About the TDB

The Drinking Water Treatability Database (TDB) has many components, described below, that will allow you to locate information on the control of contaminants of interest.

Who is the TDB of Use to?

The TDB can help drinking water utilities, water treatment process design engineers, researcher organizations, federal and state regulators, professional organizations, environmental groups, and academicians. It can be used to identify effective drinking water treatment processes, to plan for future treatment plant upgrades, to provide information to first responders to spills or emergencies, to recognize research needs, to complement literature reviews and literature searches, and to assist regulators in Best Available Technology and Contaminant Candidate List (CCL) decisions.

Which Contaminants Will You Find in the TDB?

Contaminants include those regulated in drinking water, on the CCL, of water security interest, of pesticide registration interest, and endocrine disruptors and pharmaceuticals. Over time, the number of contaminants will expand to over 200, including all those regulated in drinking water. Because control strategies for disinfection byproducts (DBPs) are different than contaminants present in source waters and entering into a water treatment plant, DBPs are not included in the TDB. Overview Pages will describe each contaminant's importance, regulation, presence on the CCL, pesticide registration, etc. For each contaminant, a Property Page will be presented. Chemical properties will include parameters such as solubility, vapor pressure and Henry's Law constant. Microbial properties will include parameters such as taxonomy, size and shape. For each contaminant, a Fate and Transport Page will present 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 will lead you to the TDB's current contaminants.

Which Drinking Water Treatment Processes Will You Find in the TDB?

The number of drinking water treatment processes in the TDB is extensive and includes those most commonly employed and those less commonly employed but known to be effective. An Overview Page will describe each treatment process. It will note 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 will lead you to these processes.

What Kind of Information Does the TDB Contain?

Upon entering the database and selecting a contaminant, you will be taken to the contaminant's Overview page, and find options for a Treatment Processes page, a Properties page, a Fate and Transport page and a References page. On the Treatment Processes page you will find a summary of the effectiveness of the various processes for control of the contaminant. After matching a contaminant and a treatment process, you will be taken to a Summary page for that combination of contaminant and treatment process, and find options for a Data page and a References page. The Summary page will describe the effectiveness of the selected treatment process for control of the contaminant.

The Data pages are the heart of the TDB. The Data pages will present rows of data representing individual references and columns of data representing process effectiveness and key process parameters and water quality parameters. You will find data like reference number, percent removal, log removal, contaminant influent concentration, source water type, pH, temperature, adsorbent type, loading rate, coagulant dose, oxidant dose, CT, and membrane type. One reference may only produce one row of data. If several studies or conditions were reported, other references may produce numerous rows of data. Concurrent processes will be linked. If, for example, powdered activated carbon (PAC) was applied during coagulant mixing, the effectiveness of adsorption and coagulation must be differentiated, and you may link back and forth between the conventional treatment and PAC Data pages

How Can You Get Help Navigating Through the TDB?

On the site navigation menu you will see the Help option, which will lead you through the TDB's functionality. This menu option will display a drop down menu when clicked. This drop down menu contains options for every tdb page.

What Kinds of References Were Used to Populate Data in the TDB?

References include many types of publications, including peer-reviewed journals, peer-reviewed conference and symposia proceedings, peer-reviewed research reports, peer-reviewed books, other conferences, symposia, research reports and books, theses and dissertations, handbooks, web pages, and trade publications. On the Data pages, references are coded to indicate these types of publications. Each reference in the TDB has a unique number. On the References pages, each reference is sufficiently cited that you can locate the original source. On the References pages, the contaminant and the treatment process within each reference are noted.

What Types of Studies are Represented?

References represent drinking water treatment studies conducted at the bench, pilot, or full-scale for laboratory waters and for surface waters and ground waters.

Are Treatment Costs Presented?

Costs are not presented. However, the Data pages indicate if a reference contains cost information.

Are Analytic Methods Described for the Contaminants?

The Data pages indicate if a reference describes or cites the analytic method used to measure the contaminant.

How Can You Contact Us With Your Comments and Critiques?

The Contact Us site navigation menu option will allow you to tell us what you like and dislike, what you'd like to see added, which contaminants you'd like to see added, what parts of the TDB you find useful, and what parts you don't find useful. We want your feedback in designing upgrades to the TDB.