Inorganic Blind Sample Project (IBSP)

Tools for Laboratory Evaluation Process for NWQL Data

Updated 04/23/2025

This page is useful for obtaining charts and data specific to NWQL performance for use in the Laboratory Evaluation Process.

External performance-assessment charts and data for the National Water Quality Laboratory inorganic and physical property analytes are available from the Inorganic Blind Sample Project for laboratory evaluations. PDFs are available for blind samples—both non-blank and blank. The links provided below will take you to PDFs containing control charts (analysis dates October 2020 through September 2024) that show performance-assessment data from double-blind samples for all analytes in the selected analytical group. A custom data pull can easily be done prior to that time if needed. For custom requests please contact the IBSP Project Chief.

If you prefer to work with the performance data directly, the data set for the performance samples—both non-blank and blank—are available via the .xlsx output links (last two links shown below). Non-blank and blank data are in one file separated into separate worksheets. The entire historical data set (back to 1985 for IBSP and 1998 for BBP) can be accessed via the last link shown.

For charts and data for different time periods than are available on this page, check out the historical charts and data sets here or contact the IBSP Project Chief. Non-blind, on-line QC data can be accessed on the NWQL's on-line QC data web-page here.

Please note: the charts and data that you might secure from this U.S. Geological Survey (USGS) web page (identified as "IBSP") have not received official USGS approval and as such are provisional and subject to revision. The charts and data are released on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from its authorized or unauthorized use.

Performance charts for non-blank, blind samples

Nutrients	Trace Elements	Major Ions, Silica, Physical Properties, Other	All Parameters

Performance charts for blind blank samples

Nutrients	Trace Elements	Major Ions, Silica, Physical Properties, Other	All Parameters

.xlsx output: File contains all parameter types and both non-blank and blind blank performance data.

Performance Data for All Parameters IBSP: FY20-24; BBP: FY20-24 (.xlsx)	Performance Data for All Parameters, Entire Dataset IBSP: 1985-2025; BBP: 1998-2025 (.xlsx)

 

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