Emissions to the atmosphere of air contaminants will be released during Project activities. However Project-related emissions are mainly expected to occur during Construction and to a much lesser extent during Operation. With the exception of the Joun regulation structure, Ouardaniye WTW, flow measurement/sampling and distribution chambers and water storage reservoirs which represent the major surface facilities, the Project components are mainly underground structures comprising of tunnels and pipelines conveying only water (raw and/or treated) to storage reservoirs and distribution networks (existing and/or future planned).
It should be noted that "Process" point sources are those not directly attributed to the combustion of fuel but released during operation of specific equipment. Though the proposed Project falls under "Category A" of the World Bank Environmental Categories, the conceptual design of the planned above-ground facilities does not include Process point sources whereby combustion or process-related emissions (stacks, fugitive emissions from fuel storage tanks, etc.) are anticipated during Operation. With the exception of on-site diesel-fueled engines/generators which supply power to the planned nine (9) pumping stations Table 3 -23 and transport operations (chemical requirements for WTW, sludge collection and disposal), routing and maintenance inspections to the constructed facilities (chambers, WTW, storage reservoirs) which are designed to be automated (i.e. unmanned), no other combustion sources and units are anticipated to burn fuel/diesel and generate emissions to the air during Operation.
Therefore, to assess the environmental impacts of the proposed Project on ambient air quality, it is more relevant to consider and examine the impacts of the anticipated Construction activities on the ambient air quality.
Based on the information provided by the Design Team and Project Proponent, Construction is expected to be carried out over three years during which major activities that could potentially impact the local air quality include:
Site Clearance and Excavation – Drilling, blasting, pipeline construction and tunnel boring works (to a lesser extent) and spoil stockpiling; and
Project-related vehicle traffic – transportation of raw material, excavated spoil, and manpower to and from construction sites.
With regards to the Assessment Area, existing air quality conditions are described in terms of meteorological conditions. Currently, no information on ambient air quality in terms of airborne contaminants in the area under assessment, released from the number of existing industrial and other potential point sources, is available.
For the sake of the assessment, the current ambient air quality shall be described qualitatively through the identification of existing point sources relevant to the Assessment Area and its vicinity and projected type of emissions anticipated to be released during Project Construction. It should also be highlighted that, in this case, cumulative impact(s) on ambient air quality are not expected to be significant given that Project-related emissions are temporary in nature and localized (to the construction sites) and shall decrease considerably upon cessation of construction activities.
Impacts from Combustion and Exhaust Emissions
With the exception of the Sibleen Cement Plant (in Ouardaniye) and the Naameh landfill (in Naameh) which are considered as the only two major existing sources of combustion (Sibleen stacks) and greenhouse gas emissions (mainly CH4 from landfill), no other important industrial facilities are identified as sources of airborne contaminants. However, additional factors and development projects including the international airport, highways/freeways and a quarry site, located in and around the Study Area are expected to affect the existing ambient air quality.
The planned construction works including pipeline construction and tunnel boring as well as the installation of surface infrastructure are expected to be carried out partly in rural degraded areas (mostly at isolated valley crossings), and partly within urban residential areas. In the latter setting, emission sources are limited to the on-going vehicular exhaust and transportation activities.
As aforementioned, Project-related emissions during Construction are limited to combustion emissions from diesel-fueled generators and equipment operated onsite, exhaust emissions from vehicle transportation and fugitive dust emissions generated during site clearance, excavation, drilling and blasting and concrete batch mixing operations for the construction of the Project-related infrastructure and linear structures (particularly pipelines).
Emissions from combustion arise from the burning of fuel and are dependent on fuel flow rate, fuel type, combustion equipment and the presence of pollution control devices. The main air pollutants likely to be associated with these emission sources include: Oxides of Nitrogen (NOX), Sulfur Dioxide (SO2), Particulate Matter (PM), Carbon Monoxide (CO) and dust. Additional pollutants can include Hydrogen Sulfide (H2S) and Volatile Organic Compounds (VOCs). The impacts associated with the above air emissions are illustrated in Table 7 -59.
