4. Demolition

This section concerns demolition subject to the Statutory Order on Waste (Ministry of the Environment, 2012) (see Section 7, Waste Management). It describes the general demolition process of a building containing PCBs seen from the building owner’s perspective. The planning begins at the stage when the presence of PCBs in the building has been confirmed and concludes when demolition has been implemented.

Requirements stipulated in the Statutory Order on Waste for screening, mapping, and notification of waste are outlined in SBi Guidelines 241, Survey and Assessment of Building-Related PCBs (Andersen, 2015).

When demolishing a building containing PCBs, PCB-contaminated materials will normally be removed physically. PCB-contaminated materials must be sorted and classified, and PCBs must be separated out from recoverable waste.

This will often take place prior to, or in connection with, the removal of building materials and structures. Methods for removing PCBs are described in Section 5.1, Physical Removal.

Demolition of buildings and plant structures are described in SBi Guidelines 171, Nedrivning af bygninger og anlægskonstruktioner (Demolition of Buildings and Plant Structures) (Lauritzen & Jakobsen, 1991).

Several special considerations relative to health and safety and protecting building occupants and the outside environment may determine the methods and costs associated with removing PCB-contaminated materials. This applies to individual interventions and to the project as a whole (e.g., waste disposal).

The duties of the building owner relative to safety and waste management in a building containing PCBs are described in Section 6, Protecting People and the Environment and Section 7, Waste Management.

The duties of other actors, including quality assurance, are not described in detail, but are subject to best management practice in the trade, to Bekendtgørelse om kvalitetssikring af byggearbejder (Statutory Order on the Quality Assurance of Construction Work) (Ministry of Business Affairs, 2010), and to Vejledning om kvalitetssikring i byggeriet (Guidelines on Quality Assurance in Construction Work) (Ministry of Transport and Housing, 2001). Furthermore, please see Nedbrydningsbranchens Miljøkontrolordning (The Demolition Sector’s Environmental Control Scheme) (Entreprenørforeningens Nedbrydningssektion, 1996b), Kvalitetssikring for nedbrydere (Quality Assurance for Demolition Workers) (Entreprenørforeningens Nedbrydningssektion, 1996a), and SBi Guidelines 171, Nedrivning af bygninger og anlægskonstruktioner (Demolition of Buildings and Plant Structures) (Lauritzen & Jacobsen, 1991).

4.1 Key Elements of the Demolition Process

Table 11 compares the typical steps in a demolition process with the interventions necessary when demolition generates PCB-contaminated waste. The phases shown exemplify a process description based on the ABR89 phase model (bips, 2006). Identification, investigation, and assessment of PCBs in buildings form part of the initiation phase and the programme phase described in SBi Guidelines 241, Survey and Assessment of Building-Related PCBs (Andersen, 2015).

Table 11. Key elements of the demolition of a building containing PCBs.

Phases	PCB-specific activities	PCB-specific results
Initiation	Building owner: – learns that the building is suspected of PCB contamination due to its year of construction or renovation activities carried out during the period 1950–1977.	Completed screening form
	– engages expert.
Programme	Expert: – implements visual inspection plus preliminary and follow-up mapping of PCB in materials. – assesses how to remove the contaminated building parts prior to demolition and consults local authority guidelines on separating and classifying materials containing PCBs. – draws up possible demolition strategies with accompanying financial estimates, including the removal of PCB-contaminated materials, demolition, and waste handling.	Mapping report, can be attached to the notification of CDW
	Building owner assesses the strategy and financial estimates, makes decisions on any supplementary surveys, and considers alternative solutions.
Proposals	Building owner makes decision in principle on demolition strategy, including removing PCB-contaminated materials, selective demolition, and waste handling.	Decision in principle
	Expert draws up project proposal for demolition.	Project proposal
	Building owner approves project proposal.
Project	Expert draws up detailed plan for removing PCB-contaminated materials, waste handling, and risk management (e.g., of unforeseen major occurrences of PCB concealed in the structure).	Key project
Invitation to tender and competitive bidding (if applicable)	Expert prepares tender material with specific requirements for handling health and safety issues, waste, and the external environment.	Tender material
	Building owner offers for tender and selects contractor.	Contract
Operational planning	Contractor plans demolition in detail.	Work and time schedule
	Building owner: – applies for demolition permission and notifies waste to the local authority. – informs neighbours as to how they will be protected against environmental impact and nuisance during the demolition work.	Application for demolition permission and notification of CDW.
Execution	Contractor starts demolition work.
	Building owner checks the demolition work. Often, an expert will supervise the work on behalf of the building owner.	Monitoring documentation
Completion	Contractor hands over the project, including documentation of work carried out, waste handling, and quality control.	Project hand-over documentation

