CityChlor Newsletter

This is the second newsletter of CityChlor, we will send this newsletter twice a year to keep you informed about the progress we make in this unique project. In this newsletter:

• 2010
• Partner and pilot test in the picture: Stuttgart-Feuerbach
• Socio-Economic viewpoint
• Technical focus: ISCO
• Workshop on-site research and monitoring for chlorinated solvents in urban areas
• Agenda

2010

Before we give you a preview on our plans for 2011 we'd like to look back at a productive first year. CityChlor has reached in 2010 over 1500 experts from the four participating countries. This focus towards specialists from all disciplines and regions of Europe is natural for CityChlor, since exchange of knowledge is the fundament of our project. Upon this basis we will elaborate an integrated approach for the complex problem of pollution by chlorinated solvents in an urban area.
Last year we listed more than 750 studies and documents in a state-of-the-art inventory and we checked our ideas and research focuses with experts from vary disciplines (technical and socio-economic) during 4 Regional and one Transnational Workshop. This year the major focus of CityChlor will be on new research at our pilot tests, but we still are interested in your ideas and knowledge. Therefore we warmly welcome you to our LinkedIn group where doubts or new insights can be discussed. When you are interested on specific aspects of our project, don't hesitate in contacting us!

In this Newsletter you can read about our German partner and pilot project in Stuttgart where a new remediation technique will be tested. During the year we will update the results on this pilot site at www.citychlor.eu so you can follow the research and remediation closely. In a following Newsletter we will go into the pilot project in Flanders where innovative characterisation techniques will be tested.

To end we will explain our goals on specific techniques and socio-economic issues. If you can help us with your experience on these aspects we are pleased to exchange information by mail or during one of the workshops the CityChlor members will attend.

Hope to meet you soon!

Partner and pilot test in the picture: Stuttgart-Feuerbach

Stuttgart, with its 590.000 inhabitants the capital of Baden-Württemberg state, is located in the center of a densely populated region in south-western Germany. In Stuttgart, no less than 39 %of the land is taken up by protected landscapes and nature conservation areas. Stuttgart is working towards the sustained development of the city based on the principle of "inner development before outer development". Therefore "recycling" of former industrial sites is a necessity, even if they are polluted with chlorinated solvents. Due to the numerous industries and a long industrial history, large-scaled groundwater contaminations are existent, especially in the industrialised city district of Stuttgart Feuerbach.

The pilot test site in Stuttgart-Feuerbach is an example for many inner urban sites, contaminated with chlorinated solvents. Since 1997, different remediation activities (soil vapour extraction and pump and treat) have been implemented without a sustainable remediation effect. Although more than 800 kg CHC have been removed until now, the concentration of CHC in the groundwater does not decrease. Conserving of the status quo remediation technique would mean:

• Further pumping for decade
• High operating costs
• Restraints for vending or developing the site

Therefore a new solution is necessary, but the conditions on the site are challenging. The low permeability and the high heterogeneity of the subsoil, the position of the source zone beneath existing buildings and the tight backyard situation requires innovative remediation approaches.
In a first ideas competition three options for remediation were chosen to be reviewed for the application on the site:

1. Overlapping large boreholes (dig & dump)
2. TUBA: In-situ remediation by steam-injection and soil vapor extraction
3. THERIS (thermally enhanced in situ remediation): thermal enhanced soil vapor extraction (thermal wells as heat source)

The favoured method: Theris

The most promising method is to apply thermal wells, the so called "THERIS-method", especially developed for the application in low permeable layers. This innovative technology will be applied in the unsaturated and in the saturated zone by installation of thermal wells for conductive heating and the wells for extraction of soil vapour. Temperatures of more than 100°C can be reached. For quality control soil heating is monitored and documented. Heating of the subsoil causes a fast change of contaminants to vapour phase and improves the permeability of the subsoil. The contaminated air is extracted and cleaned.

Compared to other in-situ remediation technologies, THERIS has the major advantage that low permeability and high soil heterogenities have only minor effects on heat propagation. The complete volatilisation of contaminants occurs at the boiling point of the water-contaminant mixture below 100°C. Transition of contaminants into gaseous phase is therefore much faster and volatilisation of liquids advances the permeability for gases in the subsoil.
THERIS is considered as a cost efficient alternative to conventional remediation methods. As a basis, a detailed site evaluation is conducted to describe the lateral and vertical spreading of the CHC-contaminated source zone. Based on site specific risks (among others hydro-geological conditions, remediation goals for soil and groundwater and foundation), the source zone treatment area will be defined and the applicability of the methods evaluated.

