OWL WATER SAMPLING DATA ANALYSIS REPORT 2003

INTRODUCTION

During 2003 two water quality sampling programs were run simultaneously. One was the Lake program similar to past years and the second dealt with Inlet sites all the way to the source near Freeville. The Inlet program was made possible through the assistance of Jim Hotaling of Cayuga County Soil and Water Conservation District and Anthony DeCaro of the City of Auburn Water Treatment Plant. They provided Amy Lewis and Mike Ronco, two Americorp volunteers, who were working with them for the year. Amy and Mike collected the samples at the various sites on Tuesdays, transported them to the laboratory at the Auburn Sewage Treatment Plant, and did the actual testing under Andy Roche's supervision. They collected samples starting on May 20th and ended on September 2nd. They also collected nitrate and phosphate data at sites before and after both the Groton and Moravia sewage treatment plants. All of the data were entered in a computer spreadsheet for later analysis. Rainfall data was obtained from Cornell University for Ithaca since it was recognized that the southern tier had distinctly different rainfall compared to the Auburn area and the majority of the Inlet was closer to Ithaca than to Auburn. The daily data was converted into weekly totals and entered into the database this fall.

Lake water quality samples were collected from June 4th through September 3rd. Twenty volunteers collected twenty-five samples weekly for testing at the City of Auburn Waste Treatment Plant for Coliform and turbidity. The volunteers also measured air and water temperatures and noted wind direction and relative strength. They recorded the sky condition and also reported any unusual observations during the week. All of the information was entered in a computer spreadsheet for later analysis. In addition, the City of Auburn provided data on six sites they monitored at the North end of the lake and in the Owasco River to the State Dam near the Lake Avenue Bridge, which was also entered into the database. Rainfall data was provided by Tony DeCaro from the Auburn Weather Monitoring Station at the Water Filter Plant on Swift Street. The daily data was converted into weekly totals and entered into the database this fall.

SUMMARY

The overall conclusion reached from an analysis of the two data sets is that the water quality in Owasco Lake remains good while a number of sites in the Inlet consistently provide high numbers. The summer of 2003 was a wetter one than the previous year and the rainfall amount in the southern part of the watershed was higher than in the northern part. Fecal Coliform input to the Inlet mainly started just South of Groton with no apparent increase from the Groton Sewage Treatment Plant. The Coliform numbers stayed relatively high and constant to the junction with Hemlock Creek. Since Pine and Hemlock Creeks generally gave low numbers, the inclusion of their waters into the Inlet actually lowered the numbers downstream of that juncture. Turbidity was also found to start rising South of Groton and continued to rise until the junction of the Inlet with Hemlock Creek at which point dilution again came into play. Feeder stream sampling in the Moravia area showed that their contribution to Coliform and turbidity was very small.

DETAILED ANALYSIS

To aid in the analysis of all of the data that was collected in 2003, it was decided to break the analysis into two portions, the Lake data and the Inlet data. The Lake data will be addressed first.

PART 1 - Lake Data

As has been done in recent years, selected sites were plotted comparing fecal Coliform and weekly rainfall over the course of the collection period. The actual data is attached as Data Sheet 1 and the plots are presented as Charts 1 and 2. This year Long Hill Road and Rounds Lane were collected with the Inlet sites so another site on the Inlet downstream of the Moravia Sewage Treatment Plant at Route 38 in West Moravia was used as the comparative site in the plots. A review of the plots shows that West Moravia and Dutch Hollow follow the rainfall line fairly well. The other sites did show slight elevations in Fecal Coliform when the rainfall was heavy but not the extremes shown by Dutch Hollow and the Inlet at Route 38. This year we also experienced one time high numbers at Gleason Drive on June 18th, at Fire Lane 26W on July 2nd, and at Ensenore on July 23rd. Whether these were due to sampling problems or lab error is unknown. The samplers were notified at the time and advised to limit exposure until a new, low reading was obtained which in fact occurred the following week.

A scan of the City of Auburn sites in Data Sheet 1 reveal a year with generally lower Fecal Coliform values compared to past experience. The two East Bathing Beach sites (the Channel and the East Bathing Beach) provided two higher values on July 23rd and August 27th which could not be explained based on rainfall or high water temperature. However, for yet another year the beach did not need to be closed by the Health Department because of high Fecal Coliform values. It is becoming more and more tempting to relate this continuing positive result to the incorporation of the two eductor pipes running from the East Bathing Beach through the seawall into the Outlet that were installed when the seawall was rebuilt in 2000. The flow of the current in the Owasco River creates a slight vacuum on the pipes resulting in flow from the East Beach area into the River. Hopefully this trend will continue.

