The Environmentally Responsible Construction and Renovation Handbook
Chapter 8 - Construction, Renovation and Demolition Waste
8.1 Introduction
The diversion of construction, renovation and demolition (CRD) waste from landfill sites is an issue that has been gaining attention within both the public and private sectors. Surveys have indicated that as much as one third of the 20 million tonnes of solid waste of municipal waste streams is generated by construction, renovation and demolition activities. Many of our landfill sites are reaching capacity. In addition, CRD waste is sometimes illegally dumped or burned, causing land, air and water pollution. The increasing costs of disposal are ultimately reflected in project costs, as contractors must incorporate anticipated disposal costs in their bid costing. Realities such as these emphasize the need for initiatives that focus on reducing and diverting as much waste as possible from CRD activities.
Incorporating the 3Rs (reduce, reuse and recycle) into construction, renovation and demolition waste management creates a closed-loop manufacturing and purchasing cycle. This significantly reduces the need to extract raw materials, reduces the amount of materials going to landfill sites and reduces the life-cycle costs of buildings and building materials
Project managers and construction contractors have long recognized the importance of reducing waste and salvaging high value construction and demolition materials such as copper and other metals. Contractors are usually careful about the quantity of materials ordered, how materials are used and how to carefully de-construct valuable materials. In most cases however, materials that are more difficult to separate and that are worth less per unit weight are still going to landfill, even when they are present in large quantities. This represents an inefficient use of natural resources and uses up landfill capacity unnecessarily.
Unfortunately, some contractors do not realize that there are new opportunities for waste minimization, while others are reluctant to implement environmental practices because they believe these practices will increase their project costs. Most contractors are concerned about the cost of the labour that is needed to deconstruct materials for reuse or recycling. However, it has been shown that effective waste management during CRD projects not only helps protect the environment, but can also generate significant economic savings. Demonstration projects have shown that the diversion of waste from landfill can reduce waste disposal costs by up to 30%. This is accomplished through reduced tipping and haulage fees and the sale of reusable and recyclable materials.
8.2 Landfill Sites
It is becoming more difficult to find suitable locations for new landfill sites, as people are increasingly opposed to the development of them in their neighbourhoods due to odours, increased traffic, and potential problems with ground and surface water contamination. Diverting CRD waste from landfill will substantially extend the useful function of existing sites.
In order to understand some of the environmental impacts that are associated with the disposal of large quantities of CRD waste, it is necessary to understand how a landfill site functions. Biodegradable waste decomposes in a landfill water and appropriate bacteria are present. Decomposition refers to the disintegration of the chemical bonds that hold material together, causing the material to break down into simpler substances. Biological decomposition can be hastened or delayed by varying conditions, including, temperature and moisture.
During the degradation process, four actions occur:
- organic matter is stabilized,
- leachate is produced,
- landfill gas is generated, and
- settlement occurs.
A complex combination of landfill liners, monitoring wells, piping, pumps and capping of landfills controls leachate flow. However, these systems are not always successful and if leachate escapes from landfill sites, it can pollute groundwater, rivers, streams and surrounding land areas.
8.3 Resource Management
The reuse, refurbishment and remanufacturing of products also diverts materials from landfill and are always preferred to disposal.
Environmental impacts due to the extraction and transformation of materials are significant. This includes habitat destruction, resource depletion, energy use, air pollution, water pollution and solid waste problems. The availability of some raw materials has decreased significantly during recent decades due to the rate at which we consume materials - both non-renewable and renewable - and the fact that we are not creating appropriate opportunities for renewable resources to replenish themselves. As a result, we must increasingly look for ways to reduce our impact on both non-renewable and renewable resources.
Products and materials with recycled content are more readily available and are a partial answer to problems of resource depletion. Recycling materials helps to create closed-loop manufacturing and purchasing cycles and significantly reduces the need to extract raw or virgin materials.
8.4 Provincial and Municipal Regulations
The construction waste management field is regulated by provincial and municipal legislation. In acknowledgement that construction and demolition materials make up such a large percentage of the waste stream, regulations exist in some parts of Canada to divert these materials from landfills or prevent them from being dumped illegally. Municipalities often manage or control CRD waste management practices at the local level. Many municipalities throughout Canada have by-laws in place banning the landfilling of specific CRD material (e.g. drywall etc). The Province of Ontario has regulations in place which require detailed waste audits for construction contracts above a certain size. These are described below.
