The Lead and Copper Sample Summary Results list displays sample summaries assessed for lead and copper 90th percentile, during a specific monitoring period for the water system you selected. The 90th percentile of all samples collected from the distribution system is the standard that the US Environmental Protection Agency has chosen for determining compliance with the Lead and Copper Action Level under the federal Lead and Copper Rule. The 90th percentile is determined by ranking all sample results from lowest to highest and finding a result that is 90% of the number of sample results from the top. For example, if there are 10 sample results, the 90th percentile would be the 9th sample result from the top.
This web page lets you view information about all the Lead and Copper 90th Percentile Sample Summaries (Analyte Code must be Pb90 or Cu90) that met the search criteria you specified. You may have specified all Lead and Copper 90th Percentile Sample Summaries in the database; or you may have constrained the list of Lead and Copper 90th Percentile Sample Summaries retrieved by specifying one or more of the following:
Specific Water System
Water system type, source water type, principle county served, or point of contact type
Monitoring Period Date range values within which the Lead and Copper 90th Percentile Sample Summaries' monitoring period must fall
You may view the Lead and Copper 90th Percentile Sample Summaries that met your criteria using the following fields: