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