Water Quality Analysis of Orleans Parish Water Bodies

Introduction

The purpose of this project was to test an urban area's nearby water bodies for nutrients and coliform bacteria introduced by non-point sources of pollution such as runoff. This water quality monitoring project was designed to test for physical and chemical variables such as water temperature, salinity, pH, alkalinity, ammonia nitrogen, carbon dioxide, chloride, hardness, nitrite nitrogen and dissolved oxygen and the biological variables, fecal coliform, Escherichia coli, and other coliform bacteria. Tests were conducted on selected Orleans Parish water bodies that drain into Lake Pontchartrain. The results of these tests were compared with EPA water quality standards to find overall water quality in the sampled areas. This information would be helpful to understand different non-point source pollutant problems entering Lake Pontchartrain. Non-point source pollution comes from diffuse land areas that sometimes contribute to surface and ground water (Line, D.E. et al, 1995). Increased nutrient levels from non-point sources have made their way into our water systems. The nutrients have caused blooms which have in turn reduced oxygen levels, a situation call hypoxia. In 1993, floods flushed nutrients from urban areas and agriculture into the Mississippi River system and eventually to the Gulf. The normal size of the hypoxia zone doubled (Gulf of Mexico Foundation, 1998). Nutrients are chemical compounds in the environment from which organisms synthesize living matter. It was also reported that ammonia nitrate concentrations are higher in the winter months with lower water temperatures (Antweiler, et al, 1995). Nitrate and nitrite can cause toxic effects on humans at high concentrations, and ammonia can be toxic to aquatic organisms. Higher levels in raw water supplies cause higher costs in the treatment process for drinking water (Antweiler, et al, 1995). The purpose of the study was to test waters to find out if the levels conform to the EPA standards.

The variables in this project are both biological and chemical. The independent variables are levels of alkalinity, ammonia nitrogen, carbon dioxide, chloride, dissolved oxygen, fecal coliform (Escherichia coli) and other coliform, nitrite nitrogen, pH, salinity, and temperature. The dependent variable is the overall water quality in Orleans Parish water bodies.

Escherichia coli or fecal coliform bacteria live in the intestines of warm-blooded animals, but can also live in other warm environments. These bacteria can be found in populations ranging from zero to thousands of colonies. High counts of fecal coliform are caused by contamination from the intestinal tract and feces of warm-blooded animals. Coliform bacteria are used to indicate the presence of pathogenic organisms (U.S.G.S., 1996).

Non-point source pollution is caused by urban runoff. This pollution affects both surface water and ground water. High nitrate-nitrogen levels and high ammonia-nitrogen levels are caused by elevated nutrient levels in the watershed (Line, D.E. et al, 1995). Nitrogen is found in inorganic fertilizers, manure, organic matter, and legume fixation (Burkart and James, 1999). Also, chemicals in water can pose health risks.

Methods and Materials

Sample sites were selected at four canals that connect to Lake Pontchartrain in Orleans Parish, LA. Four stations were chosen in the Inner Harbor Navigational Canal near Leon C. Simon Drive (station no. 01), Chef Menteur Highway (station no. 02), Florida Avenue (station no. 03), and the locks by St. Claude Avenue (station no. 04). Three stations were selected in the London Avenue Canal near Lakeshore Dr. (station no. 05), Robert E. Lee Blvd. (station no. 06), and Mirabeau Avenue (station no. 07). The three stations in Bayou St. John were located by Lakeshore Drive (station no. 08), Filmore Avenue (station no. 09), and Harding Drive at Moss Street (station no. 10). The final three sites were in the Orleans Ave. Outfall Canal by Lakeshore Drive (station no. 11), Filmore Avenue (station no. 12), and I-610 (station no. 13).

Water samples were collected by lowering a 300 ml bottle to under the water's surface with a string. The temperature was measured using a mercury thermometer and recorded in degrees centigrade. Time and date were also recorded. Latitude and longitude were recorded using a Garmin Instruments Model #75 global positioning system. The sample was then placed in an ice chest for later analysis.

The water samples were tested for chemical variables using a LaMotte model AQ-2 Aquaculture Test Kit. Analyzes included alkalinity, ammonia nitrogen, carbon dioxide, pH, dissolved oxygen, hardness, nitrite nitrogen, chloride, and salinity. One gallon of distilled water was needed for cleaning between tests and also for dilution of some samples. The test kit does contain some hazardous materials, so it was necessary to read the material safety data sheets (MSDS) provided.