4.2 Planning

When PCBs have been confirmed in a building facing demolition, consideration should be given to the following:

Follow-up mapping of PCB contamination in the building, including extent and type of contamination
Methods for removing PCB-contaminated materials and carry out demolition
Waste management
Cost estimation.

According to the Statutory Order on Waste, PCB-contaminated materials removed from the building must be sorted and classified as either hazardous waste,

waste suitable for deposition, incineration, or recovery. PCBs must be separated out from materials for recovery (see Section 7.4 Classifying Waste).

Removing PCBs and managing PCB-contaminated waste should be considered an integral part of removal and management of any other environmentally harmful substances in the building. Hence, the building owner should conduct a screening plus, if relevant, follow-up mapping of other problematic substances (e.g., lead and asbestos). Screening may be done using the year of construction, renovation history, and choice of materials.

4.2.1 Mapping

Mapping is intended to provide a general overview of the extent of the PCB contamination and facilitate the classification of waste. Moreover, detailed mapping of PCBs helps to ensure the best possible basis for project design and planning.

When the primary PCB sources have been identified, secondary and tertiary contaminations must be located. Mapping and sample collection of primary as well as secondary and tertiary sources are described in SBi Guidelines 241, Survey and Assessment of Building-Related PCBs (Andersen, 2015). During a demolition project, concealed deposits of environmentally damaging substances are often discovered. This is likely unavoidable, but a thorough mapping prior to the demolition may go a long way to ensure that no surprises occur that could have been anticipated.

The occurrence of PCBs, and possibly other environmentally harmful substances, have a bearing on applicable demolition methods and how to make the working environment safe. The occurrence of environmentally harmful substances requires the implementation of special measures relative to the construction site and the surrounding environment. On the construction site, health and safety aspects must be considered before handling the harmful substances. Furthermore, the work must be carried out in such a way as to avoid spreading contaminated materials to surroundings. The working environment is described in Section 6.1, The Working Environment, while the protection of building occupants and neighbours (if applicable) and the outside environment are described in Sections 6.2, Protecting Building Occupants and 6.3, Spreading of PCBs to the Surrounding Environment.

According to the Statutory Order on the Obligations of Building Owners (Danish WEA, 2013) building owners must, when coordinating and drawing up a Health and Safety Plan (PSS), ensure that any risks of exposure to PCBs during the construction process are identified, controlled, and clearly marked prior to commencing site work (Danish WEA, 2014).

If signed contracts are based on AB92 (Ministry of Transport and Housing,1992), the tender material must contain information about investigations carried out (e.g., contamination). If the information

supplied in the tender material is found to be inadequate, the building owner may have to pay the contractor for the extra work involved. PCBs are considered a significant risk which may have a considerable economic bearing on implementing a demolition process.

4.2.2 Strategy for Removing PCBs

The mapping will provide an overview of the extent of the PCB contamination and provide a basis for considering the methods for removing PCB-contaminated materials and demolishing the building.

As a rule, all PCB-contaminated materials are removed, and the remaining structures cleaned so that they can be classified as uncontaminated. This work may comprise the removal of PCB-contaminated materials prior to demolishing the structure (including removal of PCB-contaminated personal property, furnishings, installations), as well as removal of caulk, windows, clean-up of PCB-contaminated surface areas, etc. This means that the remaining structures can be classified as recoverable or non-recoverable materials. For example, clay and concrete can be reused to substitute natural raw materials.

Separating out secondary and tertiary contaminations from the actual building materials can be complicated and resource intensive. Which PCB-contaminated materials should be separated out and the specific removal or clean-up techniques to be used, should be assessed in consultation with the local authority. These choices also imply considerations about health and safety and protecting the exterior environment. Furthermore, decisions must be made concerning the classification and disposal of the waste.

