Wakulla Springs Nitrogen Levels Research Paper
The rapid pace of human development and the indiscriminate exploitation of natural resources are causing serious environmental degradation the world over. The once pristine natural surroundings are being polluted by industrial effluents, partially treated human waste and high level accumulation of chemicals due to misguided or poorly executed conservation projects. The Wakulla Springs area of the State of Florida is one such victim of untrammeled human development, badly envisaged eco-conservation measures and of course human greed. This essay aims to examine the causes and effects of environmental degradation of Wakulla Springs, the response of the authorities, and suggest possible remedial actions.
Wakulla Springs is located in Wakulla County, Florida, USA. The springs were known not only for once being the purest resource of freshwater in the US, but also as the best tourist destination for Cave Diving as it is home to the worlds longest and deepest cave system. Since the late nineties, unprecedented growth of Hydrilla, and other forma of algae has been observed in the Wakulla Springs area. This has been attributed to the higher levels of nitrates entering the spring system which are a source of nutrients which trigger the growth of Hydrilla and algae. The once crystal clear waters of the springs, which only used to become dark during rains now remain murky for longer duration of time forcing the glass bottom boat operators a shorter tourist season. Cave divers are too finding the globs of algae an impediment not only to visibility but also mobility as the algae grows like thick mats and blocks out passages. The boat operators too find the algal mats a hindrance as they foul boat propellers. The twin combination of Hydrilla and mat algae has severely affected the areas ecosystem as it chokes the natural vegetation and starves the waters of oxygen, which in turn affects the smaller aquatic animals and fish. Over the last decade, ecosystem determinants such as Apple snails and birds like Limpkins have reduced in numbers pointing to a possible dying ecosystem. The problem requires some examination of the unique geology of the area as both are intricately connected for finding the causes and the resolution of the problem.
The Wakulla Spring Basin can be divided into two main sections: the Northern section which forms part of the state of Georgia and Northern Leon County and the Southern section, where the Wakulla springs is actually located. In the Northern section the top soil has a layer of clay underneath while in the Southern Section the top soil has no clay layer but only sand. In the Northern section, because of the clay, rainwater does not permeate down to the porous limestone bedrock of the Floridian Aquifer system but mostly flows as streams which then flows into the Ochlockonee River and out into the Gulf of Mexico. In the Wakulla region, rainwater seeps directly through the sand into the limestone bedrock charging the water table almost instantaneously. The unique feature of the Southern region is that the limestone bedrock is closer to the surface and the whole area has a maze of sink holes, conduits, tunnels and caves which are fed with freshwater oozing up from the springs. At an average, 200 to 300 million gallons of water are pushed out through the spring heads. The city of Tallahassee lies approximately 10 miles North of Wakulla Springs. The entire terrain slopes from North to South. The important point to hoist about the geology is that the top soil of the entire area consists of unconsolidated sand. Soil hydrology dictates that there is a limit to the amount of irrigation that the top soil can absorb, after which the excess runs off and seeps into the subterranean freshwater system which underlies the entire area. As long as human development and utilization of the Florida land for agriculture, waste water management and other industrial uses maintained parity in equal proportion to the ability of the soil to absorb, the eco system remained intact. The fact that tremendous algal and Hydrilla has grown in significant proportions since the late nineties point to a number of causes of environmental degradation, which require examination.
Possible Causes of Environmental Degradation
As stated earlier, the city of Tallahassee lies at a slightly higher elevation to the North of the Wakulla springs area. In an effort to preserve the environment, the town authorities initiated a spray field agricultural project which is located on a 2600 acre expanse 10 miles north of Wakulla springs. Spray fields are supposedly environmentally friendly because the concept involves using liquid manure and manure laden waste water to grow crop forage and pasture land thus reducing the problems of waste water management. Spray fields are effective from the conservation point of view as long as the amount of manure applied does not exceed the infiltration rate of the soil or the nutrient requirements of the crops. According to Walker, The irrigation of spray fields should not exceed the infiltration rate of the soil, otherwise runoff will result(1). This is a very great possibility in the Wakulla Area as the top soil is basically sandy with shallow limestone bedrock beneath as explained earlier.
Homes in the United States normally use onsite waste water treatment systems of which the conventional septic tank system is the most common system. This system comprises of a septic tank, a subsurface wastewater infiltration system also called as a drain field, and the soil below. Thus, the wastewater generated in homes gets filtered to some extent in the drain field and then is absorbed by the soil from where it then seeps into the groundwater. The soil hydrology of the Wakulla area and in and around Tallahassee with its unconsolidated sandy topsoil makes it easier for such water to leach into the Wakulla Spring system. Human wastes are rich in nitrates. The U.S. EPA Onsite Wastewater Treatment Systems Manual estimates that 11.2 grams of nitrogen per person per day is the average total nitrogen contribution to wastewater(Anderson, Hazen & Sawyer, 9). A 2001 report of Florida Department of Environmental Protection for Wakulla Springs states that Nitrate-nitrite concentrations (ranging from 0.51-0.66 mg/L) at the sampling site were consistently higher than the values found in 80% of other Florida streams(1).
