Detailed
Environmental Impact Assessment Study:
Volume 1: Executive Summary
Proposed Municipal Solid Waste Sanitary Landfill
in Beroga, Selangor Darul Ehsan
ES-1.1 Project Proponent, Title
The Selangor State Government is proposing to develop a sanitary landfill
facility in Beroga, Selangor for the disposal of municipal solid waste (MSW)
generated from southern parts of Selangor State and Federal Territory of Kuala
Lumpur. The project is to be implemented by Worldwide Landfills Sdn Bhd (WLSB),
Selangor Government’s concessionaire for the provision of waste disposal
services in Selangor, and will replace WLSB’s Air Hitam Sanitary Landfill at
Puchong.
The project is hereafter referred to as the Beroga Sanitary Landfill or BSL
Project.
ES-1.2 Project Overview
On behalf of the Government of Malaysia, the Ministry of Housing and Local
Government has developed a Waste Management Strategy (WMS) for Peninsular
Malaysia. The recommendations of the WMS with regards to the State of
The BSL will provide sanitary landfill facilities (ie. Facilities with a high
level of environmental controls) for the disposal of MSW within a 288ha site of
mainly State Land adjacent to Sungai Langat Forest, some 22km southeast of
Kuala Lumpur. It has been designed to accept 2,000 to 3,000 tonnes of waste per
day arriving in up to 300 trucks per day, and will have an operational lifespan
of some 15-20 years from 2005. The BSL will also accept stabilized incinerator
ash from the Government of Malaysia’s Thermal Treatment Plant that is proposed
to be located on an adjacent 19ha site.
The BSL facilities will ultimately occupy only some 88 ha of the 288ha site and
will comprise of site infrastructure (offices, internal haul roads, fencing,
surface water drainage systems, etc), a Waste Reception Facility, the landfill
area (incorporating stockpile and borrow areas), and a Leachate and Landfill
Gas Treatment Facility (systems for the control of pollution from wastewater
and the flammable gas that arises from waste decomposition).
To facilitate efficient transfer of MSW from urban areas to the BSL and to
allow for prior waste reduction, reuse and recycling, several Waste Transfer
Stations/Material Recovery facilities are also proposed for development in the
waste catchment area. Initially, three waste transfer stations where waste will
be transferred from small 1 to 10 te refuse collection vehicles to bulk 20 te
purpose built transfer trailers, are proposed to support the BSL, one each in
the Hulu Langat, Shah Alam and Olak Lempit areas.
ES-1.3 EIA Requirement
The construction of a MSW landfill facility is categorized as a Prescribe
Activity (item 18(b)iv) under the Environmental Quality (Prescribed Activities)
(EIA) Order 1987.
ES-1.4 DEIA Approach
This report presents the findings of the DEIA for the BSL Project and sets out
the mitigation measures and initial actions required to eliminate or otherwise
minimize impacts to environmental, social and health receptors. The DEIA
methodology is based on the following broad approach:
· Definition of the proposed development
identifying those activities and characteristics with the potential to
contribute to, or cause impacts to, environmental, social and health receptors;
· Establishment of an environmental baseline,
highlighting receptors sensitive to potential impacts;
· Assessment of the likely extent and significance
of the predicted impacts on specific receptors according to pre-defined
criteria; and
· Development of mitigation and management
measures to eliminate or otherwise minimize predicted adverse impacts and
optimize positive aspects of the project.
Given the close proximity of the BSL and the thermal treatment plant projects,
cumulative impacts of the two waste treatment and disposal projects are, where
relevant, assessed in total in the DEIA study. The thermal treatment plant is
however, the subject of a separate DEIA.
ES-2 Statement of Need
The need for a new sanitary landfill in southern Selangor and its associated
waste transfer stations/material recovery facilities can be summarized as
follows:
· It is in line with recommendations contained
within the government of Malaysia’s Waste Management Strategy for MSW
management in Peninsular Malaysia until the year 2020.
· It facilitates regional solid waste management
with collection, treatment and disposal of MSW from several districts such that
economies of scale can be realized together with efficient and effective
management.
· It will replace the Air Hitam Sanitary Landfill
at Puchong (that will reach full capacity by mid 2005) and existing smaller
landfills and dumpsites that are rapidly reaching capacity as waste generation
increases; and
· It will increase the environmental performance
of waste treatment and disposal facilities within the waste catchment area,
replacing facilities of inferior design and operating standards.
Failure to provide new MSW disposal facilities in the southern part of the
state, would result in a severe waste management crisis for both the State and
ES-3 Project Description
ES3.1 Project Location and Site Description
The proposed project site is located in the Mukim of Semenyih, District of Hulu
Langat. The local authority for this area is Majlis Perbandaran Kajang.
Area: Total site area is about 288ha (710acres) of
Site Condition: The site is currently a logged-over secondary forest which
extends from the Sungai Lalang Forest Reserve situated to the east of the site,
with areas of the site having been cleared for opportunistic cultivation with
fruit trees; however as
Topography: The main topographical features on the site are steep sloping hills
with two pronounced ridges. The highest elevation is 360m at the centre of the
site, while the lowest elevation of about 52m can be found along Sungai
Saringgit in the south. Across the site, the valleys are typically narrow,
deeply incised and V-shaped.
Geology: Initial gravel, sand, silt and/or clays are underlain by variably
weathered to unweathered granite bedrock. Unweathered bedrock on-site was
encountered from about 8m to 32m below ground level.
Hydrogeology: Groundwater on-site was encountered at varying depths, between 2m
and 28m below ground level. Depth to water table is generally a function of
topography, with the deeper water levels observed on the higher elevations
while shallower water levels were observed in the stream valleys. It is evident
that the hilltops and hillsides are shallow groundwater recharge zones, whereas
the valley bottoms are shallow groundwater discharge zones (ie. rainwater that
soaks into permeable soils at higher elevations re-emerges at lower elevations
as surface water in the watercourses that occupy the valley bottoms, and then
continues flowing downstream as surface water before joining Sungai Saringgit
or Tekali).