Coliform Bacteria

Fecal coliform bacteria and other coliforms were tested using a membrane filtration method. The materials used to perform this test were a Millipore Co. Sterifil Aseptic membrane filtration system, 47 mm diameter filters with 0.45 m size pores, a 1 L vacuum filtering flask, a hand vacuum pump, Hach Co. m-ColiBlue24 Broth medium in glass PourRite ampules, an ampule breaker, sterilized 47 mm petri dishes pre-loaded with absorbent pads, forceps, a Miller Co. model 5200 still air incubator, and a 10-15x stereoscope.

All equipment was sterilized in an autoclave. The ampule breaker was used to break off the top of an ampule of medium which was poured onto the absorbent pad in a petri dish. The vacuum-filter was then used to filter 100 ml of sample water through the membrane filter. The first and last dishes were filtered with sterile solution as controls to verify sterile conditions. The membrane filter was then placed into the petri dish. The petri dish was inverted and placed into the incubator set at 35^oC (Figure 1). The samples were incubated for 24 hours. The next day, the stereoscope was used to count the colonies under 15x magnification. Fecal coliform colonies were colored blue, and other coliforms were colored red. Each was counted and recorded as colonies/100 ml. The dilution method was used for the December samples. A 10 ml water sample was added to a buffer solution and then filtered, and the result was multiplied by 10.

Alkalinity

Items needed for this test were bromcresol green-methyl red indicator (BCG-MR), alkalinity titration reagent B, a 20 ml titration tube, and a model 0-200 direct reading titrator.

The titration tube was filled to the 5 mL line with sample water. Four drops of BCG-MR Indicator were then added, the tube was capped, and then mixed. The sample turned blue-green. The direct reading titrator was then inserted into a small hole in the top of the alkalinity titration reagent B bottle and inverted. The plunger was withdrawn, reinserted to force out air bubbles, and then withdrawn to the zero line. The curved bottom of the plunger must be even with the line. The titrator was then placed into the center hole of the titration tube cap. While gently swirling the tube, the plunger was slowly pressed to release a drop of liquid at a time to titrate the sample until the blue-green color changed to pink. The test result was read where the plunger tip lined up with the titrator scale. Each minor division on the titrator scale equaled four ppm. Results were recorded as parts per million (ppm) total alkalinity as calcium carbonate, CaC0₃.

Ammonia Nitrogen

The test for ammonia nitrogen required ammonia nitrogen reagent #1, ammonia nitrogen reagent #2, a 10.0 mL test tube with cap, and an Octa-Slide Viewer with an ammonia-nitrogen range 0.2-3.0 ppm color chart.

The test tube was filled to the 5 mL line with sample water. Four drops of ammonia nitrogen reagent #1 were added. The cap was replaced and the solution was mixed gently for one minute. Then 12 drops of ammonia nitrogen reagent #2 were added, the cap was replaced, and the solution was mixed. It was required to wait five minutes. The ammonia nitrogen Octa-Slide color chart was then placed into the Octa-Slide Viewer. The test tube was placed into the top of the viewer and held up to a light source. Sample color was matched to a color standard on the chart and recorded as ppm ammonia nitrogen.

Carbon Dioxide

The materials needed to test carbon dioxide were phenolphthalein indicator, 1%, carbon dioxide reagent B, a model 0-50 direct reading titrator, and a 20 mL titration tube.

The titration tube was filled to the 20 mL mark with sample water. Two drops of phenolphthalein indicator, 1%, were added. The direct reading titrator was filled with carbon dioxide reagent B. The titrator was inserted into the center hole of the titration tube cap. While gently swirling the tube, carbon dioxide reagent B was added a drop at a time until a faint pink color developed and persisted for 30 seconds. The test result was read where the plunger tip met the titrator scale. It was recorded as ppm carbon dioxide, CO₂.

Chloride

The chloride test needed chloride reagent #1, chloride reagent #2, phenolphthalein indicator, 1%, a model 0-200 direct reading titrator, a 20 mL titration tube with cap, and a pipet with bulb.

One mL of sample water was placed in the tube and diluted with distilled water to the 20 mL line. The solution was mixed and then 5 mL was removed leaving 15 mL of solution. One drop of phenolphthalein indicator, 1%, was added. Three drops of chloride reagent #1 were added, the cap was replaced, and the solution was swirled. The solution turned yellow. The direct reading titrator was filled with chloride reagent #2. The titrator was then inserted into the center hole of the titration tube cap. While gently swirling the tube, the plunger was pressed slowly until the yellow color of test sample first changed from yellow to orange or orange-red. The test result was read where the plunger tip met the titrator scale. The result was recorded and ppt chloride was calculated using the following formula: ppt chloride=titrator reading × 0.02.

Salinity

Salinity was then calculated based on the chloride concentration using the following formula: ppt salinity= (1.805 × ppt chloride) + 0.03.