Table 7 59 Environmental and Health Impacts of Major Air Pollutants from Combustion Sources
Oxides of Nitrogen – NOX
NO2 is a toxic gas, even at relatively low concentrations. NOX also contributes to the formation of acidic species, which can be deposited by wet and dry processes. NOX can also increase the formation of ozone at ground level when mixed with VOCs in the sunlight atmosphere. NO is a relatively innocuous species, but is of interest as a precursor for NO2.
Sulfur Dioxide – SO2
SO2 is a toxic gas, and is known to contribute to acid deposition (wet SO2 and dry), which may impact ecosystems. Direct health effects potentially causing respiratory illness.
Particulates – PM10
Particulate matter is a complex mixture of organic and inorganic substances present in the atmosphere in either solid or liquid form. Particulate matter is inhaled and deposited within the respiratory pathways, leading to a variety of health effects.
PM10 (i.e. particulate matter with a diameter of less than 10 µm) is able to penetrate deeply into the lungs. An association has been established between elevated concentrations of PM10 and excess short term mortality and morbidity rates.
Carbon Monoxide – CO
Carbon monoxide (CO) is a colorless, odorless gas that is slightly less dense than air. When inhaled, the gas is absorbed into the bloodstream and combines with hemoglobin in the blood to form carboxyhemoglobin (COHb).
The affinity of hemoglobin for CO is more than 200 times greater than for oxygen. The result is that CO acts as a poison by reducing the amount of O2 that can combine with hemoglobin.
It should be mentioned that exhaust emissions are expected during normal operation of combustion sources. However, poor quality fuel, unnecessary idling periods, lack of maintenance, long operation period (particularly power generators) and absence of exhaust emission control units will result in the increase of atmospheric emissions of pollutants.
Generally speaking, the emissions associated with the construction activities, and vehicular exhaust will be of a Moderate effect. This impact is of a high likelihood, yet of a medium to short-term duration (3 years) and reversible nature. Accordingly, with no mitigation measures in place, this activity is likely to have a Moderate impact (3C) on the overall air quality within the Assessment Area.
However, it is recommended that various mitigation measures be adopted, including:
Using continually well designed, maintained and operated equipments / vehicles by the Contractor. Precautionary control measures for atmospheric emissions reduction could include proper engine fuel mixtures, regularly serviced exhaust emission systems, suitable engine tuning, and purchase of diesel fuel with low sulfur content (5% sulfur content) (whenever available).
Investigating the environmental benefits of employing environmentally friendly equipment by the Contractor such as machinery with higher fuel efficiency or those equipped with air pollution control devices to minimize exhaust emissions. Examples include vehicles equipped with 2 or 3 way catalytic converters;
Avoiding idling vehicles and equipment engines that are left running unnecessarily;
Reporting monthly fuel consumption records;
Adhering to the IFC emission standards for small combustion source emissions (with a capacity of up to 50 megawatt hours thermal (MWth)) as presented in (IFC, 2007b). Combustion source emissions with a capacity of greater than 50 MWth should comply with the IFC EHS Guidelines for Thermal Power.
An implementation of the above mentioned mitigation measures is likely to reduce the effect of exhaust and combustion emissions during site preparation and transport activities to Minor(2C) on the overall air quality within the Assessment Area.
Impacts from Dust Generation
The primary sources of dust generation would be related to construction activities. These sources include a combination of on-site excavation and civil works such as compaction, trenching and backfilling activities and exposure of bare topsoil and spoil piles to wind.
A considerable amount of spoil will be generated during Construction. It is expected that a net of 1.6 million tons will be produced following surface excavations, and drill and blast operations (via heavy rippers and rock breakers) particularly in areas where strong limestone rocks are found close to the surface such as in Joun Area, Wadi Abou Yabes, and Ouardaniye.
