Virginia ESC Minimum Standards Flashcards
What is Minimum Standard 1?
Stabilization
Module 5 /Page 5
What is Minimum Standard 4?
First Step Measures
Module 5 /Page 8
What is Minimum Standard 10?
Inlet Protection
Module 5 /Page 10
What is Minimum Standard 17?
Vehicular Tracking and Construction Entrances
Module 5 /Page 21
What is Minimum Standard 19?
Stormwater Management in relation to Erosion and Sediment Control
(Module 5 /Page 23)
Minimum Standard 5 refers to Earthen Structure Stabilization. According to the Virginia Erosion and Sediment Control Handbook, when should stabilization measures be applied to earthen structures?
Immediately after installation
In this case, MS-5 overrules MS-1
(Module 5 /Page 9)
What are some structural control practices that would be considered earthen structures? (Note: There are 5)
- Temporary Diversion Dike
- Diversion
- Temporary Sediment Trap
- Temporary Sediment Basin
- Stormwater Conveyance Channel
(Module 6 /Page 32-34)
Minimum Standard 8 refers to concentrated runoff. What does MS-8 try to ensure?
MS-8 wants to ensure concentrated runoff does not flow down cut or fill slopes unless it is contained within a channel, flume, or slope drain.
(Module 5 /Page 12)
What is the purpose of MS-11, outlet protection?
- To prevent scour at Stormwater outlets
- To minimize potential for downstream erosion by reducing velocity and energy of concentrated Stormwater flows
(Module 5 /Page 15)
What amount of stream crossings needed for construction in a six month period will warrant a temporary stream crossing based on MS-13?
2 times in a 6 month period will warrant a temporary stream crossing
(Module 5 /Page 17)
The state of Virginia has had the minimum standards for Erosion and Sediment Control in place since when?
A) 1970
B) 1980
C) 1990
D) 2000
C) 1990
Module 5 /Page 2
Minimum Standard 15 states that what should be stabilized immediately after work is completed?
The bed and bank of a watercourse
Module 5 /Page 19
When constructing an underground utility, MS-16 states only how many linear feet of trench may be opened at once?
500 linear feet
Module 5 /Page 20
When does MS-18, Control Removal, state that all temporary ESC measures should be removed by?
Within 30 days of final site stabilization
Module 5 /Page 22
When should soil stabilization be applied to denuded areas after final grade is reached based on MS-1?
Within 7 days after final grade is reached on any portion of the site
(Module 5 /Page 5)
If a site will be left dormant for more than one year, what action does MS-1 require?
Permanent seeding shall be applied
Module 5 /Page 5
Based on the project schedule, it is estimated that a portion of a site will see no work for three weeks. What action should be taken and why?
This section of the site should be temporarily seeded since it will be dormant for more than 14 days based on MS-1.
(Module 5 /Page 5)
Can sediment basins be considered first step measures based on MS-4?
Yes. If a practices will be needed to assure sediment does not leave the land disturbance area once site clearing, grading, and construction begins it should be installed as a first step.
(Module 5 /Page 8)
What is Minimum Standard 6?
Traps and Basins
(Module 5 /Page 10
When should a sediment trap be used and when should a sediment basin be used?
Sediment Traps are for drainage areas less than 3 acres, sediment basins should be used for drainage areas larger than 3 acres.
(Module 5 /Page 10
If a sediment trap will be functioning for a drainage area of 1 acre, how large should it be?
134 cubic yards
“The minimum storage capacity of a sediment trap shall be 134 cubic yards per acre of drainage areas”
(Module 5 /Page 10)
If a slope is found to be excessively eroding after 1 year of permanent stabilization, what does MS-7 recommend?
The slope shall be provided with additional slope stabilizing measures until the problem is corrected.
(Module 5 /Page 11)
MS-9, Water Seeps, refers to aquifers or groundwater tables. Why might this be relevant on a construction project?
Because cut and fill operation may expose shall aquifers or groundwater tables, causing the slope to erode.
(Module 5 /Page 13)
What are two negative impacts of sediment entering a storm sewer system?
Sediment can be transported to a receiving channel during high velocity storm events
Sediment may be deposited in pipes resulting in clogging during low velocity storm events
(Module 5 /Page 14)
What is an acceptable grade for outlet protection?
Outlet protections MUST be constructed at grade of 0%
Module 5 /Page 15
What material must be used to construct a causeway or cofferdam based on MS-12?
