OWL WATER SAMPLING DATA ANALYSIS REPORT 2005

INTRODUCTION

During 2005 due to budgetary constraints, testing was limited to the traditional Owasco Lake sites. Lake water quality samples were collected from June 8th through August 31st. Twenty volunteers collected twenty-five samples weekly for testing at the City of Auburn Waste Treatment Plant for Coliform and turbidity under Andy Roche's supervision. The volunteers also measured air and water temperatures and noted wind direction and relative strength. They recorded the sky condition, algae observations, 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. These data were 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 in the fall.

SUMMARY

The overall conclusion reached from an analysis of the data is that the bacterial water quality of Owasco Lake remains good. 2005 was another very wet year with most weeks recording 0.5 inches of rain or more throughout the testing period. Most of the lake sites gave low fecal Coliform numbers throughout the testing with <10 frequently determined. (<10 is set to 1 in the Data Sheet for graphical purposes; values of TNTC were set to 5000 again for graphical purposes.) The two test sites on the Inlet frequently had numbers in the hundreds to thousands. Turbidity numbers ran higher as they had in 2004 probably because of the high amount of rainfall. As was noted in 2004, the East Swimming area at Emerson Park had significantly higher turbidity than the West area again being attributed to the drainage pipes entering the lake just East of the eastern edge of the swimming area. Water temperatures in 2005 were a little higher than in 2004 with similar trends through the sampling season. Algae observations which were initiated in 2005 showed that their activity was non-existent in early June and slowly rose in incidence through July peaking in late July to early August before starting to slowly decline near the end of August. Green and brown algae where the predominant types reported with a few instances of blue-green noted.

DETAILED ANALYSIS

As had been done last year, 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, 2, and 3. The first thing that is revealed is that this past summer had a lot of rain with most weeks recording half an inch or more of rain. Conversely, the fecal Coliform numbers generally were less than in previous years with only occasional numbers TNTC (too numerous to count) signified by a value of 5000 on the spreadsheet. Many sites routinely provided a fecal coliform number <10 which was entered on the spreadsheet as 1. From a fecal Coliform standpoint, 2005 was a very good year for the lake. The swimming beach at Emerson Park also provided low numbers. Chart 3 compares the West and East sides of the swimming beach. As was reported in 2004, the East side of the designated area has higher fecal Coliform numbers than the West side. You may recall that in 2004 Gary Duckett (Cayuga County Director of Parks and Trails) found that during heavy rain events that the area behind the Agricultural Museum flooded and large quantities of water were dumped into the Lake just east of the swimming area by two large drainage pipes running under Route 38A. The water discharging from the pipes routinely read high in fecal Coliform which directly affected the readings taken from the shore on the east side of the swimming area. Again in 2005 the data shows a higher fecal Coliform number for the East compared to the West side and also the actual numbers are similar to those in 2004. The swimming area was not closed at all in 2005

The turbidity data for selected Lake sites are presented in Charts 4, 5, and 6. The turbidity seems to follow the rainfall data more closely than the fecal Coliform data did. This is not surprising since higher rainfall amounts would tend to cause more erosion and thus result in higher suspended solids in the run-off. The higher numbers seen for the East side of the Swimming Beach compared to the West side (Chart 6) are another indicator of the strong influence that the pipes under Route 38A are causing on the Swimming area. Overall the turbidity numbers were generally similar in 2005 to 2004. The water clarity continues to be high probably largely due to the action of the Zebra mussels. Seaweed growth around the lake continues to cause problems for the lake shore residents.

The water temperature data is shown in Data Sheet 3 and the air temperature data is in Data Sheet 4. Selected sites are shown graphically in Charts 7 through 10. Since many of the samples were taken as early as 6:00 AM, the air temperatures are frequently lower than the water temperatures. As it did in 2004, the water temperature gradually rises from around 20 C. in early June to a peak of around 27 in mid July and then a recession to 21 C. at the end of August. Heavy rainfall can cause the water surface temperature to dip somewhat while a relatively drier spell aids in temperature increase. The air temperature data is a bit more jumpy than the water temperature and appears to be more responsive to rainfall than the water temperature.

This year was the first in which the volunteers recorded information about algae at their test sites. Since the information was recorded as a general type of observation such as "green algae on rocks" it did not lead to a rigorous analysis. Sufficient to say that the presence of algae started out as non-existent and over the course of the sampling period it became broadly observed. Green and brown algae were typical with a few blue-green algae seen.

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.

Joe Wasileski was the water testing program coordinator and made all the preliminary arrangements and contacts. In addition he made sure that all the samplers were on board and stocked with bottles and data sheets. He also made sure that the samples were picked up promptly and delivered to the testing facility. Andy Roche's invaluable assistance with supervising the testing at the Sewage Treatment Plant in Auburn is gratefully acknowledged. Anthony DeCaro's provision of the rainfall data from the Auburn weather monitoring site at the Swift Street Water Filter Plant is also gratefully acknowledged. On behalf of the OWL Board, I want to personally thank the OWL volunteers for all of their fine efforts and to assure them that their contributions are deeply appreciated.

Submitted by:
Dick Coalson
Water Testing Group