Best Practices for Managing Construction Waste
Every construction project produces large amounts of construction waste that can cause a negative impact on the environment. On an annual basis, approximately 1 billion square feet of buildingrelated construction and demolition debris goes to landfills. This can include metal, wood, concrete, gypsum, masonry, plaster, asphalt and packaging debris. Some of it contains asbestos and lead. Construction waste management aims to lower this waste, form a better image of construction sites and make a substantial contribution to sustainable development. Less construction waste leads to fewer disposal facilities. This reduces associated environmental issues including methane gas emissions, which contribute to global climate change. Reducing construction waste offsets the need to extract and consume virgin resources, which also reduces greenhouse gas emissions.
Less wasted construction materials equals less wasted money. Successful construction waste management can lower disposal costs and new material purchases, provide revenue from material sales, and even offer tax breaks for donations.
Successful construction waste management can lead to LEED certification. “The construction and demolition waste from many metal building products can help a LEED registered project to qualify for Construction Waste Management credits in the new LEEDv4 program,” says Scott Kriner, technical director of Chicago-based Metal Construction Association and president of Green Metal Consulting Inc., Macungie, Pa. “The recyclability of metal construction products and the waste/debris can be segregated in such a way to divert this solid waste stream from going to landfills. This helps a project meet the criteria for LEED in that type of credit.”
Metal construction lends itself to minimizing and managing construction waste. In addition to its strength and light weight, and its ability to reduce construction time and costs, it’s also 100 percent recyclable and reusable. Local metal scrap yards or recyclers can accept it. Metal can be melted down and reformed into other metal products.
Also, “Well designed and fabricated metal buildings and other structures help minimize prompt scrap generation,” says Gregory L. Crawford, executive director, Steel Recycling Institute, Pittsburgh. “Steel construction products are typically engineered and fabricated for a specific building, thereby minimizing the amount of scrap or waste that needs to be managed. Unlike many other construction materials (wood framing and gypsum wallboard, for instance), heavy steel beams, steel studs, and steel wall and roof cladding are all routinely produced to specific sizes, resulting in very little construction scrap or waste.”
Waste management aims to divert construction, demolition and land-clearing debris from landfill or incineration disposal and redirect recovered materials back into the manufacturing process. Via beneficial use determination, reusable materials can be funneled back into appropriate channels. Reducing the amount of construction and demolition materials generated at job sites is an important component of construction waste management.
According to the Associated General Contractors of America, this can be done by:
• Reusing whole or parts of existing structures that might be otherwise demolished.
• Optimizing purchasing to reduce the amount of excess materials that are brought to a construction site.
• Returning unused materials to suppliers or manufacturers.
• Working with building designers and architects to create buildings that require fewer cut-offs and material customizations.
A key component to construction waste management is knowing the types of products being discarded to evaluate their salvageability, reusability, recyclability and reducibility, and then separating and organizing these items onsite. Construction waste can be comingled, but separating the useful material afterwards at a material recovery facility adds cost, contamination and decreases the likelihood of its highorder uses. Job-site source separation saves on disposal costs and potentially generates income through the sale of salvaged material.
“When tasked with the management of construction waste, regardless of the sort of construction, the most important thing to keep in mind is that the more you can segregate the materials, the better your chances of having those materials recycled or repurposed,” says Richard A. Ludt, director of environmental and public affairs, Interior Removal Specialist Inc., South Gate, Calif. “If at all possible, you want to have separate containers on the construction site for every material that you are hoping to recycle, and then an additional container for the residual or trash. By not comingling the debris you are greatly increasing the diversion rate for your project.”
Jeremy K. O’Brien, PE, director of applied research at Solid Waste Association of North America, Silver Spring, Md., agrees the most important best construction waste practice when it comes to metal is keeping it separated from the other construction waste at the construction site and to keep the metals free from contaminants (i.e., other waste discarded at the site).
