Erosion and Sediment Control Correct Questions and Answers!!

Minimum Standard 1 - ANSWER Stabilization permanent or temporary soil stabilization shall be applied to denuded areas within seven days after final grade is reached on any portion of the site; temporary soil stabilization shall be applied within seven days to denuded areas that may not be at final grade but will remain dormant for longer than 14 days; permanent stabilization shall be applied to areas that are to be left dormant for more than one year Site NOT at Final Grade - ANSWER - stabilize in 14 days - temporarily seed - mulch - permanently stabilize if dormant 1 year Site at Final Grade - ANSWER - stabilize in 7 days (recommended immediately) - permanently or temporarily seed and mulch - mulch/matting/straw Minimum Standard 2 - ANSWER Stock Piles, Waste and Borrow Areas during construction, soil stock piles and borrow areas shall be stabilized or protected with sediment trapping measures mulch prevents erosion by protecting the surface from raindrop impact and silt fence intercepts and detains from disturbed areas Minimum Standard 3 - ANSWER Permanent Vegetation permanent vegetation cover shall be established on denuded areas not otherwise permanently stabilized (permanent vegetation shall not be considered established until a ground cover is achieved that is uniform, mature enough to survive, and will inhibit erosion *there is no % associated with this*) reduce erosion and decrease sediment yield from disturbed area this is the standard used to verify that a site is ready for release of bonds or surety Minimum Standard 4 - ANSWER First-Step Measures Sediment basins and traps, perimeter dikes, sediment barriers and other measures intended to trap sediment shall be constructed as a first step in any land-disturbing activity and shall be made functional before upslope land disturbance takes place a certain amount of initial land disturbance may be required to provide access for equipment to install the perimeter controls, but site clearing and grading should be kept to a minimum until the perimeter controls are in place intercepts and detains small amounts of sediment from disturbed areas during construction operation to prevent sediment from leaving the site and decrease velocity of sheet flows and low-to-moderate level channel flow Perimeter Controls - ANSWER assures that sediment does not leave the perimeter of the land-disturbing area once site clearing, grading, and construction commences Examples: silt fences, sediment traps, sediment basins, construction entrance, temporary diversions, diversions Minimum Standard 5 - ANSWER Earthen Structure Stabilization stabilization measures shall be applied to earthen structures such as dams, dikes, and diversions immediately after installation reduce erosion and sedimentation and reduce damage from sediment and runoff to downstream or off-site areas Minimum Standard 6 - ANSWER Traps and Basins sediment traps and basins shall be designed and constructed based upon the total drainage area (not just disturbed area) to be served by the trap or basin Sediment Traps - ANSWER minimum storage capacity shall be 134 cubic yards per acre of drainage area and shall only control drainage areas less than 3 acres *stone outlet = trap* Sediment Basins - ANSWER surface runoff from disturbed areas that is comprised of flow from drainage areas greater than or equal to 3 acres shall be controlled by a basin; minimum storage capacity of a sediment basin shall be 134 cubic yards per acre of drainage area; the outfall system shall, at a minimum, maintain the structural integrity of the basin during a 25-year storm of 24-hour duration; runoff coefficients used in runoff calculations shall correspond to a bare earth condition or those conditions expected to exist while the sediment basin is utilized. Sediment Trapping Devises - ANSWER 1. place near the lowest drainage points of a project 2. install as a first-step measure [MS-4] 3. stabilize immediately [MS-5] 4. must include outlet protection for basins [MS-11] Minimum Standard 7 - ANSWER Cut and Fill Slopes roughening the surface of the slope decreases runoff, lowers the velocity runoff, increases water retention, and leads to better seed germination slopes that are found to be eroding excessively within on year of permanent stabilization shall be provided with additional slop stabilizing measures until the problem is corrected Minimum Standard 8 - ANSWER Concentrated Runoff shall not flow down cut or fill slopes unless contained within an adequate temporary or permanent channel, flume or slope drain structure outlets of these drains need outlet protection to prevent erosion from the concentrated flow size of pipe depends on drainage area temporarily conduct concentrated stormwater runoff safely down the face of a cut or fill slope without causing erosion on or below the slope Minimum Standard 9 - ANSWER Water Seeps whenever water seeps from a slope face, adequate drainage or other protection shall be provided cut and fill operations may expose shallow aquifers or groundwater tables from which water may seep through the side of a slope Minimum Standard 10 - ANSWER Inlet Protection all storm sewer inlets that are made operable during construction shall be protected so that sediment-laden water cannot enter the conveyance system without first being filtered or otherwise treated to remove sediment storm sewers are designed to efficiently transport stormwater away from the site, so when sediment enters the storm sewer system, two negative effects can occur: 1. when velocity of flow is high, much of the sediment will be quickly transported to the nearest receiving channel 2. when velocity of the flow is low, the sediment may be deposited in the pipes resulting in clogging and potential flooding of a site during storm events prevents sediment from entering storm drainage systems prior to permanent stabilization of the disturbed area Silt Fence Drop Inlet Protection vs. Block and Gravel Drop Inlet Sediment Filter - ANSWER Block and gravel drop inlet - will have to clean out regularly but won't get damaged. Minimum Standard 11 - ANSWER Outlet Protection before newly constructed stormwater conveyance channels or pipes are made operational, adequate outlet protection and any required temporary or permanent channel lining shall be installed in both the conveyance channel and receiving channel prevent scour at stormwater outlets, protect outlet structure, and minimize potential for downstream erosion by reducing the velocity and energy of concentrated stormwater flows provides energy dissipation from the concentrated discharge from a pipe or channel in order to prevent erosion and provide a stable transition must construct at zero grade (so it slows down water to slow/prevent erosion) Minimum Standard 12 - ANSWER Watercourse Construction when work in a live watercourse is performed, precautions shall be taken to minimize encroachment, control sediment transport, and stabilize the work area to the greatest extent possible during construction non-erodible material shall be used from the construction of causeways and cofferdams earthen fill may be used for these structures if armored by non-erodible cover materials use of non-erodible materials prevents damage to the stream bed and sedimentation Minimum Standard 13 - ANSWER when a live watercourse must be crossed by construction vehicles more than twice in any six-month period, a temporary vehicular stream crossing constructed of non-erodible material shall be provided Utility Stream Crossing - ANSWER help protect sediment from entering the stream from construction within approach areas and minimize amount of disturbance within the stream itself