On this page:

• Mapping Tools
• Water Quality Data
• Modeling Resources
• Contaminant Locations and Quantities
• Contaminant Properties and Toxicity

Learn more about source water assessments.

Mapping Tools

EPA Tools

• Drinking Water Mapping Application to Protect Source Waters (DWMAPS) - DWMAPS is an online mapping tool that helps state and utility drinking water professionals in concert with other state and local mapping tools to update their source water assessments and protection plans.
  • DWMAPS Data Layers - Access and download datasets displayed in DWMAPS.
• Cleanups in My Community - Cleanups in My Community enables users to map and list hazardous waste cleanup locations and grant areas, and drill down to details about those cleanups and grants and other, related information.
• EnviroAtlas - EnviroAtlas provides geospatial data, easy-to-use tools, and other resources related to ecosystem services, their stressors, and human health.
• Envirofacts - Envirofacts is a single point of access to several EPA databases, providing users with information about environmental activities that may affect air, water, and land in the United States.
• Enviromental Justice Screening and Mapping Tool (EJSCREEN) - EJSCREEN is an environmental justice (EJ) mapping and screening tool based on nationally consistent data and an approach that combines environmental and demographic indicators in maps and reports.
• Enforcement and Compliance History Online (ECHO) - ECHO searches for facilities at the community level to assess their compliance with environmental regulations.
• WATER GeoViewer - WATERS GeoViewer provides access to a stream network search for water information as well as watershed delineation and associated landscape attributes.

Other Tools

• Forest to Faucets - The U.S. Department of Agriculture (USDA) Forest Service Forests to Faucets project uses GIS to model and map the continental United States land areas most important to surface drinking water, the role forests play in protecting these areas, and the extent to which these forests are threatened by development, insects and disease, and wildland fire.
• National Pipeline Mapping System (NPMS) - NPMS is a dataset containing locations of and information about gas transmission and hazardous liquid pipelines and Liquefied Natural Gas (LNG) plants which are under the jurisdiction of the Pipeline and Hazardous Materials Safety Administration (PHMSA). NPMS also contain voluntarily submitted breakout tank data. The data is used by PHMSA for emergency response, pipeline inspections, regulatory management and compliance, and analysis purposes. This site provides access to a public viewer and the Pipeline Information Management Mapping Application (PIMMA), which is exclusively available to pipeline operators and federal, state, and local government officials granted access by PHMSA.
• WikiWatershed - This mapping toolkit, developed by the Stroud Research Center, provides a suite of mapping applications, including Model My Watershed and Monitor My Watershed. Model My Watershed lets users analyze geospatial data, model storms, and compare conservation and development scenarios in a watershed, while Monitor My Watershed maps and compares water monitoring data from multiple sources.

Water Quality Data

EPA Data

• How's My Waterway - How's My Waterway provides information about the conditions of local stream, lakes, and other waters used for recreation, swimming, fishing, and sources of drinking water anywhere in the United States, based on public information and data that states provide EPA on a two-year cycle.
• National Aquatic Resource Surveys (NARS) - NARS are a collaborative program between EPA, states, and tribes designed to assess the quality of the nation’s coastal waters, lakes and reservoirs, rivers and streams, and wetlands using statistical survey design. The NARS provide critical, groundbreaking, and nationally-consistent data on the nation's waters.
• STORET Water Quality Data (WQX) - The STORET (short for STOrage and RETrieval) Data Warehouse is a repository for water quality, biological, and physical data and is used by state environmental agencies, EPA and other federal agencies, universities, private citizens, and others.
• Water Quality Reporting Database (ATTAINS) - This database displays the most current available information provided by the states in their biennial integrated water quality assessment reports prepared under sections 305(b) and 303(d) of the Clean Water Act.
• Watershed Assessment, Tracking & Environmental Results (WATERS) - WATERS is an EPA integrated information system for the nation's surface waters. This framework allows users to access data regarding water quality, permitting, safe drinking water, and nonpoint source pollution.
• Healthy Watersheds Protection - The Healthy Watersheds program website provides tools, datasets, and guidance for assessing, protecting, and restoring watersheds, including the 2017 Preliminary Healthy Watersheds Assessments, the Recovery Potential Screening Tool, and the Watershed Index Online.

Other Federal Data

• National Water Information Center (NWIS) - NWIS provides access to U.S. Geological Survey (USGS) water-resources data collected at approximately 1.5 million sites in all 50 States, the District of Columbia, and Puerto Rico.
• National Water Quality Assessment (NAWQA) Program - NAWQA is a USGS database that helps users answer three questions: What is the condition of the Nation's streams, rivers, and ground water? How are these conditions changing over time? And how do natural features and human activities affect these conditions, and where are those effects most pronounced?
• National Wetlands Inventory Center (NWI) - NWI of the U.S. Fish and Wildlife Service produces information on the characteristics, extent, and status of the nation's wetlands and deep-water habitats. This database is used by federal, state, and local agencies, academic institutions, the U.S. Congress, and the private sector.
• Water Use Data - The USGS Water Resources Mission Area provides water information that is fundamental to national and local economic well-being, protection of life and property, and effective management of the Nation’s water resources. The site offers real-time water data, a suspended sediment database, maps, and GIS data for water resources.

