STUDIES ON THE IMPACT OF CLOSED-SYSTEM DISPOSAL SITESON THE OUTSIDE ENVIRONMENT

Masahiro IDO1, Katsuhiko HAYASHI2, Yoshijirou SHIMOMURA3
Environmental Evaluation Working Group, Research Committee for Closed-System Disposal Facilities
Chateau Takanawa 401, 3-23-14 Takanawa, Minato-ku, Tokyo, 108-0074 Japan
1
Kokusai Kogyo Co., Ltd.; 2 Maeda Corporation; 3 Pacific Consultants Ltd.

Masataka HANASHIMA, Tohru FURUICHI
Research Committee for Closed-System Disposal Facilities
Chateau Takanawa 401, 3-23-14 Takanawa, Minato-ku, Tokyo, 108-0074 Japan

ABSTRACTThe majority of final disposal sites in Japan are theopen type; however, in consideration of the impact on
the surrounding environment, many “indoor” sites thatare either covered or completely enclosed are being
constructed. At present, 44 facilities are in operation orunder construction. Moreover, seminars have been heldon the development of closed-system disposal sites
since 1989, and extensive research has been carried out
to popularize such facilities. This report summarizes theresults of studies on the impact of closed-system
disposal sites on the outside environment, conducted by
the Environment Evaluation Working Group(hereinafter called the “WG") from 2002–2004.
The WG investigated actual conditions ofclosed-system disposal sites, believing that this system
is kinder to the surrounding environment compared tothe open site, and that in an environmental impact study,
a reduction in investigation items could be expected.
The results revealed an interesting situation concerning
the noise and fine particles. The WG proposes
conducting environmental impact assessments on thedevelopment of such facilities in the future, estimating
the pollution load based on the facility structure,
landfill items, landfill method, etc.

INTRODUCTION
A number of small-scale, closed-system disposalsites have been constructed, and studies are being
conducted to determine their impact on the living
environment. It was considered that closed-system sites,
being covered structures, would have less impact on theoutside environment, and that environmental impact
assessment items could be simplified. Therefore, thedifference in environmental impact between closed andopen systems was examined, and dust and noise wereselected as items that could potentially be simplified.
The current situation concerning these items wasinvestigated at several closed-system disposal sites andthey were examined as environmental impact
assessment items.
This paper describes the situation of dust and noise
generation at closed-system disposal sites and makes
recommendations on factors impacting the living
environment and environmental impact assessment
items, considering facility structure and operation andmaintenance aspects.
OUTLINE
Objective
Field surveys on dust and noise at closed-system

Analyzed items: Cd, Pb, Cu, As, Hg, SiO2, moisture; 6 facilities,
1 sample each2) Study points
At each final disposal site, accumulated dust on theroof’s steel frame and railing was collected at aTarget facilities
random point.
In order to study dust and noise during landfill
operations (waste unloading, spreading/compacting),
Noise survey
we selected facilities with landfills in progress. The(1) Noise leveltarget facilities and survey items are shown in Table 1.
1) Study items and quantity
Primary studies were conducted at two facilities inNoise meter: 6 facilities, 8 points
2003 and secondary studies were conducted at four2) Study points
facilities in 2004.
At each facility, the noise level was measured at 4
points both indoors andTable 1 Facilities for investigation
outdoors.
Investigation
item
Investigation
Completion
Facilities for investigation
date
year
Dust
Noise
Facility details
disposal sites were carried out with the purpose of
making recommendations on environmental impact
assessment items, supposing that the items could be
simplified in the case of a closed-system facility.