The turbidity data for selected Lake sites are presented in Charts 3 and 4 and the data is given in Data Sheet 2. The turbidity for Dutch Hollow and the East Bathing Beach do seem to follow the rainfall data. There is also an apparent slight correlation with the Channel and rainfall. Overall, the turbidities are generally higher in the beginning of the testing season and decrease to lower values in July and August. Near the end of August there appears to be the beginning of an upward trend. Looking at the data in Data Sheet 2 shows higher values for turbidity at the Route 38 bridge in West Moravia and the values are correlated with rainfall amounts. Since 70% of the water entering the Lake comes from the Inlet, it is not surprising that higher turbidity values from run-off are seen with higher rainfall amounts. As we reported last year, the water clarity is very good due to the action of the Zebra mussels. Weed growth continued to increase both in density and height as well as area infested. Weed cutting was a frequent sight along the shores of the Lake. Swimmers were constantly complaining about the difficulty encountered when trying to swim in most parts of the Lake. Fortunately the Beaches at the North end are still essentially free of this persistent problem.

Water temperature data are shown graphically for a series of sites in Charts 5 and 6 with the actual data displayed in Data Sheet 3. Not surprisingly, the temperatures start out lower and increase to mid August before again starting downward. There is a slight correlation of rainfall with water temperature with high rainfall amounts causing a dip in the water temperature. As in past years, the water temperature in the Inlet as measured at Route 38 in West Moravia is lower than the sites in the Lake.

During the sampling each week it was frequently noted that the flow in the Inlet was elevated even though there had been only small amounts of rain during the week. Based on rainfall reports on the news for the Southern part of the State, it was postulated that the rainfall in the portion of the Watershed that directly fed the Inlet might be higher than the data taken at the Swift Street weather station. With assistance from Tony DeCaro, rainfall data from Cornell University in Ithaca was located. Chart 7 shows the weekly rainfall data for these two sites. The actual data is given in Data Sheet 4. It is apparent that Ithaca did receive more rain than Auburn during the past summer. The Ithaca data will be used for the Inlet sites since the majority of the Inlet watershed is nearer Ithaca than Auburn.

Part 2 - Inlet Data

The discussion will follow the format used with the Lake data. Fecal Coliform results are plotted in Charts 8, 9, 10, and 11. Charts 8 and 9 take sections of the Inlet starting at Moravia to Groton and Groton to Freeville with Long Hill Road and Rounds Lane used as reference sites in both Charts. Chart 10 shows the Groton to Freeville sites without the Long Hill and Rounds Lane inclusions to give a better representation of the Southern Inlet sites. Chart 12 shows the results for Pine and Hemlock Creeks. The actual data for all of the Charts is recorded on Data Sheet 5. For reference, the last attachment to this report is a map of the Inlet and its watershed with the sampling site numbers. The site numbers are listed in the data sheets along with the site description used on the charts.

One of the reasons for undertaking the study of the Inlet was to try to determine the source or sources of the high Coliform readings that are generally found at Long Hill Road and Rounds Lane. Reviewing Data Sheet 5 and Chart 11 revealed that Pine Creek and Hemlock Creek did not have high readings compared to Rounds Lane. The one exception was Site OWL-613, Weeks Rd. on Hemlock Creek which had high readings when there was high rainfall. Since the downstream sites did not show the same elevations in readings, it was concluded that the flow contribution from Weeks Rd. was small compared to the rest of the flow in Hemlock and Pine Creeks so that the high Coliform readings were diluted as the water moved down stream.