Darkening of Wakulla Springs water can also be attributable in some parts to natural processes also. Leaves produce tannic acid, which when falling into the water dissolve making it darker in color. Rainwater also churns up the mud and silt and thus it is common to have dark colored water in rainy seasons. Nitrates present in atmosphere fall to the ground along with rain and get combined with the spring water. Spring waters when being pushed under pressure due to the aquifer effect pick up nitrates along the way from the porous limestone where some quantities may accumulate due to the natural processes.
Identification of the Main Cause
The natural phenomenon has been occurring for ages. The earliest reports of Wakulla Springs water turning dark during rainy seasons has been reported in 1894. Thus periodic darkening of water can be explained by natural phenomenon. However, the present day situation where the waters remain darkened for almost all the year round, point to other reasons for the problem. According to some experts, the nitrate levels in the Wakulla springs were below 0.2 milligrams per liter prior 1980 before the Tallahassee spray field was built. The North West Florida Water Management Districts Report stated that the spray field accounts for 14% and the onsite systems 11%(Board of County Commissioners, p.2) of the nitrogen loading of the Wakulla spring system. The Board further emphasized the point by stating that Limited studies have identified the primary sources for this nitrogen which include both sewage effluent from onsite systems and the city of Tallahassee sewage treatment plant spray field (Board of County Commissioners, p.4). The other plant at the airport also contributed to some seepage of nitrates into the spring system. A 2005 report of the Florida Public Interest that Studies have shown that a major source of the pollution is a Tallahassee City-owned sewage treatment sprayfield, but the city has resisted efforts to clean up the facility(5). Finally the Florida state authorities comprising of City of Tallahassee, Florida Wildlife Federation, the Attorney General, the Florida Department of Environmental Protection and Wakulla County resident identified the main problem to be the spray field stating that a State-funded scientific study determined that nutrients from the Citys sprayfield were leaching through soils into the groundwater and reaching Wakulla Springs, only nine miles away(Fuller 1).
Previous Intervention Efforts and Interest Groups
Previous intervention efforts focused on the local removal of Hydrilla from the springs. These efforts saw the Park officials mechanically remove tons of Hydrilla which simply grew back quickly. The park officials then tried using herbicides to kill the Hydrilla. The herbicide method helped kill the leaves but not the tuberous roots of Hydrilla that again grew back just as fast. Thus both the mechanical method and the chemical method of intervention at the local level failed. The efforts did not address the root cause of the problem namely leaching of nitrogen from the onsite sewage treatment plants and more specifically the spray field possibly because of the conflicting aspirations of the various interest groups involved. On one hand was the Florida tourism industry which was losing millions of dollars in lost opportunity and declining numbers of tourists and on the other hand were the spray field farmers whose quest to generate profits was obviously leading to utilization of larger and larger quantities of liquid manure which was seeping into the spring water system. The environmentalist groups were vociferous in their support for resolving the problem by shutting down the spray fields and putting into practice more modern onsite waste water treatment systems in all homes up stream of the Wakulla Springs area but were facing stiff resistance from the farmers and the local authorities. The home owners were torn between concern for the environment and the high costs associated with putting a new onsite system. The City of Tallahassee which had sunk in significant amount of money in the spray field project was not too enthused with the idea of shutting down their project. Thus political, economic, social and environmental interests competed for the resolution of the problem.
Possible Policy Initiatives
The possible policy initiatives that could be examined by the authorities and all the stakeholders are many. The overall guiding principle for the policy aim would be to find a solution to the problem while trying to address the legitimate concerns of all the stakeholders. One of the initiatives could involve addressing the over 4300 onsite systems that are being used in the area just South of Cody Scarp, the elevated grounds North of Wakulla Springs. According to the Leon county report, upgrading the conventional onsite systems which cost from $5,500 to $7,500 with more efficient and sophisticated nutrient reduction systems would cost from $7,500 to $ 9000 (Board of County Commissioners, 3). The US Environmental Protection Agency has given five guidelines for management of onsite systems. These guidelines range from educating the system owner for ensuring proper maintenance of the onsite system, managing through professional maintenance contracts, ensuring that onsite systems are operating efficiently by having the owners obtain an operating permit, having public or private utility providers take an operating permit and charging the owners fixed fees, or lastly having the private or public utility provider own the entire system with the house owners paying only the fees for the services availed. Since all of the above policy options would require substantial investments by house owners and providers alike, it is likely to meet with resistance especially in this recession hit days. The policy option could then evolve to making all new onsite systems confirm to the national sanitation foundation certification limits of production of 10 milligrams per liter (mg/L) nitrogen at the outlet of the system tank in conjunction with the drain field (Board of County Commissioners, 3). The other option could look at a policy of governmental oversight by giving operating permit to house owners using onsite systems which will ensure that the stringent requirements of US environmental laws are met.