Hydrology: The site lies within the Sungai Semenyih water catchment area and is
roughly bounded by two tributaries, namely Sungai Saringgit and Sungai Tekali.
Surface water flowing from valley choke streams to the tributaries on the Site
is divided by the central peak, until the two river merge near the south-western
boundary of the site and eventually discharge into Sungai Semenyih, where a
potable water abstraction point lies approximately 24km downstream from the
Site.
ES-3.2 Site Access
The site is currently accessible from the main Federal Route 1 via State Road
B34 (leading from Semenyih to Beroga), then via a local public road that passes
through the Taman Tasik Semenyih residential housing area and a dirt track that
leads to the southwest corner of the site. The Thermal Treatment Plant (TTP)
project proposes to construct a second temporary access road for use during the
construction stage, which will bypass Taman Tasik Semenyih.
The permanent access road (to be provided by the TTP project) will originate
from B34, approximately 2km east of the existing junction to Taman Tasik
Semenyih. Access to the BSL will be via a slipway to the south of the TTP
project area.
ES-3.3 Overview of Landfill Operation
…. Upon arrival at the landfill’s Waste Reception Facility, the waste trucks
will be weighed at the weighbridges before proceeding to the active landfill
tipping area. The waste content will be visually assessed to ensure that only
permitted waste types are accepted for disposal; any hazardous or non-permitted
materials will be rejected.
The trucks will deposit their waste at the tipping area; heavy machinery such
as compactors, bulldozers and excavators will move in to spread and compact the
waste. At the end of each day, the area used for tipping will be covered with
soil to provide a protective covering for the waste to reduce odour, litter and
vermin. More durable intermediate soil covers and a final impermeable cap will
also be provided at the completion of each cell and a landfill phase
respectively.
Contaminated wastewater or leachate (generated by rain water seeping through
the landfilled area) will be collected and treated at the leachate treatment
plant. Additionally, the malodorous, flammable gas that results from anaerobic
waste decomposition, termed landfill gas, will be collected and combusted by
flaring or, when volumes permit, sent to a landfill gas utilization plant to
generate electricity.
After tipping, the trucks will return to the weighbridge for weighing before
leaving the site. The weight of the received waste will be recorded in the
computer database.
Reusable and recyclable materials recovery is currently not planned at the BSL,
it is anticipated that recoverable materials will be sorted and recovered at
the proposed Waste Transfer Stations / Material Recovery Facilities.
ES-3.4 Design Basis and Criteria
The conceptual design of the BSL was initially conceived with the aim of
meeting the following design criteria:
· A design lifespan of between 15 to 20 years,
assuming a daily waste reception of between 2,000 and 3,000 metric tones/day;
· A total waste disposal capacity of some 15
million cubic metres, primarily to dispose of MSW (about 80 – 90%) with some
non-hazardous industrial wastes.
· Maximised use of existing topographic features
such that no fill or daily cover materials need to be imported to or exported
from the site;
· Development of the 3 principal areas identified
in phases via the construction of waste containment bunds in the suitable
natural valleys identified within the project site.
· A buffer zone of a minimum 250m from waste
placement areas to the site boundary/nearest private properties; and
· To exceed the design requirements for Level 4
sanitary landfills in the Ministry of Housing and Local Government’s Technical
Guidelines on Sanitary Landfills, 1990.
ES-3.6 Key Design Features
Specific pollution control technologies/features incorporated into the design
and operation of the BSL are detailed below:
ES-3.6.1 Earthworks and Slope Stability
The BSL has been designed to minimize the earthworks (excavation and fill)
required within the waste disposal area, while balancing the earthwork
requirements across the entire site to the greatest extent practical.
· Stockpiles: Top soil and excess soil from each
landfill phase area will be stored for later reuse as waste cover material of
for landfill restoration.
· Erosion Control: Erosion control measures will
be provided to control the erosion of soil caused by the clearing of
vegetation. Site formation and final wastes slopes will be benched and sediment
basins/detention ponds provided to intercept entrained solids.
· Waste Containment Bunds: Waste containment bunds
of earth or earth/rockfill design will be installed to hold the landfilled
wastes within in landfill area or sub-area. The up-gradient height of the bunds
will generally be limited to 5m with the corresponding down-gradient height
typically ranging from 25m to 65m, depending on the valley slope.
· Slope Stability: To address the issue f
stability, the landfill has been generally designed with slopes equal to or
flatter than the effective angle of the existing ground surface, with typical
slopes of between 1V:2.0-3.0H(1 Vertical to 2-3 Horizontal) and overall
effective slopes of between 1V:3.0-3.5H. Design slope stability analysis shows
Factors of Safety exceed the minimum values specified in the MHLG Guidelines
for all slopes under both static and seismic conditions.
ES-3.6.2 Groundwater Management System
To develop the Site as a landfill, the groundwater must be managed in such a
way as to allow construction of the overlying lining and leachate collection
systems, to prevent a hydrostatic build-up of water below the base liner and to
prevent the ingress of groundwater into the overlying waste mass during the
operational life and beyond. Based on the hydrogeology of the Site the
resulting groundwater control system design consists of three components, as
detailed below:
· A granular collection system imbedded with
perforated plastic pipes to collect groundwater discharged to the base of the
deeply incised valleys;
· Extraction points of interruptions in the
collection system where the collected volume of groundwater is drawn-off and
routed into a discharge pipe and directed toward an outlet; and
· Discharge pipes, connected to the extraction
points diverting collected groundwater by gravity to the surface water
perimeter drains.
