This manuscript is an addendum to the ecological risk assessment of the marine and terrestrial ecosystem also including the environment done for the Sand Springs Petrochemical Complex. The purpose of this paper is to study the effect that dumping of heavy metals and acids in the lagoons or acid pits has had on the environment and specifically groundwater and the soil. This information is intended for risk managers in order for them to determine weather this area area requires the necessary remedial actions meant to protect the environment.
On a 235acre swathe of land in Tulsa County , Oklahoma is where we find the Sand Springs Petrochemical complex. This site is situated on the northern bank of Arkansas River and was formerly the location of Pierce Petroleum Refinery and Sinclair Refining Company between the years 1900 and 1948. The site is on an alluvial floodplain and developed as an industrial area which now consists of an abandoned solvents and used waste oil recycler, chemical manufacturers that are active and also other industrial chemical manufacturers that are found here. The water from the wells around this area are up the gradient of the contamination due to poor operation of these areas.
Q1. CONCEPTUAL MODEL THAT WILL BE USED TO GUIDE THE DECISION MAKING PROCESS FOR THIS ECOLOGICAL RISK ASSESSMENT
The main problem that is being looked at in this area is the contamination of the soil and ground water. The contamination of these two would have a ripple effect as they too would lead to an effect on the flora and fauna that exists in this area. As per the data that is available at the time of this study risks to mammals and the marine life in river Arkansas was expected to be high and the main concern was the small mammals, microorganisms in the water and migratory birds and animals . The contributors to this contamination were elements such as lead, zinc, cadmium, arsenic, manganese, silver and copper.
This study seeks to show the direct relationship between the contamination of the soil in this area and the adverse effects it translates to in the environment. The effect is centered those affected mostly by the hazardous material and this will include the terrestrial environment where the acid pits were located.
Q2. ECOLOGICAL COMPONENTS THAT WILL BE USED TO ASSESS THE BIOTIC IMPACTS TO THE ARKANSAS RIVER
The ecological components that will be used in this study to assess various animals that live in this area, both terrestrial and marine will include the water in the Arkansas River to check the condition of the fish. The soil will also be used as an ecological component as the soil in this environment can be assessed for dangerous and toxic chemical levels together with the health of the various microbes that make it their habitat. The animals on land will also be assessed and tested for evidence of any of the toxic material in their bodies as some of them may have possibly ingested them while feeding on the plants that have grown on contaminated soil.
Q3. ASSESSMENT ENDPOINTS AND THEIR RELEVANCE
The environmental components that will be used in this ecological risk assessment will include the pH level and acidity level in the soil around surface impoundments in the Arkansas river area that borders the Sand Spring Petrochemical Complex, the alkalinity level of the river itself and the Hazard Quotient that will be derived from testing the surrogate herbivores that are found in the vicinity. The purpose of these measures is to assess the risk that these organisms might be potentially facing in this environment. The endpoint of this study will include the thorough assessment of the inferences that have been gathered from these various tests.
Terrestrial animals have also born the brunt of pollution of the soil they derive their food from. The herbivores that have carved out a niche in this area are one group of animals that have been affected by the contamination of the environment by the hazardous materials. These animals may be exposed to these materials that are usually in the soil either by the incidental ingestion of the soil while in the feeding process or by ingesting the harmful chemical components that have been absorbed into the plants.
The approach that is most commonly used to assess the risk these two pathways exposure would have on the animal is known as the Hazard Quotient (HQ) approach. Toxicity Reference Value (TRV) is created in order to compare the ratio of the estimated dose that has been ingested by the animal .During these tests, if the value of the total HQ is one or less than, then the researcher accept that it is an acceptable number but if exceeds one, then the exposure from that particular area or sight may be very high and a cause of concern. To make the study easy, surrogate herbivores would be selected for this study and also for estimation of the risk that this environment poses to them. Surrogate herbivore species that have been affected by toxic materials on the soil in and around the site include horses, deer, cattle, meadow voles and mules.
