Doncaster Quarry Rehabilitation Report

This report presents a case study of the Doncaster Quarry rehabilitation project. It outlines the roles and responsibilities of key players, the objectives of the rehabilitation (restoring the landscape, ensuring public safety, and establishing suitable land use), and the proposed post-quarry land use as a community park. The report details the decommissioning process, including site services and infrastructure termination. It also covers site setup for rehabilitation, including safety provisions like benches, haul roads, boundary fences, and signage. The equipment to be used is listed, and environmental management practices are discussed, focusing on soil management (erosion control, surface water management, groundwater management, and revegetation). The report explains the quarry void rehabilitation, including benching and top dressing, and the stabilization of rock faces through grading and benching. Finally, the report includes a bibliography of relevant sources.

Quarry Rehabilitation Works Report 0
A CASE STUDY OF DONCASTER QUARRY REHABILITATION WORKS
By (Name)
Course
Professor’s name
University name
City, State
Date of submission

Quarry Rehabilitation Works Report 1
Table of Contents
1. Introduction..........................................................................................................................................2
1.1 Background........................................................................................................................................2
2. Delegation.................................................................................................................................................3
2.1 Roles and Responsibilities...................................................................................................................3
3. Preferred rehabilitation strategy............................................................................................................4
3.1 Purpose and Objectives.....................................................................................................................4
3.2 Post-Quarry Land Use strategy........................................................................................................5
4. General Rehabilitation Activities.......................................................................................................5
4.1 Decommissioning................................................................................................................................5
4.1.1 Site services:................................................................................................................................5
4.1.2 Infrastructure and Buildings.....................................................................................................5
4.2 Site setup for rehabilitation..............................................................................................................6
4.3 Equipment to be used........................................................................................................................6
4.4 Environmental management.............................................................................................................7
Soil Management Practices.................................................................................................................7
4.5 Quarry Void Rehabilitation..............................................................................................................9
4.6 Stabilization of Rock Faces.............................................................................................................10
References...................................................................................................................................................11

Quarry Rehabilitation Works Report 2
1. Introduction
1.1 Background
After being commissioned by the council to undertake the Closure and Rehabilitation works of
Doncaster Quarry, the following report outlines the various methods that will be employed in the
rehabilitation works as would be carried out by my company.
The aim of the rehabilitation works is to convert the quarry site into a safe Community
Park. The construction works include the rehabilitation of the 35 x 85 x 65-meter-deep quarry pit
and stabilize it to ensure the safety of people at the proposed community park after the
rehabilitation works.
This preliminary decommissioning and rehabilitation report features the objectives for
rehabilitation, a general plan for management of the rehabilitation process and an overall guide
to the methods to be applied in the rehabilitation of Doncaster quarry. The preliminary
decommissioning and rehabilitation plan is organized as follows:
 A description of the delegation for the execution and completion of rehabilitation strategy
 A description of the ideal methods of rehabilitation for each domain within the quarry.

Quarry Rehabilitation Works Report 3
 A description of the general rehabilitation activates.
 A description of the safety and health considerations at the quarry site during
rehabilitation
 A list of equipment and tools to be used in the rehabilitation process
2. Delegation
2.1 Roles and Responsibilities
The following are the roles and responsibilities of the key players in the rehabilitation Doncaster
Quarry:
a) Quarry Rehabilitation Manager:
 Ensure availability of all the required resources within the construction sites.
 Ensure compliance of the contractors to all the project requirements.
 Facilitate the execution of this preliminary decommissioning and rehabilitation report.
 Facilitate the planning and appraisal of the rehabilitation works.
b) Environment Manager:
 Facilitate the implementation of this preliminary decommissioning and rehabilitation plan.
 Evaluate and make recommendations for updates to this preliminary decommissioning and
rehabilitation report.
 Organize and help in staff training on site matters, environmental awareness, and the
standard safety requirements for the workers on the site.
 Inform the quarry rehabilitation manager on cases of noncompliance to the strategies and
procedures outlined in this report to ensure that proper corrective measures are undertaken
 Advice the quarry rehabilitation manager, project engineer and the contractor on the
environmental permit requirements according to the confines of the Environment Planning
and Management Acts and offer advice that would assist in achieving compliance.
c) Employees:
 Be conversant with the contents and procedures as outlined in this preliminary
decommissioning and rehabilitation strategy.
 Ensure they carry out works to completion while in compliance with the set preliminary
decommissioning and rehabilitation strategy.
 Report all issues of noncompliance to the quarry rehabilitation manager.