Provision of sampling to detect potential contamination by any leachate leaking
through the overlying landfill liner will be incorporated at the outlet
locations. If future operational monitoring identifies contamination in the
groundwater, then the liquid can be pumped to the LTP for treatment.
ES-3.6.3 Leachate Management System (LMS)
Leachate or landfill wastewater, is produced from the liquid and moisture
within waste as well as from rainwater percolating through the waste mass. The
nature of this liquid is generally malodorous and pollutive and it has the
potential to contaminate surface and groundwater resources unless it is
properly managed. Leachate management is one of the most critical systems in
the design of the BSL and will consist of various components, including:
· Leachate minimization;
· The leachate collection system; and
· A Leachate Treatment Plant (LTP)
· Leachate Minimisation -- At the BSL, leachate is
generated through gravity drainage of liquids from within the waste of
infiltration of rainfall into:
· Open waste (exposed waste surfaces);
· Daily cover (waste temporarily covered with a
minimum of 150mm of soil at the end of each day);
· Intermediate cover (waste covered with a minimum
of 300mm of compacted soil on areas left exposed for longer periods); and
· Final cover (waste covered with an impermeable
geomembrane capping system at the end of each landfill phase.)
Little can be done to reduce liquids that arrive with the waste and hence the
focus is on managing the landfill to minimize exposed waste surfaces by
covering the waste as soon as practical and minimising surface run-on to
exposed or temporarily covered wastes.
· Leachate Collection System – Leachate will be
prevented from seeping into the ground and contaminating underground water via
a liner system and then collected in a drainage layer above it.
· Impermeable Liner System; The liner system
design exceeds MHLG guidelines and broadly comprises from bottom to top;
· A groundwater underdrain (granular)
· A compacted soil layer, 300-500mm thick, of low
(<1x10-6 cm/sec) permeability.
· A 2mm HDPR (plastic), chemically resistant;
impermeable geomembrane; and
· A protective geotextile cushion.
· Leachate Collection: A gravity system will be
installed above the liner system to drain the leachate from the waste to sumps
located at the waste containment bunds. This will comprise a geocomposite
drainage layer across the landfill side slopes and, for the landfill base, a
300-500mm granular layer embedded with perforated plastic pipes sandwiched
between geotextile cushions.
· Leachate Treatment Facility – The leachate will
be conveyed in pipes running alongside internal roads, to an on-site storage
area comprising of either tanks or lagoons with a capacity to store 15,000
-20,000 m3 that will buffer the Leachate Treatment Plant (LTP). In the
treatment process, it will be treated to remove pollutants, odorous compounds
and to meet the applicable Standard A effluent discharge standards before being
discharged to Sungai Saringgit. After considering various alternatives and site
specific conditions, the conceptual design proposes a system including direct
aerobic biological treatment in a Sequencing Batch Reactor system followed by
polishing in a membrane filtration plant using a combination of Multi Media
Filtration, Ultra Filtration and Reverse Osmosis. To provide redundancy and
safeguard against breakdown and pollution of surface water resources, the
proposed LTP at the Beroga Landfill will use a dual line system. Each line has
the capacity to treat 40 m3 /hr or a total of 960 m3 /day of leachate,
comprising a total of six biological Sequencing Batch Reactor’s and 2 strings
of Ultra Filtration and Reverse Osmosis units in combination. Any effluent
found to contravene Standard A limits can be recirculated to the landfill/ LTP
thereby providing a further safeguard that all effluent will meet Standard A
prior to discharge.
ES-3.6.4 Surface Water Management System
The surface water management system at BSL is designed to control surface water
run-on fro upgradient areas (ie. Sungai Lalang Forest Reserve) and run-off from
final restoration and temporary slopes to minimize soil erosion and maintain
surface water quality. Control of potentially contaminated run-off is critical
to prevent pollution of the adjacent water courses. The drainage system around
the landfill cells will segregate uncontaminated surface run-off; contaminated
streams will be routed to undergo appropriate treatment at the LTP prior to
off-site discharge. The surface waster run-off drainage system will also help
to minimize the volumes of leachate produced. This system comprises a series of
temporary and permanent storm water channels, culverts and detention/sediment
traps designed in accordance with DID requirements.
ES-3.6.5 Landfill Gas Management System
Landfill gas is a natural by-product of the waste decomposition process under
semi-aerobic and anaerobic conditions. Typically it comprises mainly methane,
carbon dioxide and trace levels of other gases (including odorous gases such as
hydrogen sulphide). The proportions of these compounds vary over the life of
the landfill and from landfill to landfill. The quantity also varies from
little or none in the early years of operation, rising to a peak during the
operational period before gradually declining over many years following
operation of the landfill.
Landfill gas is flammable, a greenhouse gas (ie contributes to global warming)
and malodorous. Hence failure to adequately control it can result in various
environmental impacts. Conversely, once present in sufficient quantity it
presents opportunities for utilization in the production of electricity.
Consequently, a progressive approach has been adopted in the selection of
options for its control and utilization.
The components of the landfill gas management system for the BSL will vary over
the lifetime of the landfill depending on the rates of gas produced from:
· Collection and combustion in a mobile flare;
· Collection and piping for combustion in a larger
permanent flare located within the Leachate and Landfill Gas Facility area; to
· Collection and combustion in a landfill gas
utilization system consisting of a landfill gas-to-electricity generator set
fully integrated with the landfill gas collection, extraction and treatment
systems.