To gain a better look at the Main Inlet sites, data was extracted from Data Sheet 5 and presented as Data Sheet 6 using Rounds Lane as the site to compare the results from the other sites against. By viewing the actual fecal Coliform numbers, a technique suggested by Dr. Joe Wasileski, it is clear that the most southern sites generally do not have high Coliform readings except on June 3rd and September 2nd when rainfall amounts were also high. The first site with more sustained higher readings is site OWL-605, Route 38 in Groton at west South Street by Agway. Looking at the map, it is clear that the feeder streams entering the main Inlet channel are coming from the hills on the East side of Groton. Moving downstream to site OWL-605 in Groton at the Memorial Wood Bridge shows numbers for fecal Coliform similar to those at site OWL-604. Continuing downstream to site OWL-158 just north of Groton and the Groton Sewage Treatment Plant still shows numbers for fecal Coliform similar to those seen before the Sewage Treatment Plant. The effect of the Groton Sewage Treatment Plant on the Inlet water quality is judged to be minimal based on these data for 2003. Continuing this analysis heading North (downstream) reveals that the fecal Coliform numbers stay relatively constant until Hemlock Creek joins the main Inlet channel. At that point the numbers seem to drop (compare sites OWL-611 to OWL-154) except when there is high rainfall when the numbers at site OWL-154 increase. That contribution is apparently coming from the hills to the West and North of the Inlet toward Moravia but further down the hills from Pine Creek. Run-off from this area is likely. Finally, sites OWL-112 and OWL-154 are similar throughout the sampling period. From this analysis it appears that the high fecal Coliform numbers are arising in the Groton area but not directly from the Groton Sewage Treatment Plant. The values are further exacerbated by heavy rainfalls leading to run-off in the area West of Route 38 between Locke and Moravia but below the Pine Creek and Hemlock Creek watersheds. These tentative conclusions are based on data for 2003 only and should be considered in that light. Certainly the data is consistent with a somewhat less extensive study from 1993 in which that data indicated that the high fecal Coliform readings were coming from South of the Cayuga County line.

An analysis of Mill Creek, Dresserville Creek, and Filmore Creek in Moravia showed that these streams were not contributing significant fecal Coliform or turbidity to the Inlet over the course of the sampling period. No further analysis was done with this data.

In addition to collecting samples for Coliform and turbidity analyses, the Americorp volunteers also measured Phosphorus and Nitrate values before and after the Groton and Moravia Sewage Treatment Plants. The data is given in Data Sheet 7. Due to the fact that this data was only collected for 5 weeks for Phosphorus and 3 weeks for Nitrate, a rigorous analysis was not possible. About the only conclusion that can be drawn from the limited data is that the Phosphorous and Nitrate levels found in the Inlet are uncorrelated with the rainfall. Also, there is no apparent contribution from the Sewage Treatment Plants at Groton and Moravia to the values of Phosphorus and Nitrate in the Inlet.

Turbidity data are plotted in Charts 12, 13, and 14 and shown in Data Sheet 8. A casual review of the Charts indicates that the turbidity is generally correlated with the rainfall, particularly on September 2nd. In addition, the data in Data Sheet 8 shows that the turbidities of Pine Creek and Hemlock Creek are noticeably lower than the Inlet at the point of juncture. Reviewing the data from Peruville North shows that the turbidity really starts to climb at site OWL-606 at Stevens Rd. and continues to rise as the Inlet flows through Groton and on toward Locke. They continue to rise through site OWL-154 at the Route 38 bridge North of Locke before dropping somewhat at Rounds Lane. Hopefully this data will provide focus on the areas mainly responsible for the high silt level in the Inlet emptying into the South end of Owasco Lake. Continued efforts by Cayuga County Soil and Water to reduce the silt introduction into the Inlet from these areas will have a positive effect on the entire South end of the Lake.

ACKNOWLEDGEMENTS AND RECOGNITION

Each year OWL hopes that it can learn a little more about the complex factors that are impacting Owasco Lake while at the same time realizing that there are inherent year-to-year variations superimposed on these study parameters. The invaluable assistance of the OWL Water Quality Monitors allows OWL to produce a vast amount of data to be studied and evaluated in an attempt to better understand our watershed. Only with the continued dedicated efforts of this special class of volunteers can OWL hope to achieve the level of knowledge and understanding that is sought. The additional assistance from Cayuga County Soil and Water and the Auburn Water Filtration Plant with the Americorp volunteers to do the Inlet sampling and testing greatly increased the data and information that has been generated about the overall watershed. On behalf of the OWL Board, I want to personally thank both the OWL and the Americorp volunteers for all of their fine efforts and to assure them that their contributions are deeply appreciated.

Submitted by:
Dick Coalson
Water Quality Coordinator
OWL Executive Board

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