The best possible basis for recoverable building materials is achieved by selective demolition. Selective demolition implies that a thorough sorting of demolition products is made prior to, and during, the demolition work and that the site is planned so that the different fractions can be allocated to the individual material categories (Nedbrydningsbranchens Miljøkontrolordning, 1996).

An expert draws up a detailed plan for selective demolition and separating out the PCB-contaminated materials during demolition of the structure as well as sorting and handling PCB-contaminated materials on the demolition site following the removal of PCB-contaminated materials and demolition.

The physical removal of PCB-contaminated materials is described in Section 5.1, Physical Removal. The actual demolition methods are described in SBi Guidelines 171, Nedrivning af bygninger og anlægskonstruktioner (Demolition of Buildings and Plant Structures) (Lauritzen & Jacobsen, 1991).

The strategies for separating out and preparing the financial estimates should consider the existing structural conditions and where in the building PCBs have been identified (see SBi Guidelines 241, Survey and Assessment of Building-Related PCBs (Andersen, 2015), 5 Mapping the building materials (Andersen, 2015)).

Please note the following factors:

Are facade structures light- or heavy-weight?
Are some of the PCB sources concealed behind panels, flashings, or floors (concealed deposits)?
What types of ceiling or floor finishes are there and are they easy to remove?
How are power cables and ventilation ducts placed?
Which materials adjoin the PCB-containing caulk or other primary PCB sources (wood, clay tiles, or concrete)?
How many metres of caulk or grout require removal, or to what extent do surface areas need removing?
Is it possible to cut out materials adjacent to caulked or grouted joints?
Is there any exterior PCB-containing caulk that requires removing?
Is there a risk of structural failure due to the physical removal of PCB-contaminated parts prior to demolishing the structure and will the building have to be braced?
Is it feasible or advisable to implement complete removal of environmentally harmful substances prior to demolishing the carcass, or should parts of the project be implemented concurrently with the demolition (e.g., in tandem with the demolition of individual storeys)?

It is not only the PCB content (for example, in caulk) and the accompanying secondary contaminations that needs assessing prior to removal. This must also be performed for PCB content in tertiary contaminated surface areas. Removing tertiary PCB contaminations such as paint should be seen in conjunction with the removal of other environmentally harmful substances (typically lead). The building owner must assess concerns and, in consultation with the local authority, decide the needs and requirements for separating out PCBs from CDW. The choice of method is conditional on several issues, including:

The depth and character of the contamination of floor finish, walls, and other surface areas
Wall thickness and cut-out distance when removing concrete and clay from contaminated joints, windows, etc.
The removal of tiles, paving, etc.
The use of PPE, including period of occupancy, limited working hours, etc.
Measures to limit the emission of PCBs to the surroundings (e.g. containment tunnels, partition walls, and negative-pressure ventilation)
Production of PCB-contaminated waste during demolition work (e.g. sand from sandblasting, water from cutting, and rubble from manual trimming)
Collection and handling of demolition waste
The possibility of ongoing control of the demolition work carried out.

When comparing methods, it is worth remembering that high-pressure and sandblasting tools will only clean to a limited depth. Cleaning to greater depths requires milling or physical removal of large structural parts.Please also remember:

Accumulation of waste products when removing PCBs in multi-storey residential buildings may result in critical structural loads.
Physical removal of large parts of the structure may be critical to static properties and the structure may need bracing prior to demolition.

4.2.3 Waste Containing PCBs

See Section 3.2.3, Waste Containing PCBs.

4.2.4 Financial Estimates

The following factors may have economic consequences for the demolition of buildings containing PCBs:

costs associated with waste separation
concealed deposits of PCB-contaminated materials
time associated with waste separating
implications of partial demolition for building occupants (if applicable)
special concerns for neighbours and the surrounding environment

Financial calculations must be drawn up for the costs associated with handling and disposing of PCB-contaminated waste.

