Question 1

When does most pollutant transport occur?&#10;A)early in a rainfall event&#10;C)after a rainfall event&#10;B)late in a rainfall event&#10;D)before a rainfall event

Accepted Answer

Most pollutant transport occurs early in a rainfall event because at the start of rainfall, the accumulated pollutants on the surfaces are washed away by the first flush of rainwater. As the rain continues, the concentration of pollutants decreases because the surfaces are washed clean, and the remaining rainwater has less pollution to carry. Therefore, the beginning of a rainfall event is when the highest amount of pollutants is transported.

Question 2

A detention basin functions by storing water in a pond or ___________________.

Accepted Answer

reservoir

Question 3

Detention basins are designed to release stormwater ____.&#10;A)quickly&#10;C)not at all&#10;B)slowly&#10;D)after treatment

Accepted Answer

Detention basins are designed to slow down the release of stormwater, allowing time for sediment and pollutants to settle out before the water is released into the environment. This helps to prevent erosion and reduce pollution in downstream water bodies.

Question 4

The primary goal of on-site detention is to reduce the peak rate of runoff leaving the site to a level equal to or less than the predevelopment peak rate.

Accepted Answer

On-site detention is a stormwater management technique used to control peak runoff rates and volumes from a site. Its primary goal is to reduce the peak rate of runoff leaving the site to a level equal to or less than the predevelopment peak rate. This helps to prevent flooding and erosion downstream, and to protect local water quality.

Question 5

A basin designed to have a permanent pond at the bottom is called a dry basin.

Accepted Answer

A dry basin is designed to temporarily hold and manage stormwater runoff, without a permanent pond at the bottom.

Question 6

A non-structural strategy for mitigating the effects of development on stormwater runoff is ____.&#10;A)maximizing impervious surfaces&#10;B)minimizing compaction of soil&#10;C)introducing pollutants to water&#10;D)increasing parking space size

Accepted Answer

By minimizing soil compaction, the natural infiltration of water into the soil is preserved, reducing the amount of stormwater runoff. Maximizing impervious surfaces, introducing pollutants to water, and increasing parking space size will all increase the amount of stormwater runoff, exacerbating the effects of development on the environment.

Question 7

Design storms should be chosen to reflect the potential for ____________________.

Accepted Answer

The answer of Design storms should be chosen to reflect...

Question 8

In addition to controlling the quantity of runoff, detention basins can serve effectively to control water ____ as well.&#10;A)planning&#10;C)quality&#10;B)temperature&#10;D)color

Accepted Answer

Detention basins can serve as an effective means to control the quality of water. By holding water for a period of time, the basins allow for sedimentation, filtration, and biological treatment of pollutants before releasing the water. This improves the overall quality of runoff water being released into nearby water bodies.

Question 9

Off-site detention is intended to protect land in the immediate vicinity of the site from the effects of development.

Accepted Answer

The answer of Off-site detention is intended to protect land...

Question 10

The first flow of runoff is called first ___________________.

Accepted Answer

The answer of The first flow of runoff is called...

Question 11

Topographic conditions peculiar to individual sites have no bearing on the approach to detention design.

Accepted Answer

The answer of Topographic conditions peculiar to individual sites have...

Question 12

Reduction in peak runoff rate can refer to total ___________________ runoff or it can refer to runoff leaving the site at a specific location.

Accepted Answer

The answer of Reduction in peak runoff rate can refer...

Question 13

___________________ detention is difficult to accomplish but often is more effective and less costly than allowing a proliferation of small on-site facilities.

Accepted Answer

The answer of ___________________ detention is difficult to accomplish but...

Question 14

A basin that promotes recharge by storing stormwater for an extended period of time is called ____.&#10;A)a wet basin&#10;C)a sediment basin&#10;B)an infiltration basin&#10;D)a dry basin

Accepted Answer

The answer of A basin that promotes recharge by storing...

Question 15

Underground basins require additional measures to control pollution.

Accepted Answer

The answer of Underground basins require additional measures to control...

Deck 15: Detention Design