These requirements vary by location across the country. The following is a partial list of provincial and municipal legislation to be consulted prior to the handling or disposing of any CRD waste material.
Ontario's 3Rs Regulations
In 1994, the Ontario Ministry of the Environment (MOE) passed the 3Rs Regulations. Regulations 102/94 and 103/94 are applicable to construction and demolition projects consisting of one or more buildings with a floor area greater than 2,000 m².
Regulation 102/94 requires the following:
- the completion of an on site waste audit that identifies the amount and nature of the waste that will be generated;
- the development of a waste reduction workplan that outlines specific achievable diversion options for reduction, reuse, and recycling;
- the implementation of the waste reduction workplan;
- the documentation of the waste audit and workplan results on forms provided by the MOE or forms that have been designed in the same general format; and
- the retention of a copy of the audit and workplan documents on file for five years from completion of the project.
Regulation 102/94 requires that the waste audit be conducted and the workplan completed before the beginning of the CRD project.
Regulation 103/94 requires the following:
- the implementation of a source separation program for the reusable and recyclable materials listed in Regulation 102/94;
- the specification of facilities that are sufficient for the collection, sorting, handling and storage of these materials;
- the communication of the source separation program and its successes to employees, patrons, and tenants; and
- reasonable effort in ensuring that the separated waste is reused or recycled.
The project team should check with provincial environment departments to identify all relevant environmental regulations. The federal government adheres to the Ontario 3Rs Regulations as they represent best practices in the industry.
Municipal By-laws
Municipalities who own and operate municipal landfills are the decision-makers when it comes to what materials can be landfilled and what by-laws and regulations are enforced. Local requirements regarding landfill bans should be checked prior to each CRD project.
The project team should ensure that contracts made with disposal companies, state that all removed materials will go to permitted facilities.
8.5 Reducing CRD Waste
The traditional handling of CRD waste represents a lost opportunity. Most of this material is not waste, but a valuable resource. As the cost of construction materials escalates due to dwindling virgin resource availability (especially lumber), many of the materials that we throw away are becoming increasingly valuable. Almost everything - from concrete and lumber, to electrical wiring and plumbing fixtures - can be reused or recycled.
To take advantage of the value of waste materials as a resource, salvageable materials must be separated from other materials. The purpose of separating CRD waste is that there will often be markets for certain items, but once mixed or contaminated, these materials have lost their value. By separating materials, a higher value can be given to those materials that can be salvaged, thereby reducing tipping fees at landfill. In short, recovering waste and keeping it separated reduces project costs in two ways:
- it minimizes the transportation and disposal costs for landfilling this material, and/or
- the materials acquire economic value, either by selling them to a recycler or by incorporation into future projects.
8.6 Design Considerations
During the planning phase of a project, consideration should also be given to future waste diversion techniques. The construction industry has traditionally relied upon standard assembly methods, products and routines. Unfortunately, during a renovation or demolition project materials are often not easily salvaged for reuse or recycling. The result is a high percentage of waste generation. In order to combat this problem, steps can be taken early in a project to decrease waste generation during future demolition activities. Future disassembly should always be a consideration during the design phase.
By designing for disassembly, a greater percentage of materials and products may be reused or recycled with little effort, resulting in less waste generation and reduced quantities of materials entering landfills. In order to employ successful design for disassembly techniques, attention must be given to the specifics of material assemblies, product selection and connection details.
The use of reversible connections instead of nails to fasten wood framing and other materials allows for easy disassembly. Not only can the material be used again, but the screws and bolts can also be reused. In addition, by making the connections more easily accessible, disassembly will be facilitated and less waste will be generated.
Other methods of disassembly include selecting materials that are fastened by a tongue and groove connection rather than the need for an adhesive compound. Adhesive compounds produce a permanent connection that contaminates the material and affects its recyclability. Consider the use of materials that are classic and timeless so that they will endure for the life of the building and not be removed during a renovation. Material such as linoleum flooring is often left in place for the entire life cycle of a building, while carpeting is traditionally changed on a five to seven year cycle. It is also environmentally beneficial to determine from suppliers which materials and products have well-established recycling and reuse markets. Designing for disassembly results in substantially lower amounts of waste being produced during a renovation or demolition project.
Section 2 of this document identifies criteria that can be used for the environmental assessment of products and materials. The following criteria are relevant to the selection of products that will facilitate future waste diversion practices.
Reusable Products
Many products are reusable by consumers. Most consumers are aware of this fact, however, it is important to identify new reuse opportunities that may not be readily apparent.
Industry Canada has developed a document entitled Principles and Guidelines for Environmental Labelling and Advertising. This document provides a guideline for the term reusable. For a product to be deemed reusable, an application must exist that allows the end user to directly reuse the product. Where the option is not obvious, the claim must explain how the product can be reused without extensive cleaning or restoration processes. This criterion may also be used to assess the packaging materials that are associated with a product. For example, furniture can often be shipped in reusable blankets rather than in resource intensive corrugated containers.
Refurbishable Products
Refurbishable products can often be reused. However, they usually require cleaning or restoration. During the refurbishing procedure, the product remains the property of the consumer. Hence, the expense of the refurbishing process is the responsibility of the consumer.
The refurbishing procedure may be offered either in-house by the original manufacturer or may be a procedure easily accessible through outside sources. Information regarding refurbishing processes must be readily available to the consumer. The refurbishing of a product may require the utilization of additional energy and additional waste generation. However, the environmental impacts are considerably lower than first-time fabrication in almost all cases.
Remanufacturable Products
This criterion differs from refurbishing in that the ownership of the product reverts to the original manufacturers or a third party that provides the restoration services. Products recognized under this criterion are designed in a manner that allows for complete upgrading, where products can be inspected and disassembled to their individual elements and damaged pieces can be repaired or replaced. The product is therefore restored to an as new condition for resale by the fabricator.
Durability
Durability provides reduced environmental impact by minimizing the maintenance or replacement requirements of a product. This provides an efficient use of natural resources and a diversion of material from landfill.
At present, durability is generally measured by manufacturer's warranties. However, typical manufacturer warranties are generally too vague to be used as a baseline for the development of a criteria definition. Standard testing procedures and reporting requirements are currently being developed which will provide a reliable mechanism for environmental evaluation. However, until this framework is developed and accepted, building practitioners can only qualitatively access the durability of a product.
Maintenance requirements should be assessed to ensure that a product will maintain its aesthetic and functional value and manufacturer's warranties can be used to provide a marginal measure of a products durability. Product testimonials are another source of information which can be used to verify durability claims. Although this issue is marginally quantifiable, a mechanism for reliable quantitative analysis is not yet available.
Recyclable Products
The use of recyclable products provides efficient and effective use of natural resources. The benefits are achieved by diverting the products from the waste stream and directing them to a recycling facility.
A product that is recyclable can be returned for reprocessing into new material. However, a product is not considered recyclable simply because the material is technically recyclable or there are anticipated developments in the future. Recycling programs and facilities vary regionally throughout Canada. A product can only claim to be recyclable if one-third of the population has access to recycling facilities or drop-off points.
In situations where products are fabricated from numerous materials, the product design should facilitate recycling options by design for easy disassembly and identification of materials types. For example, plastic components should contain plastic sorting codes. Instructions explaining disassembly and sorting requirements for inclusion in recycling systems should also be included with products.
8.7 The CRD Waste Management Process
As with most project requirements, CRD waste management should reflect the nature and scope of the project. Smaller projects may have less on-site storage space, lower waste volumes and may be located in an occupied area. Larger projects may involve multiple subcontractors, large amounts of similar wastes and be subject to design constraints. Intense short schedules may limit the practicality of implementing waste management strategies to the same degree as projects with protracted schedules where waste management requirements will not affect the critical path. Screening is an important first step to understanding the level of effort and scheduling that will be required. Smaller projects may be able to achieve the same waste diversion through a scaled down audit and workplan, whereas larger projects often require a more detailed evaluation.
Another very important part of this early stage is commitment from the tenant or owner of the property. Some clients have a mandate to track and report on their progress in this area. This will allow for a more detailed on-site monitoring and facilitation program than is the case for those that are committed solely to meeting the minimum objectives.
