECT AT A GLANCE- PIT WITH TWO FACES OUTCOME: RESTORE HALF OF PIT INTO AGRICULTURAL LAND AND TO ENHANCE AN EXISTING WETLAND. SERVICES: EARTHWORKS TREE PLANTING FENCING HYDRO-SEEDING MONITORING SIZE: 1.90 ha (4.69 acres) COST: $35,500.00 (w/o GST)
April 18, 2008; Looking east across pool The addition of a vernal pool (above) will enhance the existing wetland (right). The vernal pool will collect excess spring run off and eventually dry out, but not without performing important habitat functions first. March 16, 2007; Looking north across wetland.
June 04, 2008; One year after construction The Scott Pit was a great success due to the cooperation and open mindedness of the landowner. With an agricultural end use and wetland enhancement coming together as one, important insight was gained and will be applied on future projects.
Case Study: Project 07-06 Christensen Quarry April 4, 2008; Looking east towards quarry and highway The Christensen quarry is located in southwestern Ontario near Hagersville. The quarry had two benches with shear rock faces and was being used as a storage area for hay and farm machinery. Safety concerns and the alleviation of a visual eye sore were the main objectives for restoration. Very little topsoil/organic material remained on the site and an adjacent highway were the biggest obstacles.
PROJECT AT A GLANCE- QUARRY RESTORATION OUTCOME: TURN SHEAR ROCK FACES INTO VEGETATED SLOPES AND CREATE LARGE FLAT AREA FOR HAY STORAGE. SERVICES: EARTHWORKS HYDRO-SEEDING SIZE: 1.40 ha (3.46 acres) IMPORTING TOPSOIL MONITORING COST: $41,910.00 (w/o GST) The rock faces were fractured and graded to a safe 3:1 (minimum) slope. Just enough topsoil to give the rock slopes a cover of 50 70 mm was imported and then applied on just the slopes. Prairie Circle was also used for the hydro-seed in hopes that the seeds of the tree species would eventually vegetate the slope.
Approximately 1.40 ha of otherwise unusable land was restored into productive space. Future monitoring will offer knowledge and experience on establishing different kinds of vegetation on rehabilitated quarry rock. July 11, 2007; Looking west across rehabilitated quarry floor
Case Study: Project 08-03 Sorenson Pit April 08, 2008; Looking east towards main face. The Sorenson Pit is located just north of Napanee, ON. The main face of the pit stands approximately 12-13m at its highest. A natural end use that incorporates the alleviation of potential liabilities inherent with steep slopes was applied to the rehabilitated area. Pits and mounds were applied to the slope to mimic the natural succession that occurs in mature wooded forests. The pits and mounds also create a barrier against trespassing.
Case Study: Project 08-03 Sorenson Pit July 15, 2008; Pits and mounds before hydro-seeding. November 12, 2008; After a full growing season.
The MAAP Program seeks out and rehabilitates abandoned aggregate pits with the emphasis on sustainable restoration based on applied research. Continuing to promote the rehabilitation of these abandoned aggregate pits into natural areas is essential to increasing habitat diversity across the province of Ontario. Sustainable approaches that expedite natural soil amendments and mimic mother nature are most effective in the establishment of native vegetation and habitat. Monitoring successes and failures will improve restoration objectives and provide insight into sustainable restoration practices for the aggregate industry.
For More Information Jesse Long Coordinator: Rehabilitation and Construction Management of Abandoned Aggregate Properties Program The Ontario Aggregate Resources Corporation 1001 Champlain Avenue, Suite 103, Burlington, Ontario L7L 5Z4 TOLL FREE: 1-8661 866-308-6272 TEL: (905) 319 1968 FAX: (905) 319-2467 jdlong@toarc.com www.toarc.com