Pipelines are expected to be excavated at 2.5 to 3 m; the depth of excavation is expected to vary among the different crossings with existing sensitivities (such as roads and culvert crossings and Ghadir River). In areas where rock (mainly limestone) is not found, the majority of the spoil is expected to consist of sand fill with rocky fragments. With regards to tunnel considerations, the selection of the Tunnel Boring Method (TBM) in lieu of the drill and cut/blast operations (usually adopted for pipelines) enables a rapid progress with an overall reduced construction timeframe. The technique is also associated with less fugitive dust emissions given the nature of the underground construction whereby civil works are carried out below surface (90 m below ground); as such emissions to the ambient air from drill and blast operations are only expected when establishing the TBMs in the first 100m of each drive.
As such, fugitive dust emissions are expected to arise during Construction from stockpiled spoil, loading and unloading operations at construction sites and planned spoil handling facilities. Further increase in ambient dust levels induced during Project Construction is associated with the movement of trucks transporting produced spoil (entrained dust). The amount of dust generated by the activity is difficult to estimate because of the lack of data to estimate the type and number of operating equipment, number of truck trips and round-trip travel distances. Factors such as vehicle speed, total truck loading, cover availability, ground/road conditions (paved/unpaved) and meteorological conditions among others would influence the amount of fugitive dust emissions released to the atmosphere. Entrained dust (fugitive PM10 emissions) from material and equipment delivery trucks traveling on paved and/or unpaved roads cannot be estimated at this stage.
However, assuming a haulage capacity of 10 – 16 tons per truck (e.g. standard dump truck), the expected overall number of truck trips for spoil transportation (±1.6 million tons) would potentially amount to 160,000 – 100,000 during Construction. At this stage, projected figures should be considered as estimates. The number of vehicle trips is anticipated to be higher taking into account the additional vehicle/truck trips for raw material, equipment and labor transportation.
However, under normal meteorological conditions, dust impacts should be limited to within several hundred meters of the activity areas (access roads, pipeline and tunnel corridors, and construction sites). The main environmental concerns associated with dust generation are likely to be limited to occupational health risk and nuisance to local residents and road commuters and Project affected communities.
Dust emissions could cause respiratory problems and irritation to construction workers and might also have an impact on drivers/commuters from reduced road visibility due to an increase in the light extinction coefficient; dust clouds would increase risk of vehicle collision.
The likelihood for dust generation during site preparation and excavation is high. This impact is of short-term duration however of Significant (4C) impact when no mitigation measures are in place. Consequently, it is concluded that the impacts associated with dust generation are substantive and require adequate mitigation throughout Project Construction and its associated activities.
Techniques for minimizing and preventing fugitive dust emissions during Construction can be accomplished through dust suppression measures. The main dust control measures, which are recommended to be considered, include the following:
Watering-down work area/s (at the tunnel and pipeline corridors, location of surface structures) particularly near sensitive receptors, at spoil handling facilities and during loading and unloading operations.
Efficient scheduling of deliveries as well as establishing and enforcing appropriate speed limits over all paved and unpaved surfaces (< 40 km/h) via a Traffic Management Plan (TMP) approved by the Project Proponent;
Traveling on existing and paved tracks wherever possible.
Maintaining stockpiles at minimum heights and forming long-term stockpiles into the optimum shape (i.e. stabilization) to reduce wind erosion;
Carrying out loading and unloading operations in closed/contained spaces while using dust-suppression methods;
Installing covers (manual and/or mechanical) on back loads of dump trucks and large vehicles before leaving a construction site to reduce as low as possible, if not, prevent, fugitive dust emissions from being released during road transportation and vehicular movement.
Following implementation of the above recommended mitigation measures as well as the Proponent's Safety, Health and Environmental Regulations and Protocols (CDR - SHE Regulations, 1995), the environmental impacts from dust generation due to site preparation, civil works and transportation activities during Construction would be reduced to a Minor effect (2C).