|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| Introduction | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The Adirondack Lake Assessment Program is a volunteer monitoring program established by the Residents? Committee to Protect the Adirondacks (RCPA) and the Adirondack Watershed Institute (AWI).� The program is now in its? tenth year and continues to grow.� The program was established to help develop a current database of water quality in Adirondack lakes and ponds.� There were 74 participating lakes in the program in 2007.� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Methodology | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Each month participants (trained by AWI staff) measured transparency with a secchi disk and collected a 2-meter composite of lake water for chlorophyll-a analysis and a separate 2-meter composite for total phosphorus and other chemical analyses.� The participants filtered the chlorophyll-a sample prior to storage.� Both the chlorophyll-a filter and water chemistry samples were frozen for transport to the laboratory at Paul Smith?s College. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� In addition to the volunteer samples, AWI staff sampled water quality parameters in most of the participating lakes as time and weather allowed.� In most instances, a 2-meter composite of lake water was collected for chlorophyll-a analysis.� Samples were also collected at depths of 1.5 meters from the surface (epilimnion) and within 1.5 meters of the bottom (hypolimnion) for chemical analysis.� Once collected, samples were stored in a cooler and transported to the laboratory at Paul Smith?s College. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� All samples were analyzed AWI staff in the Paul Smith?s College laboratory using the methods detailed in Standard Methods for the Examination of Water and Wastewater, 20th edition (Greenberg, et al, 1999).� Volunteer samples were analyzed for pH, alkalinity, conductivity, color, nitrate, chlorophyll a and total phosphorus concentrations.� Samples taken by AWI staff were analyzed for the same parameters, as well as for calcium, chloride, and aluminum concentrations. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Results Summary | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Osgood Pond was sampled three times by volunteers in 2007.� Samples were collected on the following dates: 6/14/07, 7/12/07 and 8/10/07.� Results for 2007 are presented in Appendix A and will be discussed in the following sections.� Results are presented as concentrations in milligrams per liter (mg/L) or its equivalent of parts per million (ppm) and micrograms per liter (mg/L) or its equivalent of parts per billion (ppb). | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| 1 mg/L = 1 ppm; 1 mg/L = 1 ppb; 1 ppm = 1000 ppb. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Adirondack lakes are subject to the effects of acidic precipitation (i.e., snow, rain).� A waterbody?s susceptibility to acid producing ions is assessed by measuring pH, alkalinity, calcium concentrations, and the Calcite Saturation Index.� These parameters define both the acidity of the water and its buffering capacity.� Based on the results of the 2007 Adirondack Lake Assessment program, the acidity status of Osgood Pond is considered to be satisfactory, with no sensitivity to further acidic inputs.� The pH values are satisfactory and the alkalinity values indicate no sensitivity to acidification for Osgood Pond. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ���������� Limnologists, the scientists who study bodies of fresh water, classify lake health (trophic status) into three main categories: oligotrophic, mesotrophic, and eutrophic.� The trophic status of a lake is determined by measuring the level of three basic water quality parameters: total phosphorus, chlorophyll-a, and secchi disk transparency.� These parameters will be defined in the sections that follow.� Oligotrophic lakes are characterized as having low levels of total phosphorus, and, as a consequence, low levels of chlorophyll-a and high transparencies.� Eutrophic lakes have high levels of total phosphorus and chlorophyll-a, and, as a consequence, low transparencies.� Mesotrophic lakes have moderate levels of all three of these water quality parameters.� Based upon the results of the 2007 Adirondack Lake Assessment Program, Osgood Pond is considered to be mesotrophic.� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| PH | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The pH level is a measure of acidity (concentration of hydrogen ions in water), reported in standard units on a logarithmic scale that ranges from 1 to 14.� On the pH scale, 7 is neutral, lower values are more acidic, and higher numbers are more basic.� In general, pH values between 6.0 and 8.0 are considered optimal for the maintenance of a healthy lake ecosystem.� Many species of fish and amphibians have difficulty with growth and reproduction when pH levels fall below 5.5 standard units.� Lake acidification status can be assessed from pH as follows: | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| �������������������������������� pH less than 5.0��������������������� Critical or Impaired | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| �pH between 5.0 and 6.0��������� Endangered or Threatened | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| pH greater than 6.0���������������� Satisfactory or Acceptable | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The pH in the upper water of Osgood Pond ranged from 6.67 to 7.01.� The average pH was 6.84. �Based solely on pH, Osgood Pond?s acidity levels should be considered satisfactory. