Extension project in Sonderbach

RÖHRIGgranit® is planning an extension of the Gehrenberg quarry in Sonderbach by 6.2 hectares in a southerly direction. To this end, the company is expected to submit the necessary application for approval to the Darmstadt Regional Authority in spring 2019. In the event of a positive decision, stone extraction will then be carried out step by step in the new area. The distance to the residential area in Juhöhe will be at least 400 meters.

An expansion is necessary in order to continue production at today’s level in the future, to maintain the site in the long run, and thus to ensure a sustainable supply of raw materials. RÖHRIGgranit® employs 90 people, including currently four apprentices. RÖHRIGgranit® thus ensures around 200 jobs in the region. The family business is firmly rooted in the area and committed to the region.

What does the extension project mean for neighbors?

The company is to be continued at today’s level, so that the expansion will not change anything in many respects for the local residents.

Production & production times

No increase in production is planned. The production times also remain the same.

Traffic

As the production volume will not increase, there will be no increase in truck traffic. Access will continue to be via the factory road.

Blastings

No increase in the use of explosives: the number of blastings per week remains at approximately two. No change in vibrations. Thanks to the use of the latest blasting technology, the vibrations in the surrounding places remain at the previous level.

Emissions

The dust and noise situation will remain the same. As previously, we will develop and implement measures to reduce noise and dust.

Distance to the residential area in Juhöhe

The distance will be at least 400 meters in future. For residents on the Juhöhe, there will be no visual relationship to the quarry today or in the future. The forest will also continue to perform its protective function – even if the quarrying is moving a little closer to the residential area.

Extension area

The extension comprises a 2.6-hectare woodland area. It will be carried out gradually over the next few years. RÖHRIGgranit® will previously reforest the same amount of forest elsewhere in the region in order to make up for the trees standing on the expansion area. In addition, south of the quarry an approx. 25-hectare forest area with the highest protection category “Bannwald” will be designated. In addition, some 41 hectares of protection forest remain.

Recreation

RÖHRIGgranit® will progressively relocate some forest paths and create a new network of paths in the course of the expansion. The rest area (“Gerhard Röhrig-Rast”) will also receive a new location – as a vantage point at the future edge of the quarry. An inaccessible sea of rocks is laid and can be visited by walkers in the future. In addition, another sea of rocks will be designated a natural monument.

Questions and answers

Why is such an extension necessary?

Why is such an extension necessary?

It can be anticipated that over the next few years, we will reach the limits of the previously approved mining area. An extension of the quarry is therefore the necessary prerequisite to be able to continue operations at today’s level for the next decades. And thus also in order to protect the approximately 90 jobs.

Why is the expansion planned toward the south?

Why is the expansion planned toward the south?

It was planned and thought out in all directions – also with regard to the interests of the residents. Among other things, the existing deposit qualities, the nature of the site, existing streams, as well as legally protected biotopes were taken into account. In the end, only a southbound extension was possible.

How does the authorization process work?

How does the authorization process work?

The extension is expected to be applied for in the spring of 2019 on the basis of the German Federal Immission Control Act at the Darmstadt Regional Authority. There, we submit extensive planning documents and expert reports. Formal public participation is also provided for in the procedure. This means that the application documents will be made public, and interested parties will be able to examine them. Objections to the planning can be raised within a legally regulated period, which the approval authority must take into account in its decision.

Why will there not be more vibrations despite a shorter distance to the Juhöhe neighborhood?

Why will there not be more vibrations despite a shorter distance to the Juhöhe neighborhood?

In recent years, our measurements at the Juhöhe have clearly been lower than the approved vibration levels. Measured at the nearest residential building, they are on average around 80 percent below the legal limits. We have optimized the blasting technology, and are planning to rotate the blasting direction by 90 degrees. As a result, even if the distance to the Juhöhe neighborhood is reduced, there will not be any major vibrations in future.

Why was the protection forest revoked? Will residential protection be maintained?

Why was the protection forest revoked? Will residential protection be maintained?