“Non-erodible materials”
Module 5 /Page 16
MS-14, Other Watercourse Regulations, states what?
All applicable federal, state, and local requirements pertaining too working in or crossing live streams should be met.”
(Module 5 /Page 18)
What is an approved method for cleaning paved roads based on MS-17 and when should it take place.
Sediment should be removed from paved surfaces by shoveling and sweeping at the end of each day.
(Module 5 /Page 21)
Does cleaning of roadways at the end of every work day apply to small individual lots?
Yes. “This provision applies to individual development lots as well as larger land-disturbing activities.”
(Module 5 /Page 21)
Is washing of streets permitted based on MS-17?
Yes, but only after shoveling and sweeping
Module 5 /Page 21
To meet the requirements of MS-19 what 3 components of Stormwater discharge must be addressed?
- ) channel capacity
- ) channel stability
- ) peak flow rate
(Module 5 /Page 26)
When MS-19 states channel stability must be addressed, what does that mean?
It means each structure or conduit has a permissible velocity, or the highest velocity allowed
(Module 5 /Page 26)
When MS-19 states channel capacity must be addressed, what does that mean?
Channel capacity means the volume and duration
Module 5 /Page 26
MS-19 requires natural channels to be analyzed based on what type of storm event?
The 2-year storm
Module 5 /Page 27
When natural channels are analyzed due to MS-19, what needs to be verified?
The 2-year storm needs to be used to verify that stormwater will not overtop channel banks
nor cause erosion of the channel bed or banks.
(Module 5 /Page 27)
When analyzing pipes to meet the requirements MS-19, what criteria needs to be met?
The 10-year storm must be contained within the pipe or system
(Module 5 /Page 27)
Are the “Minimum Standards” found in the Erosion and Sediment Control Laws or Regulations?
Found in the Regulations
9VAC25-840-40
What is a “cofferdam”?
A watertight temporary structure in a river, lake, etc., for keeping the water from an enclosed area that has been pumped dry so that bridge foundations, dams, etc, may be constructed.
(9VAC25-840-10 Definitions)
What is a “dike”?
An earthen embankment constructed to confine or control water, especially one built along the banks of a river to prevent overflow of lowlands; levee
(9VAC25-840-10 Definitions)
What is an “energy dissipator”?
A non-erodible structure which reduces the velocity of concentrated flow to reduce its erosive effects.
(9VAC25-840-10 Definitions)
What is a “flume”?
A constructed device lined with erosive-resistant materials intended to convey water on steep grades.
(9VAC25-840-10 Definitions)
What is a “ten-year storm”?
A storm that is capable of producing rainfall expected to be equaled or exceeded on the average of once in 10 years.
(9VAC25-840-10 Definitions)
What does “stabilized” mean?
Land that has been treated to withstand normal exposure to natural forces without incurring erosion damage
(9VAC25-840-10 Definitions)
What design concepts need to be included so that stream restoration/relocation projects are not considered man-made channels?
“Natural Channel Design Concepts”
62.1-44.15:52 A
What is “Stormwater detention”?
The process of temporarily impounding runoff and discharging it through a hydraulic outlet structure to a downstream conveyance system
(9VAC25-840-10 Definitions)
What is a “live watercourse”?
A definite channel with bed and bank within which concentrated water flows continuously
(9VAC25-840-10 Definitions)
What does “denuded” mean?
Land that has been physically disturbed and no longer supports vegetative cover.
(9VAC25-840-10 Definitions)
What one thing are minimum standards 1, 2, 3, and 5 all focused on?
-Erosion control stabilization
Module 5 / Page 4
What one thing are minimum standards 12, 13, 14, and 15 all focused on?
Water courses
Module 5 / Page 4
What one thing are minimum standards 7, 8, and 9 all focused on?
Slope protection
Module 5 / Page 4
What one thing are minimum standards 10 and 11 both focused on?
Channels, culverts, and outlets
Module 5 / Page 4
What one thing are minimum standards 4 and 6 both focused on?
Sediment control
Module 5 / Page 4
When man-made channels are analyzed due to MS-19, what needs to be verified?
The 10-year storm needs to be used to verify that stormwater will not overtop the banks
and the 2-year storm needs to be used to verify stormwater will not cause erosion of channel bed or banks.
(Module 5 /Page 27)