Last edited 10 Oct 2019

Sustainable waste management

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Contents

[edit] Introduction

Landfill is toxic, expensive and occupies space which may otherwise be used for development, minerals extraction or some other use. And the construction industry causes one third of that problem – an estimated 77.4 million tonnes of construction waste is festering in UK landfill sites.

The industry has not failed to acknowledge its role in resolving the problem and some positive steps have been taken to reduce waste to landfill, but there is room for improvement. This article addresses some of the ways site management procedures may be adapted to reduce waste to landfill.

[edit] The three R’s

Reduce, reuse and recycle are the three pillars of effective waste management and are best implemented as part of a broader strategy.

Site Waste Management Plans (SWMPs) are no longer compulsory for construction projects in England but may still be required for BREEAM assessments or by local planning authorities, and are beneficial simply as a means of demonstrating a company’s commitment to the environment.

SWMPs, which essentially describe how materials will be managed and disposed of, should be prepared before construction begins. This requires some forward-planning, for example, estimating how much waste is likely to be produced in each category, and the proportion that will be reused and recycled. The SWMP should be included in subcontracts and the plan monitored and updated as the work progresses.

Successful implementation may require site staff training on:

[edit] Reduce

The first of the ‘three Rs’ is reduce: to plan procurement to avoid waste and to save any excess materials to reduce further purchases.

Planned procurement can both minimise waste and maximise the efficient use of materials. So, avoid ordering more concrete and mortar than can be realistically used before setting. Set and crush excess concrete to use in paths and as road aggregate. Use mortar silos wherever possible.

For materials that are heated, mixed, damaged by the elements, or otherwise subject to spoilage, planning should determine the exact amount required. If materials are over-ordered, they should be returned to the supplier or used on another job. Avoid having to dispose of materials that have been damaged in transit by immediately checking goods and returning to the supplier to take on the responsibility.

Packaging, too should be reduced – particularly where it amounts to more than 50% of a delivery, which is not uncommon. Glazing racks, collation trays, plastic shrink wrapping, transport strapping and other forms of packaging can be returned to the supplier, together with a request that less packaging is used in future.

Consider what waste can be eliminated at the start of the process. For example, select durable modular metal form-systems for use in concrete construction in place of wood, as this has the benefit of being readily demountable and reusable on other projects.

[edit] Reuse

Re-using is the next best thing to reducing: it is rarely possible to order the exact quantities required, but where materials are in excess of requirements, there is often an opportunity for reuse.

Re-using starts prior to demolition when materials and components can be salvaged and used, if not on the project itself, on another job or by a local charity. There is always demand for windows and doors, wood flooring, cabinetry, architectural millwork, electrical and plumbing fixtures and mechanical equipment. Structural steel and metals are almost universally recycled and this should be standard practice for any demolition contractor. Similarly, timber brokers literally pay construction companies to take on the responsibility for disposing of wood.

Consider collaborating with local businesses and trades to identify potential opportunities for exchanging waste/reusable materials and co-ordinate trades so that surplus materials from one can be used by another. Carry out repairs on damaged goods to avoid waste, and use mechanical fasteners such as bolts, screws and nails instead of adhesives on items associated with temporary works (e.g. safety / security doors, timber hoarding, hand rails) so that they may be used again.

[edit] Recycle

An increasing number of organisations will take on goods for recycling. If a return or buy-back arrangement is not possible with suppliers, consider using an organisation such as Habitat for Humanity or ReStore.

Sorting for recycling can either be carried out on site through a contract with a waste hauler, which will provide receptacles for recyclable materials and debris and removes materials pre-sorted; or by a specialist C&D (construction and demolition) recycling firm which will sort waste off-site.

If sorting waste materials on-site, plan ahead to ensure that containers are appropriately sized and locate skips and wheelie bins close to working areas, clearly labelled. Hazardous waste must be handled and stored according to instructions and should not be mixed with non-hazardous waste.

Not all recyclable waste should necessarily be removed from site, however: in addition to using concrete and masonry to produce aggregate, consider shredding landscape materials and unpainted timber to create mulch, compost, boiler fuel chips – for use on or off-site.

[edit] Supply chain

Clearly, the success of sustainable waste management is inextricably linked to procurement. Because of this, it is important that prospective suppliers are contractually required (through the tender process) to provide their own waste recovery targets and KPIs. It will become immediately apparent that the best suppliers for a sustainable construction project are those who offer to take back excess materials and packaging, allow for staggered deliveries, and can submit sustainability reports, giving you the evidence and the confidence the entire project is a sustainable one.

For added reassurance and to comply with best practice, monitor waste management and review site practice on a regular basis. Monitoring will also help build on the success of one project for the benefit of the next.

Finally, consider offsite construction as a means of reducing waste: research has predicted that offsite construction can reduce waste by as much as 50%.

[edit] Related articles on Designing Buildings Wiki

--Trident Building Consultancy