GAUTRAIN KEEPS A WATCHFUL EYE OVER ENVIRONMENTAL IMPACT DURING CONSTRUCTION

Adherence to Gautrain’s Draft Final Environmental Management Plan (EMP) is a requirement of the Gauteng Department of Agriculture, Conservation and Environment (GDACE) and ensures that communities and natural resources are protected during construction activities.

The protection of water resources forms a vital part of the EMP and several measures have been implemented to ensure that no water pollution takes place as a result of the construction of Gautrain.

• Ground water protection during tunnelling

Tunnels often intersect water channels and low water tables.

Excavation of tunnels involves pilot drilling to test rock conditions before large scale drilling and blasting can start. It is during this stage that ground water is sealed off in order to prevent a full scale flooding of a tunnel.

When water is encountered during the excavation of tunnels, the area is immediately sealed-off by injecting grouting (a concrete mix) into the rock.

Water emanating from the tunnelling operations is filled with sediment (muddy). Instead of wasting this water, it is
collected and processed through a water purification plant situated on the construction site. The clean water can then be further utilised for drilling operations.

The tunnelling process is essentially a wet process. During the tunenling process water is used as a cooler and lubricant and prevents dust at the same time.

• Surface water protection during surface rail construction

Gautrain’s rail line will often intersect wetlands, rivers and streams. Temporary water crossings are built normally comprising of pipes covered with a concrete slab. This allows construction vehicles to cross rivers with the least risk of pollution.

To further check that surface water is not being affected by construction activities, water quality is monitored monthly. Water samples are taken both upstream and downstream from the temporary water crossings.

Should there be any contamination, investigations will be performed to find a suitable solution.

• Managing the surface water in dolomites

Dolomite rock has the unique property of forming cavities underground that could lead to sinkhole formation. Sinkholes are normally formed by ingress of surface water or leaking underground water pipes.  The management of surface water is therefore important to minimize the potential risk of sinkhole formation.

The quality of both surface and underground water is also tested on a monthly basis to ensure compliance by the Gautrain Project to the strict water quality criteria sptipulated in the Draft Final EMP.

Dolomite is found in the Centurion area where viaducts (rail bridges) will be constructed.

• Draft Final EMP Revision 5

The Revision 4 Draft Final EMP was approved on 18 December 2006. The Revision 4 Draft Final EMP had to be updated with all the conditions contained in the latest RODs issued for the Northern Variants. These conditions were included, as well as redefined objectives and targets, in the new Revision 5 Draft Final EMP. A copy is available on the Gautrain website.