4.2.5 Experience-based Price Estimates

Experience-based price estimates have been collected from several Danish cases during the period 2010–13, involving the remediation of building-related PCBs (Grontmij & COWI,2014). Furthermore, data have been obtained from a series of concrete tasks, including removal of caulk, brickwork and concrete work, windows and doors, floor finishes, paint and wallpaper, and encapsulation using silicate coatings. Unit prices for individual work processes vary greatly. For most work processes, there is a satisfactory correlation between unit price and quantity, but other issues are believed to have a considerable effect on unit prices. These include tender framework, type and size of the project, and quantities and occurrences of other environmentally harmful substances in the building. Additionally, there are physical conditions, access to the workplace, the quality of the preliminary work done by the building owner, including the preparation of preliminary investigations and tender material (Grontmij & COWI, 2014) (see Section 3.2.5, Experience-based Price Estimates).

There are examples of quotations for milling, sandblasting, or ‘Steel Re-Jetting’ for stripping paint on concrete containing PCBs. Prices and quantity of waste varied greatly (Olsen & Olesen, 2015).4.2.6 Risk Management
Risk management, see Section 3.2.6, Risk Management.

4.2.6 Risk Management

Risk management, see Section 3.2.6, Risk Management.

4.3 Evaluating the Draft Design

Removing PCB-contaminated materials during the process of demolishing a PCB-contaminated building can be extensive, expensive, and time-consuming. The building owner should make a systematic assessment as to how separating out PCBs can be done in tandem with demolishing the building and disposing of waste.

Several issues should be assessed:

Plans for selective demolition (i.e., the timing of environmental clean-up or removal of PCBs), including the building being cleared and stripped of both contaminated and uncontaminated materials.
Performing the individual work operations, especially from a health and safety perspective
The implications of the demolition work for the surroundings, including risk of dust contamination, contaminated water from cutting, etc.
Waste management and on-site storage of waste and waste disposal
Risk of critical incidents associated with handling PCB-contaminated materials. Unforeseen or concealed occurrences of PCB-contaminated materials and unforeseen high PCB concentrations in the waste may have substantial economic consequences. Waste with PCB concentrations exceeding 50 mg/kg is classified as hazardous waste and must be destroyed (see Section 7.4.1 Hazardous Waste).

4.4 Selecting a Removal Method

Selecting a method for removing the various types of PCB sources should be based on a systematic comparison of pros and cons of the different methods (see Section 5.1, Physical Removal). Removal of other environmentally harmful substances will also affect the choice of method.

Possible solutions are compared to the priorities and assessments identified by the building owner while evaluating the draft design (see Section 4.3, Evaluating the Draft Design). The building owner must assess the individual situation and, in consultation with the local authority, decide how to separate out PCBs from the CDW.

4.5 Tendering Process

A project proposal is drawn up based on preliminary surveys and appraisal of demolition methods and waste management. The project proposal should carefully reflect the priorities clarified by the building owner in the preceding process. Dividing the project into phases could be an option to mitigate problems with concealed PCB deposits, for example. The project proposal should include a financial calculation for the total project.

Based on the approved project proposal, a main project with accompanying tender material is drawn up and prepared in accordance with general guidelines for tendering processes. The tender material should address the special issues concerning health and safety, waste, and the outside environment.

The task of removing PCB-contaminated materials is commonly offered for tender as part of the demolition project. Sometimes, it may be advisable to offer the removal of PCBs as separate contract work (e.g., if the removal of PCB-contaminated materials and demolition can take place at different times).

The tender material should define and delimit the sub-processes that form part of the demolition project. The task can be executed on a subcontract basis. Therefore, methods, processes, and materials should be described separately to match a breakdown into subcontracts (if applicable). Steps must be taken to ensure that any such breakdown corresponds to, and supports, the chosen strategy for environmental clean-up and demolition.

The tender material must clearly specify requirements for the following:

Health and safety aspects
Waste separation, including disposal of contaminated waste
Preventing PCBs from spreading to the outside environment.
Access to the construction site
Access to and screening of existing premises and buildings in continued operation during the work.
Collecting potentially PCB-contaminated dust derived from removing building materials containing PCBs (e.g., the tooling of concrete, clay tiles, or timber).
Exit clean-up before demolishing the stripped structure.

Requirements are incorporated into the tender material, preferably with specifications of submission format, etc.

