Stormwater runoff from the built environment, often mixed with contaminants, has a damaging effect on local and downstream ecosystems. Porous paving products and vegetated roofing systems result in less rainwater runoff and thereby reduce surface water pollution. Stormwater treatment systems reduce pollutant levels in any water that is released. Again, quantifiable benefit and a strong track record are important determinants here of “green.”
Just how low the VOC level needs to be for a given product to qualify for inclusion in GreenSpec depends on the product category. For most products, we require certification to California’s health-based emissions standard, CDPH Std Method v1.1 standard (also referred to as California Section 01350), which tests a product’s resultant VOC concentrations in the space after a given period of time. For wet-applied products like paints, caulks, and adhesives, we still also look for VOC content instead of, or in addition to, verified low emissions; this is because emissions testing doesn’t adequately test initial offgassing, and VOC content is currently the only widely available proxy.
Included here are various erosion-control products, foundation products that eliminate the need for excavation, and exterior stains that result in lower VOC emissions into the atmosphere. Fluorescent lamp and ballast recyclers and low-mercury fluorescent lamps reduce environmental impacts during maintenance and disposal of luminaires.
Waste Crete Systems provides closed-loop concrete washout services for the construction industry using its EnviroWash line. Water left over after washing down concrete equipment—trucks, pumps, mixers, chutes, and wheelbarrows—can contain a variety of metal compounds that can impact aquatic life, including zinc, copper, and the heavy metal chromium; and the alkalinity can be as corrosive as drain cleaner (with a pH as high as 12). EnviroWash systems capture concrete wastewater in hinged hoppers and pump it into the forced weir tanks for separation and filtration. The water is pumped back into the hoppers for reuse in other washouts, and the separated solids are recycled. Water lost to evaporation needs to be replaced. A variety of EnviroWash models are available, including semi-permanent units meant for large jobsites and portable units that can handle the washout of between 15 and 100 concrete trucks. Operations in Texas only.
Concrete accessories include such items as anchors, inserts, expansion joints, waterstops, and products that prevent soil contamination from truck overages.
Filling the expansion joints in concrete construction is a good use for panels made from recycled newspaper or waste agricultural materials, because the strength requirements are minimal (though for radon control, less permeable joint sealants may be preferable).
Waterstops must be highly durable and corrosion resistant. Plasticized PVC is the most common waterstop material, but PVC is made with phthalates, an endocrine disruptor, and its production and disposal pose a number of environmental problems. GreenSpec lists products using alternatives to PVC such as EDPM and polypropylene.
The wastewater from washing down concrete equipment on the jobsite has a pH as high as 12 (similar to drain cleaner) and can potentially contain toxic metals. Concrete washout systems capture this wastewater for proper disposal, preventing it from entering the groundwater. These systems also minimize solid concrete waste leftover at the jobsite.
Rebar supports for concrete formwork hold rebar in place during pours and have minimal structural requirements. GreenSpec lists plastic products listed here with high recycled content, plastic.
GreenSpec also lists structural elements that serve as thermal breaks between balconies and buildings—a major area of heat loss, and one requiring special attention.
Ratings and Commentary