The WFD seeks to constantly improve the quality of inland and coastal waters by severely restricting compounds that are persistent, bioaccumulative or are ecotoxic such as dichloromethane (priority substances) or totally phasing out (by 2025) compounds like mercury (priority hazardous substances).
Environmental Quality Standards (EQS) are limits that are set for priority substances in receiving waters. Most priority substances are either metals, pesticides or fire retardants. For the pharmaceutical industry, chlorinated materials/solvents like dichloromethane, chloroform, 1,2-dichloroethane and carbon tetrachloride are probably most relevant.
Environmental Quality Standard (EQS) for dichloromethane has been set to 20μg litre-1. Any discharge contributing >1% of this level is likely to be scrutinised by the regulatory agency, hence the remediation of aqueous waste streams contaminated with dichloromethane will be difficult and costly.