Another policy option that has to be looked at is the problem of the Tallahassee Spray field, which has been identified as the main cause for the nitrates reaching Wakulla Springs. One solution is to shut down the spray field and relocate it to a different area where the terrain does not slope towards Wakulla Springs. This option however, involves millions of dollars of capital investment, which is not likely to find favor with any of the stakeholders. The other option is to revert to the original role of the spray fields; i.e. nitrate removal from waste water reaching it from Tallahassee homes rather than profit making commercial agriculture. This option though attractive, will surely impinge on the interests of the farmers who have plowed in substantial investments in the spray fields. The third policy option is to upgrade the onsite systems, as well as the spray field waste water treatment systems by which the levels of nitrates are substantially removed. Also, diverting the now to other landscaping projects and golf courses could help reduce the load on the spray fields. While embarking on such a course of action it must be ensured that stringent levels of nitrogen outputs from the new onsite systems are adhered to lest a localized problem becomes a generalized problem encompassing a greater geographical area. Already the City of Tallahassee has pledged to invest more than $ 160 million to overhaul its Thomas P Smith and Lake Bradford Road wastewater facilities(Fuller, 1). The plan involves treating household waste water with new improved methods so that a significant amount of nitrates are removed before the water is used by the South east spray fields. The new treatment will reduce levels of nitrogen by more than 75% over six years(Fuller, 2).
One component of nitrogen loading has been attributed to the livestock which use the South East spray fields as a grazing ground. The livestock eat the vegetation and deposit manure far in excess of the soil absorption capacity. A policy decision on removal of livestock from the spray fields would help in reducing the overall nitrate flow into the Wakulla Spring system. Also, the application of fertilizers over and above the wastewater input to increase agricultural yield in the spray field is a contributory factor in increasing the nitrate levels. A policy decision to remove both the livestock as well as the extra addition of fertilizers has been taken in 2006 by the City of Tallahassee officials and this measure will contribute to the decrease in nitrogen loading of the Wakulla Springs system.
Operation of the Spray field in consonance with the weather is yet another option for reducing the nitrates run off. Presently, the operators blindly follow a set routine owing to operation compulsions and commercial imperatives of producing a healthy yield of crops. Thus, liquid manure is sprayed irrespective of the climatic conditions. Should the spraying of the spray field with the manure laden wastewater be restricted during times of heavy rainfall, it would reduce the nitrate runoff into the Wakulla Spring system.
Any action plan of such magnitude cannot be executed in isolation and interagency cooperation and coordination is required right from the federal level, to the state level and down to the grassroots level. At the federal level, support from the federal agencies such as the US Environmental Protection Agency would be required in terms of specific guidelines, studies and involvement in implementation plans. The all-important question of financial support from federal funds is also required to be looked at. Monies from the Florida state as well as support from the State authorities would also be required as entire financial burden cannot be shouldered only by a couple of counties and the City of Tallahassee. Since the causes and effects of nitrogen loading extend beyond county jurisdiction, an is required to be set up. Some of these measures have already been taken. The Wakulla Spring Basin Working Group and the Wakulla County Interagency work group meetings are already taking place to address the problem. Education of the people would form an important part of the effort required. In this regard, efforts of the authorities as well as non-governmental organizations, environment protection groups and the local residents would be required. Some of the initiatives which already have been implemented are; holding workshops on saving Wakulla Springs, field trips of officials and community members to affected the areas, institution of environmental protection awareness programs in schools and colleges across the state. Interagency cooperation would also be required for monitoring the future health of the spring system. This would include assessing the effects of corrective actions initiated and recommending new steps to be taken. Monitoring the spring system requires resources and expertise, which the federal agencies have in plenty and thus a generous quantum of federal assets could help in a long way. Civic action by county officials such as storm water management, cleaning of city drainage system and ensuring that citizens adhere to correct civic practices are other steps that require interagency cooperation.
Thus it can be concluded that the environmental degradation of the Wakulla Springs system has been due to human development and over-exploitation of the natural habitat. High levels of nitrates leaching from the Tallahassee spray fields and the onsite sewage treatment plants used by home owners are reaching the spring system leading to a spurt in the growth of Hydrilla and mat algae. The effect of this degradation has led not only to serious losses to the Florida tourism industry but also the fragile ecosystem of the region. The action plan required to overcome the environmental degradation would involve all levels of government starting from federal support, state support and local administration together with other NGOs and local activist groups. The actionable plan would include upgrading the facilities of the spray fields and the onsite sewage treatment plants used by home owners, realigning the use of the spray fields so that conservation and removal of nitrates remains its main utility and an all round civic action plan to address sanitation issues.