ES-3.6.6 Final Cover/Capping System
The final cover and capping system will be designed to reduce rainwater
infiltration, minimse landfill gas migration, support vegetative growth and
provide a barrier between the waste residue and the environment. As the waste
is placed in lifts and brought to the final design elevation, an intermediate
cover soil is to be placed and compacted across the surface. The final capping
system cross-section selected for use includes, from bottom to top, above the
waste:
· Intermediate Cover Soil Layer – a minimum of
300mm thick;
· Geomembrane Capping Layer – a minimum 1mm thick,
plastic
impermeable geomembrane flexible enough to allow for settlement of the final
landform;
· Geocomposite Drainage Layer – the geocomposite
(geotextile/geonet/geotextile) will serve as the drainage layer over the
impermeable geomembrane cap surface;
· Soil Cover Layer – minimum 600mm thick soil
cover layer designed to protect the underlying geomembrane and goecomposite
drainage layers of the capping system from potential damage; and
· Topsoil Layer – designed to be nominally 100mm
thick to support vegetative growth on the final cover surface. The topsoil
stripped from the existing ground surface and stockpiled at the outset of
landfill development, possibly mixed with compost, will be used.
ES-3.6.7 Final Landform
The long-term restoration and landscaping strategy for the BSL site will aim to
maximize the potential visual benefits of the project and minimize any adverse
impacts. The final configuration of the capping system will e a series of !V:3H
slopes with 1.5m wide benches spaced at 5m intervals vertically, and a 5m wide
bench every 25m in elevation (every 5th bench). The overall effective slope of
the capping system will be approx. 16 degrees (1V:3.5H) and a top surface
sloping at approximately 5 degrees (1V:11.5H). These grades provide efficient
and controlled stormwater flows, slope stability in excess of MHLG Guideline
minimum Factor of Safety values and are compatible with the surrounding
topography.
ES-3.6.8 Environmental Monitoring System
The Environmental Monitoring System will provide a means to check that all
equipment and technologies used for the sanitary landfill are performing at
their optimum; the system will include the following aspects:
· Permanent monitoring boreholes for groundwater
quality;
· Quality of groundwater extracted from the
underlying groundwater collection system;
· Leachate composition and quantity;
· Treated discharge effluent quality;
· Surface water quality and visual inspection; and
· Landfill gas quality and quantity.
ES-3.7 IMPLEMENTATION
The duration of each of the principal landfill activities can be summarized as
follows:
· Advance Works – 12 to 14 months;
· Construction (landfill formation) / landfill
operation – 15 to 20 years;
· Landfill Closure and Restoration – continues
over 15 to 20 years; and
· Site Aftercare – for decades as the waste
gradually decomposes.
First waste is due to be received by mid 2005 to replace the Air Hitam Sanitary
Landfill that will have already reached capacity. Hence the Advance Works and
Construction stage is proposed from early 2004.
ES-4 Project Options
This section looks at the alternatives available to the BSL project as proposed
in the context of:
· A comparison of the alternative technology
options for waste management in Selangor;
· A comparison of landfill technology options;
· Landfill area siting and phasing options; and
· The ‘No Project’ Option and potential impacts
thereof.
The site at Beroga has been provided by the State government for the express
use for municipal solid waste treatment and disposal in the context of other
demands on State Land in southern Selangor. The consideration of alternative
sites for the landfill is not within the scope of the current study.
ES-7 SUMMARY OF KEY ENVIRONMENTAL SOCIAL AND HEALTH IMPACTS
ES-7.1 Advance Works and Construction Stage
ES-7.1.1 Soil Erosion
Potential increases in soil erosion rates will start during site clearance and
endure until restoration and reinstatement measures take hold. The potential
for soils to undergo erosion, and the extent to which the erosion occurs, will
be a function of the occurrence of intense precipitation events (rain), the
extent/steepness of slopes and soil nature. Soil erosion can cause an increase
in sedimentation of downstream water bodies, landslides and flooding unless it
is adequately controlled.
Soil erosion modeling shows that during the construction stage of the proposed
landfill, soil erosion impacts could be significant if poorly controlled.
However, with adequate control measures, the eroded sediments can be contained
on-site. It is therefore crucial that soil erosion control measures are fully
implemented and efficiency maintained, particularly given the steep nature of
the on-site terrain. Control measure include construction and maintenance of
adequately sized detention ponds and sediment basins prior to the clearing of each
new landfill phase, minimization of exposed soil/time it is exposed, terracing
of exposed slopes, and grass seeding/lining of cut slopes during the early
stages of construction. The off-site impacts of sedimentation are discussed
below.
ES-7.1.2 Surface Water
Key impacts to surface water during the Advance Works and Construction Stage
include elevated suspended solids and organics in construction site run-off
from cleared areas, construction vehicles/equipment maintenance areas and the
risk of flooding of downstream areas.
A water quality modeling study was undertaken utilizing the water quality model
component of the MIKE11 model for a range of normal (silt traps
operating/detention ponds in place) and abnormal scenarios (failure of
controls). Suspended solid levels would increase dramatically with commensurate
significant impacts to water quality without the controls working effectively.
Provided that the detention ponds/sediment basins are designed according to
recommendations in the Drainage and Irrigation Department (DID)’s Urban
Stormwater Management Manual, negligible flooding risk is expected downstream.
The modeling has shown that sediment basins size requirements are greater than
those required for flood prevention. The sizes estimated as part of the
conceptual design are large, at 3400, 3000 and 7600 m3 for the LTP area, Waste
Reception Area and landfill Area A, respectively. Hence it is essential they
are of a robust design and appropriately sited during detailed design of the
BSL. In addition WLSB will prepare an Erosion and Sedimentation Control Plan
prior to construction in accordance with the DID Urban Stormwater Management
Guidelines.
ES-7.1.3 Air Emissions & Air Quality
Ambient air quality at the proposed site and its surroundings may be impacted
by dust emissions from landfill development activities (e.g land clearing,
earthworks, transportation of earthmass / construction materials). Construction
activities have the potential to result in adverse impacts on air quality as
well as generating significant local nuisance effects if uncontrolled.
