unit 105 - 15 - Waste & Pollution

​Waste and pollution

​Protecting health, safety and the environment when working in the construction and build environment sector

​People problems

​Within the construction industry, as well as in the wider working environment, most waste problems arise from people not segregating their rubbish.

This happens despite numerous environmental awareness campaigns

​Site practices

​On site it is good practice to monitor segregation of waste so that where possible it can be recycled.

Wood, brick, concrete, glass, plastic, rubber and metals are some of the materials that can be recycled from a construction site undergoing demolition.

On new builds, there is an even bigger focus on the need to recycle as work is proceeding.

​Benefits of recycling:

​Benefits of recycling:

• Conserves resources for future generations.
• Prevents emissions of many greenhouse gases.
• Prevents water pollutants.
• Saves energy & create Jobs
• Supplies valuable raw materials to industry.
• Stimulates the development of greener technologies.
• Reduces the need for new landfills and incinerators.

​Construction waste classifications

​ • Unwanted materials: generated during construction processes. For example: demolished concrete fragments, brick pieces, wood, plastic wastes etc.



• Reuse: the process of using a material again for the same or a different function. For example: using coarse aggregate, obtained from concrete waste, for preparation of fresh concrete.



• Recycling: the process of converting waste materials into new ones for reduction of waste of potentially useful materials.

Multiple Choice

What is Unwanted Materials in construction waste classifications ?

• Organic waste
• Non-biodegradable waste
• Hazardous waste
• Recyclable waste

Multiple Choice

What is Reuse Materials in construction waste classifications ?

• Salvaging and repurposing materials from demolition or construction sites for use in new projects
• Leaving materials from demolition or construction sites to rot and decay
• Using only brand new materials for every construction project
• Throwing away all materials from demolition or construction sites

Multiple Choice

What is Recycling Materials in construction waste classifications ?

• Burning waste materials for energy production
• Dumping waste materials in landfills
• Using waste materials as decorations in construction projects
• Sorting and processing waste materials for reuse in new construction projects

​Concrete waste

​When structures made of concrete are demolished or renovated, concrete recycling is an increasingly common method of utilising the rubble.

Concrete was once routinely delivered to landfills for disposal, but recycling has several benefits that have made it a more attractive option now we have greater environmental awareness, more environmental laws and the motivation to reduce construction costs.

Concrete aggregate collected from demolition sites is put through a crushing machine. Crushing facilities accept only uncontaminated concrete, which must be free from impurities.

Metals such as rebar are accepted, since they can be removed with magnets and other sorting devices and melted down for recycling elsewhere.

The remaining aggregate chunks are sorted by size. Larger chunks may go through the crusher again. After crushing has taken place, other particulates are filtered out through a variety of methods including hand-picking and water flotation. Smaller pieces of concrete are used as gravel for new construction projects.

Construction and demolition waste consists of concrete, bricks, timber, sanitary ware, glass, steel and plastic. One reason for the increase of construction and demolition waste is that many old buildings, concrete pavements, bridges and other structures have overcome their age and limit of use, due to structural deterioration beyond repair, and need to be demolished.

​Construction recycling problems

​One of the main issues for construction and demolition waste management is the lack of appropriately located recycling facilities.

If the site does not have a recycling facility set up on the site, this could lead to illegal practices performed by contractors to save money on skips.

This dumping of rubbish is also called ‘fly tipping’.

​Site waste management plans

​A key requirement of a waste management plan is to determine the types, quantities and qualities of waste that need to be removed from the site.

On-site waste sorting areas would need to be set up, such as designated skips for plasterboard or a location for decommissioned cable, pipework or ducting until they can be disposed of.

​Outcomes of a waste management plan

​• Reduced consumption of resources.

• Reduction of emissions and other byproducts of the process to air, water and land.

• Reduction of production (of waste) and increased recycling of waste.

​Leaving the site in a good condition

​Prior to the site being set up there should be a site investigation to determine whether there has been any initial ground contamination. If so, its extent should be established during soil investigation.

If contamination is found, necessary actions should be enforced to restore a polluted site into a condition suitable for safe construction work.

​Waste management and pollution control

​Waste should be prevented or reduced at the source by proper planning and designing whenever feasible.

Waste that cannot be prevented or reduced should be reused whenever feasible. Waste that cannot be prevented, reduced or reused should be recycled in a safe and environment friendly manner. (Recycling means treating the material to recover a useful product.)

Waste that cannot be prevented, reduced, reused or recycled should be treated in an eco-friendly manner, and energy should be derived from it, if possible.

​Air pollution control

​Control of air pollution requires limiting the emission of air pollutants into the atmosphere. Six major air pollutants are:

Carbon monoxide Ozone Sulphur dioxide Nitrogen dioxide Particulate matter Lead (automobile emissions)

There are also air emission standards for friable asbestos during activities such as disposal of asbestos or its related materials.

​Pollution from the use and maintenance of motor vehicles and construction equipment must be controlled. Fumes from site vehicles must be controlled where possible.


Releases from stationary sources such as boilers, furnaces and the burning of waste should be controlled.


Smoke and fumes have a serious effect on people’s health and an overall detrimental effect on the environment.

​Construction dust

​Construction dust poses a serious health risk and can cause lung disease if not managed correctly, as covered in The Control of Substances Hazardous to Health Regulations 2002 (COSHH). Where the dust cannot be reduced it must be controlled through:

• damping down with water
• on-tool extraction
• wearing Respiratory Protective Equipment (RPE)
• limiting people near the area and rotating employees carrying it out
• enclosing the work using sheeting or screens
• using general mechanical ventilation.

Multiple Choice

What PPE Should you wear to prevent Noise ?

• Steel-toed boots
• Hard hat
• Safety goggles
• Ear protection (earplugs or earmuffs)

​Noise control

​Noise can be defined as unwanted sound. A noise problem comprises of three interrelated problems:

1. Source

2. Receiver

3. Transmission path between source and receiver.

The transmission path is usually the atmosphere.

​Noise safety

​The safety guidelines to noise pollution are:

• Procuring equipment with inbuilt noise control: Eradicate.

• Moving the noise source away from the work area: Reduce.

• Building sound absorbing total enclosure surrounding the noise source: Isolate.

• Using silencers whenever possible: Control.

• Using personal safety gear: PPE.



This is also known as ERIC P.

​Land contamination

​There is very little difference between pollution and contamination, especially in environmental terms.

Pollution is something which is not welcomed in the environment.

Contamination refers to a substance which has been introduced to another substance, generally causing an adverse affect.

Pollution clean-up/remediation of soils or water would involve exactly the same actions as contamination clean-up.

Drag and Drop

​

Placeholder

is something which is not welcomed in the environment.

Placeholder

refers to a substance which has been introduced to another substance, generally causing an adverse affect.

Drag these tiles and drop them in the correct blank above

Pollution

Contamination

Noise

Health Effects

​Health effects

​ • Chronic exposure to chromium, lead and other metals, petroleum, solvents, and many pesticide and herbicide formulations can be carcinogenic.

• Chronic exposure to benzene at sufficient concentrations is known to be associated with higher incidence of leukemia.

• Organophosphates and carbamates can induce a chain of responses leading to neuromuscular blockage.

• Mercury is linked to higher incidences of kidney damage.

​Risk assessment on land or a site

​The purpose of preliminary risk assessment is to develop an initial conceptual model of the site and establish whether or not there are potentially unacceptable risks.

Information collection may include:

• desk study

• site reconnaissance

• additional desk study and exploratory site investigation.