Teamwork is essential to the success of an environmentally responsible-CRD project. Communicating and working together with designers, energy efficiency experts, water conservation specialists, and other facility personnel ensures efficiency, avoids duplication of effort, and facilitates future cooperation. Communication allows team members to coordinate future work with current renovation or demolition activity.
A summary of the waste audit and waste reduction workplan, based on the audit inventory results, should be incorporated into the general contract specifications. This should emphasize the cost savings that can be achieved through responsible waste mangement practices, and should also include site management plans, monitoring and reporting requirements. This information should be included as a guide to the contractor and the workplan should present recommendations. The audit and workplan results are estimates that cannot account for all the conditions that may exist at a particular site. Unacticipated conditions ro problems that have a negative impact in actual diversion rates should not result in penalties for the contractor. They should, however, be documented to substantiate the variance from the expected result and to provide insight for future projects.
The waste audit is integrated throughout the project's design and implementation process. Project modifications are represented below:
Request For Proposal: The request for proposal for potential prime consultants should include a requirement for the basic contract to include a waste management specialist on the team and a commitment to specify environmentally preferred materials where applicable. The additional sections should give the flexibility to adjust the waste requirements in light of the recommendations made by the Waste Management Specialist on the CRD Waste Assessment checklist, workplan or Waste Management Report.
Prime Consultant: The prime consultant should have an in-house specialist or an additional subcontractor to perform and integrate the waste audit and workplan throughout the project.
Waste Specialist: The waste specialist will be responsible for developing the audit and workplan and will, in most cases, also be responsible for the implementation and follow-up of the workplan.
Waste Management: This includes auditing the project for the types and quantities of materials and expected wastes, generating a workplan for the reduction, reuse, and recycling of these materials, monitoring the wastes and reporting all successes.
Project Designers: The project designers should schedule the waste audit early in this phase so that opportunities resulting from the reuse of materials or reduction of waste can be incorporated. This is especially important for the construction aspect of the project.
Construction Documents: The construction documents should include the waste reduction workplan and the specifications should include environmental clauses for material procurement and waste management.
Contract Administration: This phase includes providing direction to the general contractor, facilitating the implementation and tracking of the workplan and reporting on the results.
General Contractor: The general contractor is ultimately responsible for responding to applicable legislation and meeting the contract specifications.
The project team should remember that waste management in CRD projects is a relatively new field for most contractors. As with the procurement of any services, a clear description of the project requirements in the tender documents is necessary to ensure the respondent and the client are aware of the responsibilities, deliverables and results that are expected. The client will maximize cost savings if the tender documents clearly demonstrate that there is potential for the salvage of materials.
8.8 Integrating CRD Waste Management
The following section summarizes the development and incorporation of a waste diversion program into a project.
Planning Activities
CRD waste management should be incorporated into all projects. This is accomplished in-house by including environmental requirements into each request for proposal. These requirements include the need for a waste specialist on the team and individuals who are willing to co-operate with the waste reduction strategy, and who are experienced in reuse and recycling operations.
The project team should ensure the project timeline allows sufficient time for material sorting and salvage activities to maximize material recovery. These activities may take additional person-hours compared to a traditional demolition where minimal salvage is performed.
Project designers should be made aware of the waste reduction objectives at the planning stage of the project. Their participation will allow for design considerations that will reduce waste generation during future renovations. Designers should be encouraged to design with maximum use of standard-sized materials and where possible, to include pre-fabricated systems. Designers should also consider the use of recyclable, reusable, refurbishable or remanufactureable products.
The Waste Audit
The purpose of a construction, renovation, or demolition waste audit is to identify the types and quantities of waste materials that will be produced during the project. The Ontario 3Rs Regulations identifies materials that must be included in the waste audit.
For construction projects they are:
- brick and Portland cement concrete;
- corrugated cardboard;
- unpainted drywall;
- steel (e.g. ductwork, frames, studs); and
- wood (including painted, treated, or laminated wood).
For demolition projects, they are:
- brick and Portland cement concrete;
- steel; and
- wood (not including painted, treated, or laminated wood).
However, there are often significant quantities of other materials that can also be included in the waste audit. These include:
- rigid plastic, plastic film, and polystyrene packaging;
- wooden shipping pallets;
- doors and hardware;
- thermal insulation;
- ceiling tiles;
- architectural hardware such as curtain rods;
- leftover paint;
- carpeting, and hardwood flooring; and
- window glass.