The impact of fugitive dust on off-site receptors will depend on both the
quantities of dust entrained into the atmosphere and the distance of receptors
from the source of dust. Larger dust particles (>30µm in diameter) may
undergo impeded settling, but are likely to settle out within a distance of
about 100m from source. Fine particles (<30µm in diameter) have much slower
gravitational settling velocities and are much more likely to have their settling
rate retarded by atmospheric turbulence. However, given the distance to the
nearest community area (~ 2 km away), dust impacts at community areas are
expected to be minor, especially once the temporary construction road is
available. Construction activities must follow “good site practices”
recommended in the DEIA to control dust emissions.
ES-7.1.4 Noise
Noise levels of up to 72dBA are conservatively predicted at the boundaries near
the Waste Reception Area and Landfill Gas and Leachate Treatment Facilities
respectively. At Taman Tasik Semenyih (~2.5km from the site boundary), noise
levels are predicted to be below 31dBA.
ES-7.2 OPERATIONAL STAGE
ES-7.2.1 Soil Erosion
Soil erosion will be a similar concern during the operation of the landfill as
construction activities will continue throughout the Operational Stage. In
addition, whilst landfilling is ongoing in one phase, the subsequent phase will
likely be under construction. Additional soil erosion source during the
Operational stage will be erosion of exposed intermediate cover in filled or
partially filled cells. Completely filled landfill cells will be turfed to
reduce soil erosion rates.
During operation of the landfill cells, the erosion rate will at times be
significant depending on the size of open soil areas on site. However, sediment
will be contained in permanent detention ponds/silt traps that will be
constructed according to landfill phasing. Final design and location of
sediment traps are yet to be decided, but are likely to be down gradient of
each landfill phase rockfill bund or in adjoining valleys. Where possible they
will be maintained during the operation of each phase to ensure operational
soil erosion is adequately controlled.
ES-7.2.2 Groundwater
ES-7.2.2.1 Sources of Impact
Potential impacts from the uncontrolled flow of leachate into the groundwater
system include degradation of groundwater quality, soil contamination and
adverse impacts to surface water quality.
ES-7.2.2.2 Design Controls
Risks of soil and groundwater contamination can be minimized via effective
procedural and hardware controls; long term groundwater protection measures
included in the design are the leachate lining and collection systems, and the
groundwater management system. However, in spite of the control measures, leaks
of leachate through isolated defects in the liner installation and piercing of
the liner by accidental damage are inevitable. Typical leakage rates for MSW
sanitary landfills similar to the BSL range between 50 to 200 litres/ha/day.
ES-7.2.2.3 Evaluation of Impacts
A preliminary groundwater modeling study has been conducted on a conservative
basis. Analysis of the regional hydrogeology shows that due to groundwater
divide, groundwater from the landfill site within the Sungai Seringgit
catchment cannot migrate to adjacent catchments such as Sungai Rinching. In the
case of the BSL site, the groundwater naturally flows from higher elevations to
the base of the steep sided valleys, emerging as surface water and discharging
into the streams below the landfill areas, and ultimately, Sungai Saringgit or
Sungai Tekali. As such any groundwater contamination will be largely confined
within the Site. No groundwater abstraction points or direct groundwater users
are identified between the two rivers were any groundwater is expected to
discharge. Other sensitive groundwater receptors in the region including the
Semenyih Dam (~10 kmnorth of the site) and the mineral water abstraction points
at Kampung Sompo, Lenggeng, Negeri Sembilan (~14km southeast of the site) are
located beyond the zone of potential impact.
On the understanding that groundwater will discharge to surface water courses,
an initial calculation of the likely worst case groundwater pollutant loading
was undertaken to be included in the surface water quality impact assessment.
ES-7.2.2.4 Mitigation
The recommended mitigation measures include implementation of quality work
procedures/quality inspection checks to ensure the liner system is installed
with integrity, and monitoring of the groundwater quality from both monitoring
wells and from the outlet of the groundwater management system’s discharge
pipes. Provision has been made to route any contaminated groundwater to the
LTP.
ES-7.2.2.5 Residual Impacts
Provided that the control measures are implemented and maintained accordingly,
adverse impacts to groundwater and surface water can be avoided.
ES-7.2.3 Hydrology and Surface Water
ES-7.2.3.1 Sources of Impact
The principal sources of impact during the Operational Stage of the BSL are
water pollution due to sediment discharge, flooding in downstream areas and
water pollution due to planned and unplanned discharges to surface water,
including leachate, sewage and potentially contaminated groundwater discharge.
Water quality impacts due to sediment and wastewater/leachate predictions
during the Operational Stage have been evaluated taking into consideration the
cumulative effects from the Thermal Treatment Plant and the BSL.
ES-7.2.3.2 Controls
A two-train leachate treatment plant of 80m3/hr capacity will be constructed to
treat the collected leachate to meet Standard A discharge limits and other
additional design parameters, to ensure acceptable impacts to the receiving
environment. A leachate storage tank/lagoon with a capacity of 15,000 to 20,000
m3 and holding time of at least 10 days will also be provided to buffer the LTP
from major precipitation events and during down-time of the treatment process.
ES-7.2.3.3 Evaluation of Impacts
A water quality modeling study has been conducted in support of the water
quality assessment. The scenarios considered in the modeling study include both
normal and abnormal events, with all landfill systems and the TTP working as
planned and with partial and complete breakdown of the LTP. All scenarios
included an estimate for contaminated groundwater discharge.
· For normal operations (LTP/TTP complying with
Standard A discharge limits), modeling results predicted that the cumulative
impact has a minor localized effect upon water quality in the river system. For
all pollutants, there is no detectable difference in pollutant concentrations
in Sungai Semneyih or at the PUAS water treatment plant.
· Abnormal operations: Modeling results indicate
that failure of the LTP would result in the sudden degradation in local river
water quality (in respect of DO, BOD, TSS, COD, ammoniacal nitrogen, phosphorus
and heavy metals), and commensurate impacts to aqualtic life, if the abnormal
discharge were sustained. The model however predicts a reasonably rapid
response and recovery to normal water quality conditions, ie within 12 hours.
