Contaminated Sites Ordinance (CSO)
English is not an official language of the Swiss Confederation. This translation is provided for information purposes only and has no legal force.
Art. 7 Preliminary investigation
1 Based on the list of priorities, the authorities shall require a preliminary investigationto be carried out within a reasonable period for sites in need of investigation. This shall normally consist of a historical and a technical investigation, so that the need for monitoring and remediation can be assessed (Art. 8), and the environmental hazard evaluated (risk assessment). 2 The historical investigation shall establish the possible causes of the pollution of the site, in particular: a. the events and the temporal and spatial history of developments at the site; b. the procedures used for handling environmentally hazardous substances at the site. 3 Based on the historical investigation, a performance specification shall be prepared on the aim, extent and methods of the technical investigation. The performance specification shall be submitted to the authorities for comment. 4 The technical investigation shall establish the type and quantity of substances at the site, the likelihood o
Art. 8 Assessment of the need for monitoring and remediation
1 Based on the preliminary investigation, the authorities shall assess whether the polluted site is in need of monitoring or remediation in accordance with Articles 9–12. In doing so, they shall pay due regard to effects caused by other polluted sites or by third parties. 2 They shall state in the Register whether a polluted site is: a. in need of monitoring; b. in need of remediation (contaminated site); c. in need of neither monitoring nor remediation.
Art. 9 Protection of groundwater
1 Subject to paragraph 1bis, a polluted site is deemed to be in need of monitoring to protect the groundwater, if: a. any of the concentration values specified in Annex 1 is exceeded in the eluate of the material at the site; b. for groundwater water protection areas Au, the concentration of substances originating from the site immediately downstream of the site exceeds 10 % of one of the concentration values specified in Annex 1; c. for groundwater outside water protection areas Au, the concentration of substances originating from the site immediately downstream of the site exceeds 40 % of one of the concentration values specified in Annex 1. 1bis If after several years of monitoring a site, it is established that, considering the evolution of pollutant concentrations and the characteristics of the site, it is highly probable that the site will not need remediation under paragraph 2, the site is deemed no longer to be in need of monitoring. 2 A polluted site is deemed to be in need of
Para. 1 let. c — Amended by No I of the O of 9 May 2012, in force since 1 Aug. 2012 (AS 2012 2905). Para. 1bis — Inserted by No I of the O of 9 May 2012, in force since 1 Aug. 2012 (AS 2012 2905). Para. 2 let. a — Amended by No I of the O of 22 March 2017, in force since 1 May 2017 (AS 2017 2589). Para. 2 let. b — Amended by Annex 5 No 5 of the O on the Protection of Waters of 28 Oct. 1998, in force since 1 Jan. 1999 (AS 1998 2863). Para. 2 let. b — In accordance with Article 29 para. 1 let. A o
Art. 10 Protection of surface waters
1 Subject to paragraph 1bis, a polluted site is deemed to be in need of monitoring to protect the surface waters, if: a. any of the concentration values specified in Annex 1 is exceeded in the eluate of the material at the site which is susceptible of affecting surface waters; or b. in water that flows into surface waters, a concentration value specified in Annex 1 is exceeded for substances originating from the site. 1bis If after several years of monitoring a site, it is established that, considering the evolution of pollutant concentrations and the characteristics of the site, it is highly probable that the site will not need remediation under paragraph 2, the site is deemed no longer to be in need of monitoring. 2 For the protection of surface waters, a polluted site is deemed to be in need of remediation if: a. in water that flows into surface waters, the concentration of substances originating from the site exceeds by tenfold a concentration value specified in Annex 1; or b. it i
Para. 1 — Amended by No I of the O of 9 May 2012, in force since 1 Aug. 2012 (AS 2012 2905). Para. 1bis — Inserted by No I of the O of 9 May 2012, in force since 1 Aug. 2012 (AS 2012 2905).
Art. 11 Prevention of air pollution
1 For the protection of persons from air pollution, a polluted site is deemed to be in need of monitoring if its interstitial air exceeds a concentration value specified in Annex 2, and the emission originating from the site reaches places that may regularly be frequented by persons for longer periods. 2 For the protection of persons from air pollution, a polluted site is deemed to be in need of remediation if its interstitial air exceeds a concentration value specified in Annex 2, and the emission originating from the site reaches places that may regularly be frequented by persons for longer periods.
Art. 11 — Amended by No I of the O of 22 March 2017, in force since 1 May 2017 (AS 2017 2589).
Art. 12 Prevention of pollution of the soil
1 Soil that is a polluted site or part thereof is deemed to be in need of remediation if a substance in the soil exceeds a concentration value specified in Annex 3. The foregoing also applies to soil that is already subject to a restriction of use. 2 Soil that is not in need of remediation in accordance with paragraph 1 despite being polluted sites or parts thereof, and the impacts of polluted sites on soil are assessed in accordance with the Ordinance of 1 July 1998 on the Pollution of Soil.
Art. 12 — Amended by Annex No II 2 of the O of 26 Sept. 2008 on the Charge for the Remediation of Contaminated Sites, in force since 1 Jan. 2009 (AS 2008 4771). Para. 2 — SR 814.12
Art. 13 Action of the authorities
1 For polluted sites in need of monitoring, the authorities shall require a monitoring plan to be drawn up and suitable measures to be taken to detect a real danger of harmful effects or nuisances before these become manifest. The monitoring measures shall be applied until there is no longer any need for monitoring in accordance with Articles 9–12. 2 For sites that are in need of remediation (contaminated sites), the authorities shall require that: a. a detailed investigation be carried out within a reasonable period; b. the site be monitored until completion of remediation.
Para. 1 — Amended by No I of the O of 9 May 2012, in force since 1 Aug. 2012 (AS 2012 2905).