After an inspection in 2004, an operator specialised in animal experimentation for marketing medicines adopted an action plan to ensure compliance relative to guidelines pertaining to the regulatory thresholds of the facility’s liquid effluent, especially for a pH below 5.5 (pH: 2.5). This effluent consisted of detergents composed of phosphoric and sulfamic acids stemming from the drainage of several washing machines installed in 1985. On 27th July, 2005, the operator informed the inspectorate of a major delay in setting up the industrial effluent neutralisation plant, caused by the replacement of a damaged pipeline. On 29th July, an inspection ordered as a result of the risk of infiltration in soils and sub-soils observed the near complete destruction of 5 m of asbestos cement pipe transporting acid effluent. On 1st September, the operator stated that another pipe deterioration was discovered following production of an exploration video for the purpose of assessing the network’s condition. All activities leading to overflows in the damaged pipes were stopped and only resumed following validation of repairs and verification of the seal. The date of these spills remained unknown. Field recordings showed pipeline deterioration and exposure to acid splattering on several underground cables. A hydrogeologist’s expert opinion, along with the initial diagnosis and simplified risk analysis, concluded the absence of any influence on the groundwater and surface water environments, rated as an ‘ordinary site’ for the zone affected by acid water infiltration. A Prefecture emergency order to stop all overflows within 48 hours and official Prefecture notification were both adopted. A complete assessment of the condition of pipes responsible for transporting industrial effluent, plus a repair schedule depending on the level of evaluated seriousness, was to be established. The compliance status with regulatory thresholds for liquid effluent needed to be achieved in conjunction with start-up of the neutralisation plant.