Skip to main content
U.S. flag

An official website of the United States government

Maryland-Delaware-D.C. Water Science Center

Welcome to the USGS Water Science Center serving Maryland, Delaware, and Washington, D.C. We operate streamgages, observation wells, and monitoring stations that provide the reliable scientific information needed to understand our natural world.

News

Spring 2025 Newsletter - In The Flow

Spring 2025 Newsletter - In The Flow

Fall 2024 Newsletter - In The Flow

Fall 2024 Newsletter - In The Flow

Spring 2024 Newsletter - In The Flow - Maryland-Delaware-DC Water Science Center

Spring 2024 Newsletter - In The Flow - Maryland-Delaware-DC Water Science Center

Publications

Predictive modeling reveals elevated conductivity relative to background levels in freshwater tributaries within the Chesapeake Bay watershed, USA

Elevated conductivity (i.e., specific conductance or SC) causes osmotic stress in freshwater aquatic organisms and may increase the toxicity of some contaminants. Indices of benthic macroinvertebrate integrity have declined in urban areas across the Chesapeake Bay watershed (CBW), and more information is needed about whether these declines may be due to elevated conductivity. A...
Authors
R. Fanelli, Joel Moore, Charles C. Stillwell, Andrew Sekellick, Richard Walker

Seasonally varying contributions of contemporaneous and lagged sources of instream total nitrogen and phosphorus load across the Illinois River basin

Quantifying nutrient sources in streams, their temporal and spatial variability, and drivers of that variability can support effective water resources management. Yet a lack of data and modeling capabilities has previously prevented comprehensive quantification across both space and time. Here a dynamic SPARROW (Spatially Referenced Regressions on Watershed attributes) model that...
Authors
Noah Schmadel, Olivia L. Miller, Scott Ator, Matthew P. Miller, Gregory E. Schwarz, Dale M. Robertson, Andrew Sekellick, Kenneth Skinner, David A. Saad

A spatial machine learning model developed from noisy data requires multiscale performance evaluation: Predicting depth to bedrock in the Delaware River Basin, USA

Spatial machine learning models can be developed from observations with substantial unexplainable variability, sometimes called ‘noise’. Traditional point-scale metrics (e.g., R2) alone can be misleading when evaluating these models. We present a multi-scale performance evaluation (MPE) using two additional scales (distributional and geostatistical). We apply the MPE framework to...
Authors
Phillip J. Goodling, Kenneth Belitz, Paul Stackelberg, Brandon Fleming

Science

Decoding Harmful Algal Blooms: Unraveling the Mystery

Harmful algal blooms (HABs) are a significant environmental concern due to their potential effects on health, ecosystems, and economies. Algal toxins, which are toxic compounds produced by certain species of cyanobacteria and algae, are commonly linked to these blooms. It's important to note that algal toxins can still be present even when a bloom is not visible, highlighting the need for ongoing...
link

Decoding Harmful Algal Blooms: Unraveling the Mystery

Harmful algal blooms (HABs) are a significant environmental concern due to their potential effects on health, ecosystems, and economies. Algal toxins, which are toxic compounds produced by certain species of cyanobacteria and algae, are commonly linked to these blooms. It's important to note that algal toxins can still be present even when a bloom is not visible, highlighting the need for ongoing...
Learn More

Natural Solutions for Reducing PFOS Pollution in Our Environment

Per- and polyfluoroalkyl substances (PFAS) are a group of over 14,000 different man-made compounds that are widely used in various industrial and consumer products and linked to various health issues. Perfluorooctanesulfonic acid (PFOS) is a persistent synthetic chemical within the PFAS group, recognized for its widespread use and persistence in the environment. The U.S. Geological Survey is...
link

Natural Solutions for Reducing PFOS Pollution in Our Environment

Per- and polyfluoroalkyl substances (PFAS) are a group of over 14,000 different man-made compounds that are widely used in various industrial and consumer products and linked to various health issues. Perfluorooctanesulfonic acid (PFOS) is a persistent synthetic chemical within the PFAS group, recognized for its widespread use and persistence in the environment. The U.S. Geological Survey is...
Learn More

Per- and Polyfluoroalkyl Substance (PFAS) Core Technology Team

The Per- and Polyfluoroalkyl Substance (PFAS) Core Technology Team (CTT) within the Environmental Health Program partners with external and internal stakeholders to develop and apply analytical methods for measuring PFAS in complex matrices, addressing environmental health issues related to transport, distribution, fate, effects, and exposure.
link

Per- and Polyfluoroalkyl Substance (PFAS) Core Technology Team

The Per- and Polyfluoroalkyl Substance (PFAS) Core Technology Team (CTT) within the Environmental Health Program partners with external and internal stakeholders to develop and apply analytical methods for measuring PFAS in complex matrices, addressing environmental health issues related to transport, distribution, fate, effects, and exposure.
Learn More
Was this page helpful?