instructor: dr mehdi mokhtari for master of science students april 2012 lesson 7
TRANSCRIPT
Instructor:
Dr Mehdi Mokhtari
For Master of Science Students
April 2012Lesson 7
Preparing a site for an sanitary operation
Terrain Upgrading
One of the first steps in the development of a sanitary landfill
involves the removal of all objects that may interfere with
the operation and movement of vehicles and equipment
like trees, shrubbery, and other interfering vegetation
Secondly, the site must be graded so as to eliminate interfering
surface irregularities.
The surface of the site should be contoured such that a
controlled runoff is promoted and ponding is prevented.
Appropriate measures should be employed for minimizing
problems associated with erosion, the generation of dust, and
sedimentation.
Roads
With large sites, these access roads would be extended from the
site’s entrance to the vicinity of the working area.
The roads should be designed to support the anticipated
volume of pedestrian and vehicular traffic.
Adequate drainage should be provided to prevent the roads
from flooding during wet seasons
Ideally, the roadway should consist of two lanes (minimum
total width, 7 m)
However, the width should be at least 3.5 m for a one-lane
road and 6 m for a two-lane road.
Typical cross-section of access road
Because the location of the working face is constantly changing, roads
for the delivery of wastes from the permanent road system to the
working face usually are temporary in terms of nature and construction.
Temporary roads may be constructed by compacting the native soil and
by digging drainage ditches.
Traffic consisting of more than 50 trips/day probably
would justify the use of calcium chloride as a dust
inhibitor, or of binder materials such as soil cement or
asphalt
Traffic consisting of more than 100 to 150 trips/day
would necessitate a base plus a binder
Measurement of Weight
The importance of having an accurate knowledge of
the gravimetric and volumetric amounts of wastes
delivered to the disposal site
Types of scales range from highly automated
electronic scales to simple, portable beam versions.
UTILITIES
Ideally, electrical, water, and sanitation
services should be provided
STRUCTURES
Office space (recordkeeping and the required clerical activities)
House employee facilities
Sheltered area for equipment storage, maintenance, and repair
A facility to serve as a scale house.
Buildings that will be used for less than 10 years should be of
temporary construction and preferably be movable.
The design and construction of all buildings should take into
consideration landfill gas migration and differential
settlement of the fill
Fencing Access to the landfill site should be controlled preferably by
building a fence around the entire perimeter of the site or, at the
very least, around the locations of easy access to equipment and
wastes by unauthorised individuals
A fence also serves to restrict access to the waste by animals,
screens the landfill, and delineates property lines.
Fencing of about 1.5 m in height and with a minimum of 5 cm
openings usually is adequate.
Litter fences should be erected in the immediate vicinity of the
working face to control blowing paper and other litter. A low
(about 1 m) fence usually suffices at a trench operation;
whereas, a 2 to 3 m height may be necessary at a windy, area-
type operation.
Portable litter fence
Important Factors That Must Be Considered in the Design of Landfills
Source:
Handbook of Solid Waste Management (2002)George Tchobanoglous Frank Kreith
Landfill Layout (Summary)
Landfill Operation
Some of the more important operational procedures that must
be considered for all methods of landfilling include:
Site Preparation and maintenance
Environmental control
Hours of operation
Procedures during inclement climate
Site Preparation and maintenance
1-Clearing and grubbing
2- Installation of leachate control systems
3- Erection of structures
4- Installation of utilities
5- Constructions of roadways
6- Soil stockpiling
Installation of leachate control systems
slope: - 1 5%
Gas vent
General maintenance
The site manager is the person responsible for the
preparation of a detailed maintenance schedule.
Specific dates should be scheduled for the performance
of the following tasks:
Collection and disposal of litter
Relocation of portable fences for the management of litter
Maintenance of gates, fences, and structures;
Maintenance of drainage system and final cover
Preparation and upkeep of final site maps
As areas of the site are completed, a series of maps indicating
the status of filling phases should be updated.
The maps should identify:
1. Areas used for special wastes
2. The fill depth of the various areas
3. The type of waste disposed
Road maintenance
Maintenance of access roads, If performed well, road
maintenance often is an expensive operation.
The roads must be inspected and repaired frequently
(cleaning, filling holes,…)
Environmental control
The most commonly used types of environmental
controls include:
Impermeable barriers (liners)
Leachate collection and treatment systems
Landfill gas management systems
Cover systems
Vectors and pests Flies, mosquitoes, rodents are an occurrence at landfill sites.
Vectors can be controlled by frequently placing an adequate quantity
of compacted soil over the wastes
Mosquito control is best accomplished by preventing the
accumulation of stagnant water anywhere on the site
Occasionally, rats and mice may be delivered to the site with
the solid waste. If Shelter occurs in areas adjacent to or in
some neglected portion of the site, extermination by the local
health department will be necessary.
Birds generally are attracted to a landfill in search of food.
The bird problem is best met by rapidly and completely
covering all wastes
Birds at the landfill site are not only a nuisance; they can
cause serious problems if the landfill site is located near an
airport
Techniques to control birds at landfill sites include the use of
noisemakers, recordings of the sounds made by birds of prey,
and overhead Wires
Because seagulls descend in a circular pattern when landing,
it appears that the wires may interfere with the birds’
guidance
Operating hours
The operating hours at a landfill typically are set by
the collection schedules.
Operating hours may be modified based upon the
quantity of waste produced during a certain time.
Inclement climate
Long periods of excessive rainfall, freezing
temperatures, or extreme heat can disrupt routine
operation of a landfill.
One of the more effective means of managing high
rainfall is to construct and maintain drainage canals
on the periphery of the site to divert water from the
wastes.
Landfills in arid and semi-arid regions may be
operated without liners and leachate collection
systems.
In fact, it has been suggested that the best sites for
landfills are in arid regions
Important Factors That Must Be Considered in the Operation of landfills
(Summary)
Solid Waste Filling Plan
The specific method of filling will depend on the
characteristics of the site, such as the amount of available
cover material, the topography, and the local hydrology and
geology
To assess future development plans, it will be necessary to
prepare a detailed plan for the layout of the individual solid
waste cells example of such a plan
filling plan for single-lift landfill
filling plan for a multi lift landfill
Summary of U.S. Environmental Protection Agency Regulations for Municipal Solid Waste Landfills
Source: 40 CFR Parts 257 and 258, 1991
Typical Equipment Requirements for Sanitary Landfills
Crawler tractor with dozer blade High track crawler tractor with trash blade
crawler tractors are most commonly used
steel wheel compactor with trash blade
Dragline (for excavation of cell and trenches)
Thanks for Attention