Ecology Fall 1998

The objective of this project was to survey and sample water from different geographical locations. Attempts were made to select sites in environments with variables that would affect the levels of the desired characteristics. The sites were then sampled and various titration-based tests were performed on the samples. The results were then recorded and analyzed. Attempts were made to hypothesize why certain sites contained the levels of the present elements.

INTRODUCTION

Eight sites were selected from Louisville, Elizabethtown, and Flaherty, Kentucky. Those sites included tap water, two different underground well sights, a farm pond, Freeman Lake, a water treatment plant, and two sights along

Beargrass Creek. Samples from these locations were tested for dissolved oxygen, carbon dioxide, hardness, nitrate, phosphate, and finally, pH. All of the tests performed were titration-based tests except for the pH test. It involved use of a battery-powered pH meter. The testing method involved exposing the water sample to a specific reagent and then exposing it to a second or third reagent to determine the level of the desired element. This method was used for the dissolved oxygen, carbon dioxide, and hardness tests. Nitrogen tablets were used for the nitrate tests and a phosphorous reagent was used along with an oil-based reagent for the phosphate test.

The dissolved oxygen test was performed in order to determine if the water samples were capable of supporting life. The amount of oxygen present is important for both wildlife and human use and consumption. An absence of oxygen can cause anaerobic decay of organic materials. The carbon dioxide test was also performed to see if the water sample had life-supporting capabilities. High levels of carbon dioxide leads to stagnation and is also an indicator of water pollution. There is a delicate balance between too much and not enough carbon dioxide to support life.

The hardness test was performed to determine the sample’s capacity to precipitate soap. This precipitation is caused primarily by calcium and magnesium. Hardness is a quantitative measure of ions in water. Domestic measuring and control of hardness is necessary to prevent scaling and clogging of pipes.

The pH of the samples was monitored in order to see what type of concentration was most common in the sites sampled. Various plants and animals require a specific pH in order to function and survive.

It is important to monitor nitrate and phosphate levels so as to have an idea of their concentration. High levels of both can cause health concerns for humans as well as pose damage to wildlife. High nitrate levels can lead to decreased respiratory effectiveness.

PROCEDURE

The first site tested was domestic tap water from a residence in Meade County. The water in the residence is drawn from an underground well. It was expected that the hardness levels would be high at this site. It was also expected that nitrate levels would be high due to use of natural and commercial fertilizers.

The second site was an underground well in Meade County. It was expected that hardness, pH, nitrate, and phosphate levels would be similar to those of the tap water. Both sites rely on the same area for water.

The third site as another underground well in Meade County. All levels were expected to be similar to those of the other underground well. The wells are approximately fifty yards apart. It is assumed that they are drawing off of the same water supply.

The fourth site tested was a farm pond in Meade County. The pond is assumed to be healthy as it supports a large stock of fish, turtles, and frogs. High nitrate levels were expected, as runoff from neighboring fields is known to seep into the pond. It was also expected that the carbon dioxide and dissolved oxygen levels were acceptable because of the amount of wildlife supported by the pond.

The fifth site tested was Freeman Lake in Elizabethtown, Kentucky. The water is used as a city water source. It was expected that the lake had acceptable levels of carbon dioxide and dissolved oxygen since the lake supports a large stock of fish and waterfowl.

The sixth site was a water treatment plant adjacent to Freeman Lake. It was expected that the hardness levels would drop significantly from the lake to the treatment plant. It was noted that the water sample from the treatment plant was much cleaner and fresher than water taken from the lake.

The seventh site tested was a portion of Beargrass Creek. This particular sample was taken before the sewage overflow across the road from campus. It was expected that carbon dioxide levels would be high because the water is stagnant and slow moving. It was observed that large amounts of trash and pollution were present in the creek.

The eighth and final site tested was also a portion of Beargrass Creek. This sample was taken after the sewage overflow. It was expected that nitrate levels would be higher than those recorded from before the overflow due to the presence of sewage. Otherwise, it was expected that the other levels would be similar to those from before the overflow.

RESULTS*

*Graphical representation of all data is attached.

CONCLUSION

It was concluded, through analysis of the results, that the oxygen levels recorded were fairly consistent with one another with the exception of the domestic tap water. This makes sense, as tap water does not necessarily support aquatic life. The farm pond was observed to be the healthiest of the natural bodies of water when considering the carbon dioxide levels. The only other surprise with the carbon dioxide was the high concentration at Freeman Lake. This could be explained by the fact that the sample taken was from a shallow portion of the lake near the shore. The pH levels were largely inconclusive. As a general observation, all sites exhibited a pH between eight and nine. The observed hardness levels were not surprising. It was expected that the tap water site had a high hardness level and that the hardness would drop significantly from the Freeman Lake sample to the treatment plant sample. Nitrate and phosphate levels were inconclusive for the most part. It was expected that the nitrate level would be higher in the sample from Beargrass Creek after the sewage overflow than from the sample from before the overflow.

This project has many possible research extensions. Had more time been available, it would have been desirable to perform multiple trials for each site. Relying on one sample leaves a large margin for inconsistency and chance.

Graphs of Chemical Properties