Data Source
The Lead in School Drinking Water (LISDW) data are test results from sampling conducted by the Washington State Department of Health (DOH) staff between January 2018-August 2025.
Rationale for Inclusion
The LISDW data can provide information about potential lead contamination and lead levels in public schools’ drinking water systems in Washington. This will allow both the public and school employees to have an in-depth view of lead contamination at their schools and school districts.
Information About the Data
The LIDSW data presented are from water sampling carried out by DOH both prior to and after the enactment of Chapter RCW 28A.210.410 RCW and Chapter 43.70.830 RCW in 2021, which made lead testing in school drinking water a requirement for schools built or all plumbing replaced before 2016, and lowered the remediation lead level to greater than 5 parts per billion (ppb) – “elevated lead level.”
- Years: 2018-2024
- Coverage: Public schools that had lead sampling and testing carried out by DOH
- Geography: State, County, School District, and Individual School
- Statistics: Total number of schools sampled, Total number of samples, Percentage of results by sampling result category, county, school, district, and fixture type
Caveats
- Please note that Chapter 28A.210.410 RCW and Chapter 43.70.830 RCW enacted in July 2021, changed the requirements for testing school drinking water for potential lead contamination. (1) Lead testing in drinking water at schools used to be voluntary and is now mandatory for all public schools in Washington built or with all plumbing replaced before 2016, to conduct initial testing between 2014 and 2026 and every five years thereafter. (2) The law reduces the remediation lead level from greater than 10 ppb to greater than 5 ppb.
- While some test results obtained before 2021 may have met the previous threshold and therefore did not require remediation at the time of sampling, those fixtures may now require remediation to meet the lower remediation threshold requirement of RCW 28A.210.410.
- The data does not contain test results from external contracted testing outside of DOH, e.g., schools who have done sampling through contractors. Please contact the school district directly for complete testing data.
Information About the Selectable Layer
On the “Lead Testing by Geography” tab, you can click on either the county, district, or school name in the school list to filter results and map to show that location or you can click a dot on the map to filter for that specific school. You can further filter by school year in the 2022-Forward testing dashboard. The dropdown menus will restrict the school list to either the specified county, district, or school for easier selection.