4.6 Project Planning and Execution

A demolition project involving a building with PCB-contaminated materials is designed and implemented according to the principles applicable to any construction or renovation project in accordance with Almindelige Bestemmelser for Teknisk Rådgivning og Bistand (General Conditions for Technical Consultancy and Support) (ABR89) and Almindelige Betingelser for Arbejder og Leverancer i Bygge- og anlægsvirksomhed (General Conditions for Work and Supply in Construction Work) (AB92) (see SBi Guidelines 171, Nedrivning af bygninger og anlægskonstruktioner (Demolition of Buildings and Plant Structures) (Lauritzen & Jakobsen, 1991)). The contractor plans the removal of PCB-contaminated materials in detail and prepares quality control plans.

The building owner has a duty to assist in complying with health and safety legislation when designing and executing demolition projects involving materials containing PCBs. Consequently, the building owner is responsible for drawing up a Health and Safety Plan, PSS, and for coordinating the work. Careful layout of the workplace is necessary, specifically regarding the working environment, to mitigate the risk of spreading PCBs to the outside environment, to make provisions for users in adjacent rooms or buildings, and to ensure a rational demolition process. This is described in Section 6, Protecting People and the Environment.

Pursuant to Article 13 of the Statutory Order on Waste and prior to commencing the demolition work, the building owner must undertake mapping and notify the local authority (Ministry of the Environment, 2012) (see Section 7, Waste Management). Consequently, waste must be notified to the local authority and subsequently disposed of according to local authority guidelines.

Contractors commence the work and should do the following:

Establish a construction site including the required environmental facilities for separating and storing waste and set up protective measures for health and safety
Check PCB-contaminated materials and areas (e.g. making sure that areas have been correctly marked)
Remove environmentally harmful substances including PCBs and separate out PCB-contaminated waste
Implement the demolition of the stripped down structure and continue separating out PCB-contaminated waste
Dispose of waste in accordance with classification and local authority guidelines.

4.7 Control and Documentation

Contractors must document the work performed on an ongoing basis. The building owner or their adviser should prepare a plan for assuring, controlling, and documenting the quality of the work during implementation. The building owner should ensure the efficacy of the plan through ongoing documented inspection of the work in the implementation phase.

In addition to the usual procedures for quality assurance in construction work, a calculation for the type and quantity of PCB-contaminated building materials for landfill and destruction must be made.

It is advisable that the specific PPE used during the process be documented by the contracting enterprise. Filter changes should be an integral part of the documentation for the supply of fresh air and for large ventilation systems filtrating exhaust air to the surrounding environment. These and similar requirements should be incorporated into the tender material, preferably with specifications of submission format, etc.

Generally, the rules of the Danish WEA and the Danish EPA must be complied with (see Section 6, Protecting People and the Environment and Section 7, Waste Management). Furthermore, please see Nedbrydningsbranchens Miljøkontrolordning 1996 (The Demolition Sector’s Environmental Control Scheme) (Entreprenørforeningens Nedbrydningssektion, 1996b), Kvalitetssikring for nedbrydere (Quality Assurance for Demolition Workers) (Entreprenørforeningens Nedbrydningssektion, 1996a), and finally SBi Guidelines 171, Nedrivning af bygninger og anlægskonstruktioner (Demolition of Buildings and Plant Structures) (Lauritzen & Jacobsen, 1991).

Project supervisors and consultants have a duty to describe special risks and other issues relevant to health and safety when dealing with building-related PCBs (see Section 6.1.1, Operators’ Duties). Depending on the methods chosen, project supervisors must make detailed descriptions of structural and design issues that may affect the cutting out of contaminated building materials or have implications for the stability of the building. Accuracy and careful execution are essential to the actual clean-up work. Even minute quantities of caulk left on the edges of concrete slabs or trodden underfoot can have a negative overall effect on the removal of PCBs and separation of uncontaminated building materials for recovery.

4.8 Communicating with Neighbours

It may be necessary to inform neighbours and others in the local area of the planned work. A time schedule should, as far as possible, be presented and resubmitted in the event of later changes. If the building or the area is not vacated see Section 3.8, Communicating with Occupants and Other Involved Parties.