Environmental Standards Flashcards

Under the EPA Construction General Permit, NPDES stormwater coverage is required when a project disturbs at least how much land?

Answer: One acre, or less if part of a larger common plan of development

Sites that disturb one acre or more, or that belong to a larger common plan disturbing one acre or more, need NPDES permit coverage.

What does a builder submit to get coverage under a stormwater construction general permit?

Answer: A Notice of Intent (NOI)

Operators file a Notice of Intent to get coverage, then a Notice of Termination once the site is finally stabilized.

Which is an EROSION control rather than a SEDIMENT control?

Answer: Hydroseeding and erosion control blankets

Erosion controls keep soil in place, while sediment controls capture soil after it has moved.

What is the main purpose of a stabilized construction entrance made of crushed stone?

Answer: To reduce trucks tracking sediment onto public roads

Coarse stone shakes mud off vehicle tires before they reach paved streets.

To work properly, a silt fence should be installed:

Answer: Along the contour, with the fabric toe trenched into the soil

Following the contour with the toe buried keeps runoff from undercutting the fence and lets sediment settle behind it.

Under EPA's 2022 CGP, how often must sites (outside reduced-frequency conditions) be inspected?

Answer: At least every 7 calendar days, or every 14 days plus within 24 hours of a 0.25-inch storm

The CGP lets operators inspect either weekly, or biweekly plus within 24 hours after a storm of 0.25 inch or more.

Where should a contractor rinse out concrete trucks and chutes on a permitted site?

Answer: In a designated, lined concrete washout area

Concrete washwater is highly alkaline, so it must be contained in a designated washout and kept out of storm drains and waterways.