USGBC Updated LEED-Green-Associate Exam Questions and Answers by koby

Acomposting toileteliminates water use by not requiring any water for flushing, unlike traditional or low-flow fixtures:

“Composting toilets… operate without water use, thus eliminating indoor water demand for flushing.”

WaterSense toilets and low-flow lavatories reduce water use but do not eliminate it.

A 100% vegetated roof coverage best addresses both heat island effect and rainwater runoff from the roof only. A vegetated roof, also known as a green roof, is a layer of living plants thatcovers the roof surface. A vegetated roof reduces the heat island effect by providing shade, evapotranspiration, and insulation, lowering the roof temperature and the surrounding air temperature. A vegetated roof also reduces rainwater runoff by retaining and absorbing precipitation, decreasing the volume and peak flow of stormwater leaving the roof. The other options are not as effective as a 100% vegetated roof coverage in addressing both heat island effect and rainwater runoff from the roof only. A 100% high-albedo roof reflects more solar radiation than a conventional roof, reducing the heat island effect, but it does not reduce rainwater runoff. A 20% high-albedo and 80% conventional roof has a lower reflectance than a 100% high-albedo roof, resulting in a higher heat island effect, and it does not reduce rainwater runoff either. A 50% standing seam copper and 50% vegetated roof has a lower vegetated area than a 100% vegetated roof, resulting in less shade, evapotranspiration, insulation, retention, and absorption, leading to a higher heat island effect and more rainwater runoff. References: LEED Green Associate Candidate Handbook, page 27; USGBC, [Sustainable Sites], page 3.

In LEED v4 BD+C, the Rainwater Management credit is part of the Sustainable Sites (SS) category. This credit aims to reduce the volume and improve the quality of stormwater runoff by mimicking the natural hydrology of the site.

“The intent of this credit is to reduce runoff volume and improve water quality by replicating natural hydrology and water balance of the site.”

– LEED v4 BD+C Reference Guide, SS Credit: Rainwater Management

Key components include:

Managing rainfall on site using green infrastructure,

Promoting infiltration, evapotranspiration, and reuse,

Addressing both quantity and quality of runoff.

This credit does not fall under:

Water Efficiency (A) – which focuses on reducing potable water use indoors/outdoors.

Location and Transportation (C) – which addresses site accessibility and connectivity.

Energy and Atmosphere (D) – which deals with building energy systems.

Correct answer: B. Sustainable Sites

According to the EPA and emphasized by LEED:

“The preferred waste management strategies described by the U.S. Environmental Protection Agency (EPA) are source reduction, reuse, recycling and recovery.”

"Reduce" or "source reduction" is the top strategy for avoiding waste altogether.