Construction waste

Construction waste can be categorized as follows: Design, Handling, Worker, Management, Site condition, Procurement and External.  These categories were derived from data collected from past research concerning the frequency of different types of waste noted during each type of these activities.[9] Examples of this type of waste are as follows:

Construction site in Amsterdam

Steel is used as reinforcement and structural integrity in the vast majority of construction projects. The main reasons steel is wasted on a site is due to irresponsible beam cutting and fabrication issues. The worst sites usually end up being the ones that do not have adequate design details and standards, which can result in waste due to short ends of bars being discarded due to improper planning of cuts.[10] Many companies now choose to purchase preassembled steel reinforcement pieces. This reduces waste by outsourcing the bar cutting to companies that prioritize responsible material use.

Concrete Mixer

Premixed concrete has one of the lowest waste indices when compared to other building materials. Many site managers site the difficulties controlling concrete delivery amounts as a major issue in accurately quantifying concrete needed for a site. The deviations from actually constructed concrete slabs and beams and the design amounts necessary were found to be 5.4% and 2.7% larger than expected, respectively, when comparing the data from 30 Brazilian sites. Many of these issues were attributed to inadequate form layout or lack of precision in excavation for foundation piles. Additionally, site managers know that additional concrete may be needed, and they will often order excess material to not interrupt the concrete pouring.[10]

It is often difficult to plan and keep track of all the pipes and wires on a site as they are used in so many different areas of a project, especially when electrical and plumbing services are routinely subcontracted. Many issues of waste arise in this area of the construction process because of poorly designed details and irresponsible cutting of pipes and wires leaving short, wasted pipes and wires.[10]

The second leading cause of construction waste production is inproper material storage. Exposure to the elements and miss handling by persons are due to human error.[10] Part of this human error can lead to illegal dumping and illegal transportation volume of waste from a jobsite.[11]

Recycling Trucks

Most guidelines on C&D waste management follows the waste managing hierarchy framework. This framework involves a set of alternatives for dealing with waste arranged in descending order of preference. The waste hierarchy is a nationally and internationally accepted concept used to priorities and guide efforts to manage waste. Under the idea of Waste Hierarchy, there is the concept of the "3R's," often known as "reduce, reuse, recycle." Certain countries adopt different numbers of "R's." The European Union, for example, puts principal to the "4R" system which includes "Recovery" in order to reduce waste of materials.[12] Alternatives include prevention, energy recovery, (treatment) and disposal.

It is possible to recycle many elements of construction waste. Often roll-off containers are used to transport the waste. Rubble can be crushed and reused in construction projects. Waste wood can also be recovered and recycled.

Some certain components of construction waste such as plasterboard are hazardous once landfilled. Plasterboard is broken down in landfill conditions releasing hydrogen sulfide, a toxic gas. Once broken down, Plasterboard poses a threat for increases Arsenic concentration Levels in its toxic inorganic form.[13] The traditional disposal way for construction waste is to send it to landfill sites. In the U.S., federal regulations now require groundwater monitoring, waste screening, and operator training, due to the environmental impact of waste in C&D landfills (CFR 1996).[14] Sending the waste directly to a landfill causes many problems:

Landfill

• Waste of natural resources
• Increases construction cost, especially the transportation process[15]
• Occupies a large area of land
• Reduces soil quality
• Causes water pollution (Leachate)
• Causes air pollution
• Produces security risks etc.[16]

Where recycling is not an option, the disposal of construction waste and hazardous materials must be carried out according to legislation of relevant councils and regulatory bodies. The penalties for improper disposal of construction waste and hazardous waste, including asbestos, can reach into the tens of thousands of dollars for businesses and individuals.

Waste Incinerator

Waste-to-energy facilities burn more than 13% of solid municipal waste. The toxic fumes emitted by WTE plants can contain harmful chemicals such as mercury and other heavy metals, carbon monoxide, sulfur dioxide, and dioxins.

Dioxin was used as a waste oil in Times Beach, Missouri. Days after the chemicals were introduced to the community animals began dying. By the time the EPA deemed dioxins to be highly toxic in the 1980s, the CDC recommended the town be abandoned entirely due to contaminated waste products in the area. By 1985, the entire population of Times Beach had been relocated, prompting Missouri to build a new incinerator on the contaminated land. They continued to burn 265,000 tons of dioxin-contaminated waste until 1997.

