Maine Department of Environment Protection lake monitoring and assessment, 1970s-2011, compiled all ME DEP programs for metadata unpublished data

Much of the lake monitoring in the state is done to assess "trophic state" or the
productivity of the water. Our 30 year record includes data on over 1000 of our 5785 lakes,
including parameters such as transparency, conductivity, alkalinity, total phosphorus and
chlorophyll-a. These, along with extensive data sets from the University of Maine and clarity
readings from volunteers, have produced one of the most comprehensive lake data sets in the
country. DEP regular monitoring includes annual Baseline Sampling Program and special projects
of one or more years’ duration. Each year between August 10 and September 10, we visit
over 100 lakes and take a number of types of data. The timing coincides with the period when
lakes usually show their worst water quality: lowest dissolved oxygen, lowest transparency and
highest algae and phosphorus levels. Besides these measures, we sample for conductivity,
alkalinity and acid neutralizing capacity (ANC), true and apparent color, and a variety of
cations and anions. Lakes sampled generally include TMDL lakes, 33-50 lakes in the VLMP, lakes
of special concern (e.g., anecdotal report of algal bloom), long-term monitoring lakes in
ecoreserves and special project lakes.