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Alkalinity | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Alkalinity (acid neutralizing capacity) is a measure of the buffering capacity of water, and in lake ecosystems refers to the ability of a lake to absorb or withstand acidic inputs.� In the northeast, most lakes have low alkalinities, which mean they are sensitive to the effects of acidic precipitation.� This is a particular concern during the spring when large amounts of low pH snowmelt runs into lakes with little to no contact with the soil?s natural buffering agents.� Alkalinity is reported in milligrams per liter (mg/L) or microequivelents per liter (meq/L).� Typical summer concentrations of alkalinity in northeastern lakes are around 10 mg/l (200 meq/L). | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lake acidification status can be assessed from alkalinity as follows: | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Alkalinity less than 0 ppm��������������������� Acidified | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������� Alkalinity between 0 and 2 ppm����������� Extremely sensitive | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������� Alkalinity between 2 and 10 ppm��������� Moderately sensitive | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������� Alkalinity between 10 and 25 ppm������� Low sensitivity | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������� Alkalinity greater than 25 ppm�� Not sensitive | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The alkalinity of the upper water of Osgood Pond ranged from 26.8 ppm to 31.6 ppm.� The average alkalinity was 28.9 ppm.� These values indicate that Osgood Pond has no sensitivity to acidification. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Calcium | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Calcium is one of the buffering materials that occur naturally in the environment.� However, it is often in short supply in Adirondack lakes and ponds, making these bodies of water susceptible to acidification by acid precipitation.� Calcium concentrations provide information on the buffering capacity of that lake, and can assist in determining the timing and dosage for acid mitigation (liming) activities.� Adirondack lakes containing less than 2.5 ppm of calcium are considered to be sensitive to acidification. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The calcium in the upper water of Osgood Pond in 2005 was 5.00 ppm.� In the bottom water, the calcium concentration was 4.50 ppm in 2005.� This suggests that Osgood Pond is currently not sensitive to acidification.� Calcium was not measured in 2007 due to the lack of a site visit by AWI staff. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Calcite Saturation Index | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The Calcite Saturation Index (CSI) is another method that is used to determine the sensitivity of a lake to acidification.� High CSI values are indicative of increasing sensitivity to acidic inputs.� CSI is calculated using the following formula: | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������� ���������������������� ��Ca ��������������������Alk� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| CSI = - log10 �40000�� - log10� 50000� ? pH + 2 | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Where Ca = Calcium level of water sample in ppm or mg/L | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������������������� Alk = Alkalinity of the water sample in ppm or mg/L | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������������������� pH = pH of the water sample in standard units | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Lake sensitivity to acidic inputs is assessed from CSI as follows: | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������� CSI greater than 4������������������� Very vulnerable to acidic inputs | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������� CSI between 3 & 4����������������� Moderately vulnerable to acidic inputs | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������������������� CSI less than 3������������ Low vulnerability to acidic inputs | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� CSI values for Osgood Pond were found in 2005 to be 2.36 in the sample taken from the upper water, and 2.75 in the bottom water sample.� These values classify Osgood Pond as having low vulnerability to acidic inputs.� CSI values for 2007 could not be calculated without calcium levels. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Total Phosphorus | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Phosphorus is one of the three essential nutrients for life, and in northeastern lakes, it is often the controlling, or limiting, nutrient in lake productivity.� Total phosphorus is a measure of all forms of phosphorus, both organic and inorganic.� Total phosphorus concentrations are directly related to the trophic status (water quality conditions) of a lake.� Excessive amounts of phosphorus can lead to algae blooms and a loss of dissolved oxygen within the lake.� Surface water (epilimnion) concentrations of total phosphorus less than 10 ppb are associated with oligotrophic (clean, clear water) conditions.� Concentrations greater than 25 ppb are associated with eutrophic (nutrient-rich) conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The total phosphorus in the upper water of Osgood Pond ranged from 18 ppb to 20 ppb.� The average concentration was found to be 19.3 ppb.� These values are indicative of mesotrophic conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Chlorophyll-a | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Chlorophyll-a is the green pigment in plants used for photosynthesis, and measuring it provides information on the amount of algae (microscopic plants) in lakes.