“Tortoises or land turtles are land-dwelling reptiles of the family of Testudinidae, order Testudines. Like their marine cousins, the sea turtles, tortoises are shielded from predators by a shell. The top part of the shell is the carapace, the underside is the plastron, and the two are connected by the bridge. The tortoise has both an endoskeleton and an exoskeleton. Tortoises can vary in size from a few centimeters to two meters. Tortoises tend to be diurnal animals with tendencies to be crepuscular depending on the ambient temperatures. They are generally reclusive animals. The biggest operational difference between tortoises and turtles is that tortoises are unable to swim; indeed, they cannot float, whereas turtles can” (www.answers.yahoo.com/question/index?qid=20080409144910AAbkGR8&show=7, retrieved 4/19/2008).
“The Galápagos tortoise (or Galápagos giant tortoise), is the largest living tortoise, endemic to nine islands of the Galápagos archipelago. Adults of large subspecies can weigh over 300 kilograms (660lb) and measure 1.2 meters (4 ft) long. Although the maximum life expectancy of a wild tortoise is unknown, the average life expectancy is estimated to be 150-200 years. The Galápagos tortoises have very large shells (carapace) made of bone which is an integral part of the skeleton. The bony plates of the shell are fused with the ribs and other bones to form a rigid protective structure. When a tortoise feels threatened it can withdraw its head, neck and forelimbs into its shell for protection, presenting a thick shield to a would-be predator. The legs have hard scales that provide an effective armor when withdrawn” (www.wikipedia.org/wiki/Gal%C3%A1pagos_tortoise, retrieved 4/19/2008).
“In the 19th century, Charles Darwin, a biologist from England, set off on the ship HMS Beagle to investigate species of the Galapagos Islands. After spending time on the islands, he soon developed a theory that would contradict the creation of man and imply that all species derived from common ancestors through a process called natural selection. Natural selection is considered to be the biggest factor resulting in the diversity of species and their genomes. One of the prime motives for all species is to reproduce and survive, passing on the genetic information of the species from generation to generation. When species do this they tend to produce more offspring than the environment can support. The lack of resources to nourish these individuals places pressure on the size of the species population, and the lack of resources means increased competition and as a consequence, some organisms will not survive. The organisms that die as a consequence of this competition are not totally randomly. Darwin found that those organisms more suited to their environment were more likely to survive. This resulted in the well known phrase ‘survival of the fittest’, where the organisms most suited to their environment had more chance of survival if the species falls upon hard times. Those organisms who are better suited to their environment exhibit desirable characteristics, which is a consequence of their genome being more suitable to begin with. This 'weeding out' of less suited organisms and the reward of survival to those better suited led Darwin to deduce that organisms had evolved over time, where the most desirable characteristics of a species are favored and those organisms who exhibit them survive to pass their genes on. As a consequence of this, a changing environment would mean different characteristics would be favorable in a changing environment. Darwin believed that organisms had 'evolved' to suit their environments, and occupy an ecological niche where they would be best suited to their environment and therefore have the best chance of survival. As the above indicates, those alleles of a species that are favored in the environment will become more frequent in the genomes of the species, due to the organisms higher likeliness of surviving as part of the species at large” (http://www.msnbc.msn.com/id/8727984/-storyContinued, retrieved 4/20/2008).
Wednesday, April 23, 2008
Tuesday, April 15, 2008
Sunday, April 13, 2008
Mini-Project 5
Tarpon Springs, Pinellas County, FL
Site Background:
The Tarpon Springs plant produced elemental phosphorous using phosphate ore mined from deposits in Florida. The plant was originally constructed and operated by Victor Chemical Company, which began production in 1947. The Stauffer Chemical Company obtained the plant from Victor Chemical in 1960 and continued to manufacture elemental phosphorous until the plant closed in 1981. The 160-Acre site (130 acres dry) is situated along the Anclote River approximately two miles upstream of the Gulf of Mexico. The site is approximately 1 mile north of the City of Tarpon Springs. Surrounding land use includes light industrial, commercial, recreational, and residential.
The Remedial Investigation was started in 1993 and completed in 1996; the site was listed on the National Priorities List. The contaminants of concern include heavy metals, radionuclides, Polynuclear Aromatic Hydrocarbons, and elemental phosphorous. Media contaminated include on-site soils, on-site waste ponds, and ground water.