Dioxins are a family of chemicals produced as a byproduct during the manufacturing of many pesticides and construction materials like carpeting and PVC. These chemicals exist in the environment attached to soil or dust particles that are invisible to the naked eye.

Dioxins break down slowly. It still threatens public health at low levels. Since industry has mostly stopped producing dioxins, one of the largest contributors releasing harmful dioxins left in the United States is waste incineration. Dioxins have been proven to cause cancer, reproductive and developmental issues, and immune system damage. Rates of cancer such as non-Hodgkin's lymphoma and soft tissue sarcoma rise significantly the closer one lives to the pollutants' source.

Waste management fees, under the 'polluter pays principle', can help mitigate levels of construction waste.[17] There is very little information on determining a waste management fee for construction waste created. Many models for this have been created in the past, but they are subjective and flawed. In 2019, a study method was proposed to optimize the construction waste management fee. The new model expands on previous ones by considering life-cycle costs of construction waste and weighs it against the willingness to improve construction waste management. The study was based out of China. China has a large waste management issue, and their landfills are mostly filled in urban areas. The results of the study indicated different waste management fees for metal, wood, and masonry waste as $9.30, $5.92, and $4.25, respectively. The cost of waste management per square meter, or just under 11 square feet, on average was found to be $0.12.[18] This type of waste management system requires top-down legislative action. It is not a choice the contractor has the luxury of making on his/her own.

In the European Union (EU), there is now significant emphasis on recycling building materials and adopting a cradle-to-grave ideology when it comes to building design, construction, and demolition. Their suggestions are much clearer and easier at the local or regional level, depending on government structure. In the 2016 EU Construction & Demolition Waste Management Protocol, they emphasize the benefits beyond financial gains for recycling such as job creation and reduced landfilling. They also emphasize the consideration of supply and demand geography; if the recycling plants are closer to urban areas than the aggregate quarries this can incentivize companies to use this recycled product even if it is not initially cheaper. In Austria, there are new improvements in the recycling of unusable wood products to be burnt in the creation of cement which offsets the carbon footprint of both products.[19]

The EU urges local authorities who issue demolition and renovation permits to ensure that a high-quality waste management plan is being followed, and they emphasize the need for post-demolition follow-ups in order to determine if the implemented plans are being followed. They also suggest the use of taxation to reduce the economic advantage of the landfills to create a situation where recycling becomes a reasonable choice financially. However, they do include the fact that the tax should only apply to recyclable waste materials. The main points of how the Europeans choose to address this issue of waste management is through the utilization of the tools given to a governing body to keep its people safe. Unlike in the United States, the EU's philosophy on waste management is not that it is an optional good thing to do when you can but a mandatory part of construction in the 21st century to ensure a healthy future for generations to follow.

Taxing landfill has been most effective in Belgium, Denmark and Austria, which have all decreased their landfill disposal by over 30% since introducing the tax. Denmark successfully cut its landfill use by over 80%, reaching a recycling rate over 60%. In the United Kingdom, all personnel performing builders or construction waste clearance are required by law to be working for a CIS registered business.[20] However, the waste generation in the UK continues to grow, but the rate of increase has slowed.[21]

A panorama of construction waste in Horton, Norway

The United States has no national landfill tax or fee, but many states and local governments collect taxes and fees on the disposal of solid waste. The California Department of Resource Recycling and Recovery (CalRecycle) was created in 2010 to address the growing C&D waste problem in the United States. CalRecycle aids in the creation of C&D waste diversion model ordinance in local jurisdictions. They also provide information and other educational material on alternative C&D waste facilities. They promote these ordinances by creating incentive programs to encourage companies to participate in the waste diversion practices. There are also available grants and loans to aid organizations in their waste reduction strategies.[21] According to a survey, financially incentivizing stakeholders to reduce construction waste demonstrates favorable results.  This information provides an alternative way to reduce the cost so that the industry is more careful in their project decisions from beginning to end.[22]