Errata 3Ts for Reducing Lead in Drinking Water in Schools: Revised Technical Guidance TIP: Some schools may opt to clean the aerators prior to collecting initial first draw samples. However, EPA recommends that the collection of first draw samples without aerators should only be permissible if the outlet does not normally have an aerator, or if your school has a documented routine maintenance program for removing, cleaning, and replacing aerators on drinking water outlets. If your school does not have an aerator maintenance program in place, removing, cleaning, and replacing the aerators prior to sampling for diagnostic purposes will provide sampling results that cannot be assured to represent the water that the children and staff are routinely drinking from the outlet. This text was inserted into section 4.4.1 of the guidance. Eliminating Particulate Lead as a Source of Lead in Drinking Water Alternative Step 2: If initial first draw sampling results reveal concentrations higher than 20 ppb in the 250 ml sample for a given outlet, a contributing source of the elevated lead levels could be the debris in the aerator or screen of the outlet. By cleaning the aerator or screen and retesting the water following the initial first draw sampling procedures you can identify whether or not the debris is a contributing source to elevated lead levels in your facility. Determining aerator/screen debris contribution: Scenario 1: Your initial first draw sampling result was higher than 20 ppb, you decide to see if the aerator is a contributing source of lead in the water. After cleaning out your aerator you take another first draw sample.* The results come back less than or close to 5 ppb or the detection level. This result tells you that the debris in the aerator was contributing to elevated levels in your school. Continue to clean out the aerator on a regular basis and this outlet is O.K. to use. However, please note that without regular maintenance this tap may serve water with elevated lead levels. Scenario 2: Your initial first draw sampling result is 25 ppb, you decide to see if the aerator is a contributing source of lead in the water. After cleaning out your aerator you take another first draw sample.* The second sample result is very close or equivalent to the 25 ppb sample. Since your initial first draw sample and alternative second first draw sample results are similar, the problem is upstream from the aerator. Continue to follow the sampling protocol and do your follow-up flush sampling. Scenario 3: Your initial first draw sampling result is 60 ppb, you decide to see if the aerator is a contributing source of lead in the water. After cleaning out your aerator you take another first draw sample.* The second sample result is 25 ppb. While your results are lower, but still above 20 ppb, this tells you that the aerator or screen is a contributing source and that the plumbing upstream of the aerator is contributing as well. If this situation occurs, you should continue with follow-up flush sampling to target the additional contributing sources. * When taking your second first draw sample, please remember to follow the same sampling procedure as your initial first draw sample. This text was inserted into section 4.4.2 of the guidance. Please note that this Errata accompanies the December 2005 version of the 3Ts for Reducing Lead in Drinking Water in Schools: Revised Guidance Document. ------- Exhibit 4.2: Sample Strategy Flowchart Collect and analyze morning initial first draw samples from outlets (initial round) and initial Hush samples from service connections / Outlet O.K. to use. The debris in the aerator was %> / likely contributing to the elevated lead levels. Clean out the aerators ^ on a regular basis to help minimize reoccurring contamination from \. lead particles. / Is the *'\ ./ lead level xx in the initialllrst draw'\ sample at or /•' "~\ below 20 <'' Collect and | analyze follow-up ! flush samples j (interior plumbing) ,,/ Is lead level in \ tbllow-up flush samples X. less ihan 20 pph? ,<'' NO NO YES ' Does the outlet x. have an aerator or / "\. screen? / NO YES I Outlet O.K.. to use ; ! Clean the debris and collect i another first draw sample. NO /' Is the lead level in the sample at or below \ 20ppb? YES NO ^/Are lead levels xx -'' in interior plumbing '... follow-up flush samples.--- x close to 5ppb? YES ; *f The outlet is a source of lead ,-'Are lead levels inX ,.interior plumbing lbllow-uf>^ flush samples greater than or equal to lead levels ^ ^ observed in _/' x. initial sample? / NO Select remedy. jYES The interior plumbing is the source of lead. Are lead „-' Levels in service \ connection flush sample(s) greater than or equal to lead levels observed in interior vpiuinbing follow-up fluslv* samples? f' The service connection is a source of lead. NO The interior plumbing and outlet are sources of lead. /Are lead'X, .> levels in service'-. ^/ connection flush \ \ samples close to /' 5ppb? v NO The interior plumbing and service connection arc sources of lead. YES I The interior plumbing is j ! a source of lead. j This is an updated version of exhibit 4.2 from the original document. ------- |