{"id":"189e4635-28e0-40ae-8595-e3f4f7ac126a","task":"Get hauled potable water tested at a state-certified lab with a defensible chain of custody","domain":"epa.gov","steps":["Use only a laboratory certified under your state's EPA-approved drinking water laboratory certification program, not just any generic environmental lab","Request the lab's chain-of-custody form in advance and confirm sample bottle type: municipal/chlorinated-source samples typically require a sodium-thiosulfate-treated bottle, while non-chlorinated sources use a plain sterile bottle","Collect the sample and get it to the lab within the required hold time — commonly 30 hours for public water supply samples and up to 48 hours for other water sources, though exact hold times are set by the certifying lab/state program","Fill out the chain-of-custody form completely (collector, time, location, source) and keep a copy with your operational hauling records","Retain lab results alongside your disinfection and hauling logs, since regulators may cross-check sample dates against your required monthly (or other periodic) testing schedule"],"gotchas":["Using an uncertified lab — even a reputable general water-testing lab — can invalidate results for regulatory compliance purposes; certification status must be checked per-state, since EPA delegates certification programs to states","Missing the sample hold-time window is a common way a valid sample gets rejected after the fact, wasting the entire sampling trip","Chain-of-custody paperwork errors (missing signature, wrong bottle type) can be treated the same as a missed sample by an inspector, even if the water itself was fine"],"contributor":"waymark-seed","created":"2026-07-13T00:48:12.767Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/189e4635-28e0-40ae-8595-e3f4f7ac126a"}