Quarry Rehabilitation Works Report 4
d) Contractor:
 Prepare the preliminary closure and rehabilitation report for the quarry.
 Ensure works are done to completion according to the specifications of this preliminary
decommissioning and rehabilitation report.
 Report the progress of work to the quarry rehabilitation manager.
3. Ideal Strategy of rehabilitation
3.1 Rehabilitation Objectives
The main objectives of this rehabilitation plan include:
 Restoration the landscape within and around the Doncaster quarry to the original topography
of the area;
 Guarantee the safety of the general public within the rehabilitated area by stabilization of soil
and rock faces;
 Ensure that land uses proposed for the rehabilitated site are practical, suitable and adaptable
to the surroundings;
 Put in place measures to limit occurrence of landslides, rock falls, soil erosion, sedimentation
and other undesirable phenomena on the rehabilitated site;
 Ensure the soil materials are stored and used in the most appropriate manner; and
 Ensure the provision of post-rehabilitation vegetation cover at the quarry site to afford long-
term stability of the site.
This preliminary decommissioning and rehabilitation strategy outlines the procedures and
systems that will be used to ensure the above-mentioned objectives are fulfilled. The report
covers the rehabilitation of all operational and functional activities and the related infrastructure
to be undertaken as part of the Doncaster Quarry rehabilitation process. Construction activities
aimed at achieving restoration of the site will be guided by this strategy for rehabilitation.
3.2 Proposed Land Use after Quarry rehabilitation
The quarry site will be used as a Community Park to benefit the people of the surrounding
community.

Quarry Rehabilitation Works Report 5
4. Proposed Rehabilitation Actions
4.1 Decommissioning of the Quarry
Detailed plans outlining the decommissioning process will be established. The plans will give
detailed information and procedures pertaining to decommissioning of each equipment,
equipment inventory and the potential for scraping and salvaging the equipment.
The decommissioning plans should detail the how:
 Operations will be finished and the procedures separation and dismantling of equipment;
 To get rid and dispose chemicals kept at the quarry site; and
 The quarry site will be tendered and given to the demolitions and rehabilitation contractor.
The following sections outline the key aspects related to the termination of the site services,
infrastructure and buildings for site decommissioning. The decommissioning plan will assume
that all services available on site will be terminated and infrastructure destroyed and confiscated
from the site:
4.1.1 Site Amenities:
All services in the quarry such as power, data, telephone, and water will be isolated,
disconnected, and terminated for safety.
However, termination should be carefully done to allow for recovery of potential resalable or
recyclable material where possible.
4.1.2 Buildings Infrastructure
All open ditches will be dewatered before the commencement of demolition works.
In addition, all equipment used in the quarry will be degassed, de-oiled, isolated, and
depressurized. All hazardous material should be properly disposed of from the site
4.2 Site setup for rehabilitation
General safety Provisions at the site are:
a) Benches and Haul Roads:

Quarry Rehabilitation Works Report 6
Proper bench and haul road design are important. They must be suitable and wide enough for the
machinery and loads used on them without risk of instability or accidents (Hoek & Bray, 1981).
Apart from wide enough haul roads, the slope of the haul roads should be gentle to avoid
accidents.
b) Amenities: Amenities should be clearly labeled and placed at locations that are
accessible to all the workers at the site. The amenities include a site cafeteria, washrooms
and worker's houses/hotels,
c) Boundary fences: The quarry rehabilitation project should have a good perimeter wall to
keep off unauthorized individuals from accessing the site during the rehabilitation works.
This is for the safety of local residents and that of the workers during the rehabilitation.
d) Signage: The rehabilitation site should be fitted with adequate signage. The signage will
include at cliff edges, at vehicle turning points and forklift reversing areas, areas at risk of
falling rocks before stabilization of rock cliffs and all other appropriate locations (Hoek
& Bray, 1981). All these signs are to ensure the safety of workers and visitors to the site
during the entire rehabilitation process.

Quarry Rehabilitation Works Report 7
4.3 Equipment to be used
The following are the equipment to be used in the rehabilitation process:
 Conveyor belt
 Crushers
 Forklifts
 Front end loaders
 Hammer drills
 Saws
 Trucks
 Wheel Loaders
 Hoisters
 Excavators
 Sheep’s foot rollers
4.4 Environmental management
Soil Management Practices
During the rehabilitation process, it important to carry out appropriate topsoil management
practices which will include: erosion and sediment control, surface water management,
groundwater management, dewatering of the quarry pit, and vegetation.
a) Erosion and sediment control.

