Direct and indirect analysis of contamination levels in lakes of two adjacent areas

  In the state of Florida there are more than 2.5 million acres of fresh water available; rivers, streams, springs, artificial canals, wetlands, and lakes. Polk and Osceola Counties are under a class III classification, which means that are considered recreational waters, and people can carry out fishing and/or swimming activities within the facility. Some of the problems these lakes face is eutrophication due to pollutants such as phosphorous, nitrogen, and growth of cyanobacteria, impacting directly the quality and public health. The aim of this analysis is evaluating the effect of the presence of Total phosphorus and Total nitrogen in the water quality, and an indirect analysis of cyanobacteria by the evaluation of Secchi Disk and Chlorophyll-a analysis, in order to identify statistically differences between two counties in Florida state, to contribute with a possible improvements and ecological buffer plan to be used to reduce pollution in the lakes of the state of Florida.

Based on this premise, it is intended to analyze secondary data on the quality of the water in the lakes of Polk and Osceola counties by evaluating the trophic status in each lake, and statistically evaluated using ANOVA, histograms and pareto analysis.

Results obtained determined that lakes from Osceola County are more contaminated that lakes from Polk County since it has three lakes in eutrophic status vs two lakes in eutrophic conditions at Polk County (from 52-69 for Osceola County and 42-59 for Polk County). Similar pattern is observed when evaluating histograms and pareto plots for each parameter between the counties. ANOVA test showed that F>F critical and p-value<α, demonstrating that there is difference between both counties.

After the analysis was completed, it is recommended an evaluation by zone and improve water quality. It has been demonstrated that there is a need of new alternatives for the conservation and preservation of lakes in the state of Florida. Buffer zones are an alternative that can be very beneficial to conservation of lakes functioning also as a natural home for the flora and fauna. For the zone studied, it is recommended the use of Riparian buffers. These systems are known to improve and maintain water quality; at the same time protecting and improving fish and wildlife habitat.