Final disposal site in Y village

2003.10.9○○

1998. 3

Final disposal site in S town

2003.10.8○○

1998. 7

Final disposal site in N town

2004.10.5○－

2002.11

Final disposal site in K town

2004.10.6○－

2002.11

Final disposal site in KZ town

2004.10.12○－

2003. 3

Final disposal site in Y town

2004.10.28○－

2001. 3

Content of study
Dust survey(1) Measurement of dust concentration
1) Study items and quantity
Gravimetric method: 6 facilities, one point both indoors and outdoors
Digital dust meter: 6 facilities, total of 4–6 points indoors andoutdoors
2) Study points
At each facility, measurements were taken near
the generation source, near the vent, and at impact
points and control points set up outside the facility.
The impact points were points likely to be affected
and the control points were points unlikely to beaffected.
(2) Measurement of heavy metals in accumulated
dust1) Study items and quantity

Details of the facilities areshown in Tables 2 and 3.
Conditions during waste
unloading and spreading/compacting operations areshown in Photos 1 to 8.

STUDY RESULTS
Dust survey
Dust concentration① Final disposal site in Y village
At this site, water spraying was seldom
conducted and at the time of the study, simulated
waste unloading and spreading/compacting
operations were carried out. As a result, indoor
dust concentration rose above normal conditions
to approximately ten times higher than the control
point. Furthermore, peak concentration at the
point near the work area appeared immediately,
and a reduction in concentration was seen
relatively soon after the completion of operations.
This is presumably due to the walls having manyslit-shaped vents with three-way shutters that wereleft open during operations to allow the air to venteasily. Also, dust concentration near the shutter
openings was found to be close to the indoor
concentration.

Table 2 Details of facilities (First investigation)
Institution name
Reclaiming material
Landfill operation term
Maintained area
Reclaiming area
Scale of
Reclaiming capacity
facilities
Average height oflandfill

Scale offacilities

Final disposal site in Y village
Incinerator residue,
Nonflammable crushed waste
1998 to 2006 (Eight years)
5,951 m2
800 m22,660 m3

Final disposal site in S town
Crushed nonflammable residue
1998 to 2003 (Five years)
36,000 m2
950 m27,100 m3

5.0 m

7.5 m

Method of feeding waste

Feeding from the feeding stage(Head 2 m)

Feeding from the feeding stage(Head 5 m)

Method of covering with
soil

None

None

Frequency

None

Volume ofwater

0 m3/dWatering② Final disposal site in S town
At this site, water spraying was conductedduring waste unloading, and at the time of thestudy normal unloading and spreading/compacting
operations were carried out. However, theconcentration at the indoor points was 50 to 100
times higher than at the control point, and theconcentration outside the ventilation fan was 5
times higher than the control point. In addition,
peak dust concentration was detected during waste
unloading operations in the lower portion of the
facility, although not in the upper portion. This
could be due to the small number of openings in
the facility. The dust generated in the lower
portion could not be quickly discharged throughthe ventilation system in the upper portion.
Afterwards, dust generated during spreading/compacting operations gradually reached theupper portion of the facility and peakconcentration was later detected there.
③ Final disposal site in N town
At this site, dust concentration was low during
both unloading and spreading/compacting
operations, and no significant difference wasfound between concentrations at the impact pointand control point outside the facility. In the
behavior check on smoke from the preliminary

When waste is turned on,
OthersAverage amount of daily
precipitation during year (5m3/d)
smoke candle, smoke discharged from the roof fan
spreads on the roof, so the impact is presumably
less than from smoke discharged from the sides.
④ Final disposal site in K town
At this final disposal site, dust concentration
during waste unloading was high and as a result,high concentration was also found at the impact
point outside the facility. Also, because waste was
unloaded from a height of 4.5 m in the unloading
operations, dust concentration was momentarily
high, but then quickly decreased. An increase indust concentration was also found during
spreading/compacting operations. However, theconcentration was comparatively low and only aslight increase in concentration was found at the
impact point.
⑤ Final disposal site in KZ town
At this site, dust concentration was low during
unloading and spreading/compacting operations.
Outside the facility, a slight increase inconcentration was found at the impact point
during loading operations, but no difference wasfound during spreading/compacting operations.
Furthermore, a difference of 10–20 min was foundin peak dust concentration near the generation
source and near the vent. This is presumably due
to the large interior spatial capacity of the facility.