Quarry Rehabilitation Works Report 8
The quarrying activities commence with the stripping of the topsoil and removal vegetative
cover. It is therefore critical to carefully rehabilitate and restore the soil by putting measures to
check erosion in place.
Erosion due to runoff will be controlled by the use of the following techniques:
 Surface roughening to help reduce the velocity of flow of water, increase infiltration and
trap the sediments e.g. using benches.
 Revegetation of the quarry area once the surface of the rocks has been top dressed.
Revegetation will also help hold the soil particles together on the slopes created by the
filling of the quarry.
 Use of geotextiles. Geotextiles can be used to stabilize channel floors or to protect
seedlings on planted slopes until they become established. It can also be used to separate
soil and riprap to prevent the soil from being eroded from beneath the riprap.
b) Surface water management
The aim of surface water management is to develop a system for the control of water movements
in the rehabilitated land. Retention dams should be set up at the site for the capture of surface
runoff.
Sedimentation tanks present in the quarry will be retained to facilitate the regulation of water
flow and sedimentation within the rehabilitated land.
The structural integrity of all dams around the high wall shall be examined and a determination
made whether upgrading works will be required for the retained dams (GSS Environmental,
2011). Any remaining dams that will not be required will be removed and original paths of
drainage are to be restored wherever possible.

Quarry Rehabilitation Works Report 9
c) Groundwater management and dewatering of the hole
The water beneath the surface of the quarry floor needs to be removed and quarry pit floor made
workable, dry and stable enough.
The main approach to dewatering will be pumping by use of deep wells. Cased boreholes should
be sunk around the quarry site and pumping stations set up to draw the water from beneath the
surface and channel it for other uses (DECC, 2008). Perimeter dewatering wells are to be used to
intercept lateral groundwater flow into the quarry pit and lower the level of groundwater as the
rehabilitation process will be going on.
Water in the pit can be pumped away by use of in-pit pumps. In-pit pumps drawing through
sumps or external pumping from an array of wells around the quarry pit will also be used.
d) Revegetation
The preferred method of revegetation of the rehabilitated land is direct seeding since it allows a
far greater rate of success; it limits the need for continuous maintenance (e.g. watering) and is the
most efficient method of achieving a successful rehabilitation program.

Quarry Rehabilitation Works Report
10
However, tube stock method will also be used in the planting of indigenous trees and shrubs
around the rehabilitated quarry site. Not all native trees and shrubs are suited for direct seeding
due to their natural germination needs. Thus, to increase the biodiversity of the rehabilitated
quarry, direct seeding will be supplemented by tube stock planting.
4.5 Quarry Void Rehabilitation
Benches will be made in the quarry pit remaining after quarrying stops. The benches will be top
dressed with material and native shrub and tree species will be sown directly onto these benches.
The aim is to ensure that the hole attains geotechnical stability (Cement Sustainability Initiative
(CSI), 2011).
The floor of the pit will be leveled to allow water to drain away and the spread with a top
dressing. The floor will be seeded in a similar manner to that on the benches with a mixture of
native trees and shrub species.
The rehabilitation will involve the following:
 Preparation of the surface of the area by ripping;
 Placement of about 100 mm of top dressing on the benches around the edge of the pit;
and
 Planting shrubs and trees species on the surface of the benches.

Quarry Rehabilitation Works Report
11
 At the closure of the quarry, the final bench will be shaped and the floor of the pit re-
profiled and revegetated with indigenous plant species adaptable to the local
environment.
4.6 Stabilization of Rock Faces
To guarantee the safety of people in the quarry during and after rehabilitation, all the rock faces
on the slopes of the quarry pit should be maintained in a state that poses minimal risk of slope
failure and rock falls. To achieve this, the contractor may need to batter back the formed benches
to guarantee a general stable slope angle.
The following are the major considerations in examining the geotechnical integrity of high walls:
 The projected long-term level of water in the quarry void;
 Height, slope angle and spacing of intermediary benches;
 Bearing capacity of the high wall; and
 The impact of physical factors such as surface runoff on the stability of the high wall.
The criteria specified above should be investigated and confirmed before closure of the quarry.
The following are the methods to be used in the stabilization of the rock faces:
a) Grading:
Grading includes shaping the rocky slopes of the quarry pit into a more stable configuration. It
includes flattening of the slope or sculpting the slopes into more natural appearance making
benches.