“This is usually done by locating one or more Dumpster containers dedicated to metals on the construction site,” he says. “Historically, the markets for metal scrap have been strong enough to justify the effort and costs associated with placing the metals in a separate Dumpster and hauling them to a scrap yard. Current scrap metal prices for steel scrap are on the order of $200 per ton. The environmental benefits are generally based on the reduction in energy needed to produce new metal products from recycled metals, as compared to producing metals from virgin ore.”
Dumpsters can come in multiple sizes with flexible delivery and pickup times to meet construction or demolition project needs. Unfortunately, some job sites cannot handle a large number of Dumpsters. For that, different haulers can provide options like smaller containers, waste corrals and even container-less systems. All construction waste management devices should be marked and designated with large letters and different languages with a list of acceptable materials.
Materials intended for salvage or reuse can be damaged or destroyed if not correctly stored. “Ferrous scrap management is essential to keep it clean and, as required, sorted into different grades,” says Crawford. “Clean, segregated scrap comes from thoughtful planning and vigorous execution throughout the entire demolition or construction project.” Do not allow construction waste to accumulate on-site. Pack, crate or band it, if possible, to keep it organized. Store items in a secure and weather-protected area until removed or transferred. Routinely inspect construction waste to determine construction material efficiency by construction crews. Check garbage Dumpsters daily for misplaced construction waste.
A plan for waste
For effective construction waste management, develop a plan consisting of waste types, quantity by weight, methods of disposal, and handling and transportation procedures. LEEDv4 requires a construction waste management plan for new or revitalization building construction. The plan should be kept at the site as a reference and distributed to all subcontractors working on the project. It should be prepared at the start of the projects and updated accordingly.
“Incorporate a plan for waste avoidance and recycling into the project from the first stages, rather than trying to force fit it into the process after waste has already been generated,” says Sara Bixby, deputy executive director, Solid Waste Association of North America. “By doing so it may be possible to source some building supplies that are recyclable or recoverable rather than disposable and to refine the quantities purchased. Setting up a system that allows for the segregation of recyclable materials from waste at the job site also improves recovery of any material, not just metal.”
Understanding the conditions affecting waste management costs and recycling options in your area is the key to developing a successful waste management plan. “Working with the waste collector and area recyclers at the planning stages makes for better decisions and success throughout the project,” Bixby says. “Consideration of the materials used can help target recoverable materials and the delivery specifications. Understanding where those materials will be used can drive placement of containers, which helps increase recovery. The waste collector can help optimize Dumpster sizing and frequency of service.”
The Cost of Waste
MCN asked two industry experts to explain in their own words waste management expense.
Tipping fees are not normally a budgetary line item for a construction project. The tipping fees are generally rolled in to the price of rented Dumpsters for the debris. As far as a percentage of the total budget, that is entirely dependent on the sort of construction and/or demolition you are engaging in. A typical commercial interior or tenant improvement project generally allocates 3 to 5 percent of the budget to demolition, and wrapped up in that percentage is the hauling, diversion and disposal of all debris created during the demolition.
Richard A. Ludt, director of environmental and public affairs, Interior Removal Specialist Inc., South Gate, Calif.
Waste generated during construction must be hauled and disposed at a construction waste landfill if it is not recycled. Hauling prices vary depending on the hauling distance. A rule of thumb is that hauling waste in transfer trailers costs on the order of $3 per round trip mile. Therefore, for a load of 10 tons and a distance of 20 miles, a cost of $12 per ton would be incurred. Tipping fees are the prices charged for the disposal of waste at a landfill. For construction waste, tipping fees are in the range of $30 to $50 per ton or more depending on location. Therefore, by recycling a ton of steel, a construction manager could receive recycling revenues of about $100 to $200 per ton (depending on local markets) and avoid tipping fees of about $40 per ton while incurring hauling costs of
$12 per ton. This example illustrates the reason why most construction sites automatically target metals for recycling.
Jeremy K. O’Brien, PE, director of applied research, Solid Waste Association of North America, Silver Spring, Md.