Proper operation of the LTP and the TTP according to design is hence crucial to
ensure minimal impacts to river water quality.
The modeling results also indicate that the far-field effects of failure of the
LTP would be small, with changes to water quality at the PUAS water abstraction
point almost undetectable with no effect on its operation.
ES-7.2.3.4 Mitigation
Whilst the two train LTP design proposed, together with the buffer storage,
does afford some redundancy and allows time to rectify breakdowns, it is
recommended that WLSB consider a three train design of equivalent capacity such
that failure of one train would still enable all effluent to be treated by the remaining
two trains for limited periods during almost all of the landfill life. In any
event, the LTP will incorporate continuous monitoring of influent and treated
effluent quality and include alarm systems to alert personnel of any
abnormality in the LTP operations.
ES-7.2.3.5 Residual Impacts
Provided all design control measures are implemented, there will be no
significant impact to receiving water quality from the discharges from the BSL
and TTP projects under normal operating conditions. In the event of discharge
of untreated effluent from the BSL TTP, localized impacts will be significant,
but negligible downstream in Sungai Semenyih and at the water intake point.
ES-7.2.4 Air Emissions and Air Quality
Potential key air quality impacts during the Operational Stage of the landfill
may arise as a result of the following:
· Dust emissions from ongoing cell
construction/waste handling operations;
· Landfill gas generation and disposal:
· Possible fires in the waste management area and
lateral migration of LFG to on-
site underground services and off-site buildings
resulting in hazards to human
health/fire/explosion.
· Air quality and global warming effects from
fugitive emissions
of LFG that escape to atmosphere (estimated at 20-40% of the total generated).
Estimated fugitive emissions of the greenhouse gases methane and carbon dioxide
will represent a relatively insignificant contribution to total Malaysian
greenhouse gas emissions.
· Air emissions from landfill gas flaring/utilization;
and
· Odour emissions from the waste handling and
degradation processes.
ES-7.2.4.1 Air Emissions from the Flare System
Air quality impacts as a result of the principal operational air emissions from
the landfill flare have been evaluated in an air dispersion modeling study,
using the USEPA approved Industrial Source Complex Short Term (ISCST3) model.
The LFG flare system will emit several air pollutants including combustion
products (NO2, SO2, CO, PM10) and trace constituents such as hydrogen chloride
and hydrogen fluoride. Emissions from the LFG flare under normal and maximum
design conditions are predicted to result in highly localized but negligible
air quality impacts. Post year 2007, the TTP will be operational and combined operational
emissions have been assessed. Impacts distinct to the LFG flare are difficult
to distinguish from those of the TTP alone, other than highly localized areas
around the flare (within 1km of the site).
ES-7.2.4.2 Odour Impacts
The generation and release of odorous compounds from waste materials during
transport, handling and disposal operations are inevitable and unavoidable
consequences of these types of operation. The primary sources of odour
emissions considered are uncovered wastes and the LTP at the BSL site and, for
the cumulative impact assessment, odour emissions from the TTP waste pit.
An assessment of odour impacts has been included in the air dispersion modeling
study using the USEPA ISCST3 Model. In the assessment, an odour nuisance criteria
of 5 OU/m3 has been used (ie this is the level of odour at the receptor that
would be expected to result in annoyance/odour complaints in the vent of
repeated exceedances).
The predicted maximum ground level odour concentrations under worst case weather
conditions at community areas as a result of estimated cumulative BSL and TTP
odour emissions range from 0.1 to 2 OU/m3. As such, odour concentrations
resulting in odour annoyance/complaints are not likely to occur, although
occasionally, under worst case weather conditions (Class F). These weather
conditions typically only occur at night, when waste will have been covered
with inert soil material significantly reducing the likely impact from that
modeled. Modeling results under typical daytime weather conditions (Class A),
when waste will be exposed to atmosphere, show considerably lower odour
concentrations and impacts well below the odour nuisance criteria.
Cumulative Impacts
The BSL is the dominant source of odour emissions as compared to the TTP. Its
design includes a wide range of measures (both procedural and hardware) to
control/minimize emissions of odorous compounds. It is considered important to
ensure that the leachate storage facility is covered and open waste areas are
covered with inert soil as soon as possible after placement (daily cover). No
new residential areas should be permitted within 1.5km of the site.
Despite the application of the proposed odour control measures, some temporary
odour nuisance may still occur and odours may also be detectable on occasions
in the general areas immediately adjacent to the site. Although these impacts
are expected to be intermittent in occurrence and temporary in nature, some
complaints may be received from the community.
ES-7.2.5 Noise
Noise levels resulting from landfill operations and the operation of TTP have
been predicted and compared with environmental noise criteria stipulated in the
DOE’s Guidelines for the Siting and Zoning of Industries, 1994.
Predicted noise levels over most of the project site boundaries are expected to
e below the 65dba guideline during the BSL Operational Stage. However, noise
levels at the east boundary (Sungai Lalang Forest Reserve – operations of Phase
A) and south boundary (next to the Waste Reception Area during all phases) are
predicted to be more than 70dBA, exceeding the 65dBA boundary noise limit even
after the application of cost effective mitigation measures. Conversely at the
surrounding communities in the vicinity of the project site, noise levels will
be well below the DOE daytime and night-time noise limits.
Noise levels due to the increased traffic volumes along the Beroga-Semenyih
road are predicted to generally increase by ~6dBA (ie up to 73dBA) during the
peak hours for the landfill operation.
