Tolerance limits for air emissions that apply in Switzerland for the different HCH isomers.
Published on 01/07/2021
During an intensive period of re-assessment, project leaders from Novartis identified the following four areas that warranted improvement: further onboarding of Swiss and German authorities to support project resumption; communicating more effectively with the neighboring community; selecting a new remediation company; and boosting health and security measures (such as, e.g., regular air and screening analyses, new, sealed construction tents, improved air filters, etc.).
One key finding was that remediation could only be successfully continued in close cooperation with Swiss and German authorities. Although the French DREAL was the lead authority, the remediation project had the potential to also affect Switzerland and Germany, and alignment with all key stakeholders became a priority.
The team contacted the Office for Environment and Energy (Amt fuer Umwelt und Energie, AUE) of the canton of Basel-City and the Basel Air Hygiene Office (Lufthygieneamt beider Basel, LHA) as well as the Department of Environment of the District Office of Loerrach (Umwelt und Klimaschutz).
The initial joint meetings focused on understanding the different requirements of French and Swiss legislation. As part of its prefectural order of 2012, DREAL had specified emission measures for the remediation project regarding air, dust, surface water and groundwater. For example, maximum air values for HCH emissions were derived from a risk assessment (Évaluation quantitative des risques sanitaires, EQRS). To determine the values, the EQRS identified the hazard, estimated the dose-response relationship and evaluated the potential exposures.
While the remediation project had to formally comply with the limits defined in the French prefectural order, tolerance values for α-, β- and γ-HCH (150/30/300 ng/m3) were agreed with the Swiss authorities in addition to the existing French regulation. A further objective was to reduce dust emissions by approx. 90 %. DREAL accepted these tolerance values in addition to the EQRS values to ensure that communication to the public was consistent.
