Lake Pontchartrain Basin:  Bottom Sediments and Related Environmental Resources

Appendix D
Sediment Database


This appendix provides the full sediment data in eight linkable tables in three formats (see appendix A for list of tables). The Microsoft® Access format presents the eight tables under a single database (pont_db.mdb). In Microsoft® Excel (spreadsheet) format the eight tables are available as tabbed sheets within "pont_db.xls". The tab-delimited version is presented as eight text files in a single directory, sed_data/db_txt. A ninth table has been added in each format for reference use only and lists the Chemical Abstracts Service (CAS) Registry numbers. Users with the appropriate software may click on the linked file names below and open the data directly into the application. 

The spreadsheet version is convenient for data analysis and graphical display. The database version is suited for complex data manipulation and querying, transfer to other formats, and creation of special interpretive tables. The tab-delimited version permits transfer of the data to any desired software.

Quality Control and Methodology Differences

The data tables contain information from many sources and alternative methodologies that are not always directly comparable. Also, unresolvable problems or uncertainties were found within some data sets. Results of quality screening are abbreviated in the "Q" fields (qualifier fields) next to each concentration field, and important notes about methods and sample types are given in other fields. A " W" preceding other notes in the quality-control field signifies unresolved problems suggesting that the data be checked before use. "0" in a concentration field means that the constituent was below detection limit for the method utilized. Commonly occurring annotations are shown as abbreviations or others may be described in text. Users are responsible for selection of data for their specific purposes. Definitions of screening codes and additional data quality notes are provided in appendix B or can be downloaded as a Microsoft® Word document below.

Note that all data are given as presented in raw form by original sources.

Downloadable Data

As discussed in the database structure section, this database is not normalized. Qualifier and descriptive fields are in the same tables with analytical data fields, rather than placing them in separate tables. This is partly designed to avoid the separation of critical background information and quality designations from analytical data. Redundancy is permitted where this offers a template to permit data entry in original format. For example, both state plane coordinate and latitude/longitude fields are provided. Preserving data in original form and units is a critical element of this database and minimizes the need for secondary users to refer to obscure original sources.

1. The Access databases were created in version 8.0 (Access 97) and must be imported if used with lower versions.
2. The Excel files can be opened with version 5.0 or higher.
3. Windows users may download the WinZip utility from,  and Macintosh users may download StuffIt Expander from for use in restoring the compressed .zip files.


Appendix Index
A. Data Dictionary
B. Quality Control Notes
C. Consolidated Data Table
D. Sediment Database
Chapter J Contents
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