Table 3 Details of facilities (Second investigation)

Reclaiming area

Final disposal site
in N town
1,000 m2

Final disposal sitein K town
590 m2

Final disposal site
in KZ town
5,813 m2

Final disposal sitein Y town
2,300 m2

Reclaiming capacity

4,500 m3
Incinerator residue,
Crushed remainder

24,860 m3
Incinerator residue,
Noncombustible
matterNoncombustible
matterWaste
inthe
Collection vehicle
travels down theroad from the hall,and is unloaded
into the landfill
bottom.
(Head 1 m)

13,500 m3

Reclaiming material

1,994 m3
Incinerator residue,
Noncombustible
matterNoncombustible
matterWaste
inthe
Collection vehicle
is fed from thefeeding stage.
(Head 4.5 m)

Item

Method offeeding waste(At
investigation)

Kinds ofwaste

Crushed remainder

Method

The
waste
is
packed in flexible
containers, carried
to the landfill by avehicle fitted witha crane, and thenremoved from theflexible containers.

Incinerator residue,
Crushed remainder
Crushed remainder
Waste
at
the
recycling center iscarried by belt
conveyer, and falls
from the duct into
the landfill.

Twice/dayOccasionally(Almost everytime)
Once/day

4.2 m3/d

2 m3/dMoisture conditions ofreclamation material

Overall watering in
the morning andevening.
Moist
conditions
were
observed.

Overall wateringeverymorning.
Moist conditions
were observed.

Capacity of ventilated air(including capacity ofreclamation )12,954 m3

6,035 m3

66,860 m3

37,000 m3

Number

φ900×5

φ600×4

φ600×10

φ600×9φ400×3

Amountof wind1,150 m3/min

480 m3/min

1,200 m3/min

1,400 m3/min

Position

Top part: 5(GL + 8.9 m)

Side (both sides):Each 2 (GL + 5 m)

Side (one side): 10(GL+ 3.3 m)

Filter

None

None

Remarks－－

Method of covering with
soil
Watering

Ventilator(Exhaust fan)Frequency
Volume of
water

None

⑥ Final disposal site in Y town
At this site, indoor dust concentration was very
high during both unloading and spreading/Once a year

None

Twice/dayNone

15 m3/d

0 m3/dWatering according No watering. Dry
toreclamation conditions
werematerial.
Moist observed.
conditions
were
observed.

Side (one side): 12(GL + 14 m)
Fiber filter
None
1×2 m (for φ600)
1×1 m (for φ300)
Ten
inspiratory The device used forside ports are on ventilating the hallthe other side.
is mainly a louver(GL + 3.3 m)
type, although asuction type is usedin the landfill layer.

compacting
operations.
An
increaseinconcentration was also found at the impact points
and control points outside the facility. The

【During unloading operations】

Photo 1 (N town)

Photo 2 (K town)

Photo 3 (KZ town)

Photo 4 (Y town)

Photo 7 (KZ town)

Photo 8 (Y town)【During spreading/compacting operations】

Photo 5 (N town)

Photo 6 (K town)

spreading/compacting operations conducted at thetime of the study generated more dust than normalso the concentration was extremely high. However,the concentration at the impact point was lower
than that during unloading operations. This could
be because the wind direction changed during thestudy, eliminating the dust impact. In addition, a
10-min difference was found between the peak
dust concentration near the generation source andnear the vent, due to the large interior spatial
capacity of the facility.

and copper exceeded the reference values.
③ At the final disposal site in N town, lead and copper
exceeded the reference values.
④ At the final disposal site in K town, lead and copper
exceeded the reference values.
⑤ At the final disposal site in KZ town, lead, mercury
and copper exceeded the reference values.
⑥ At the final disposal site in Y town, lead, mercury
and copper exceeded the reference value, and themercury concentration was high.