All of these materials can be quantified using floor plans, specifications, site visits, and/or interviews. For some projects, such as the demolition of old buildings, floor plans may not be available. When this occurs, it may be necessary to cut-away sections of surface materials, such as gypsum and ceiling tile in order to verify internal components such as joists, insulation, and sound baffles.
Material quantities are usually estimated in units of volume based on the overall building dimensions, structural components and assembly. However, waste diversion is usually expressed in units of weight. The auditing process should use conversion factors to convert the material volumes to weights. Conversion factors can be found in The Ontario 3Rs Regulations and in architectural and engineering publications.
It should be noted that a waste audit is not intended to identify, quantify, or specify handling information for hazardous wastes such as ballasts that contain PCBs or paint that contains lead. Handling procedures for these materials should be addressed in an environmental impact assessment and/or a designated substances report.
Waste Reduction WorkPlan
The purpose of a waste reduction workplan is to identify opportunities, and to explain the required actions for diverting from landfill the materials identified in the audit. The initiatives outlined in the waste reduction workplan should follow the 3Rs hierarchy of reuse, recycle and reduce, with priority being apportioned respectively. The following is a description of the reduction, reuse, and recycling options for CRD waste.
Reuse
Materials can be reused in a number of ways. Again, proper planning before the project begins will facilitate the implementation of an effective waste diversion program for the project.
In construction related projects, the design phase allows for the use of materials that have been deconstructed elsewhere. The materials may be reused on or off-site, or for a similar or different application to their original function. Contractors can reuse materials such as metal studs and fiberglass insulation salvaged on Project A to build and insulate new walls on Project A, or they can use damaged concrete blocks from Project B as backfill on Project C.
During demolition projects, proper deconstruction planning can allow for material to be salvaged in a reusable form. Contractors can divert materials from landfill by sending them to used building material depots for reuse by a third party. When the need for this alternative is anticipated, the waste reduction workplan should include a list of potential off-site end users. If end users are identified, it is suggested that letters of intent be obtained. These letters should include the potential purchase price, minimum quantities, and handling and shipping details where appropriate.
When contacting potential end users, it is important to specify the type of materials, volume, weight and condition of the materials to be diverted. On-site storage and handling limitations and the expected construction and demolition schedule should also be specified.
Many building systems such as demountable partitions consist of a number of components such as metal framing, plastic moulding and gypsum wallboard. These systems can be taken apart and the constituent components may be used individually. However, it should be noted that the individual reuse of one component often reduces the reusability of other components. For this reason, it is recommended that the components be considered as a system for evaluation purposes. By maintaining the integrity of the system it becomes more marketable and hauling and tipping fees to landfill can be dramatically reduced.
Recycling
In some situations materials cannot be reused. When this occurs, waste diversion can still be achieved by recycling.
The waste reduction workplan should also identify materials for which recycling opportunities exist. The workplan should contain a list of potential recyclers. When contacting and identifying potential recyclers, it is important to specify the material types, the volume, and the weight. The workplan should identify on-site storage and handling limitations and the expected construction and demolition schedule. It is also suggested that letters of interest be obtained from the recycler, including the potential purchase price, minimum accepted quantities and handling and shipping details.
It should be noted that recyclers typically pay more for separated materials that are free of contaminants than for materials that are co-mingled or mixed with contaminants.
Reduce
The amount of material generated by a demolition project is defined by the project scope.
There is little potential for waste reduction, therefore comments presented below focus on construction projects. Reduction initiatives directly affect the amount of resources that are used and the amount of waste that is generated, during a project. Due to the nature of the activity, the design phase of construction related projects offers the greatest potential for waste reduction. Although the full potential may not be achievable due to cost and design constraints, for example, proper planning during the design stage can ensure that structure dimensions correspond to standard construction material dimensions. This not only reduces the amount of waste that is produced, but also reduces the need for cutting and decreases labour costs.
Waste reduction can be achieved by making contractors accountable for the waste they generate. Under these conditions, contractors will try to minimize their waste in order to maintain their profit margins. Another method for reducing on-site waste generation levels is to include a take back policy for packaging. A clause in purchase contracts can stipulate that packaging be either returned in empty delivery trucks, or at a later time.
