Science & Technology

Air Quality Trends - How to Interpret the Graphs

This page provides an example graph and explains what the lines represent.

Informational Webinar on Identifying Additional Areas Subject to Mitigation Plan Requirements Under the 2016 Exceptional Events Rule

This meeting and webinar information regarding mitigation plan requirements under the 2016 exceptional events rule.

WhAEM2000 BBM Files - Sioux Falls, South Dakota

WhAEM2000 (Wellhead Analytic Element Model) binary base map browser for Sioux Falls Quadrangle, South Dakota. Files serve as geographic basis for groundwater modeling.

WhAEM2000 BBM Files - Sioux City South, Nebraska

WhAEM2000 (Wellhead Analytic Element Model) binary base map browser for Sioux City South Quadrangle, Nebraska. Files serve as geographic basis for groundwater modeling.

WhAEM2000 BBM Files - Butte North, Montana

WhAEM2000 (Wellhead Analytic Element Model) binary base map browser for Butte North Quadrangle, Montana. Files serve as geographic basis for groundwater modeling.

Forward Models

Geophysical forward or predictive models

WhAEM2000 BBM Files - Elm River, South Dakota

WhAEM2000 (Wellhead Analytic Element Model) binary base map browser for Elm River Quadrangle, South Dakota. Files serve as geographic basis for groundwater modeling.

Bioaccumulation and Aquatic System Simulator (BASS)

On Bioaccumulation and Aquatic System Simulator (BASS), a model that simulates the population and bioaccumulation dynamics of age-structured fish communities.

Water Quality Standards Regulations: New York

Information related to Water Quality Standards for New York.

Society of Toxicology (SOT) 2025 Conference

SOT 2025 Event Webpage

Arsenic Treatment Technology Demonstrations

EPA’s research for the new Arsenic Rule focused on the development and evaluation of innovative methods and cost-effective technologies for improving the assessment and control of arsenic contamination.

DOE RESL Method P-2: 32P Fish, Vegetation, Dry Ash, Ion Exchange

This method uses Cerenkov counting and liquid to determine scintillation phosphorus in soil, sediment, wipes, air filters and vegetation.

EPA Method 524.2: Measurement of Purgeable Organic Compounds in Water by Capillary Column Gas Chromatography/Mass Spectrometry

SAM lists this method for preparation and analysis of water samples to address carbon disulfide, 1,2-dichloroethane, acrylonitrile and methyl acrylonitrile, using GC-MS.

Additional Areas Subject to Mitigation Plan Requirements Under the Exceptional Events Rule

This page contains letters and documents associated with mitigation plans under the Exceptional Events Rule.

EPA Method 350.1: Determination of Ammonia Nitrogen by Semi-Automated Colorimetry

SAM lists this method for preparation and analysis of drinking water samples for ammonia, using visible spectrophotometry.

EPA Method 335.4: Determination of Total Cyanide by Semi-Automated Colorimetry

SAM lists this method for preparation and analysis of drinking water samples to determine total cyanide, using semi-automated colorimetry.

Method 200.7: Determination of Metals and Trace Elements in Water and Wastes by Inductively Coupled Plasma-Atomic Emission Spectrometry

SAM lists this method for preparation and analysis of drinking water samples for total arsenic, thallium and vanadium, using inductively coupled plasma-atomic emission spectrometry.