Heavy metals in accumulated dust
Accumulated dust consists of scattered particles
from the landfilled waste and is, therefore,
considered to have almost the same components asnormal scattered dust. The heavy metals in theaccumulated
dust
were
evaluated
using“Environmental Standards for Soil Contamination”
and “Specified Standards for Specified Areas Basedon the Soil Contamination Countermeasures Law” asa reference.
As a result, the following conditions were found at
the various facilities:

Noise survey① Final disposal site in Y village
This site does not generate loud noise, apart fromthe spreading/compacting operations carried out after
unloading.
Duringthespreading/compacting
operations, the noise level within the facility
boundaries did not exceed the standard value of noise
regulations for specified construction works, whichwere used as a reference. However, the noise level at apoint 13.5 m from the opening exceeded theenvironmental standard values.
② Final disposal site in S town
At the final disposal site in S town, the sound of theventilation fan that runs during indoor operations is asource of loud noise. The spreading/compacting① At the final disposal site in Y village, copper
exceeded the reference value.
② At the final disposal site in S town, lead, mercury

operations also generate noise. However, in each case,the noise generated did not exceed the standard valueof noise regulations for specified construction works.
On the other hand, noise levels at a point 8.8 m fromthe opening exceeded environmental standard values,
regardless of whether or not spreading/compacting
operations were being conducted. At this facility, only
one of the four walls has a large opening, and that wallis installed with two large-sized ventilation fans.
Because the operating sound of the fan was greater
then the noise generated from the spreading/compacting operations, the noise level was the same
regardless of whether or not spreading/compacting
operations were being carried out.
Based on the above, although the covering has agreat effect on noise control, consideration must be
given to the operating sound of the ventilation fan andthe noise from the opening during spreading/compacting operations.

CONSIDERATIONS
Equipment at the disposal site
Ventilation system
Depending on the structure of the ventilation
system, the dust generated indoors is discharged ina concentrated manner and the operating sound of
the ventilation fan is greater than the noise of thelandfill operation. Therefore, when installing theventilation system, the structure and position of
installation should be selected in consideration of
the waste type, the landfill construction method, andthe surrounding environment.
Unloading system
The unloading operation is a large factor in dust
and noise generation. Therefore, when selecting thestructure and method of the unloading system, it isnecessary to assess various aspects such as theshape and moisture conditions of the landfill waste,
the amount of dust generated during unloading
operations, operating efficiency, etc.
Water spraying system
Water spraying not only reduces dust but also
plays an important role in promoting thestabilization of waste. Therefore, the structure of awater spraying system for the overall facility should
be determined from the viewpoint of promoting
waste stabilization, and a local water spraying
system should be a separate installation for securing
the work environment during unloading andspreading/compacting operations and reducing theenvironmental impact that accompanies indoor
ventilation.
Operation and maintenance of final disposal site
Method of transporting waste
The dust generation conditions change dependingon the drop unloading condition, the vehicle
approach to the landfill site, the use of flexible
containers and the ducting, etc. The moisture
conditions of the waste and whether or not water
spraying is carried out during unloading are also
important factors. Therefore, when selecting themethod of transport, it is necessary to consider its
suitability to the type of waste to be landfilled inorder not to generate dust. Furthermore, when
unloading waste, facility openings should be closed
whenever possible.
Spreading/compacting operation
A lot of dust is generated when spreading waste
and the concentration of dust is greatly affected by
the spreading method and moisture conditions of
the waste. Therefore, efforts should be made to
conduct operations that do not generate dust, basedon the type and moisture conditions of the waste,
while carrying out adequate water spraying. When
conducting spreading operations, it is also necessary
to close the facility openings.
Ventilation to reduce dust accumulation
We observed facilities that quickly reduced dust
concentrations and those that did not, depending on
the capacity and structure of the ventilation system.
Therefore, it is necessary to consider installing
additional ventilation according to the height of thecompleted landfill surface, which changes from day
to day. Furthermore, the analysis results on heavy
metals in accumulated dust showed large quantitiesof heavy metals. Therefore, facility operation andmaintenance should include structural improvement
such as putting filters on the ventilation openings.
Attire for working indoors
In this study, the accumulated dust was found tocontain heavy metals. Therefore, on-site workers
should be sure to wear a dust mask and clothing thatfits snugly at the neck, wrist, and ankles. It is also
necessary to conduct studies on the heavy metals
contained in the dust and based on the results,
examine the issue of indoor work clothes, referringto the “Work Manual for the Dismantling of Waste
Incinerators”, not leaving the facility in the indoor
work clothes, the installation of an air shower, etc.
Relocation of roof
In this study, the dust that accumulates on theroof’s steel frame and railings was found to containheavy metals. Therefore, it is necessary to consider
Table 4
Life environment
impact factor

