Which statement best differentiates construction site erosion controls from post-construction stormwater controls?

Which statement best differentiates construction site erosion controls from post-construction stormwater controls?

• A. Erosion controls are temporary during land disturbance; post-construction controls are permanent systems designed to treat or manage runoff after development.
• B. Erosion controls are permanent; post-construction controls are temporary measures during land disturbance.
• C. Erosion controls address sediment only; post-construction controls address water quality only.
• D. Erosion controls apply only to residential sites; post-construction controls apply only to commercial sites.

Answer: (A)

Temporary erosion controls during land disturbance are designed to keep soil on site and prevent sediment from leaving the construction area, whereas post-construction stormwater controls are permanent features installed after development to treat or manage runoff over the long term. Erosion controls are used only while grading and soil disturbance are happening, with quick-revegetation and stabilization to minimize erosion. Post-construction controls remain in place after construction ends to meet water quality and runoff management goals, using practices like detention basins, bioswales, rain gardens, or permeable pavements. This timing and purpose distinction is why the statement is best: it correctly identifies erosion controls as temporary during land disturbance and post-construction controls as permanent systems designed to treat or manage runoff after development. Other options don’t fit because they reverse permanence, limit controls to a single pollutant or site type, or ignore the timing difference.

Temporary erosion controls during land disturbance are designed to keep soil on site and prevent sediment from leaving the construction area, whereas post-construction stormwater controls are permanent features installed after development to treat or manage runoff over the long term. Erosion controls are used only while grading and soil disturbance are happening, with quick-revegetation and stabilization to minimize erosion. Post-construction controls remain in place after construction ends to meet water quality and runoff management goals, using practices like detention basins, bioswales, rain gardens, or permeable pavements. This timing and purpose distinction is why the statement is best: it correctly identifies erosion controls as temporary during land disturbance and post-construction controls as permanent systems designed to treat or manage runoff after development. Other options don’t fit because they reverse permanence, limit controls to a single pollutant or site type, or ignore the timing difference.