� Chlorophyll-a concentrations are also used to classify a lakes trophic status.� Concentrations less than 2 ppb are associated with oligotrophic conditions and those greater than 8 ppb are associated with eutrophic conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The chlorophyll-a concentrations in the upper water of Osgood Pond ranged from 5.67 ppb to 6.24 ppb.� The average concentration was 5.91 ppb.� This is indicative of mesotrophic conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Secchi Disk Transparency | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Transparency is a measure of water clarity in lakes and ponds.� It is determined by lowering a 20 cm black and white disk (Secchi) into a lake to the depth where it is no longer visible from the surface.� This depth is then recorded in meters.� Since algae are the main determinant of water clarity in non-stained, low turbidity (suspended silt) lakes, transparency is also used as an indicator of the trophic status of a body of water.� Secchi disk transparencies greater than 4.6 meters (15.1 feet) are associated with oligotrophic conditions, while values less than 2 meters (6.6 feet) are associated with eutrophic conditions (DEC & FOLA, 1990). | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Secchi disk transparency in Osgood Pond ranged from 2.5 meters to 2.7 meters.� The average transparency was 2.6 meters.� These values are indicative of mesotrophic conditions. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Nitrate | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Nitrogen is another essential nutrient for life.� Nitrate is an inorganic form of nitrogen that is naturally occurring in the environment.� It is also a component of atmospheric pollution.� Nitrogen concentrations are usually less than 1 ppm in most lakes.� Elevated levels of nitrate concentration may be indicative of lake acidification or wastewater pollution. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The nitrate in the upper water of Osgood Pond ranged from 0.0 ppm to 0.2 ppm.� The average nitrate concentration was 0.13 ppm.��� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Chloride | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Chloride is an anion that occurs naturally in surface waters, though typically in low concentrations.� Background concentrations of chloride in AdirondackLakes are usually less than 1 ppm.� Chloride levels 10 ppm and higher is usually indicative of pollution and, if sustained, can alter the distribution and abundance of aquatic plant and animal species.� The primary sources of additional chloride in Adirondack lakes are road salt (from winter road de-icing) and wastewater (usually from faulty septic systems).� The most salt impacted water in the Adirondacks usually has chloride concentrations of 100 ppm or less. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The chloride was not measured in 2007 due to the lack of a site visit by AWI staff. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| � | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Conductivity | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Conductivity is a measure of the ability of water to conduct electric current, and will increase as dissolved minerals build up within a body of water.� As a result, conductivity is also an indirect measure of the number of ions in solution, mostly as inorganic substances.� High conductivity values (greater than 50 mohms/cm) may be indicative of pollution by road salt runoff or faulty septic systems.� Conductivities may be naturally high in water that drains from bogs or marshes.� Eutrophic lakes often have conductivities near 100 mohms/cm, but may not be characterized by pollution inputs.� Clean, clear-water lakes in our region typically have conductivities up to 30 mohms/cm, but values less than 50 mohms/cm are considered normal. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The conductivity in the upper water of Osgood Pond ranged from 50.4 mohms/cm to 62.5 mohms/cm.� The average conductivity was 56.5mohms/cm.����� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Color | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The color of water is affected by both dissolved (e.g., metallic ions, organic acids) and suspended (e.g., silt and plant pigments) materials.� Water samples are collected and compared to a set of standardized chloroplatinate solutions in order to assess the degree of coloration. The measurement of color is usually used in lake classification to describe the degree to which the water body is stained due to the accumulation of organic acids.� The standard for drinking water color, as set by the United States Environmental Protection Agency (US EPA) using the platinum-cobalt method, is 15 Pt-Co.� However, dystrophic lakes (heavily stained, often the color of tea) are common in this part of the country, and are usually found in areas with poorly drained soils and large amounts of coniferous vegetation (i.e., pines, spruce, hemlock).� Dystrophic lakes usually have color values upwards of 75 Pt-Co.� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Color can often be used as a possible index of organic acid content since higher amounts of total organic carbon (TOC) are usually found in colored waters.� TOC is important because it can bond with aluminum in water, locking it up within the aquatic system and resulting in possible toxicity to fish (see Aluminum).�� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| The color in the upper water of Osgood Pond ranged from 44 Pt-Co to 70 Pt-Co.