Other Components .1 Labor Camps

Two options have been considered for labor camps, one on the Left Bank and the other on the Right Bank. It is estimated that during peak construction the number of construction workers may go up to 2,500.

Option 1 – Left Bank

About 100 barracks are available for labor camp on the Left Bank but all of these need major repair. These barracks were previously used during the original construction of the Tarbela Dam project and are very derelict with doors, windows and roofs in need of replacement. In addition, water supply lines, sewerage and electricity would need to be installed and the area around the barracks cleared from the overgrowth and shrubbery.

There are however sufficient numbers of barracks available that could be used following appropriate refurbishment.

Option 2 – Right Bank

About twenty barracks are also available on the Right Bank Colony which were used as labor camp during the construction of Ghazi Barotha Barrage. The condition of these barracks is similar to those on the Left Bank.

In addition there are around 15 houses adjacent to these barracks, which are presently residences of WAPDA employees. In order to use these barracks, the occupants of these houses would have to be moved to 26 vacant houses available in Right Bank Colony.

The houses would require renovation and the surplus could be used as residences for the consultant’s staff.

Labor Camp Inputs and Outputs

There would be inputs of different types including food stuff, utility items and personal belongings and outputs would include the solid and liquid wastes produced from the camps.

Machinery and Vehicles

The following list outlines the major machinery and vehicles that are envisaged to be required for the project construction works:

Machinery and vehicles needed for construction Hydraulic excavators

There are two potential sources for construction material in the project:

Material quarries used by contractors for previous projects could potentially be a suitable source and yield sufficient quantities; and

New areas in the vicinity of the project could be identified for material.

Reuse of Major Quarries / Sites

The remnants of the main concrete mixing plant from the construction of Tarbela Dam are still evident today. Spoil dumps are also visible on the terrace and along the river bank cut face. The sources of aggregate for the concrete during construction are as follows:

Coarse Aggregate – procured from the river bed through dredging; and

Fine Aggregate – sand can be obtained from the Left Bank quarry near the Sobra Colony.

It is anticipated that both of these sources can provide the required materials in sufficient quantities, the quantities required are still being calculated by the Design Team.

However, with the construction of Ghazi Barotha, the water level in the river valley has been elevated therefore making excavation of coarse aggregate from the river bed more difficult.

If required core material in particular silt and clay, can be procured from the Gandaf area in the west/northwest of Tarbela Dam. The Gandaf area is about 15 to 20 km from Tarbela and a tunnel across the ridge was built for the easy and quick transportation of

the core material. Presently the Gandaf area has been developed into an industrial area;

however, the available terraces can be explored for this type of core material.

The rip rap/stone pitching material was previously obtained mainly through the required excavations from tunnels and spillways. Limestone from spillways was used as rip rap in the upstream slope, while the carbonaceous schist material of metamorphic nature was used in the downstream side of the embankment.

Currently, it appears that these sources will not provide any material, however the nearby areas can be studied for this purpose.

Potential Material Sources

As well as the major quarry areas discussed above, the following areas have been identified as alternative sources for the aggregates for the concrete:

Coarse Aggregate – potential suitable areas for sandy gravel material include the deltaic and island areas that presently exist. The water bay area downstream of the Right Bank has also been proposed and the quartzite rock crops along the road extending to the river is deemed to be sound and durable in nature for use;

Fine Aggregate – the sand from Qibla-Bandi and Lawrancepur, nearly 30 to 40 km respectively from the Right Bank, can provide good sources that are well established, recognized and well studied and have been used previously in the Ghazi Barotha Hydropower Project;

Core Material – some potential terraces for silt and clay are likely to be identified in the Gandaf area industrial zone. The ultimate decision on the source will be determined by the potential environmental and social impacts;

Rip Rap / Slope Protection and Pitching Material – the required excavation for the powerhouse and penstock construction will provide quartzite to be used as rip rap for the upstream slope and the graphitic schist in the near vicinity can provide pitching stone on the downstream side.

Alkali Silica Reaction (ASR) Potential

From the existing concrete structures, the coarse aggregate from the Indus River and the fine aggregate (Lawrancepur sand) have proven to be as potentially reactive to Ordinary Portland Cement (OPC). However, studies and testing can be done to determine the ratio of OPC to slag cement to control the reactive nature of the aggregates.

Alternatively, the nearby cement factories can provide low alkali cement on demand, while pozzolon sources have not been established thus far in Pakistan.

3.5.3 Waste Generation and Disposal

Areas identified for excavated material disposal are approximately 2 km from the proposed new powerhouse site along the road leading to the Right Bank WAPDA Colony. The proposed area is on the same river terrace adjacent to the site where old TJV contractor had established their main concrete mixing plant.

It is estimated that 2.5 Mm³ of excavated material will be generated by the Project. In addition, it is estimated that up to 1 ton of solid waste, may be generated per day at the workers camps during the peak construction period as well as up to 1,000 liters per day of sewage waste.