the environmental impact of relocating the roof. If
the roof is reused, it is necessary to ensure that there
is no health hazard by conducting a preliminary
study, referring to the “Work Manual for theDismantling of Waste Incinerators” and eliminating
the accumulated dust prior to relocating the roof.
RECOMMENDATIONS ON ENVIRONMENTAL
IMPACTASSESSMENT
ITEMS
FOR
CLOSED-SYSTEM FINAL DISPOSAL SITES
At a final disposal site, it is compulsory to examine
the impact on the living environment that occurs fromthe disposal of waste. In the case of a closed-system
disposal site, there is less impact on the living
environment compared with an open-system disposal
site, and it is believed that environmental impact
assessment items can be simplified. Dust and noise

Living environment impact factors and investigation items
in closed-system final disposal sites (Proposal)
Discharge ofprocessing
water fromleachate
treatment
facilities

Operation of
Reclamation
Stenchfacilities
work
generation(Ventilationfrom facilities
equipment and(Landfill site)leachate treatment
facilities)◎★

Matters forinvestigation Life environment
impactinvestigation item
Dust, etc.
Nitrogen dioxide
Air
(NO2)
pollution Suspended
particulate matter(SPM)
Biochemical
oxygendemand◎☆
(BOD)
Chemical oxygen◎☆
demand (COD)
Water
Suspended solids
pollution
◎☆
(SS)
Total
nitrogen◎☆
(T-N)
Total phosphorus◎☆
(T-P)
Level of noise
Noise
◎★
◎★
Vibration Level of vibration◎☆
◎☆
Density of specificmalodorous◎☆
Stenchsubstance
Stench density◎☆
Note) Open (management) system: ◎; Closed system: ☆; ★ (Investigated this time)

Running ofwaste
transportation
vehicle

◎★
◎☆
◎☆

◎★
◎☆

were selected as items that could potentially be
simplified, and field surveys were conducted toinvestigate them as environmental impact assessment
items.
As a result, it was found that even with aclosed-system disposal site, it is necessary to conduct
environmental impact studies on the same items as anopen system. However, it is possible to simplify thecontents, depending on the study item.
Based on the above, the recommended environmental
impact assessment items for closed-system final
disposal sites are as shown in Table 4.
CONCLUSION
In this study, it was believed that environmental
impact assessment items for closed-system disposalsites could be simplified compared with open-system
disposal sites. Field surveys on dust and noise wereconducted and environmental impact assessment items
were investigated.
The results were as follows:① Regarding dust, it was found that the concentration
increased outside the ventilation fan and that theconcentration outside the facility openings was
about the same as that indoors. The concentration ofheavy metals in the accumulated dust was also
found to be high.

② Regarding noise, although the covering had a large
effect on noise control, its benefit was reduced whenlandfill operations were carried out with the
openings left open. The operating sound of theventilation fan was also found to be a source ofnoise.
Based on the above, although the factors that impact
the environment differ between open and closed
systems, the environmental impact assessment items
for closed systems need to be the same as those foropen systems.
ACKNOWLEDGEMENTS
We express our sincere appreciation to Mr. Nobuyuki
Maeda (Hazama Corporation), Mr. Tadashi Takase(JDC Corporation), and Mr. Tatsuya Kametani(Towakagaku Ltd.) for their cooperation and assistance.
REFERENCES
・Ministry of Health, Labor and Welfare, Work Manual
for the Dismantling of Waste Incinerators, Japan
Safety Appliances Association, published June 7,
2001