In a tobacco reuse plant, the batch production of tobacco leaves resulted in a heavy pollutant load that clogged the site’s wastewater treatment plant, causing an overflow of inadequately treated effluent into the Sarthe River. Notified by local health and social services, the inspection authorities for classified facilities observed the presence of large quantities of suspended solids, in flocculant form, at the river surface (at the time in a low water period). Traces of pollution were visible over 2 km of riverbank. The operator reduced plant activity, commissioned a specialist to pump the sludge that was saturating the plant and channelled wastewater treatment plant discharge to a retention basin. The interruption of plant discharge for 10 hours allowed for natural purification of the watercourse. The inspectorate recorded its findings. The local authority issued a warning for the operator to comply with discharge values listed in the Prefectural order.