ES-7.2.6 Land Use
The minimum buffer zones from the waste disposal areas to the nearest privately
owned property is set at 250m. This reduces conflicts with surrounding
sensitive receptors. Potential conflict on land use compatibility is the
permanent loss of agricultural land (ie orchards at the southern section of the
site) due to land acquisition and more difficult access to forest reserves by
the Orang Asli from the nearby Kampung Orang Asli Kachau and Kampung Orang Asli
Beroga. Potential conflict with current residential areas (ie Taman Tasik
Semenyih) may result in a reduction in property values in the vicinity. In
addition, the land use of the proposed site may conflict with future built
developments (residential/institutional) that may be planned for the area.
However the proposed TTP project, immediately adjacent to the BSL site, would
be compatible with the proposed landfill project. Further the BSL is not
expected to have a significant conflict with the regional trend for the area,
which is mainly agricultural and conservation status.
Future development in the vicinity of the BSL (1.5km) should be limited to
low-density development such as:
· Waste recycling and supporting ancillaries;
· Landscape plant nurseries;
· Utilities;
· Wood industries and forest conservation
activities;
· Cemeteries; and
· Agricultural based industries.
The agricultural zoning of the area and conservation status of the forest
reserves should be maintained and future re-development of agricultural areas
in the vicinity for residential purposes should be kept minimum, at least until
the operational life of the landfill is complete. In particular, it is
specifically recommended that no built development be permitted on agricultural
plots immediately to the south of the TTP and the BSL.
ES-7.2.7 Traffic
An increase in the number of vehicles on public roads due to operational
vehicles generated by the proposed BSL has the potential to cause road traffic
congestion and accidents. Increases in traffic volumes during the Advanced
Works (2004/5) of the BSL are not expected to be great as most construction
vehicles will remain on site. Once operations commence in 2005, waste will be
transported to the BSL in either 40 m3 (20te) purpose built waste transfer trailers
(up to 105 truck/day originating at the Waste Transfer Stations) or smaller
1-10te refuse collection vehicles (direct from community refuse collection).
Peak BSL traffic flow will comprise a total of 300 trucks/day.
From the period 2005-7 the TTP project will be under construction and reach a
peak in traffic movements in 2007 of 755 vehicle trips/day. Once operational,
TTP peak traffic movements will comprise 278 truck trips/day and 626 passenger
car movements/day.
A cumulative traffic impact study has been undertaken for normal and worst case
conditions at key junctions en-route to the BSL/TTP projects. Impacts could be
significant without planned improvements to the existing road network. It is
strongly recommended that the state government provides a proposed dedicated
access route (or Semenyih bypass) by connecting the KASEH Highway (expected to
be completed in 2006) to Jalan Beroga to obviate the need for most trucks to
pass through Semenyih town, improve safety and mitigate traffic impacts to acceptable
levels.
ES-7.2.8 Social Impacts
The local community was consulted regarding the possible impacts of the
proposed BSL. Overall the community has requested that the economic benefits
generated by the project will benefit local communities through the employment
of local workers and contractors. In addition, the residents are concerned
about the possible negative property value/amenity effects as a result of the
proposed BSL.
The social impact assessment details impacts that may occur during the different
phases of the BSL project due to changes such as:
· The generation of new employment and economic
development: This has positive effects on the economies of the local
communities, particularly if the proponent can successfully ensure the employment
of local workers and contractors. The effects of foreign worker employment will
also need to be managed by the proponent.
· Land acquisition and resource loss: The loss of
land and access to natural resources may result in the loss of economic activities
such as farming and aquaculture and may cause social displacement as residents
leave the locality to seek alternative income. The use of the site for the BSL
may also restrict the economic activities of the Orang Asli. Compensation
measures are an important mitigation measure to reduce the severity of impacts
as a result of land acquisition and resource loss.
· Reduced amenity due to noise, dust, exhaust
emissions and odour : This has economic impacts for local businesses and
effects on community cohesion. Residents may be less active in the community if
the outdoor environment is poor. In addition, reduced amenity has impacts on
property value. The controls and mitigation measures proposed in the DEIA to
manage and reduce emissions will assist in minimizing these impacts.
ES-7.2.9 Public Health
The anticipated health impacts are classified
into the following categories:
· Eye and respiratory related diseases:
construction workers are expected to be susceptible to eye and respiratory
diseases due to their routine exposure to dust and exhaust emissions on site.
These effects could possibly be mitigated through pre-employment health
screening, induction training and the use of PPE. The environmental health risk
assessment (EHRA) indicates that the percent changes in mortality and morbidity
due to both maximum exposure and highest community exposure to the incremental
PM10 from the proposed sanitary landfill are both not significant. The increase
in respiratory and cardiovascular morbidity, mortality and patient care due to
increase in ambient PM10 concentrations associated with the operation of the
proposed sanitary landfill is expected to be very minimal.
· Disease Related to Contamination of Heavy Metals
in Surface and Groundwater: the calculated hazard indices for exposure to the
selected water pollutants (ie mercury, arsenic, cadmium, nickel and
chromium(IV) through swimming exposure are less than 1, indicating
non-hazardous, non-carcinogenic health effects over a lifetime exposure
duration of 70 years to the predicted concentrations of these pollutants in the
river water. The total lifetime excess cancer risk associated with swimming in
the immediately downstream of the LTP discharge point and Sungai Tekali
confluence is expected to be (between 1.5 to 2.3x10-5) in excess of the 10-6
lower acceptable risk level but below the 10-4 upper acceptable risk level.
However, in practice, the likelihood of the public swimming in the river
stretch (adjacent to the sanitary landfill) is considered low given the
physical conditions/constraints of the river itself (the first river stretch is
shallow and narrow while the second river stretch is a shallow concrete monsoon
U0drain).
· Pathogenic micro-organisms related diseases:
Non-communicable (ie. between humans) but propagated through unhygienic
conditions and vectors. Possible impacts may be mitigated by implementing a
vector and pest control programme, conducting regular hygiene inspections and
implementing a waste management programme.