Dissolved Oxygen

Items required for analysis of dissolved oxygen were manganous sulfate solution, alkaline potassium iodide azide reagent, sulfuric acid, 1:1, sodium thiosulfate, 0.025N, starch indicator solution, a model 0-10 direct reading titrator, a 20 mL titration tube with cap, a plain plastic pipet with bulb, and a 60 mL glass water sample bottle.

The sample bottle was rinsed with sample water. The bottle was then filled to overflowing with sample water, tapping the edge to dislodge any air bubbles. Eight drops of manganous sulfate solution and 8 drops of alkaline potassium iodine azide reagent were added. The cap was replaced and the solution was gently mixed by inverting 15 times. A precipitate formed and was allowed to settle below the shoulder of the bottle before proceeding. Eight drops of sulfuric acid, 1:1, was added, the cap replaced, and solution was gently mixed until the precipitate had dissolved. A clear-yellow to brown-orange color developed. The titration tube was filled to the 20 mL line with the fixed sample and the cap was placed on the tube. The direct reading titrator was filled with sodium thiosulfate, 0.025N. The titrator was inserted into the center hole of the titration tube cap. While gently shaking the tube, the plunger was slowly pressed to release one drop at a time until the yellow-brown color reduced to a very faint yellow. The pipet was used to add 8 drops of starch indicator solution. The solution turned blue. The titration was continued until the blue color just disappeared. The result was read where the plunger tip matched the titrator scale. Each minor division on the titrator scale equaled 0.2 ppm. The result was recorded as ppm dissolved oxygen.

Hardness

The materials used for the hardness test were hardness reagent #5, hardness reagent #6 solution, hardness reagent #7, a 20 mL glass titration tube with cap, a model 0-200 direct reading titrator, and a plastic 0.5 mL pipet.

The 0.5 mL pipet was used to add 0.5 mL of the saltwater to the titration tube. The test tube was filled to the 12.9 mL line with distilled water. Five drops of hardness reagent #5 were added. The cap was placed on the tube and the solution was mixed. Five drops of hardness reagent #6 solution were added, the tube was capped, and was gently shaken. The direct reading titrator was filled with hardness reagent #7. The titrator was inserted into the center hole of the titration tube cap. While gently swirling the tube, the plunger was slowly pressed to add hardness reagent #7 until the red color changed to clear blue. The result was read where the plunger tip met the titrator scale. The result of the diluted method was then multiplied by 25.8. It was recorded as ppm total hardness.

Nitrite Nitrogen

The materials used to analysis the water samples for nitrite nitrogen were mixed acid reagent, color developing reagent, a 0.1 g plastic measuring spoon, a 10.0 mL plastic test tube with cap, an Octa-Slide Viewer, and an Octa-Slide, nitrate nitrogen, 0.05-0.8 ppm range color chart.

The test tube was filled to the 2.5 mL line with the sample. The sample was then diluted to the 5 mL line with mixed acid reagent. The 0.1g spoon was used to add 0.1 g of color developing reagent. The tube was capped and the solution was mixed by inverting for one minute. The solution was required to set for 5 minutes. The nitrite nitrogen Octa-Slide was inserted into the Octa-Slide Viewer and the test tube was placed into the top of the viewer. The sample color was matched to a color standard. The result was recorded as ppm nitrite nitrogen. To record the result as ppm nitrite, the reading would have to be multiplied by 3.3.

pH

This test required a wide range pH indicator, a 10 mL plastic test tube with cap, an Octa-Slide Viewer, pH range 5.0-10.0.

The test tube was filled to the 5 mL line with the sample water. Eight drops of Wide Range pH indicator were added, the cap was replaced, and the solution was mixed. The pH Octa-Slide was put into the Octa-Slide Viewer and the test tube was placed into the top of the Viewer. The sample color was matched with the color standard and the result was recorded as pH units.

Results

Two hundred and thirty-four tests for 9 chemical compounds and twenty-six biological samples were completed from 13 stations from 4 Orleans Parish, LA canals and Lake Pontchartrain. Concentrations that were recorded in parts per million (ppm) were converted to milligrams per liter (mg/L), and data were recorded in parts per thousand (ppt) were converted to milligrams per gram (mg/g). Results of each test by station are presented in Figure 2.

