Remediation of Contaminated Sites

STATUS February 2023
The investigations into the extent of the contaminated site have been largely completed; the northern boundary in the area of the main parking area is still being secured by further soil sampling. Salzburg Airport is endeavoring to implement the technical remediation of the contaminated site as comprehensively and quickly as possible as a result of the entry of firefighting foam containing PFAS from the company fire department. The issue of PFAS is currently of concern throughout Europe. In Austria, the provinces of Salzburg, Upper Austria and Styria are currently affected. However, the Federal Environment Agency is carrying out far-reaching investigations throughout Austria, and experts assume that such contamination of groundwater cannot be ruled out in the other federal states either.
A hydraulic securing measure will be used as initial measure for securing the contaminated site. The ultimate goal of the Contaminated Sites Remediation Act is to permanently secure aforementioned contaminated sites. To this end, the airport is already in contact with the agency responsible for funding contaminated site remediation measures, Kommunalkredit Public Consulting GmbH (KPC). 
The annual report to KPC must include the following information on the ongoing safeguarding measures:

• Summary assessment of the regularly measured relevant pollutants as well as statements about their development.
• Summary assessment of the effectiveness of the measures on the basis of the results of the preservation of evidence with regard to the relevant pollutants and the relevant protected resource groundwater.
• Prognosis of the further development of the relevant pollutants in the object of protection as well as estimation of the future operating expenditure (duration/scope)
• Protective measure for optimizing the plant with regard to the economic operation of the plant and the scope of measures for the preservation of evidence 
• on the basis of the above mentioned points, justification of the necessity and expediency of continuing the measures

The annual report is also sent to the Umweltbundesamt GmbH (Federal Environmental Agency).

Statement on the remediation variant study by the Federal Environment Agency (UBA)
Due to the identified "PFAS extinguishing foam contaminated site" in the groundwater plume of Salzburg Airport, this site was classified as a "Priority 1 contaminated site" in accordance with the criteria for priority classification. For the remediation of this contaminated site, the GWU Geologie-Wasser-Umwelt GmbH, on behalf of the Salzburger Flughafen GmbH, submitted the remediation variant study on October 21, 2022. Based on the current state of knowledge, the best option identified, appears to be fundamentally suitable for achieving the remediation objective, provided that the measures are planned and executed appropriately and suitable control measures are implemented in addition.

Please find the statement of the Federal Environment Agency, Department of Contaminated Sites, here: Statement on the remediation variant study (German Version)
 

2018: Special measuring program "Trace substances in groundwater" detects elevated levels
The Federal Ministry of Sustainability and Tourism found elevated levels of so-called PFAS (perfluorinated surfactants) substances in groundwater during the investigation. The airport reacted immediately and promptly after the Ministry's measurement results became available. It must be emphasized that at Salzburg Airport, only extinguishing agents that complied with all legal requirements and technical standards were used at all times. The state of scientific knowledge and the legal requirements based on it are constantly evolving, and what was state of the art a few years ago and absolutely necessary for safety reasons, may lead to costly remediation work a few years later.

Brief Explanation PFAS
PFAS is an abbreviation for per- and polyfluorinated alkyl substances, also known by the older name PFC.

Applications of PFAS
PFAS substances, such as those contained in fire-fighting foams, have been used in many technical areas and in industry in recent decades. Examples are the production of non-stick coated pans, cake pans, water and dirt repellent textile clothing, paints, varnishes, polishing agents and many other products of everyday life.  

Determining the cause and first steps
In coordination with the authority, the potential causes for the PFAS contamination were first determined. This revealed that airport firefighting foam was the cause of the contamination. As an immediate measure, firefighting tests using this foam agent were immediately prohibited and a new firefighting foam was purchased. The fire extinguishing agent samples and fire extinguishing exercises, which are still required by law, are no longer carried out on the airport site, but on the premises of an authorized waste disposal company. A comprehensive situation report was drawn up in close cooperation with the relevant authorities. Initial considerations for remediation of the contaminated site have already been made.

Historical Review
The PFAS-containing extinguishing foam has already been used in the 1960s until 2018. PFAS-containing extinguishing foams are not specific to Salzburg; this type of extinguishing agent was and is used worldwide to fight special fires (liquid substances such as gasoline, kerosene, heating oil, tar, alcohol, etc.). At Salzburg Airport, extinguishing foams have never had to be used in an emergency. The quantities of extinguishing agents used in extinguishing agent tests and legally prescribed extinguishing exercises are very small. 

Preparatory work for the remediation of contaminated sites
All measures for the remediation of the contaminated site are being coordinated with experts from the Federal Environment Agency, the state's official experts, the Salzburg GWU, the Salzburg Hydrological Investigation Office and renowned German PFAS experts. All affected residents of whom the airport or the authorities have knowledge on the basis of the data currently available, have already been personally contacted and informed. From the current expert point of view, there are no problematic uses of the affected groundwater.

Goal
The goal is to find the best possible remediation solution for the environment, people and nature. The measures are based on the groundwater limit value that will apply in the EU member states from January 2026 (sum of PFAS of 0.10 μg/l).