Construction and Demolition Debris Recycling
The next trend in integrated waste management
Keith A. Howard, P.E., Deputy Director, Lee County Solid Waste Division, Fort Myers, Florida; and Ziad Y. Mazboudi, P.E., Environmental Division Manager, City of San Juan Capistrano, California; members of the APWA Solid Waste Management Committee
Before the recent housing crisis (and certainly upon recovery), the construction business was booming. Houses were being built everywhere with new developments popping up. In concert with this development, the commercial construction industry was following suit. The forgotten effect of this growth: waste. Construction and Demolition Debris, or C&D, can make up 30% of the waste generated by a community with the other percentages attributed to commercial waste at 35% and residential at about 35%. As these materials are bulky and heavy, their impact on available disposal space is great. Referring to C&D waste, William Turley, Executive Director of the Construction Materials Recycling Association, noted in the February 5, 2007 issue of Waste News, "Whether you like it or not, regulation and legislation do affect this business. They affect all business." C&D Debris is no longer a hidden waste and as such shares the responsibility in preserving public resources such as landfill capacity.
C&D Debris is comprised of many items and most of them are recyclable in some shape or form depending on availability of recycling resources in a geographic area. As with all resource recovery efforts, reduction and reuse should always be evaluated.
Concrete - Concrete and roofing tiles can be reused as clean fill or can be crushed and reused as aggregate. Many DOT departments accept crushed concrete as approved aggregate in certain applications.
Metals - As evidenced by the rash of construction thefts seen across the country, the market for metal is strong. Excess aluminum siding, rebar and other metals are readily recycled.
Fiber - Paper and cardboard are easily recycled. Many materials such as flooring tiles and appliances are delivered in cardboard boxes.
Wood - Waste lumber from framing, roofing and flooring can be ground and used onsite, used as fuel (nontreated wood only), or incorporated into smaller projects.
Asphalt Shingles - Although not commonplace, asphalt shingles are being used to partially replace the asphalt in pavements. Shredded shingles can also be used as an alternative to soil for daily cover at landfills and can be combusted for energy in a waste-to-energy plant.
Drywall - The paper from drywall can be recycled and the gypsum wallboard can be used as an amendment for soils. There are also some drywall recycling facilities that generate new drywall from scrap.
Fixtures - Fixtures such as toilets, sinks, cabinets and molding, especially from deconstruction/demolition projects, have many reuse possibilities. Check local listings, but chances are there is a Habitat for Humanity ReStore or similar store near you that will take these materials for resale.
An example of quality recyclables being disposed at a job site
Why isn't more being done?
The C&D industry, as noted by Mr. Turley, has historically been obscured from the recycling push. Most communities' recycling programs focus on political expediency versus recycling efficiency. Residential waste represents only one-third of what is generated whereas commercial waste represents the other two-thirds; yet, most communities start out their recycling programs with curbside recycling. The next step seen around the country is business recycling. Cities like Austin, TX; Alexandria, VA; Mecklenberg, NC; and Lee County, FL, as well as numerous communities in California and Washington, have taken steps to mandate commercial business recycling. These programs are by no means the norm but are increasing. C&D is on the radar and communities in California such as San Juan Capistrano and San Jose, the City of Chicago and most recently Lee County, FL are taking this next step to incorporate C&D into their integrated management strategies.
Taking the next step
In California, most communities use a model based on deposits for construction permits. Communities require a 50% diversion of material, although some like Dana Point require 75%. The deposit is returned to the contractor after the project demonstrates that the 50% diversion was met. The City of Chicago assesses a penalty on projects for recycling efforts less than 50% of material generated on the project. For a 10,000-square-foot project the penalty is $1,000 for each percentage point less than 50%. The Lee County, FL ordinance is a hybrid of both. Contractors are given the opportunity to recycle and must submit documentation and a recycling affidavit upon completion of the project. If the recycling goal is not met, the permittee is responsible for a set diversion fee based on the type and size of the project.
A model program
The City of San Juan Capistrano, CA requires that, except for a list of small projects that were exempt from the ordinance, all construction and demolition projects must recycle a minimum of 50% of their debris material. The steps towards compliance include:
Another example of numerous recyclables in C&D containers at a construction site
Often when constructing new ordinances, there are unforeseen consequences or loopholes that are used to avoid the impacts of the ordinance. One of the issues confronted in San Juan Capistrano was the level of economic incentive for contractors. The initial ordinance did not have a minimum deposit such that many small projects, whose deposit was $50-$100, would choose to lose the deposit and pass these costs on to the customers. In neighboring cities, the minimum has been increased to upwards of $2,000. Another positive step taken by the City was a public-private partnership with a local solid waste hauler to operate a pilot C&D recycling facility at the local landfill. This pilot was so successful that the hauler has just finished constructing a permanent facility in the area. Needless to say, as with some recycling programs, recycling can create a net positive impact in a community through job development of a new industry and encourage local investment in technology and manufacturing for uses of the recycled materials such as asphalt shingles to roads (www.shinglerecycling.org), glass to aggregates (www.broward.org/waste/awards.htm), or reuse of lumber scraps (www.ruralcap.com/asd/rebound).
Dwindling landfill space and rising construction material costs are not due to change anytime soon. The wave of Green Building developments and LEED-certified projects promotes a high level of C&D recycling as well as encourages project deconstruction where applicable. The push for responsibility from the construction industry will continue to increase as with other waste generating segments of communities. Given that most construction materials have some valid reuse or recycled value, the industry should share the burden. If we are adamant about recycling at home, there is no reason why we can't extend this enthusiasm to our place of work and the job site.