After a year and a half of data collection and another year or two of planning prior to that, the first phase of the Nipper Wildlife Sanctuary water quality study has been completed. Lochmueller Group produced a summary report discussing the data, what it might indicate, and provided recommendations for continuing the study.
Based on 2016 sampling by the Sangamon County Soil and Water Conservation District, which showed reduction in nitrate from the outlet to Lick Creek compared to the wetland by the nature center, we wanted to expand the study to see if the Nipper wetlands were preventing nutrients from neighboring agricultural lands getting into Lick Creek. This would have a positive effect on the water quality in the Lake Springfield watershed. So in 2018, the Nipper Foundation, with assistance from the Brandt Foundation and The Friends of the Sangamon Valley, embarked on a formal water quality study of run off from the agricultural fields, wetlands, and outflow from the wetlands to Lick Creek.
In our first 18 months, we’ve found that the outflow concentrations from the last wetland are substantially lower than the inputs coming in from the agricultural field, especially for suspended solids, nitrogen, and phosphorus. We don’t yet have enough data to do a detailed quantitative evaluation, but what we’ve seen thus far has provided enough impetus to continue the study for at least another two years and possibly longer. A qualitative evaluation indicates anywhere from a 50-70% reduction in levels of nitrate, total nitrogen, and phosphorus as water passes through the wetland cells. This information is very preliminary and will certainly be modified as additional information is gathered.
The summary report, written by the Lochmueller Group’s Joe Bartletti and Bryan Cross, makes recommendations for additional sampling and provides suggestions for tweaking the sampling plan we’ve been using. More data is needed to gain a better understanding of the hydrology, the role that groundwater plays in the wetlands, and overall water budget. Standardizing the conditions under which samples will be taken and when samples are collected should help increase the usability of the data and help in comparisons from year-to-year or season-to-season.
We’re also initiating a similar study of the constructed wetlands on Mary Lou Tyner-Lael’s property in rural Morgan County. Mary Lou’s restoration is a different age than Nipper’s, the topography is different, and there is an additional wetland cell. It will be interesting to see how Nipper and the Lael property differ.
Thanks very much to Northwater for developing the sampling plan and training, to Lochmueller Group for pulling the data together and providing a final report, to Vern LaGesse, Charlene Falco, Mike Kennedy, Nick Klobuchar, and Jeanne Handy for helping with sample collection and lab analysis, to PDC Labs for sample analysis, and not least to the Nipper Foundation and Brandt Foundation for funding and support.