CLC 2nd Annual Forum Presentations - Environmental Findings 2011
Before viewing the presentations given at the CLC’s 2011 Forum, please take a moment to read this summary describing the Conservancy’s work which informed the presentations by Larry Beals the Conservancy’s limnological consultant, and Maria Rose, the City of Newton’s Environmental Engineer.
The Conservancy’s activities during the summer of 2011, carried out by our many dedicated volunteers, including the following:
> Survey of the Crystal Lake watershed
> Water sampling and laboratory analysis
> Monitoring water visibility and temperature
Based on the Conservancy’s work thus far, it appears that the lake is generally healthy, though there are certain Lake areas and City and community practices that can be improved to preserve it for the future. We intend to continue the monitoring work we have begun so as to obtain a clearer picture of the ongoing health condition of the lake over a longer period of time.
Watershed Survey: Volunteers surveyed properties on all 34 streets in the Crystal Lake watershed to establish a baseline record of the watershed’s surface conditions and an understanding of stormwater movement. Storm water drainage, vegetation, erosion, land use, sources of pesticide/herbicide, and potential pollution problems were all evaluated. A summary of survey findings is as follows:
• Other than some minor erosion, there did not appear to be visible problems with stormwater run-off from properties in the watershed
• Lakeside observations revealed no visible water quality issues
• Invasive plant species appear to be reasonably under control, although there are minor pockets of such growth
• Lawn fertilizers and pesticide use could not be accurately assessed via visual observations
Water Sampling and Laboratory Analysis: Volunteers assisted with a very involved water sampling program to assess Crystal Lake’s water quality and to identify factors that might be affecting the overall health of the lake. Water samples, taken from land and by boat by trained volunteers in both wet and dry weather, were collected from eleven different locations around the lake at six different occasions and analyzed by a state-certified lab. The comprehensive tests included bacterial analysis and counts (E. coli and Enterococcus); herbicides and pesticides; fertilizer components such as nitrite, nitrate, ammonia and phosphorus; and arsenic. It is important to note that the sampling methodology used did not include protocol necessary to test specifically for the safety standards for swimming.
The results of CLC’s sampling generally were as follows:
• Bacterial test results were variable depending on location and date of testing. Most, but not all, were below Maximum Contaminant Limits
• Nitrogen test results were comparatively low and typically below detection limits
• Phosphorus test results were generally low with minor elevations above detectable levels in some areas
• Pesticides, herbicides and arsenic were not detected
Water Monitoring: For the second year, volunteers conducted weekly monitoring of the Lake. Temperature and visibility readings were recorded, at three different depths, at six specific sites around Crystal Lake between July and November. Water visibility was excellent and there were no unusual temperature changes, especially in the lower, cooler levels of the lake. No algae blooms were detected during the summer and early fall; however, a bloom did occur in late November. The late algae bloom could be attributed to the normal cycle of lakes as they turn over their respective layers both in the spring and the fall. Such turnover could cause settled phosphorus to be released which would encourage and feed algae growth.
The Conservancy has also observed oil sheens which often occur after the first flush of rainwater off the surrounding watershed pavement and can be observed on the surface of the Lake near the outfalls. Additionally, there appears to be large amounts of sand from the winter road treatments that gets washed into the lake and has gradually built up over time. Both conditions may have opportunities for correction.
2nd Annual Forum Presentations (PDF versions):
• Larry Beals (Limnologist) Presentation
• Maria Rose (Environmental Engineer for the City of Newton) Presentation
For more detailed information about the CLC’s testing procedures and results, please see the following:
• Understanding Water Sampling and Putting the CLC Sampling into the Appropriate Context
The Conservancy’s activities during the summer of 2011, carried out by our many dedicated volunteers, including the following:
> Survey of the Crystal Lake watershed
> Water sampling and laboratory analysis
> Monitoring water visibility and temperature
Based on the Conservancy’s work thus far, it appears that the lake is generally healthy, though there are certain Lake areas and City and community practices that can be improved to preserve it for the future. We intend to continue the monitoring work we have begun so as to obtain a clearer picture of the ongoing health condition of the lake over a longer period of time.
Watershed Survey: Volunteers surveyed properties on all 34 streets in the Crystal Lake watershed to establish a baseline record of the watershed’s surface conditions and an understanding of stormwater movement. Storm water drainage, vegetation, erosion, land use, sources of pesticide/herbicide, and potential pollution problems were all evaluated. A summary of survey findings is as follows:
• Other than some minor erosion, there did not appear to be visible problems with stormwater run-off from properties in the watershed
• Lakeside observations revealed no visible water quality issues
• Invasive plant species appear to be reasonably under control, although there are minor pockets of such growth
• Lawn fertilizers and pesticide use could not be accurately assessed via visual observations
Water Sampling and Laboratory Analysis: Volunteers assisted with a very involved water sampling program to assess Crystal Lake’s water quality and to identify factors that might be affecting the overall health of the lake. Water samples, taken from land and by boat by trained volunteers in both wet and dry weather, were collected from eleven different locations around the lake at six different occasions and analyzed by a state-certified lab. The comprehensive tests included bacterial analysis and counts (E. coli and Enterococcus); herbicides and pesticides; fertilizer components such as nitrite, nitrate, ammonia and phosphorus; and arsenic. It is important to note that the sampling methodology used did not include protocol necessary to test specifically for the safety standards for swimming.
The results of CLC’s sampling generally were as follows:
• Bacterial test results were variable depending on location and date of testing. Most, but not all, were below Maximum Contaminant Limits
• Nitrogen test results were comparatively low and typically below detection limits
• Phosphorus test results were generally low with minor elevations above detectable levels in some areas
• Pesticides, herbicides and arsenic were not detected
Water Monitoring: For the second year, volunteers conducted weekly monitoring of the Lake. Temperature and visibility readings were recorded, at three different depths, at six specific sites around Crystal Lake between July and November. Water visibility was excellent and there were no unusual temperature changes, especially in the lower, cooler levels of the lake. No algae blooms were detected during the summer and early fall; however, a bloom did occur in late November. The late algae bloom could be attributed to the normal cycle of lakes as they turn over their respective layers both in the spring and the fall. Such turnover could cause settled phosphorus to be released which would encourage and feed algae growth.
The Conservancy has also observed oil sheens which often occur after the first flush of rainwater off the surrounding watershed pavement and can be observed on the surface of the Lake near the outfalls. Additionally, there appears to be large amounts of sand from the winter road treatments that gets washed into the lake and has gradually built up over time. Both conditions may have opportunities for correction.
2nd Annual Forum Presentations (PDF versions):
• Larry Beals (Limnologist) Presentation
• Maria Rose (Environmental Engineer for the City of Newton) Presentation
For more detailed information about the CLC’s testing procedures and results, please see the following:
• Understanding Water Sampling and Putting the CLC Sampling into the Appropriate Context