The results from the Inner Harbor Navigational Canal, stations 01, 02, 03, and 04, are presented in Table 1. Averages and ranges are summarized in Table 2. Average water temperature for the 4 stations was 14.7 ⁰C and the range was 11-18 ⁰C. Salinity averages were 8.23 mg/g and the range was 3.4-12.4 mg/g. Alkalinity means were 86.88 mg/L with a range of 60-128 mg/L. The average concentration for ammonium nitrogen was 0.2 mg/L with no variation. Carbon dioxide averaged 6.38 mg/L with a range of 3-10 mg/L. The pH readings averaged 7.47 and ranged from 7.25-8. Average dissolved oxygen was 7.82 mg/L and the range was 6.8-9.6 mg/L. Hardness averaged 2.03 mg/g with a range of 1.3-2.9 mg/g. The mean for nitrite nitrogen was 0.05 mg/L with no variation. Chloride concentrations averaged 4.54 mg/g and ranged 1.84-6.88mg/g. The results from the London Avenue Canal, stations 05, 06, and 07, are presented in Table 3. Averages and ranges are summarized in Table 4. Average water temperature for the 3 stations was 15.5 ⁰C and the range was 12.6-18 ⁰C. Salinity averages were 6.89 mg/g and the range was .75-10.3 mg/g. Alkalinity means were 63.65 mg/L with a range of 44-85 mg/L. The average concentration for ammonium nitrogen was .24 mg/L with a range of .2-.4 mg/L. Carbon dioxide averaged 7.7 mg/L with a range of 4-12 mg/L. The pH readings averaged 7.29 and ranged from 6.5-8. Average dissolved oxygen was 7.35 mg/L and the range was 6-9 mg/L. Hardness averaged 1.65 mg/g with a range of .31-2.6 mg/g. The mean for nitrite nitrogen was 0.05 mg/L with no variation. Chloride concentrations averaged 3.8 mg/g and ranged .4-5.68 mg/g.

The results from Bayou St. John, stations 08, 09, and 10, are presented in Table 5. Averages and ranges are summarized in Table 6. Average water temperature for the 3 stations was 15.4 ⁰C and the range was 11-18 ⁰C. Salinity averages were 8.34 mg/g and the range was 6.53-10.1 mg/g. Alkalinity means were37.67 mg/L with 45-72 mg/L as the range. The average concentration for ammonium nitrogen was .2mg/L with no range. Carbon dioxide averaged 8.1 mg/L with a range of 6-9 mg/L. The pH readings averaged 7 and ranged from 6.75-7.25. Average dissolved oxygen was 8.6 mg/L and the range was 6.6-10 mg/L. Hardness averaged 2.27 mg/g with a range of 1.5-2.1 mg/g. The mean for nitrite nitrogen was 0.05 mg/L with no variation. Chloride concentrations averaged 4.59 mg/g and ranged 3.6-5.6 mg/g.

The results from the Orleans Ave. Outfall Canal, stations 11, 12, and 13, are presented in Table 7. Averages and ranges are summarized in Table 8. Average water temperature for the 3 stations was 15.25 ⁰C and the range was 11-18 ⁰C. Salinity averages were 6.45 mg/g and the range was 1.62-10.9 mg/g. Alkalinity averaged 75.35 mg/L with a range of 50-108 mg/L. The average concentration for ammonium nitrogen was .44 mg/L with a range of .2-.8 mg/L. Carbon dioxide means were 8.5 mg/L with a range of 5-13 mg/L. The pH readings averaged 7.3 and ranged from 7-8. Average dissolved oxygen was 8.59 mg/L and the range was 7.4-9.6 mg/L. Hardness averaged 1.53 mg/g with a range of .83-2.3 mg/g. The mean for nitrite nitrogen was 0.09 mg/L with .05-.2 mg/L as the range. Chloride concentrations averaged 3.55 mg/g and ranged .88-5.92 mg/g. Finally, the averages and ranges from all 13 stations are summarized and listed in Table 9. Water temperature averages for the 13 stations was 15.21 ⁰C and the range was 14.7-15.5 ⁰C. Salinity averages were 7.48 mg/g and the range was 6.45-8.34 mg/g. Alkalinity means were 65.89 mg/L with a range of 37.67-86.88 mg/L. The average concentration for ammonium nitrogen was .27 mg/L with a range of .2-.44 mg/L. Carbon dioxide averaged 7.67 mg/L with a range of 6.38-8.5 mg/L. The pH readings averaged 7.27 and ranged from 7-7.47. Average dissolved oxygen was 8.09 mg/L and the range was 7.35-8.6 mg/L. Hardness averaged 1.87 mg/g with a range of 1.53-2.27 mg/g. The mean for nitrite nitrogen was 0.06 mg/L with 0.05-0.09 mg/L as the range. Chloride concentrations averaged 4.87 mg/g and ranged 3.55-7.54 mg/g.

