The drinking water samples largely reflect samples collected from residential sites , though there were two studies that measured Pb in drinking water at schools . Compliance monitoring for the LCR do not require monitoring of schools and daycare facilities unless the school manages their own drinking water system . While the U.S. EPA does not currently require testing at schools and daycare facilities , the agency does provide guidance for reducing Pb in drinking water at these sensitive sites ( U.S. EPA , 2005 and . A recent survey conducted by the U.S. Government Accountability Office ( GAO , 2018 ) found that 59 % of schools did not test , or were unsure if they tested , for Pb in tap drinking water . Of the 41 % of schools that did test for Pb in drinking water , 37 % found elevated levels . School districts varied in the threshold used for determination of elevated Pb . School districts reported using either the 15 ppb standard for compliance monitoring for public water systems , or the 20 ppb action level suggested in the 3Ts for Reducing Lead in Drinking Water in Schools ( U.S. EPA , 2006 ) guidance document for schools and daycares , while others reported using more conservative action levels than 15 ppb . The difference in the LCR and 3Ts standards is reflective of the difference in goals . The LCR standards are intended to identify system - wide problems to inform water treatment protocols , whereas the guidance for schools and daycares are intended to identify issues with specific drinking water outlets ( U.S. EPA , 2006 ) . Identifying the extent of Pb contamination at schools and daycares is essential to understanding the exposure burden for children from their total environment . Currently there is very limited data available for levels of Pb in drinking water at schools and daycares . The availability of multi - media exposure data is even more limited for these sites . In our review , we identified Pb concentration data in soil and drinking water for a limited number of school sites . Our review did not identify data sources for dust Pb loadings at U.S. schools . Considering the substantial amount of time that children spend at these alternative locations , it is imperative that there is a better understanding of potential Pb exposure at these sites to successfully reduce Pb exposure and overall BLLs for this vulnerable population .