Environmental Site Design and BMPs (Basics)

Question 1

What is the belief that Environmental Site Design is grounded in?

Answer 1

Environmental balance can be maintained as new communities are developed throughout our watersheds if basic principles are obeyed.

(Module 6 / Page 2)

Question 2

Describe the contrast between the old view of stormwater and Environmental Site Design’s view of stormwater.

Answer 2

The old view of stormwater was as a waste product in need of disposal, but ESD views stormwater as a precious resource that must be used carefully

(Module 6 / Page 2)

Question 3

In the field of stormwater management, what does (Tv) stand for?

Answer 3

treatment volume

Module 6 / Page 5

Question 4

In the field of stormwater management, what does (LID) stand for?

Answer 4

Low Impact Development

Module 6 / Page 8

Question 5

What would (TP) stand for with regards to BMP Pollutant Removal Effeciencies?

Answer 5

total phosphorus

Module 6 / Page 9

Question 6

In the field of stormwater management, what does (EMC) stand for?

Answer 6

Event Mean Concentration

Module 6 / Page 9

Question 7

In the field of stormwater management, what does (MTD) stand for?

Answer 7

Manufactured Treatment Devices

Module 6 / Page 8

Question 8

In the field of stormwater management, what does (HSG) stand for?

Answer 8

Hydrologic Soil Group

Module 6 / Page 9

Question 9

In the field of stormwater management, what does (CN) stand for?

Answer 9

Curve Number

Module 6 / Page 15

Question 10

What is a filter strip (Design Standard 2)?

Answer 10

Vegetated Areas that treat sheet flow delivered from adjacent impervious and managed turf areas by slowing runoff velocities and allowing sediment and attached pollutants to settle and /or be filtered by the vegetation.

(Module 6 / Page 12)

Question 11

What is soil restoration or soil compost amendments (Design Standard 4)?

Answer 11

a Environmental Site Design Practice applied after construction to deeply till compacted soils and restore their porosity by amending them with compost.

(Module 6 / Page 14)

Question 12

What are vegetated roofs (Design Standard 5)?

Answer 12

alternative roof surfaces that typically consist of waterproofing and drainage materials and an engineered growing media that is designed to support plant growth.

Question 13

What are the two types of vegetative roofs? What are the differences?

Answer 13

Intensive and Extensive

• Intensive vegetated roofs have a deeper growing media layer that ranges from 6” to 4’ thick, which is planted with a wider variety of plants, including trees.
• Extensive vegetated roofs have a shallower growing media (2-6”), which is planted with carefully selected drought tolerant vegetation.

(Module 6 / Page 15)

Question 14

What is permeable pavement (Design standard 7)?

Answer 14

an alternative paving surface that allows stormwater runoff to filter through voids in the pavement surface into an underlying stone reservoir, where it is temporarily stored and/or infiltrated.

(Module 6 / Page 17)

Question 15

What 4 layers would you expect to see in a permeable pavement?

Answer 15

• Surface pavement layer
• Underlying Stone Aggregate
• Reservoir Layer
• Filter Fabric

(Module 6 / Page 17)

Question 16

Which stormwater design specification has the greatest runoff reduction capability?

Answer 16

Infiltration practices

Module 6 / Page 18

Question 17

What type of sites should avoid using Infiltration Practices?

Answer 17

Any site designated as a stormwater hotspot

Module 6 / Page 18

Question 18

In the field of stormwater management, what does (CPv) stand for?

Answer 18

channel protection volume

Module 6 / Page 21

Question 19

Describe the function of stormwater filters (Design Specification 12).

Answer 19

Stormwater filters capture, temporarily store, and treat stormwater runoff by passing it through an engineered filter media, collecting the filtered water in an underdrain and then returning it back to the storm drainage system.

(Module 6 / Page 22)

Question 20

What type of site would a stormwater filter be ideal for?

Answer 20

A small, highly impervious site

Module 6 / Page 22

Question 21

What is a wet pond? (Design Specification 14)

Answer 21

a permanent pool of standing water that promotes a better environment for gravitational settling, biological uptake, and microbial activity.

(Module 6 / Page 24)

Question 22

In the field of stormwater management, what does (ED) stand for?

Answer 22

Extended Detention

Module 6 / Page 25

Question 23

In general, what five categories are the BMPs compared in relation to each other?

Answer 23

• Annual runoff volume reduction (RR)
• Phosphorus/Nitrogen mass load removal
• Phosphorus/Nitrogen EMC reduction by BMP treatment process
• Channel protection
• Flood mitigation

(Module 6 / Page 25)

Question 24

In the field of stormwater management, what does (RR) stand for?

Answer 24

Runoff Reduction

Module 6 / Page 14

Question 25

What 3 design specifications are commonly used with soil compost amendments?

Answer 25

- Simple rooftop disconnection - Filter Strips - Grass Channel (Module 6 / Page 14)

Question 26

What type of soils are soil compost amendments generally not applicable for? What type of soils can benefit by using soil compost amendments?

Answer 26

Hydrologic Soil Groups A and B Soil Compost Amendments can benefit Hydrologic Soil Groups C and D (Module 6 / Page 14)

Question 27

What 5 alternative practices are commonly used with rooftop disconnections?

Answer 27

- Soil compost amended filter path - Dry well or French drain "Micro-infiltration" - Rain garden "Micro- bio-retention" - Rainwater harvesting - Storm-water Planter "Urban bio-retention" (Module 6 / Page 11)

Question 28

What is the "primary component" of a bio-retention practice?

Answer 28

The filter bed | Module 6 / Page 19

Question 29

What is a bio-retention filter bed made of?

Answer 29

Typically a mixture of sand, soil, and organic material with a surface mulch layer (Module 6 / Page 19)

Question 30

What is a dry swale?

Answer 30

A bio-retention cell that is shallower, configured as a linear channel, and covered with turf or other surface material. (Module 6 / Page 20)

Question 31

What does an under-drain system typically consist of?

Answer 31

A perforated pipe and within a gravel layer. | Module 6 / Page 20

Question 32

Wet swales, constructed wetlands, and wet ponds are an ideal environment for what three things?

Answer 32

- Gravitational settling - Biological Uptake - Microbial Activity (Module 6 / Page 21)

Question 33

What is the only situation that an Extended detention pond or a constructed wetland should be considered?

Answer 33

If there is remaining treatment volume or channel protection volume to manage after all other upland runoff reduction practices have been considered and properly credited. (Module 6 / Page 25)

Question 34

What two benefits can temporary ponding bring about?

Answer 34

- Enables particulate pollutants to settle out - Reduces the maximum peak discharge to the downstream channel (Module 6 / Page 25)

Question 35

Extended detention ponds are normally combined with what other 2 practices?

Answer 35

Either wet ponds or constructed wetlands | Module 6 / Page 25