AAI uses a septic leachate detector
Septic Snooper) to help locate, indirectly, potential sources of excess
nutrients (nitrogen and phosphorus), bacteria and other substances that
tend to lower water quality or increase the rate of lake eutrophication.
By detecting elevated electrical conductivity of the lake water and
substances that fluoresce, the instrument alerts the operator to
potential "hot spots" along the shoreline. Household
wastes (graywater) and sewage wastes contain substances that increase
electrical conductivity (e.g., chlorides in wastes products) or that
fluoresce (e.g., urine breakdown products and detergents). Runoff
from other cultural activities (e.g., road salt, plant fertilizers, pet
and livestock wastes) can also cause these two variables to increase
near the shoreline. Detection by the instrument indicates a
potential source of pollution, but does not identify the substances
causing the elevated conductivity or fluorescence.
A water sample at the hot spot is
collected for laboratory analysis of selected chemical and
bacteriological variables. Results of the analyses can help
characterize the potential problem. A water sample is also taken
from the center of the lake as a control to compare with the shoreline
hot spot samples. If one or more of the measured variables from a
hot spot is substantially greater than the corresponding variable(s)
from the control sample, then there is an indication of a potential
source input from the shoreline property.