Cleanup Progress: Threat Mitigated by Physical Clean-up Work
Under a removal action, the Stauffer Management Company removed approximately 33,000 gallons of elemental phosphorous contained in on-site above-ground tanks in 1997-1998.
The EPA signed a Record of Decision in July 1998 calling for in-situ solidification/stabilization of pond material above the water table; consolidation and on-site capping of contaminated soils and other materials; and institutional controls to prevent future residential land use at the site.
The EPA and Stauffer Management Company initially signed a Consent Decree in 1999 to implement the selected remedy. In response to public comments, the initial Consent Decree was withdrawn and additional geophysical studies were performed at the Site. The additional studies were conducted during 2000-2004 to evaluate the suitability of the remedy. The geophysical studies concluded that the remedy can be safely implemented at the Site. Stauffer Management Company and EPA signed another Consent Decree for the design and cleanup at the Site in April 2005.
The Consent Decree was lodged with the district court in June 2005.
The long term cleanup plan is in the remedial design phase. The design may be completed by early-2008.
EPA recently decided to change the in-situ solidification component of the remedy (see Summary of Explanation of Significant Differences dated June 2007). EPA plans to substitute a groundwater “cut off” wall for the use of in-situ solidification (ISS) to reduce the potential for contaminant migration from the former waste ponds. EPA plans to make this change because of implementation issues identified during the pilot testing of the ISS technology. During this testing, a reaction occurred between elemental phosphorus and the cement slurry which contributed to a fire in the test area. In addition, there is debris in portions of the old ponds which makes solidification impracticable. Some of the debris likely contains residual elemental phosphorus.
The use of a cut off wall will reduce the movement of groundwater contamination. The wall would be installed below ground around the perimeter of the former waste ponds. Modifying this component of the remedy will avoid the problems associated with implementing ISS at full scale.
Other components of the remedy, including capping and restrictions regarding future on-site groundwater use and land use, remain unchanged. The capping called for in the ROD will cover contaminated soil including the area inside the subsurface cut off wall and will form a protective barrier designed to prevent contact with contaminated materials.
Community Involvement: The community has been very involved in the Superfund process. The EPA awarded a Technical Assistance Grant (TAG) to Pi-Pa-TAG, Inc. in May of 1996. The EPA assisted the community in forming the Anclote Community Advisory Group (ACAG) in the June 2000.
www.epa.gov/region4/waste/npl/nplfln/statusfl.htm Retrieved 4/10/2008
The Superfund program was created by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), amended by the Superfund Amendments and Reauthorization Act (SARA). The acts established authority for the government to respond to the release/threat of release of hazardous wastes, including cleanup and enforcement actions. Long term cleanups at National Priority List (NPL) sites last more than a year while short term /emergency cleanups are usually completed in less than a year. Our Federal Facilities Program monitors and provides assistance to federal facilities in Region 4 to ensure compliance with environmental regulations and policies under CERCLA. The Office of Superfund Remediation and Technology Innovation, under the Office of Solid Waste and Emergency Response provides the policy, guidance and direction for our knowledge managment programs.
The Superfund and Federal Facilities Restoration programs are helping state and local governments all over the Southeast region realize significant real estate and development opportunities by assisting in cleaning up Superfund sites for reuse through our land revitalization effort. We are collaborating with our state and local partners to help restore land and watersheds that have been contaminated, deforested and eroded by mining in the past.
Hot Topic Cleanup Site Information
(Adobe PDF Reader Required)
* Jax Ash Cleanup, Jacksonville, Florida
EPA Region 4 successfully negotiated a complex Consent Decree with the City of Jacksonville for the cleanup of the Jacksonville Ash/Brown’s Dump Superfund Sites in 2007. This settlement entails approximately $100 million in Remedial Design/Remedial Action, one of the largest settlements in the history of Region 4, and will address more than 1.6 million cubic yards of contaminated soil located in four neighborhoods in downtown Jacksonville, Florida. The remedy will provide for the removal or isolation of contaminated soil and address concerns about both public health and property values for thousands of residents in low-income environmental justice neighborhoods.
Point of Contact: Joe Alfano
Cast Attorney: Caroline Philson
Enforcement Project Manager: Janice Thomas
Civil Investigator: Annette Fields
www.epa.gov/region4/waste/sf/index.htm Retrieved 4/10/2008
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