The Arkansas River is also home to a fish of different species such as the striped bass, the shovelnose sturgeon and in the high seasons, the paddle fish can also be found in this area. After the construction of the Keystone Dam in the year 1964, critics were quick to point out that this dam would hamper the migration of the fish and that this curtailed migration might end up having a negative effect on the fish population. However, the engineers of this project had earlier on met with scientists and had a descent amount of information about the river and its marine composition and built a dam which was adjustable. The fact that the gates were adjustable meant that the downstream transportation of eggs and larvae would be possible during the spawning season and also at the same time maintain the habitat of the non-migrant fish species such as the silversides, dartes and minnows.
However, a steep decrease of the fish species here was observed and this was directly attributed to mushrooming of industries and chemical sites such as Sand Spring Petrochemical Complex. The run-off containing chemicals such as anthracene , benzene , toluene, lead and chromium were responsible for the deaths of these fish in large numbers due to dissolution of what can be termed as free-metal ions such as chlorides and sulfates, for example the metal cadmium when dissolved can form a free ion Cd+2 or in other occasions it can combine with carbonate (CO3-2) forming a free ion metal known as cadmium carbonate (CdCO3). These metals would have adverse effects in hampering the fixation of oxygen in the water. This would in turn mean that the fish would end up fighting for the reduced amount of oxygen available and others dying.
Plants are also victims of this form of environmental degradation. The soil around the Arkansas is also affected by the acid sludge dumped in these areas. Areas around Bald Eagle Roost are most affected as the chlorinated solvents and heavy metals that have contaminated sludge are usually dumped here. The plants that are exposed to these chemicals in most instances usually wither away and die while those that survive end up being able to survive with this reality are stunted in growth and show no sign of good health. This ends up hurting the beautiful Arkansas landscape.
Q4. MEASUREMENT OF ENDPOINTS AND HOW DATA WILL BE COLLECTED
The collection of data will be done by use of scientific methods of data collection. The Soil Microbial Community Toxicity (SMCT) Test would be used to determine the toxicity level of the various chemical components that are found in the soil by comparing the natural soils microbial population and the sample taken. The Soil on the surface is usually collected and then further reinforced by adding dry alfalfa that has been ground to powder. The test substance will then be added to the sample of moist soil and incubated in a n environment of darkness at 22 degrees celsius. Analysis would happen after five days and the soil sample would be reviewed for NH3 and NO3 concentrations to determine the microbial health of the microbes in the soil be determining through nitrification and ammonification respiration.
Secondly, the pH level of the soil in this area will also measured using a meter and a probe or kit. The samples will be taken and sent to the lab for assessment.
Q5. HOW THE ENDPOINTS WILL FIT THE MODEL
These various endpoints will fit in the model as they would serve to show the lethal levels of the various harmful that can either be found in animals, soil or the water in the Arkansas river. These endpoints would also be helpful in determining the next course of action for the stakeholders of the firm and this may include halting all activities at the site or it could also mean continuing with normal industrial processes but having an elaborate clean up at the same time to ensure that the danger to the environment is always mitigated. This would also fit the endpoint of this research as this concrete evidence brought forth by the scientific data will be used to make deliberations about possible course of actions to be taken. The most commonly expected course of action however would be an elaborate cleanup process sanctioned by the stakeholders of Sand Springs Petrochemical Complex
Q6. ANALYSIS THAT WOULD BE CONSIDERED AS SIGNIFICANT IN THIS RISK ASSESSMENT
In the Soil Microbial Community Toxicity (SMCT) Test the sample that would be mixed with the ground alfalfa would be tested in between 5 to 28 days for NH3 and NO3 concentrations to determine the microbial health of the microbes in the soil be determining through nitrification and ammonification respiration.
While measuring the pH level in the soil it is important to note that the right pH level for plants to thrive is usually the neutral level which is usually approximately 6.5 to 7.5. The buffering capacity, otherwise known as the alkalinity of the water will also be measured by collecting water sample and its capacity to resist changes in pH measured. The results will be in milligrams per liter and need to be neutral (4.2) to show normal and anything above or below this will show an anomaly.
While measuring the the Hazard Quotient (HQ) in the soil and animals, the Toxicity Reference Value (TRV) will be created in order to be able to compare the ratio of the estimated dose that has been ingested by the animal. It is important to note that if the value of the total HQ is found to be one or less than, then the researcher accept that it is an acceptable number but if exceeds one, then the exposure from that particular area or sight may be very high and a cause of concern.