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About MDCB

    Water Quality Data Elements

"Good Data Documentation for Effective Data Sharing"

The broad metadata categories which characterize all types of data—who, what, when, where, why, and how—are being used to develop a modular* WQDE approach that can be tailored to specific types of data.

Many different entities collect water quality monitoring data and many different kinds of data are collected. These data are useful to the data collectors and give us important information about drinking water quality and aquatic health.

AND, these data could be more useful to others to answer:
  • similar questions ("Do their conclusions support mine?");
  • unrelated questions for which their collection was not intended; and
  • future questions that have yet to be asked
  • Common concerns in using another's data are:

  • Are their data of similar quality as my own?
  • Were their data collected in a comparable way?
  • Were their data based on the same type of samples?
  • These concerns can be summed up as:
    "How can we tell if water quality datasets are comparable and can therefore be combined for a given use?"

    The Water Quality Data Elements (WQDEs), developed by the Methods Board and the National Water Quality Monitoring Council (NWQMC), are intended to address these concerns.

    WQDEs are lists of the minimum elements or metadata that give a data user information about the data so that they can make an informed decision as to the quality of those data, and the comparability of those data for their question or purpose. WQDEs should be readily available to other interested parties, along with the data, to facilitate information sharing and data exchange. Lists are divided into modules specific to different types of water quality monitoring analyses (e.g., chemical, microbiological, toxicological, biological).

    The proposed lists are not a set of required information. They are intended as a means to help data collectors and database managers more effectively characterize their data and thereby, promote the use of those data by others.

    Water Quality Data Element Lists


    The Modular Approach

    The modular approach allows the entire data element list to be divided into subsections (or modules) that can be developed independently as needed for different types of monitoring data (e.g., chemistry, field biological assessments). Some of the modules - contact (who), location (where), date (when), and objective (why) - are "universally" pertinent to all types of water quality monitoring data. Other modules—parameter sampled (what) and sample collection and analyses methods (how)—are often particular to the type of parameter being monitored and perhaps even the specific parameter. Click to view the draft/approval status of the various WQDE modules...

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    Last Update: September 15, 2004