This report highlights important environmental justice and climate work at sites as well as our achievements protecting human health, engaging communities, revitalizing cleaned up sites and innovating through science and technology.

Groundwater modelers should be familiar with and have access to systematic methods for translating physical subsurface geology into a numerical representation. Other hydrogeologists will benefit from understanding the process. This book introduces techniques for creating the underlying geologic framework of groundwater flow models. It is arranged around a hypothetical site with contaminated groundwater, beginning with a discussion of data collection and geologic interpretation, then delves into the steps required to build a realistic numerical model. The reader will find that many of the methods and calculations can be applied with tools as simple as paper and pencil. Links to publicly available computing resources are provided where possible.

EPA is issuing an Advance Notice of Proposed Rulemaking (ANPRM) asking the public for input regarding potential future designations of per- and polyfluoroalkyl substances (PFAS) under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).

Chlorinated solvents have been used for a variety of commercial and industrial purposes, such as degreasers, drycleaning solutions, paint thinners, herbicides, pesticides, resins, glues, and a host of other mixing and thinning solutions.

PAHs are formed by the incomplete combustion of coal, oil, gasoline, garbage, residential wood burning, and other organic materials. They are are one of the most common contaminants of concern (COC) addressed at Superfund sites, particularly in soil.

CCA is a pesticide that has been used as a preservative in pressure-treated wood since the 1940s. Manufacturers have voluntarily discontinued its use in pressure-treated wood for residential use. CCA is still used in products such as utility poles, pilings, docks, and retaining structures.