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Drinking Water Treatability Database (TDB)

The Drinking Water Treatability Database (TDB) presents referenced information on the control of contaminants in drinking water for use by 

  • drinking water utilities,
  • first responders to spills or emergencies,
  • treatment process designers,
  • research organizations, and
  • academicians.

The TBD provides referenced information gathered from thousands of literature sources assembled on one site. The literature includes bench-, pilot-, and full-scale studies of surface water, groundwater and laboratory water. The literature comes from peer-reviewed journals and conferences, other conferences and symposia, research reports, theses, and dissertations.

The TDB includes over 60 regulated and unregulated contaminants and their properties. Contaminants include those

  • regulated in drinking water,
  • on the Contaminant Candidate List (CCL),
  • of water security interest,
  • of pesticide registration interest, and
  • endocrine disruptors and pharmaceuticals.

An overview tab includes a contaminant's importance, regulation, presence on the CCL, pesticide registration, etc. For each contaminant, a property tab includes parameters such as solubility, vapor pressure and Henry's Law constant. Microbial properties include parameters such as taxonomy, size and shape. For each contaminant, a fate and transport tab presents parameters such as volatilization half-life and biodegradation half-life that may be useful in assessing the contaminant's presence in source waters.

The Find a Contaminant page leads to the TDB's current contaminants. However, because control strategies for disinfection byproducts (DBPs) are different from contaminants present in source waters and entering into a water treatment plant, DBPs are not included in the TDB.

The TDB includes more than 25 treatment processes used by drinking water utilities. An Overview Page describes each treatment process. It notes key process parameters such as coagulant dose, oxidant dose, filter loading rate, filter depth and contact time, and key water quality parameters such as pH, temperature, turbidity and alkalinity, upon which the treatment process effectiveness depends. The Find a Treatment Process page leads to these processes. The database can do the following:

  • Identify effective drinking water treatment processes
  • Plan for future treatment plant upgrades
  • Provide information to first responders to spills or emergencies
  • Recognize research needs
  • Complement literature reviews and literature searches
  • Assist regulators in Best Available Technology and CCL decisions

Costs are not presented. However, the Data pages indicate if a reference contains cost information. The Data pages also indicate if a reference describes or cites the analytic method used to measure the contaminant.

Navigating the TDB

Find a Contaminant.  This page retrieves information on the following:

  • A particular contaminant
  • Any treatment processes that have been tested for a particular contaminant
  • The properties of that contaminant
  • Fate and transport information. 

On the page, there are multiple search options for finding a particular contaminant:

  • Search box – Enter a contaminant name, CAS number, any synonyms, and the contaminant type (microbial, radiological, or chemical). Clicking on the search button displays relevant results. If there are no results after performing a search, an error message displays.
  • Rolodex search – Clicking on the first letter of a contaminant's name displays contaminants displays contaminants whose names begin with that letter. A second rolodex appears that allows sorting by contaminant type.
  • Manual Search – Search through the matrix to find a contaminant. The matrix shows the contaminants' name, CAS numbers, any synonyms, and types (microbial, radiological, or chemical).

When the page loads initially, all contaminants display in the results matrix. The results list alphabetically by contaminant name. After selecting a contaminant, the contaminant's overview page with the following five tabs display:

  1. Overview – This tab contains a text description of information on the selected contaminant. The CAS number, synonyms, and contaminant type appear above the overview of the contaminant. Any contaminant images display along the right side of the page with the appropriate captions. View the reference information at the bottom of the page in citation format.
  2. Treatment Processes – The treatment processes display in alphabetical order and provide a short description of the Contaminant and Treatment Process. To access the information about the Contaminant / Treatment Process, click the hyperlinked name. A text description outlining useful information about the Treatment Processes as they relate to the contaminant may appear above the list of treatment processes.
  3. Properties – This tab displays a list of parameters that provide details about the contaminant. Columns are sortable by clicking on the column headers. To restore the list to the default sort order, click the "Restore Default Sort Order" link above the table. Exporting information from the table into a spreadsheet file allows for further manipulation. Click the "Export to Spreadsheet" link.  To review the reference information, click on the reference number hyperlink in the reference column.
  4. Fate and Transport – This tab displays a list of parameters that provide details about the contaminant. Columns are sortable by clicking on the column headers.  To restore the list to the default sort order simply click the "Restore Default Sort Order" link above the table. Exporting information from the table into a spreadsheet file allows for further manipulation. Click the "Export to Spreadsheet" link. To review the reference information click on the reference number hyperlink in the reference column.
  5. References – This tab lists reference information for the selected contaminant. Columns are sortable by clicking on the column header. This tab provides the most comprehensive group of reference information on a particular contaminant within the TDB. Exporting information from the table into a spreadsheet file allows for further manipulation. Click the "Export to Spreadsheet" link. 

Find a Treatment ProcessThe Find a Treatment Process tab allows a manual search for a particular treatment process. The treatment processes are listed alphabetically. To get details about a treatment process, select the treatment process name.  Upon selection, the following tabs display:

  1. Overview – This tab provides a text description of information on the treatment process. Any treatment process images display along the right side of the page with the appropriate caption. View the reference information at the bottom of the page in citation format.
  2. Contaminants – This tab allows a search ;for particular contaminants tested against selected treatment process. Selecting a contaminant displays the Contaminant / Treatment Process Summary page. If there are fewer than 20 contaminants related to the treatment process, the search functionality is hidden. If over 20 contaminants, see Find a Contaminant instructions.
  3. References – This tab provide a list of reference information for the selected treatment process. The columns are sortable by clicking on the column headers. Exporting information from the table into a spreadsheet file allows for further manipulation. Click the "Export to Spreadsheet" link.

The Contaminant / Treatment Process Summary. The page provides an overview of the effectiveness of the combination. Any images display along the right side of the page with the appropriate caption. The names of the contaminant and treatment process are active links back to the contaminant overview page or the treatment process overview page. View reference information at the bottom of the page in citation format. Upon selection, the following tabs display:

  1. Overview – This tab provides an overview of information about the selected contaminant and treatment process combination. The page provides an overview of the effectiveness of the combination. Any images display along the right side of the page with the appropriate caption. The names of the contaminant and treatment process are active links back to the contaminant overview page or the treatment process overview page. View reference information associated to the page at the bottom of the page in citation format.>
  2. Data - This tab displays information for the selected contaminant and treatment process combination. Columns are sortable by clicking on the column headers. Exporting information from the table into a spreadsheet file allows for further manipulation. Click the "Export to Spreadsheet" link. Click on a cell describing a concurrent process. It links to the Data Page for the same contaminant and concurrent process. To review the reference information click on the reference number hyperlink in the reference column.
  3. References - The references tab provides a list of reference information for the selected contaminant / treatment process. The columns are sortable by clicking on the column headers. Exporting information from the table into a spreadsheet file allows for further manipulation. Click the "Export to Spreadsheet" link.

Future Upgrades to the Drinking Water Treatability Database

Each year, as resources allow, the number of contaminants in the TDB will increase to include other regulated and unregulated drinking water contaminants. EPA will also upgrade information on contaminants already in the TDB to keep it current. The bottom of each page shows when additions and upgrades were made to the TDB. Each contaminant Overview page indicates the most recent literature search date for the contaminant.

Technical Contact

We appreciate your feedback in designing upgrades to the TDB. Please let us know what you like and dislike; what you'd like to see added; which contaminants you'd like to see added; and what parts of the TDB you find useful or not useful.

  • Email: tdb@epa.gov
  • Phone: Karen Kleier Schrantz, 513-569-7288
  • Mail:
    Karen Kleier Schrantz
    USEPA
    26 West Martin Luther King Drive
    Mail Code: 681
    Cincinnati, OH 45268