Revocation of the protection forest is subject to high requirements. An examination has shown that the protective effect still persists, and that the project is of general importance due to its relevance for the raw material supply of the region. Corresponding areas for reforestation elsewhere have already been selected and approved in consultation with the responsible authorities. This is a necessary prerequisite for the application under the German Federal Immission Control Act (BImSchG). In any case, the following applies: substitute afforestation will be carried out before deforestation. In addition, it is planned to redesignate approx. 25 hectares of Bannwald with the highest protection category.

What effects will the extension have on flora and fauna?

What effects will the extension have on flora and fauna?

This aspect will also be considered in the approval procedure. As applicants, we see it as our responsibility to take all necessary measures to continue to protect the flora and fauna. Our quarry is already home to eagle owls, peregrine falcons, yellow-bellied toads, and other rare species. Appropriate measures are taken to keep the impact on these species to a minimum. To this end, we keep in constant touch with the authorities and nature conservation associations.

Planning began back in 2014. Why does Röhrig inform the public now?

Planning began back in 2014. Why does Röhrig inform the public now?

The planning and approval of an extension project is a lengthy process. We did not want to communicate it until we knew that our project could actually be implemented in terms of planning and approval. At the 2016 application conference, the responsible authorities formulated various requirements for this. These must be fulfilled before the application for approval can be submitted. After two years of further planning and preparation, we are confident that we will be able to meet the formulated requirements. This means that we can now also present a feasible overall plan, and respond in detail to questions and concerns from citizens. We deliberately scheduled our citizens’ information event a few months before the application was submitted, i.e. still at an early stage of the actual approval procedure. The application is expected to be submitted in spring 2019.

How are vibrations caused by blastings recorded?

How are vibrations caused by blastings recorded?

Wir messen und dokumentieren unsere Sprengungen seit über 20 Jahren kontinuierlich. Die dabei aufgezeichneten Ergebnisse haben bei jeder einzelnen Messung die  erlaubten Grenzwerte deutlich unterschritten. Die ermittelten Messwerte werden an die Überwachungsbehörde übermittelt.  Zusätzlich werden Einzelmessungen an verschiedenen Stellen vorgenommen. Auf Wunsch von Anwohnern wurden auch Messungen in anderen Wohngebäuden durchgeführt. Die Messung selbst erfolgt durch kalibrierte und zugelassene Erschütterungsmessgeräte am Fundament und/oder auf der obersten Deckenebene der Wohngebäude.

All measurements carried out at our measuring points within the framework of vibrations comply with generally applicable norms, and meet the highest evaluation standards used in Europe for blasting vibrations. Vibrations measured in buildings are assessed according to DIN (Deutsches Institut für Normung) 4150 Vibrations in Construction. This standardization is subdivided into effects on people in buildings and effects on buildings. In particular, the effect on people in buildings is one of the few standards in Europe that evaluates human sensation, thus creating an objectively assessable framework.

Why are there no stronger vibrations despite a shorter distance to the Juhöhe neighborhood?

Why are there no stronger vibrations despite a shorter distance to the Juhöhe neighborhood?

In recent years, our measurements on the Juhöhe have clearly fallen below the approved vibration values. Measured at the nearest residential building, they are on average approx. 80 percent below the legal limits. New techniques such as 3-D surveying, the determination of the blast hole course, and the use of electronic igniters keep the measured values at a low level.

As part of the planned extension, we want to rotate the blasting direction by 90 degrees in order to direct the vibrations in an east-west direction as far as possible. In addition, the height of the blasting walls is to be reduced from a height in some cases of approx. 26 to 30 meters to approx. 10 to 20 meters. As a result, even if the distance to the Juhöhe neighborhood is reduced, vibrations well below the legal limits can be expected in the future.

Do you have any further questions?

steinbruch@roehrig-granit.de
Tel. +49 6252 7009-0

Your contacts:
Horst Gottmann, Stefan Koob, and Marco Röhrig