Jefferson County Closed Landfill Groundwater Monitoring

To help Jefferson County streamline post-closure monitoring and reporting required by Jefferson County Public Health and Ecology (under WAC 173-304), Aspect developed a database to manage over 20 years of data to support statistical analyses on the groundwater quality data. The groundwater monitoring program includes groundwater sampling, water-level measurements, groundwater-flow direction and velocity, in addition to statistical data analysis. Our statistical analyses includes:  Time Series Plots, Sen’s Slope Estimator Plots and Mann-Kendall Tests, Box and Whisker Plots, and Mann-Whitney and Kruskal-Wallis Tests. The statistical methods efficiently evaluate if groundwater resources could be impacted by potential releases from the landfill.