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Lay Monitoring Program     Lay Monitoring Program


Citizen groups are becoming increasingly involved in monitoring, education, protection and restoration projects in Vermont. VTDEC provides assistance and training to volunteers whenever possible. Watershed Associations are presently active on many rivers and lakes in the state.

The Vermont Lay Monitoring Program equips and trains local lake users to measure the nutrient enrichment of lakes by collecting water quality data following a rigorously documented and quality assured methodology. This citizen monitoring program is mainly based on trophic parameters and monitors approximately 40 lakes and 25 Lake Champlain stations per year. All Lake Champlain stations and many inland lakes in the program are sampled for chlorophyll-a, total phosphorus, and Secchi disk transparency. The remaining inland lakes in the program, from which limited data are needed, are sampled only for Secchi disk transparency. All sampling occurs on a weekly basis during the summer. The tremendous success of the Lay Monitoring Program is largely due to the many volunteers. Since the development of the Lay Monitoring Program in 1979, valuable data has been generated on many lakes including Lake Champlain. In addition to their standard monitoring, Vermont's citizen lake monitors also assist in the ANS Watchers Program (see below), and in collecting valuable data for the Lake Bioassessment Program.

The Citizen Lake and Watershed Survey Program provides survey sheets and technical training for volunteers, lake and watershed associations, and other interested groups to enable them to perform screening-level assessments to identify potential sources of pollution to lakes by conducting in-lake, lakeshore, and lake watershed surveys. Click here for more information.

The Vermont Invasive Patrollers (VIP) trains citizen volunteers to monitor for the presence of invasive aquatic species. Click here for information and workshop schedule, or contact Bethany Sargent or call (802) 490-6129. For more information on aquatic invasive species in Vermont click here.

Hose sampling

What is the LMP?

The Vermont Lay Monitoring Program is a cooperative effort between the Vermont Department of Environmental Conservation and lake users. People from all walks of life who are actively involved in lake protection make up the Lay Monitoring Program.

The LMP was established in 1979 and continues today with the same goals:

  • to describe water quality conditions on each lake participating in the program;
  • to establish a database on each lake useful for documenting future changes in water quality; and
  • to educate and involve lake residents in lake protection.

The LMP samples a lake for total phosphorus, chlorophyll-a concentration, and water clarity.

Total phosphorus is collected to determine a lake's level of nutrient enrichment. Since phosphorus is typically the limiting nutrient in a lake system, when in excess, it is the nutrient that can cause the most productivity (aging) in the lake. Excessive phosphorus feeds aquatic plants, algae and other plankton (free floating, aquatic life), increasing a lake's productivity.

Filling in datasheet

Chlorophyll-a is the green pigment in plants and algae. The concentration of chlorophyll-a in a lake is used to describe the amount of algae in the lake. Generally, lakes with high phosphorus concentrations will have increased algae growth. Water clarity is measured by using a Secchi disk, an eight inch diameter, black and white painted disk. The disk is lowered into the lake by a rope, marked in meters, until it disappears from sight, at which point the lake's transparency is measured. Generally, the more algae, the lower the water clarity.


Why measure total phosphorus, chlorophyll-a and water clarity? The primary cause of lake problems is from increased phosphorus. Human activity along a lake's shoreline and in the watershed can accelerate the amount of phosphorus entering a lake.

Sources of phosphorus include:

  • shoreline erosion
  • fertilizer run-off
  • run-off from dirt roads
  • failing septic system
  • agriculture runoff
  • residential runoff
  • erosion from logging
  • erosion from construction

Recording the site Lat-Long

Unnaturally high levels of phosphorus cause excessive aquatic plant and algae growth, which lowers the water clarity. Additionally, nuisance plant and algae growth can interfere with boating, swimming, fishing and other recreational activities. As the excessive growth dies back each year it falls to the lake bottom, causing sediments to build up more rapidly. When the natural environment of a lake is altered, the species of fish and other wildlife in the lake may also change.

How to join the LMP

All water quality sampling equipment is provided by the Department of Environmental Conservation. The monitor supplies the time, boat and gas. Sampling takes place weekly between June 1st and September 1st.

For more information about this program contact Bethany Sargent or call (802) 490-6129, the VT LMP Coordinator

Filtering samples


View the Data


              2014 Lay Montitoring Program Report (PDF, 8 MB)

35 Year Vermont Lay Monitoring Program Report - Inland Lakes (1979-2013) (PDF, 8 MB)

35 Year Vermont Lay Monitoring Program Report - Lake Champlain (1979-2013) (PDF, 2 MB)

2012 Lay Monitoring Program Report - Lake Champlain 15 MB

2012 Lay Monitoring Program Report - Inland Lakes 8 MB

Lay Monitoring Lake Water Quality Data - from 1979 to Present.
Individual Lake Reports with LMP Data

Spring Phosphorus Lake Data


Additional Resources

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Helpful local, regional and federal volunteer monitoring web sites

Directory of Vermont Watershed Groups

Vermont LaRosa Laboratory Services Program

The Lake Champlain Basin Program

UVM Watershed Alliance

The River Network

Volunteer Water Quality Monitoring National Facilitation Project (USDA College Extension).

EPA Volunteer Monitoring

EPA Nutrient Pollution, Policy and Data

Vermont Acid Rain Program

VT DEC Watershed Management Division 1 National Life Drive, Main 2  Montpelier, VT  05620-3522  Tele: 802-828-1535   Fax: 802-828-1544


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