Construction Management Introduction

Reducing the environmental impact of the construction process begins with managing necessary demolition responsibly. Many materials can be salvaged for reuse or collected for recycling, often by specialized waste receivers. These services can actually save money for the contractor or owner, because transportation costs and dumping fees are reduced and some items are worth cash.
Protecting the site from undue damage to soils, vegetation and air quality and preventing stormwater contamination during excavation and construction is the second part of responsible construction.
The third part is ensuring that construction waste is minimized, recyclables are recovered and toxic releases on site are minimized.
The final part is ensuring that building occupants are protected from construction-related health hazards during renovations, or during first occupancy after completion.

Demolition Planning

Surveying the demolition site for salvageable and recyclable materials, and hazardous wastes requiring special handling, is a necessary step in responsible demolition. A salvage survey can be done at the same time as a site environmental survey, where contaminated soils, asbestos or other hazards may be present. The general contractor, owner or architect can specify the removal of all reusable and recyclable materials in the demolition contract, require on-site separation and materials processing where practical and cost effective, and turn materials over to an appropriate receiver.

Preserving large shrubs and ornamental and shade trees on construction sites also saves money otherwise spent for new plant materials, helps to protect neighbors’ privacy and maintain important qualities of the neighborhood.

Recycling Waste from Building Demolition

Solid waste disposal is one of the key environmental problems affecting all America’s major urban areas. In Los Angeles, construction waste makes up 15% to 25% of the total solid waste stream. The Santa Monica Sustainable City Program has a proposed goal of diverting 70% of solid waste from the landfill by the year 2010. Construction and demolition waste diversion is an important part of that effort.

Solid waste recycling measures were initiated in Los Angeles in the 1960s, and were accelerated by the state solid waste Bill 939 in 1990. The 1994 Northridge earthquake created huge quantities of demolition waste in the region as damaged buildings were demolished. This galvanized cities and entrepreneurs into action, and produced expanded services including concrete and masonry crushing and many new receiving programs for separated and mixed loads of recyclable demolition materials. A strong building product recycling industry is now operating in the Los Angeles region, which greatly aids environmentally conscious designers and contractors.

Salvaging reusable construction materials such as doors, beams, woodwork, plumbing fixtures, bricks and ornamental metals not only reduces landfill, but creates jobs and serves a strong market for historical components. After salvaging reusable materials, separating recyclable metals and concrete, masonry and pavement waste for processing are the next most valuable steps. Utilizing all appropriate steps for salvage, separation and recycling of demolition waste substantially reduces solid waste volume to landfills, and usually saves the contractor money in dumping fees.

Reducing and Recycling Construction Waste

Unlike demolition waste, as much as 80% of waste generated during construction is reusable or recyclable since it is relatively clean and therefore marketable. Recyclers purchase metal scrap from structural steel, piping, concrete reinforcement and sheet metal work. Corrugated cardboard and gypsum are highly recyclable if uncontaminated, and will also be picked up by buyers. A great deal of wood scrap can be reused on site, while excess is accepted as fuel or fiber by many businesses. The main wastes that are difficult to recycle are plastics, mineral and glass fiber insulation, roofing and containers for paints, adhesives and caulking.

Construction and demolition waste recycling is most effective if it is included in the construction contract specifications, because many key steps in successful recycling programs, such as separation, occur on the construction site.

Minimizing the Handling and Release of Toxics on the Construction Site

Construction sites are sources of many toxic substances, such as paints, solvents, wood preservatives, pesticides, adhesives and sealants. Even with careful management, some of these substances are released into air, soil and water, and many are hazardous to workers. For these reasons, the best choice is to avoid their use as much as possible by using low-toxicity substitutes and low VOC (volatile organic compound) materials. Many new materials and methods are now available that are less toxic and safer for workers. See the Materials chapter for more detail on safe materials.

Many other activities on site will also release toxic pollutants. For example, trucks and machinery use fuels, hydraulic fluids and coolants that can leak if equipment breaks down, or may be spilled on site. Planned maintenance and worker training must be employed to minimize release of these toxic materials.

Using low-pollution construction equipment such as electric motor-driven equipment and propane-powered engines also helps to reduce pollution on the jobsite.

Minimizing Energy and Water Use During Construction

Energy-efficiency and water-conservation measures are generally applied only to finished buildings, but some steps can also be taken during construction. Using high-efficiency sources and automatic controls can reduce electricity used for temporary and security lighting. Water use for washing, irrigation and dust control on site can also be reduced by conservation and recycling.

Minimizing Storm Water Pollution and Protecting Soils and Vegetation During Demolition and Construction

Santa Monica’s Urban Runoff Reduction Ordinance requires every applicant to submit an Urban Runoff Mitigation Plan for the building site to the City’s Engineering Division during the permit process. The purpose is to prevent runoff from entering the stormwater system and polluting Santa Monica Bay. The construction period is particularly important because disturbed soil, concrete fines, fertilizer, oils and other wastes from construction are produced. On-site collection and settling of storm water, prohibition of equipment wash downs, and prevention of soil loss and toxics release from the construction site are necessary to minimize water pollution.

Existing vegetation can also be protected and reused after construction in some cases, reducing the need for new plant materials and preserving existing landscapes.

Protecting Building Occupants from Health Risks During Construction

Workplace safety regulations protect the health of construction workers, but an adequate degree of protection should also be provided for occupants of buildings undergoing remodeling or renovations. Dust and vapors from construction areas are easily transported into occupied zones by air currents, people moving between zones, and by ventilating and air-conditioning systems.

Many health safety experts now recommend that airtight barriers be placed around construction zones in occupied buildings, particularly those, such as elementary schools and health care facilities, with highly vulnerable populations. Another step is providing independent ventilation of the construction zone to maintain negative air pressure relative to occupied areas. Finally, scheduling unavoidably dusty and high-emission operations during unoccupied hours allows clean-up and curing to occur before occupants return, which helps to avoid health risks and liability.

Protecting Building Occupants from Health Risks During Early Occupancy

Indoor air quality is often poorest in buildings immediately after construction is complete; however few regulations exist to protect building occupants during this period. Liquid finishes such as paints, sealers and adhesives release volatile gases during curing that cling to carpets, gypsum board and other porous surfaces and are then released over time. Dusty operations, such as finishing gypsum board, installing insulation and ceiling tile, and sanding or grinding hard floor surfaces leave large residues of nuisance or hazardous dust that accumulate on interior finishes, in ceiling cavities and ducts, to be released later into the occupied zone. A proactive approach that minimizes occupant exposure to health hazards through careful construction procedures will go far toward reducing complaints and limiting owner and contractor liability.