· Physical injuries: Caused primarily by
occupational-related accidents, animal bites, etc. Activities such as land
clearing, tree-felling, earthworks, construction of facilities present various
occupational hazards to the workers on site. These risks can be mitigated
through the provision of appropriate training, emergency response procedures
and the provision of adequate PPE.
· Physiological disorders: Medium to long-term
physical illnesses such as loss of hearing, cancer, etc resulting from exposure
to undesirable working/living conditions. The risks of this type of illness can
be managed through pre-employment health screening, the use of appropriate PPE
and worker education and training.
· Psychological disorders: Some workers may suffer
from depression and anxiety disorders due to working and accommodation
conditions, and their relationships with fellow workers. The psychological
wellbeing of some members of the communities may be affected due to
disturbances created by landfill activities. Mitigation measures for workers
include the adherence to standards regarding working conditions. The wider
community can benefit from health awareness programmes.
· Communicable diseases: Include SARS,
tuberculosis, infectious respiratory diseases, sexually transmitted diseases
(including HIV/AIDs) and hepatitis. Education and training programmes are
essential to the management and reduced infection rates of communicable
diseases.
ES-7.2.10 Landscape and Visual Impacts
The predominant landscape impacts will be the loss of vegetation cover and
changes in topography as a result of excavation, the application of landfill
and the capping and closure of the landfill. Visual impacts will predominantly
be viewed from the settlement of Taman Tasik Semenyih and the site of the
proposed University Nottingham in Malaysia and Balau mixed development area.
Visibility will be reduced due to haze and cloud on most days of the year.
However the fundamental components of the landfill, such as the clearing of
vegetation, application of geotextile layer and the application of refuse will
be visible from these viewpoints. The overall effect on the landscape and
visual character of the locality is expected to be minor.
ES-7.2.11 Risk Assessment
Risk assessment seeks to address the effects of abnormal or unplanned events in
terms of likelihood and the severity of any consequences. The consequences are
usually related to off-site human receptors in terms of loss of life, injury,
or illness or to impact to the environment. The events relevant to operation of
a landfill are those associated with construction (catastrophic landslides or
collapse, unplanned events such as severe sedimentation or erosion leading to
surface water pollution and downstream flooding) and:
· Leakage of the liner system and contamination of
solid, groundwater and/or down gradient surface water resources;
· Failure of the Leachate Treatment Plant
resulting in prolonged discharge of untreated leachate into the adjacent
rivers;
· Catastrophic failure of the leachate storage
tanks/lagoons and discharge of up to 20,000 m3 of leachate to surface water
resources;
· Risks associated with leakage and lateral
migration of Landfill Gas in the vicinity of landfill areas;
· Risks to human health from fugitive emissions of
landfill gas that may disperse off-site; and
· Risks of landfill gas explosion and fires in and
around the landfill.
… WLSB is committed to adhering to good management practices and implementation
of appropriate preventative and control measures during all stages of the
project to manage the risks to within levels which are as low as reasonably
practicable. An emergency response plan must therefore be prepared to address
residual scenarios both on and off-site.
ES-7.3 Landfill Aftercare Stage
ES-8 ENVIRONMENTAL MONITORING & MANAGEMENT
ES-8.1.1 Environmental Management
The development of an Environmental Management Plan is recommended for both the
advance works & construction stage and the Operational / Aftercare Stages.
EMP should provide monitoring programmes for:
· Air emissions;
· Landfill gas screening;
· Surface water quality;
· Site drainage discharge quality;
· Silt trap discharge quality;
· Treated leachate discharge quality;
· Soil and sedimentation;
· Groundwater;
· Noise; and
· Aquatic biology.
EMP should also provide plans for soil and sedimentation control, traffic
management, community relations and landscaping and revegetation. Environmental
and safety audits are recommended to check for compliance with regulations and
to provide reference material to allow for effectiveness of the EMP to be
reviewed and updated as required.
ES-9 Cost Benefit Analysis
A cost benefit analysis has been carried out for the project. Due recognition
has been given to both internal and external impacts of the landfill project.
The costs – both capital costs and operating costs – have been obtained from
WLSB and are assessed to be in line with international and other Malaysia
projects of a similar nature.
The annual volume of waste has been assessed conservatively, considering that
the final number and location of landfills in Selangor is yet to be finalized.
The direct economic benefit from the project is limited to the revenue from the
landfill disposal fee. The main external impacts of the landfill, which have
been included in the analysis covers:
· Air pollution;
· Soil and water pollution;
· Disamenity costs; and
· Greenhouse gas emission.
The direct revenue from the landfill is set to cover the operating costs of the
landfill without making a contribution to the capital costs. Consequently the
result is that the direct cost benefit analysis yields a negative rate of
return. However taking the externalities into consideration the internal rate
of return is 27.5% per annum without energy recovery and 67.3% per annum if
energy is recovered from the landfill gas.
Scenario
Net Present Value Internal Rate of Return
(RM Million) (% per
Annum)
Base case (No
externalities) -84.2 N/A
Base + externalities -energy
recovery 61.3 27.5
Base case + externalities + energy
recovery 196.9 61.3
The project is therefore considered economically highly viable.
ES-10 CONCLUSION
….. It is concluded that providing the proposed and recommended mitigation
measures are incorporated, and the environmental, social, health and safety
management of the facilities is addressed in the ways described within this
report, then associated environmental, social and health impacts can be
maintained within acceptable levels.
*********************************************************************
Dateline of submission of comments is 15 April 2004, addressed to
Ketua Pengarah Jabatan Alam Sekitar (Director General, Department of
Environment)
Aras 6, Block C4 Pusat Pentadbiran Kerajaan Persekutuan
62662 PUTRAJAYA
(Attn: Pn Hazian Yaakob)
Tel: 03-8885 8304 , Fax:03-8889 1045
Last
modified 4/8/04 1:32:58 PM