Modeling Resources

EPA Resources

• Ground Water Models to Assess Exposure - Ground Water Models to Assess Exposure provides access to the EPA Center for Exposure Assessment Modeling (CEAM) catalogue of simulation models and database software designed to quantify the movement and concentration of subsurface contaminants.
  • Wellhead Analytic Element Model (WhAEM) - WhAEM is a ground-water flow model designed to facilitate capture zone delineation and protection area mapping in support of the Wellhead Protection Programs (WHPP) and Source Water Assessment Planning (SWAP) for public water supplies in the United States.

  • Wellhead Protection Area (WHPA) Model - WHPA is a semi-analytical groundwater flow simulation program used for delineating capture zones in a wellhead protection area.

• Hydrologic and Water Quality System (HAWQS) - HAWQS is a web-based water quantity and quality modeling tool that employs the Soil and Water Assessment Tool (SWAT) modeling engine.

• Recovery Potential Screening (RPS) Tool - The RPS tool provides a systematic approach for comparing watersheds, their condition and how well they may respond to restoration or protection efforts.

• Surface Water Models to Assess Exposure - Surface Water Models to Assess Exposure provides access to the EPA Center for Exposure Assessment Modeling (CEAM) catalogue of simulation models and database software designed to quantify movement and concentration of contaminants in lakes, streams, estuaries, and marine environments.

Other Federal Resources

• MODFLOW - MODFLOW is USGS's modular hydrologic model. The family of MODFLOW-related programs provide users with tools to simulate and predict groundwater conditions and groundwater/surface-water interactions.

Contaminant Locations and Quantities

EPA Resources

• Discharge Monitoring Report (DMR) - Learn which Clean Water Act-regulated facilities are discharging pollutants in your watershed. This tool calculates loadings from EPA's Integrated Compliance Information System for the National Pollutant Discharge Elimination System (ICIS-NPDES).

• National Contaminants Occurrence Database (NCOD) - The NCOD site is an outlet to other databases information on regulated and unregulated contaminants occurring in public drinking water systems, including:

  • Unregulated Contaminant Monitoring Rule (UCMR) - This site provides access to occurrence data for contaminants that are suspected to be present in drinking water, but do not have health-based standards set under the Safe Drinking Water Act (SDWA). The monitoring dataset provides EPA and other interested parties with nationally representative data on the occurrence of contaminants in drinking water, the number of people potentially being exposed, and an estimate of the levels of that exposure. it provides the basis for future regulatory actions to protect public health.

  • Six-Year Review of Drinking Water Standards - This site provides access to compliance monitoring data that were collected to evaluate regulated contaminants levels in drinking water.

• Toxic Release Inventory (TRI) - This site provides access to data and tools on the management and release of certain toxic chemicals that may pose a threat to human health and the environment, including the TRI Explorer, Risk Screening Environmental Indicators (RSEI), and My Right-to-Know (myRTK) application.

Other Federal Resources

• Spatially Referenced Regression on Watershed (SPARROW) - This USGS model estimates the origin, fate, and transport of nitrogen and phosphorous in watersheds across the United States.

Contaminant Properties and Toxicity

EPA Resources

• ChemView - ChemView is a tool for searching chemical health and safety information for specific chemicals regulated under the Toxic Substances Control Act (TSCA). This site does not contain confidential business information.
• Integrated Risk Information System (IRIS) - The IRIS Program identifies and characterizes the health hazards of chemicals found in the environment, through chemical risk assessments.

• Water Contaminant Information Tool - This database provides information on over 800 drinking water and wastewater contaminants, including pathogens, pesticides, and toxic industrial chemicals. It provides information on treatment options and response guidelines. This information is sensitive and password-protected. Access is granted to drinking water and wastewater utilities, State Primacy (primary enforcement) Agencies, and federal officials, including government laboratory personnel.

Other Federal Resources

• Chemical Facility Anti-Terrorism Standards (CFATS) - CFATS is a regulatory program focused specifically on security at high-risk chemical facilities. The Cybersecurity and Infrastructure Security Agency (CISA) manages the CFATS program by working with facilities to ensure they have security measures in place to reduce the risks associated with certain hazardous chemicals and prevent them from being exploited in a terrorist attack.
• Computer-Aided Management of Emergency Operations (CAMEO) Chemicals - This National Oceanic and Atmospheric Administration (NOAA) database and suite of software applications can be used to plan for and respond to chemical emergencies. It includes a database of hazardous substances and chemical datasheets for physical properties, health hazards, and recommendations for firefighting, first aid, and spill response. Mobile and desktop applications available.

• Toxicology Data Network (TOXNET) - A National Institutes of Health (NIH) resource for searching databases on toxicology, hazardous substances, environmental health, and toxic releases. Linked databases include:

  • CHEMIDplus - A dictionary of over 400,000 chemicals with information on chemical structure, names, and synonyms and links to resources.

  • Hazardous Substances Database (HSDB) - A database that focuses on the toxicology of potentially hazardous chemicals. It provides information on human exposure, industrial hygiene, emergency handling procedures, environmental fate, regulatory requirements, nanomaterials, and related areas.

  • TOXLINE - A bibliographic database with citations from specialized journals and other sources. It provides references covering the biochemical, pharmacological, physiological, and toxicological effects of drugs and other chemicals.