Water: Lead & Copper Rule
Summary of lead action level exceedances for medium (3,300-50,000) and large (>50,000) public water systems
The Lead and Copper Rule (LCR) requires that systems conduct monitoring of lead from customer taps - generally every six months, annually, or triennially, depending on the levels of lead observed in drinking water (i.e., less frequent monitoring if levels are low). In some cases, small systems can monitor every nine years. If 10% of the homes that are tested have lead levels greater than the action level (AL) of 15 ppb, the system must increase monitoring, undertake additional efforts to control corrosion and inform the public. For each monitoring period, a system (or the state) must calculate the lead level at the 90th percentile of homes monitored. For example, if a system monitors 100 homes, it sorts its results from the lowest to the highest concentration and reports the concentration it observed in the 90th sample. It is important to note that exceeding the action level, in and of itself, is not a violation of the regulation. A utility is assessed a violation when it fails to carry out the actions required by the regulations when the action level is exceeded.
The Safe Drinking Water Information System/Federal Version (SDWIS/FED) holds information that water systems are required to submit to states. Since 2002, states have been required to report to EPA the 90th percentile lead concentrations reported by water systems serving more than 3,300 regardless of whether the system is over the action level (note: states could report since 2000).
A report that follows below summarizes findings for systems that (1) serve more than 50,000, and (2) serve from 3,300 to 50,000 people for data in SDWIS/FED as of June 1, 2004. We have also provided a table that shows up to date information from SDWIS/FED as of the end of January 2005. The data show that about 96% of the utilities that monitored and reported 90th percentile results are below the action level. There does not appear to be a widespread problem with elevated lead levels across the country comparable to that currently being observed in the District of Columbia. EPA will provide updates to this data periodically.
The summary report and spreadsheets below provide information on individual utilities, based on data they provide to states. In addition to reporting data on the results of lead monitoring to states, utilities must also include the results of tap monitoring in the annual water quality reports they provide to customers. Customers should read this annual report to find out more about lead levels in their drinking water and how their utility is working to reduce lead levels in drinking water, and contact them if they have any questions.
January 2005 data showing medium and large water systems exceeding the Action Level since January 2003
90th Percent Lead Level Information for Water Systems Serving More Than 3,300 People - (Updated as of June 1, 2004)
- Full Summary (PDF 32 pp, 739 K, about PDF)
June 28, 2004 - revised version posted that includes Table 6 (missing from initial version)
- All Sample Data (MS Excel 6 MB)
- California Data (MS Excel 471 K)
- Maximum Sample per Public Water System (PWS) (MS Excel 1.5 MB)