Debris and fill

Construction and demolition (C&D) debris is produced in constructions, renovations, excavations, and demolitions. This includes work on buildings, roads, and utilities.

This type of waste is usually divided into two main legal categories: clean fill (comprised of excavated earth, concrete, and stones); and another category for all other debris.

Clean fill is less regulated by the State than other types of C&D debris, and can be used to grade or level other construction sites for no fee.*NYSDEC, Subpart 360-8.2(1)(a).

Source separation

Some contractors separate the debris on the job-site into a series of materials, including metal, wood, masonry, and cardboard. Others commingle all materials, which may or may not be separated later at a processing facility.

Source separation has the benefit of increasing recycling rates and generating the best prices for materials.

However, capacity for source separation depends on a series of factors, including space for different containers, and phasing of demolition and construction work.

In New York City, source separation of materials is rare, mostly due to space constraints at job-sites.*Construction and Demolition Waste Manual, NYC DDC, May 2003.

To a processing facility or transfer station

When collection trucks are full, they usually head to a C&D debris processing facility.

Processing facilities will either receive a single type of material for recycling; or mixed materials, from which they will recover certain recyclables.

Clean fill can be taken directly to other construction sites for use in grading terrain.

C&D debris is sometimes taken to transfer stations. Transfer stations can accept C&D debris that's mixed with other types of solid waste, which processing facilities can't. But their fees are higher and they usually don't recover materials for recycling, sending almost everything to landfills or incinerators.

Arriving at a processing facility

C&D debris processing facilities are in many ways similar to waste transfer stations. They are primarily logistical centers for debris, consolidating loads from smaller trucks into bigger ones before sending it for disposal.

Processing facilities are subject to regulations by the State's Department of Environmental Conservation that are different from transfer stations'. They are only allowed to handle C&D debris that is not mixed with putrescible solid waste. Another requirement is to control dust, so many facilities hose the debris with water to stay in compliance.

Separating materials

Inside the facility, workers will direct drivers on where to unload the debris. The main objective is to keep different materials separated, so that recyclables can be recovered and sold.

In some cases, processing facilities may grind materials to be used as "alternate daily cover" at landfills. This material can substitute soil used daily at landfills to cover solid waste, state regulations permitting.

Some states or municipalities may even designate this practice as a form of recycling, but this is controversial, as it can significantly alter a city's recycling rate due to the considerable weight of this material.*"San Francisco’s Famous 80% Waste Diversion Rate," Samantha MacBride, 2013.

How much is actually recycled?

Recycling rates for C&D debris are difficult to estimate for New York City for a few reasons.

First, the collection and disposal are entirely handled by private companies, and there are more than 1,000 that can serve customers in the city. Second, reporting requirements, formatting, and data availability vary across different states. Last, debris often changes hands between C&D processors, making tracking difficult.

Different studies by the City have estimated a 40% recycling rate for non-fill C&D materials, while estimates from fill material can range from 60% to 100%.*Construction and Demolition Waste Manual, NYC DDC, May 2003; PlaNYC, 2013.

Other opportunities for recycling

Currently, the majority of materials recycled from C&D debris in the US are metal, concrete, and masonry. However, there are many opportunities to recover other materials from this waste stream.*"More Jobs, Less Pollution," p. 17, Tellus Institute, 2008.

For example, one interesting recycling opportunity is gypsum, a mineral that's the main component of wallboard. If done properly, gypsum can be recycled indefinitely. Gypsum can also generate hydrogen sulfide when landfilled, a dangerous gas, which has lead to it being banned from landfills in other countries.*"Drywall (Gyproc Plasterboard) Recycling and Reuse...," MDPI Recycling, 2016.

Sending it "away"

Materials that are not recovered for recycling are either sent by truck to landfills or to other C&D processors for further separation and processing.

There are no active landfills in New York City, and the debris can sometimes travel to landfills that are hundreds of miles away, if their tipping fees are competitive enough to offset the transportation costs.

Long Island also receives a significant quantity of C&D debris and clean fill generated in New York City.

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But this is just a part of the story.

As part of its commitment to become a zero waste city by 2030, New York is seeking to significantly reduce commercial and residential waste disposal.

However, in its zero waste plan, the City does not mention any strategies aimed at reducing the disposal of C&D debris. Currently, New York City has no mandatory requirements for C&D recycling.

Demolition sites also present many opportunities for salvaging and reuse of construction materials that could be incentivized through public policies.*Construction and Demolition Waste Manual, NYC DDC, May 2003.