Some suggestions for reducing waste on a construction project include:
- detailed framing layouts allow for optimized use of material through accurate take-offs;
- reduce waste allowances from the traditional 10% to a more responsible 5%;
- issue clear instructions to tradespeople as to which materials are designated for which component of the structure;
- specify durable products, such as kiln dried lumber that is less likely to warp on site;
- specify pre-cut materials to minimize site cutting and waste;
- materials should arrive on site as they are needed during the construction process - this way less materials are wasted by weathering, improper storage or on-site damage;
- instruct the contractor to inspect each material delivered and immediately return damaged goods;
- preference should be given to suppliers who will offer credit for unused materials;
- materials should be stored on a level surface and elevated above grade level;
- materials should be protected from exposure to the elements;
- give preference to suppliers who will retrieve their packaging materials;
- incorporate prefabricated elements into the design;
- specify the purchase of materials in bulk to minimize packaging waste; and
- inventory all surplus materials so that future orders can be adjusted.
Implementation of a Waste Reduction and Recycling Program
The project team should also clearly outline who is responsible for the implementation of the waste reduction workplan. The general contractor is responsible for ensuring that subcontractors adhere to the terms of the tender documents, including all specified waste diversion initiatives. The project team is also responsible for ensuring that the general contractor makes the subcontractors aware of the waste diversion initiatives.
The project manager should appoint a facilitator for the project. A facilitator is a person who is responsible for assisting the general contractor and all subcontractors with the implementation of the waste reduction workplan throughout the project. The facilitator ensures that the implementation of waste diversion initiatives is made as simple as possible. Specifically, this includes the following:
- meeting with the successful contractor to go over the waste diversion specifications to answer any questions that may be brought up;
- providing checklists for the project manager and general contractor to assist in the implementation of this program;
- providing disposal tracking forms for the project to support the reporting structure which will be established. The project manager can track the disposal of material leaving the site to ensure that the spirit of the project is being met and to provide follow-up figures for the case study at the end of the project; and
- providing telephone assistance to the general contractor throughout the demolition process to ensure that any concerns may be promptly dealt with to maintain the spirit and schedule of the project.
The facilitator may be one of the following individuals depending on the nature of the work and on the size of the project:
- a contracted waste specialist;
- a member of the Prime Consultants team;
- a waste specialist hired by the prime consultant, or
- an experienced member of the General Contractors team.
The tender documents should clearly indicate whether or not a facilitator has been appointed for the project, who the facilitator will be and a description of the facilitator's role.
8.9 Measurement and Documentation of the Waste Diversion Successes
The successes of a CRD waste diversion project should be communicated to employees, patrons and tenants. The communication of the project successes is very important since reported successes for the current project, particularly the achievement of cost savings, will help obtain buy-in for future projects.
The most effective way to communicate the CRD waste management project successes is to prepare a success measurement document. In large, phased projects, it is recommended that a monitoring report be provided by the prime consultant at the end of each phase so that resulting recommendations can be incorporated into subsequent phases. This ensures that there is continual improvement in the process and that substantial opportunities are not missed. It is suggested that a waste management success measurement report contain the following information:
- a summary of the weight and volume of the materials that were actually generated throughout the project;
- a summary of the weight and volume of the materials that were reduced, reused, and recycled; and
- a summary of the costs and savings related to the waste management project including added labour costs and shipping and disposal costs and savings.
The facilitator should compare this quantitative information, which should be obtained from the tracking sheets and interviews with the general contractor, with the information contained within the waste audit report. The use of the waste material tracking sheets is essential while the project is occurring. It is the responsibility of the facilitator to ensure the sheets are all signed by both the truck driver and the receiver at the recycling facility. It is suggested that the facilitator address significant discrepancies between the audit material weights and volumes and the actual material weights and volumes. This will assist in further refining the process and understanding the contractor's approach for future efforts.
Based on the facilitator's observations, the report should also contain the following qualitative information:
- the condition of the reusable/recyclable materials upon shipping/receiving;
- the general and subcontractors' responses to the project including criticisms and suggestions that may have been offered;
- a summary of problems incurred and potential solutions;
- feedback from local market sources; and
- a list of recommendations for future projects.
It is suggested that the project manager state in the RFP that this quantitative and qualitative information is to be collected and included in the success measurement report. This will help to ensure that the appropriate data is collected throughout the project.