The goal is to monitor and understand the health of Bella Vista waters. Currently the analysis has 11 water quality parameters, listed below. The data for the analysis is collected for each lake and stream site every month.
- Photic Depth
- Secchi Depth
- Dissolved Nitrogen (Nitrate/Nitrite)
- Total Nitrogen
- Dissolved Phosphorus (Orthophosphate)
- Total Phosphorus
- E coli
Most of these water quality parameters focus on measuring things that affect plankton. There are two types of plankton: phytoplankton (tiny plants) and zooplankton (tiny animals). Plankton are a vital part of the food web, feeding larval fish and adults of some fish species, so it is important that we monitor them.
Photic depth and secchi depth both measure water clarity. Photic depth measures how deep light penetrates the water, while secchi depth is how deep humans can perceive an object. Photic depth is important because it defines where plankton can thrive. Like all plants phytoplankton need access to sunlight so they can grow, thus they need to inhabit the photic zone, the bottom of which we measure as the photic depth. Zooplankton eat the phytoplankton and also inhabit the photic zone. Secchi depth can then be used as a proxy for how well plankton are doing.
Turbidity and chlorophyll both help explain photic and secchi depths. Turbidity measures particles leading to cloudiness. Turbidity results from sediments and organic material like plankton. Chlorophyll is the photosynthetic pigment in algae and plants and measures the phytoplankton component of turbidity. The ideal scenario is that virtually all turbidity is explained by plankton.
Conductivity measures the dissolved ions, or charged particles, in water. These dissolved ions are things like salt. There needs to be ions in the water for the health of the plankton community, but it also should not be excessively high.
The measurement for pH indicates how acidic or basic the water is: 0 is very acidic, 14 is very basic, and 7 is perfectly neutral. This scale is logarithmic, so each whole number on the scale is a factor of 10 stronger in acidity or basicity then the previous. For example, pH 4 is ten times more acidic than pH 5 and 100 times more acidic then pH 6, and pH 10 is ten times more basic than pH 9. Natural waters usually range from pH 6-9.
Nitrogen is important for growth in plants and animals. Dissolved nitrogen in freshwater comes mainly from nitrate, and to a smaller degree nitrite, and is readily absorbed by plankton. Total nitrogen includes dissolved nitrogen compounds as well as nitrogen bound to sediments and in organic material like plankton.
Phosphorus is important for growth in plants and animals. Dissolved phosphorus in freshwater comes almost entirely from orthophosphate and is readily absorbed by plankton. Total phosphorus includes dissolved phosphorus compounds as well as phosphorus bound to sediments and in organic material like plankton.
E. coli is a bacteria that is naturally present in the environment and inside animals. Humans have E. coli present in the lower sections of the gastrointestinal tract, but these bacteria can cause illness if large numbers are introduced to the upper sections, i.e. the mouth and stomach. The Arkansas Department of Health threshold for safety is 126 colony forming units of E. coli (cfu) per 100mL.