Reclamation: Strategies and Stages
Giant draglines dig 25 to 30 feet into the earth to get at the valuable ore, which is part of what the phosphate industry calls “matrix.” Matrix is a mixture of sand, clay and the phosphate mineral. This strip mining leaves 50 to 60 foot deep holes or pits interspersed with piles of cast earth, and the resulting landscape has been described by some as resembling a “moonscape.” The scars, however, do not have to last forever. Reclamation is a regular part of the mining process.
Reclamation planning begins before the phosphate ore is removed from the ground with the aim of either returning the mined-out site as closely as possible to its former condition or making it usable for some other purpose. Reclamation is not always an easy task and it has required the development of many innovative techniques. Improving reclamation techniques is an ongoing focus of research.
Many years ago, most mined-out areas were simply left as they were. Over time, nature healed the earth with vegetation cover, and these areas became homes to wildlife and places for recreational activities, especially fishing in the water-filled pits.
As society became more concerned about the quality of the environment and as communities grew closer to mining and processing areas, the phosphate industry came under increasing pressure to return the landscape to a condition similar to the way it was before it was mined. Ecologists pressed for increased regulations to protect certain ecologically sensitive areas from being mined at all, and they also called for more extensive reclamation of many other areas.
A Florida law, effective July 1, 1975, requires reclamation (to make suitable for beneficial use or habitat) of each individual acre of land that is mined pursuant to mandatory phosphate reclamation standards. These standards relate to safety, hydrology, contouring, revegetation, wildlife habitat, and the timing of reclamation. Complete restoration, or returning the land to its original condition, is required only for wetland areas.
Taxes collected on each ton of phosphate rock mined are used to help pay for the reclamation of areas mined prior to July 1, 1975, most of which are now in private ownership. These taxes also help pay for preserving environmentally sensitive lands through the State of Florida’s Conservation and Recreational Lands (CARL) Program.
The mining companies are fully responsible for reclamation of land mined after 1975, according to the conditions set forth in their mining permits.
The major phosphate mining region is in central Florida (in Polk, Hillsborough, Manatee, and Hardee Counties). One mining company operates in northern Florida (Hamilton County). The Florida Department of Environmental Protection Bureau of Mine Reclamation is responsible for administering the rules related to the reclamation of lands mined for phosphate after June 1975 and the rules related to Environmental and Wetland Resource Permits for phosphate mined lands.
Before a phosphate company mines the first bucket of material, a detailed study of the land to identify plants and animals, water supplies, and potential archaeological sites must be done. This study helps generate a reclamation plan that is submitted to the DEP and other local, state and federal agencies for approval. If approval is given, then the mining can begin. As mining is completed, the reclamation process begins.
Phosphate mining disturbs about 5,000-6,000 acres of land annually; approximately 25-30% of these lands are isolated wetlands or wetlands connected to waters of the state, according to the Florida Bureau of Mine Reclamation.
Besides planning, there are two additional stages of land reclamation: contouring and revegetation. Contouring is the stage in which the mined land is reshaped to resemble pre-mining topography and drainage. Revegetation provides for the replacement of plant communities as well as for agricultural opportunities. Once reclamation has been satisfactorily completed in accordance with permit requirements, the operator of the mine may be “released” from further obligation to maintain or improve the reclaimed land. Reclaimed land may be used for recreation, pasturage, industry and homes, as well as wildlife habitat. Lakes are often created on mined land. Although these lakes have wetland fringes along their shores, the open water portions do not substitute for wetlands because they do not provide the same habitat, vegetation or ecosystem functions as do wetlands.
Phosphate companies are required to restore the essential function of wetlands destroyed by mining before they can be released. Most wetland restoration projects are continually and actively managed by phosphate mining companies at great expense. The primary challenges in wetlands restoration are creating and maintaining the appropriate hydrologic regimes and controlling invasive or opportunistic plant species.
Technical issues associated with reclamation include hydrology, water quality, wetland and other wildlife habitat replacement and mitigation, waste clay disposal, forestry, crop production, soil development, native vegetation establishment and exotic weed control. Today the Integrated Habitat Network (IHN) plan, prepared by the Bureau of Mine Reclamation, provides a conceptual framework for the reclamation and permitting efforts for phosphate mining in Central Florida. The IHN provides for ecologically-based construction of wildlife corridors, which are to be associated primarily with the land adjacent to major river systems and their tributaries.
According to the December 2002 Florida Department of Environmental Protection Bureau of Mine Reclamation “Rate of Reclamation Report,” 166,722 acres of Florida land have been mined since the mandatory reclamation law passed July 1, 1975. Of those acres, 51,628 (31%) have been reclaimed and released and another 52,678 have been reclaimed through revegetation for industrial use, making a total of 104,386 reclaimed acres. That is 63% of what has been mined from 1975-2002.
Under current practice there is not a standardized, post-release, quantitative assessment of phosphate mine reclamation and restoration projects, but each is considered on a case by case basis according to the conditions contained in the permits. Once the Bureau of Mine Reclamation releases the reclamation project area the Bureau is no longer in control of the land.
Reclaimed lands are used for many purposes. There are several parks, such as Mary Holland Park in Bartow, on reclaimed land. Reclaimed land uses also include golf courses, housing developments, office complexes, cattle grazing and citrus groves.
The value of reclaimed land as wildlife habitat is also important. As growth and development have destroyed wildlife habitat elsewhere, reclaimed land provides a much-needed refuge for all kinds of bird and animal life. The many lakes found on reclaimed lands offer waterfowl places for feeding and resting during their migrations. Careful planning of reclamation projects has also allowed for the creation of wildlife corridors, which allow animals to roam between reclaimed and unmined areas.
Reclamation is not instantaneous. For example, it takes time for trees to grow into a forest and for wildlife to migrate back. This means it takes time to know if reclamation efforts are completely successful. Success can be defined in many ways, depending on what the goal of the reclamation was – wildlife habitat, citrus grove, recreation or something else.
Research continues to attempt to answer questions, such as why a certain animal may not have returned to a reclamation site and what can be done to solve the problem. Is it because the habitat is not yet suitable or that the animals need help or sufficient time to recolonize?
The goal is to continuously improve reclamation techniques and especially to improve the ability to restore the hydrologic and ecological functionality of reclaimed lands to better mimic natural environments.