The results from the fecal coliform (FC) and other coliform (OC) testing are presented in table 10. The November average for fecal coliform was 39.3. The December average for fecal coliform is 169.6. The ranges were from 0 at station 10 in Bayou St. John to 340 at station 02 in the Inner Harbor Navigational Canal. Other coliform counts ranged from 102 at station 06 in the London Ave. Canal to too numerous to count (TNTC) at stations 04, 05, 07, 11, 12, and 13.

Discussion

Samples of water bodies near urban areas were tested for nutrients and coliform bacteria which may have been introduced by non-point sources of pollution such as runoff. Orleans Parish, LA was an ideal choice, due to the concerns of people to reduce the pollution entering Lake Pontchartrain.

Bacterial water quality standards are set by the EPA. They are different for different regions. For Louisiana, the standard for marine primary (which is for full body contact such as swimming) is 200 fecal coliform colonies per 100 mL of sample water. The standard for marine secondary (which is for recreational uses like boating) is 1000 FC colonies per 100 mL of sample water (United States Environmental Protection Agency [U.S. EPA], 1998). In the November samples, none of the stations exceeded the 200 colony standard. In the December samples, stations 01, 02, 03, 06, 12, and 13 had a fecal coliform count higher than 200 colonies in a 100 mL sample. The higher counts in December may have been because of the amount of rainfall during that month.

The primary nutrients tested for in this study were ammonia nitrogen and nitrite nitrogen. No nitrite levels were found above 0.2 mg/L. The maximum level allowed by the U.S Environmental Protection Agency is 1.0 mg/L for drinking water (Antweiler, et al, 1995). The levels in this study were well below that figure. Ammonia nitrogen does not have a maximum limit regulation, however, under the right conditions of temperature and pH it can be harmful to aquatic life. Those conditions exist in the Mississippi River at a level of 0.6 mg/L (Antweiler, et al, 1995). Two samples in this study were equal to or greater than 0.6 mg/L. They were 0.6 mg/L at station 12 and 0.8 mg/L at station 13, both in the Orleans Ave. Outfall Canal.

Future samples at different times of the year, during different temperatures, and after rainfalls may show more trends. This data indicates that it's unsafe to swim in 3 of the 4 water bodies tested during this study. However, the waters remain safe for other recreation such as boating. Recently in the news, it was reported that millions of dollars will be spent on repairing damaged sewer systems in Orleans Parish. It was also reported that the result of the repairs will be less pollution entering our water bodies.

Bibliography

Antweiler, Ronald C., Donald A. Goolsby, and Howard E. Taylor. (1995). Nutrients in the Mississippi River. U.S. Geological Survey Circular 1133. Denver, CO: U.S.G.S.

Burkart, M.R., & James, D.E. (1999). Agricultural-Nitrogen Contributions to Hypoxia in the Gulf of Mexico. Journal of Environmental Quality, 28(3), 850-859.

Gulf of Mexico Foundation. Monitor. Corpus Christi, TX, May 1998.

Line, D.E., et al. (1996). Nonpoint sources. Water Environment Research, 68(4), 720-733.

United States Environmental Protection Agency. (1998). Bacterial Water Quality Standards for Recreational Use. Retrieved January 4, 2000 from the world wide web: http://www.epa.gov/cgi-bin/claritgw

U.S. Geological Service. (1996). Water Resource Data Louisiana Water Year 1996. Baton Rouge, LA: U.S.G.S.

Acknowledgments:

I would like to thank Marine Biologist, John Dameier, for his assistance with this project. He showed me how to perform these tests properly. He also helped by using an autoclave to sterilize the equipment and recounted the coliform bacteria to verify the numbers.

Appendix

Table 1a. Inner Harbor Navigational Canal 11/26/99

Table 1b. Inner Harbor Navigational Canal 12/26/ 99

Table 2. Inner Harbor Navigational Canal, Summary 11/26/99 and 12/26/99

Table 3a. London Avenue Canal, 11/26/99

Table 3b. London Avenue Canal, 12/26/99

Table 4. London Avenue Canal, Summary, 11/26/99 and 12/26/99

Table 5a. Bayou St. John, 11/26/99

Table 5b. Bayou St. John, 12/26/99

Table 6. Bayou St. John, Summary

Table 7a. Orleans Ave. Outfall Canal, 11/27/99

Table 7b. Orleans Ave. Outfall Canal, 12/26/99

Table 8. Orleans Ave. Outfall Canal, Summary

Table 9. All Stations

Table 10. Fecal coliform (FC) and other coliform (OC) bacteria colony counts.

Figure 1. Petri dishes containing incubating fecal coliform and other coliform colonies.

Figure 2. Water Quality Results