USGS scientists recently completed a study that tested Milwaukee-area streams for 64 organic waste compounds (OWCs) from 2006 to 2009. OWCs are domestic, agricultural, and industrial chemicals that enter our streams and lakes through stormwater runoff, atmospheric deposition, leaking septic or sanitary systems, unregulated discharges, and improper disposal. While some OWCs are relatively innocuous, others are toxic at elevated concentrations. Some can even interfere with animals’ hormone systems and cause cancer and birth defects.
The study found at least one OWC in every sample collected, while most contained at least 12 OWCs. The most common and highly concentrated OWC were polycyclic aromatic hydrocarbons, or PAHs, which come from coal-tar-based pavement sealants, coal-fired power plants, wood burning, and vehicle emissions. In some streams, PAHs were detected at levels that could be harmful to aquatic life.
To learn more about this study, check out the press release, full report, and related Milwaukee Journal Sentinel article.