Earthology funds soil sampling for Riveredge Nature Center's wetland restoration project

Riveredge Nature Center in Saukville, Wisconsin is teaming up with Ducks Unlimited to restore wetlands on their property adjacent to the Milwaukee River floodplain. This land was previously used for dairy and cropland for many decades. Some agricultural chemical contaminants can linger in the soil for many years and present adverse effects to wildlife if they come into contact with the contamination. Earthology staff reviewed the project and recommended that soils be tested before construction. Furthermore, we offered to pay for the analysis to reduce the financial impact on Riveredge - Earthology believes it is important to support partners with similar missions. On April 21, 2026, Earthology staff teamed up with Riveredge staff to collect soil samples in the former agricultural areas adjacent to the planned wetland restoration. Earthology staff has experience with identifying and remediating chemical contamination so that any wildlife that moves into the new wetlands can forage and breed safely. Soil samples from three locations were sent to CT Laboratories in Baraboo, Wisconsin. The lab performed the analyses for metals, organochlorine pesticides, polychlorinated biphenyls (PCBs), and total phosphorus.

The good news is that almost all the contaminant results were less than their detection limits and therefore, not problematic to wildlife. Only phosphorus levels were elevated, as expected, at all three sites (ranged from 784 to 1,030 mg/kg). While phosphorus at these concentrations is not directly toxic, it can cause extensive algae growth (“blooms”) in water bodies, including wetlands. These algae (e.g., cyanobacteria), in turn, may be directly toxic to humans and wildlife, and under bloom conditions, can also cause oxygen depletion in the water and result in fishkills. The best way to remediate excess phosphorus in soil is simply to grow and harvest some herbaceous plants or plant longer-lived shrubs and trees to sequester the phosphorus. If there is excess phosphorus in the water, adding flocculant or aerating the water (adding oxygen) can reduce the bioavailable phosphorus and help prevent algae blooms. Earthology is assisting Riveredge with continued phosphorus monitoring and remediation, if needed, as the wetlands will be constructed this summer.

Earthology and Riveredge staff collect a soil sample for contaminants analysis