Water Quality Monitoring

Slide 1


Step one in managing the watershed is to know what processes are at work and what threats we are facing. We accomplish this through research and water quality monitoring. We are fortunate to have one of the most extensive data sets in the Northeast. Our sampling program began in 1980 and has been through several transformations over the years as funding sources, sampling protocols, and research projects have changed. Historically, we have had five sites located on Lake Wallenpaupack. Today’s program evaluates water quality on the bottom of the lake and at the surface at two locations.

Funding availability rendered it necessary to reduce our number of sites, and having an extensive dataset made our choices scientific. We analyzed trends in the data and were able to determine that several of the sites were statistically similar. The two sites we monitor today give us a representative evaluation of the lake. Our historical data has also allowed us to look back at trends in water quality and evaluate our programs.We sample once per month during the growing season (May through October) on our Lab Boat. Keep your eyes peeled if you’re on the water and you might even catch us in the act! Our sampling events look at the water quality from several approaches and each sampling site has the same protocol.

First, we look at the physical attributes of the water. Temperature, dissolved oxygen, conductivity, specific conductivity, pH, and oxidation reduction potential are recorded at one-meter intervals throughout the water column.

Secondly, we look at the chemistry of the water. Samples are taken from one meter below the surface and one meter above the bottom. The samples are preserved, if necessary, and sent to a laboratory for analysis of Phosphorous, Nitrogen, Total Suspended Solids, and Alkalinity. Chlorophyll a is also sampled. This green pigment is found in plants and is necessary for them to photosynthesize. By measuring Chlorophyll a we can determine the amount of active photosynthetic plant material (algae and phytoplankton) in the water. This is important because these plants produce oxygen during the day when they are photosynthesizing and consume it at night while they go through a process called respiration. This can have a profound effect on water quality.

Lastly, phytoplankton and zooplankton are sampled. These samples are analyzed for species diversity and density and serve as biological indicators of the trophic state of the lake. The “trophic” state of the lake refers to the productivity of the lake in terms of nutrient availability for plant growth. For more information and detail on our sampling program and Lake Wallenpaupack’s water quality, check out our Annual Reports, available in PDF on this site.

Water quality monitoring continues to be an integral part of our mission. We know what our pollutants are; we know from where in the watershed they originate; and we know what we have to do to address them.