Nutrients

Eutrophication and harmful algal blooms (HABs) are becoming an increasing concern in the Great Lakes. Although there is a total maximum daily load (TMDL) for phosphorus in the Milwaukee Estuary, abundance/biovolume of potential HAB-producing cyanobacteria and cyanotoxin presence in Milwaukee-area rivers and the estuary are largely unknown. USGS evaluations of nutrients in the MMSD Watercourse...

In urban areas, the term “stormwater” refers to the precipitation (either rainfall or snowmelt) that isn’t absorbed by the ground, but rather flows off impervious surfaces such as roads, roofs, and parking lots. Stormwater flows into storm drains and is typically routed directly to streams, which often results in flooding and sometimes combined sewer overflows (CSO) as well. Stormwater can also...

There are many kinds of chemical, physical, and biological contaminants contained in water and sediment, and new or “emerging” contaminants are continually being discovered. USGS investigations of contaminants in the MMSD Watercourse Corridor Study include studies of PFAS, PAHs, microplastics, and wastewater contamination as well as modeling long-term trends in water quality.

Since 2000, the USGS and MMSD have been partners in the Milwaukee Area Watercourse Corridor Study. The USGS has applied a multi-disciplinary approach to monitor and assess stream water quality within studies of aquatic communities, geomorphology and habitat, water and sediment, and streamflow. Results are provided to MMSD and watershed management agencies for planning and decision-making.

The fractured bedrock aquifers of southwest Wisconsin are often overlain by shallow soils, so private wells are potentially vulnerable to contamination by nitrate and pathogens from the land surface. The goal of this study is to evaluate the extent and causes of private well water contamination in three southwest Wisconsin counties.

Studying lakes provides an improved understanding of lake ecosystem dynamics and valuable information that helps lead to sound lake-management policies. The USGS collects hydrologic data in lake settings, studies water and nutrient budget development, conducts source-loading analysis, explores groundwater interactions, and performs lake water-quality modeling.

Edge-of-field monitoring focuses on identifying and reducing agricultural sources of excess nutrients which can threaten the health of streams, rivers, and lakes. Edge-of-field monitoring assesses the quantity and quality of agricultural runoff and evaluates the effectiveness of conservation practices that aim to reduce nutrient loss.

As agricultural land in the Minnesota River Basin is retired, tile drains are removed or broken and riparian corridors are planted to reduce runoff. Early studies saw decreased sediment and nitrogen and improved biological indicators but no significant changes in phosphorus. This project continues to investigate the linkages between riparian buffer extent, age, and continuity; stream water; and...

Decaying organic materials, like leaf litter, can release excess nutrients into local streams and lakes, causing eutrophication and algal blooms. To determine if a municipal leaf collection and street cleaning program can reduce nutrients in stormwater runoff, the USGS measured phosphorus and nitrogen in stormwater from residential areas in Madison, Wis.

Great Lakes Restoration Initiative edge-of-field monitoring focuses on identifying and reducing agricultural sources of excess nutrients which threaten the health of the Great Lakes. The USGS supports these efforts by utilizing edge-of-field monitoring to assess the quantity and quality of agricultural runoff and evaluate conservation practices that aim to reduce sediment and nutrient loss.

The U.S. Geological Survey, in partnership with the National Park Service began a project in 2012 exploring levels of the algal toxins in surface drinking water and recreational waters in 3 National Park Service Parks: Sleeping Bear Dunes National Lakeshore, Isle Royale National Park, and Pictured Rocks National Lakeshore.

Permeable pavement is a porous urban surface which catches precipitation and surface runoff, storing it in the reservoir while slowly allowing it to infiltrate into the soil below. This study will evaluate how well different types of permeable pavement reduces the amount of pollutants and runoff volume.