� The average color was 53.3 Pt-Co.� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Aluminum | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� Aluminum is one of the most abundant elements found within the earth?s crust.� Acidic runoff (from rainwater and snowmelt) can leach aluminum out of the soil as it flows into streams and lakes.� If a lake is acidic enough, aluminum may also be leached from the sediment at the bottom of it.� Low concentrations of aluminum can be toxic to aquatic fauna in acidified water bodies, depending on the type of aluminum available, the amount of dissolved organic carbon available to bond with the aluminum, and the pH of the water.� Aluminum can form thick mucus that has been shown to cause gill destruction in aquatic fauna (i.e., fish, insects) and, in cases of prolonged exposure, can cause mortality in native fish populations (Potter, 1982).� Aluminum concentrations are reported as mg/L of total dissolved aluminum. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ����������� The aluminum in the upper water of Osgood Pond was not measured in 2007 due to the lack of a site visit by AWI staff. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Dissolved Oxygen | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| �������� The dissolved oxygen in a lake is an extremely important parameter to measure.� If dissolved oxygen decreases as we approach the bottom of a lake we know that there is a great amount of bacterial decay that is going on.� This usually means that there is an abundance of nutrients, like phosphorous that have collected on the lake bottom.� Oligotrophic lakes tend to have the same amount of dissolved oxygen from the surface water to the lake bottom, thus showing very little bacterial decay.� Eutrophic lakes tend to have so much decay that their bottom water will have very little dissolved oxygen.� Cold-water fish need 6.0 ppm dissolved oxygen to thrive and reproduce.� Warm water fish need 4.0-ppm oxygen. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ��������� The dissolved oxygen and temperature profiles for Osgood Pond for 2000 - 2005 are presented in Appendix A.�� The dissolved oxygen gradually decreases from the surface to the bottom in Osgood Pond.� The oxygen level is sufficient for cold and warm-water fish survival, although the temperature is probably too warm for cold-water fish.� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Summary | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| �������� Osgood Pond was a moderately productive lake during 2007, mesotrophic in nature.� Based on the results of the 2007 Adirondack Lake Assessment program, the acidity status of Osgood Pond is considered to be satisfactory, with no sensitivity to further acidic inputs.� The pH values are satisfactory and the alkalinity values indicate no sensitivity to acidification.� The past calcium concentrations for Osgood Pond currently indicate no sensitivity to acidification. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| ��������� With eight years of data we can detect water quality trends, and it is also possible to compare the current data with the data collected from 2000-2006.��� Over the last eight years the pH has stayed fairly stable with a slight drop in 2006.� The last two years have been dramatically different when it comes to weather conditions in the AdirondackPark.� The Adirondacks had a very wet summer and year in 2006 but a very dry summer and year in 2007.� This led to a trend that showed itself in many lakes including Osgood Pond the past two years.� During 2006, this extra moisture led to falling pH?s due to the acidic nature of our rainwater but, during the dry summer of 2007, pH values rebounded in Osgood Pond.� Alkalinity values also followed this pattern and increased during 2007.� More rain in 2006 led to more runoff from the surrounding watershed.� This extra runoff increased the total phosphorous levels in Osgood Pond.�� This has led to increased algae growth, as shown by increased chlorophyll a levels during 2006.� This has also led to decreased transparency readings in 2006.�� The dry year of 2007 has led to the opposite trend.� There was less runoff, thus very little change in the total phosphorous and less algal growth.� This led to large dramatic changes and an increase in Secchi disk transparency readings in 2007 due to the lack of algae growth.� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Literature Cited | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| � | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| DEC & FOLA.� (1990).� Diet for a SmallLake: A New Yorker?s Guide to LakeManagement.� | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| New York State Department of Environmental Conservation & The Federation of Lake Associations, Inc.: Albany, New York. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Greenberg, A.E., Eaton, A.D., and Leseri, L.A. (editors).� (1999).� Standard Methods for the | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Examination of Water and Wastewater, 20th Edition.� American Public Health Association: Washington, D.C. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Potter, W. (1982).� The Effects of Air Pollution and Acid Rain on Fish, Wildlife and Their | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Habitats ? Lakes.� Technical Report FWS/OBS ? 80/50.4.� United States Fish and Wildlife Service, Biological Services Program: Washington, D.C. | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Appendix A | ||||||||||||||||||||||||||||||||||||||||||||||||||||
| Click here for Water Quality Data | ||||||||||||||||||||||||||||||||||||||||||||||||||||