Click here for all information about Stuttgart and it's pilot site.

Socio-Economic viewpoint

End of January a meeting in Utrecht was organised on Socio-economic issues of CityChlor. Our integrated approach implies a solution for financing, communicating and organising these remediation projects and this within the best legal framework. Because CityChlor started from a technical problem (pollution) it proves to be difficult to review this problem from another viewpoint. Non technical experts don't always see the benefit of CityChlor for them. That's why we put a lot of energy in these topics, we set out priorities analysed the information we gathered in our inventory. Conclusion is that we still can use extra input from socio-economic experts on literature and on experiences as well. To answer this need we organised a workshop on risk perception in Paris on March 17th and 18th. During this meeting we shared methods for community involvement and insights on risk perceptions. On June 9th we will organise a similar workshop on economical aspects and the next day June 10th, the topic will be the legal challenges of this kind of pollution. When you are an expert on these themes or you know someone who is please contact us so we can invite them.

Technical focus: ISCO

One of the techniques that won't be tested in a pilot site but that will be part of CityChlor in the form of desk study is remediation by in-situ chemical oxidation for the treatment of the source. We will evaluate this technique and translate it into guidelines (Code of Best Practice) or adjust existing guidelines. Remediation experts and contractors are often little enthusiastic to apply new techniques, as there are no or little guidelines available and they are unsure on whether a technique will be accepted by the authorities. For this obstacle we are still collecting relevant studies and experiences so we hope on your input, then we will be able to make this technique more acceptable by the authorities.

Workshop on-site research and monitoring for chlorinated solvents in urban areas

The absentees on the CityChlor-workshop on the 10th of March in Utrecht were wrong. To make an area oriented approach in a large area -such as the Utrecht station area the Dutch pilot site for Citychlor - with many known but possibly also unknown pollutions possible, traditional research techniques simply won't work anymore. This was the main message from Leen Ruberecht (MWH). To investige a large complex area one should work with a conceptual site model (CSM). The CSM is a very dynamic model which goes further than concentrating on the pollution itselfs, think of geo-hydrolic modelling a good concept of the different soil strata a.s.o. Innovative techniques are the tools to answer questions and fine-tune the CSM. In the morning an overview was given of different techniques and specialists from the Netherlands, Belgian, Australian en German presented their innovative techniques what led to some interesting discussions. After a tasty lunch, the whole group went outside for a practical presentation of two of the innovative research techniques. The techniques presented in Utrecht won't only be investigated behind desks, but also put into practice at the different CityChlor pilot sites. The information generated out of these pilots will contribute to the main goal of the CityChlor-project: to improve the quality and minimise pollution of soil and groundwater by developing an integrated approach to tackle the threats caused by contamination with chlorinated solvents in urban areas.
Even the chairman of the day prof. Huub Rijnaarts -who has over 25 years experience in innovative research and monitoring techniques - was impressed of the quality and diversity of the techniques presented.
In short, it will be rewarding for soil remediation experts, policy makers, politicians, and other stakeholders to follow our project!

See all presentations on the website

Agenda

In the (near) future the following events will take place:

26-27 May 2011 - Symposium In-situ Environmental Monitoring and Policy

25-27 May 2011 - NICOLE (Network for Industrially contaminated land in Europe) netwrork meeting
Kulturhuset, Islands Brygge 18, 2300 Copenhagen, Denmark

June 8th 2011 - Economical Workshop, target groups are environmental economists or financial experts of the industry

June 9th 2011 - Legal Workshop in, target groups are legal advisors and Soil policy makers of the 4 contributing countries.

On our Citychlor website you can find dates of workshops and seminars or documents on relevant topics. But we like two-way-communication and therefore we are interested in hearing from you. Do you want to work with us on this innovative approach or do you have a question that isn't answered on our website? Please send us an e-mail and we will send the answer as soon as possible. You can also become a member of our discussion group on LinkedIn (you must have a -free- LinkedIn account) 

Exchange of knowledge