Craney Island Dredged Material Management Area

1. In the beginning, there was Harold Waterfield, a survey-boatman for the Corps of Engineers who later became a civil engineer. He developed the idea of a dredged placement area just off of the then-existing Craney Island. In 1948 approximately 3,400 acres of bottom land was deeded in fee simple by the Commonwealth of Virginia to the United States. The upland area is 2,500 acres, each side is approximately 2 miles long with the boundary extending 1,000 feet beyond the water lineIn the beginning, there was Harold Waterfield, a survey-boatman for the Corps of Engineers who later became a civil engineer. He developed the idea of a dredged placement area just off of the then-existing Craney Island. In 1948 approximately 3,400 acres of bottom land was deeded in fee simple by the Commonwealth of Virginia to the United States. The upland area is 2,500 acres, each side is approximately 2 miles long with the boundary extending 1,000 feet beyond the water line

2. Craney Island is well-sited. Because of its location to the channels it serves, it can receive material in 2 ways. Material is either pumped directly into the site from nearby channels, or more remote locations use a bottom dump barge and deposit material in the rehandling basin. The rehandling basin is simply a hole that we dredge upon its filling.Craney Island is well-sited. Because of its location to the channels it serves, it can receive material in 2 ways. Material is either pumped directly into the site from nearby channels, or more remote locations use a bottom dump barge and deposit material in the rehandling basin. The rehandling basin is simply a hole that we dredge upon its filling.

3. We have started replacing the 20 year old spillboxes at Craney Island. Spillbox #4 was replaced in 2005. The replacement of the northern most spillbox #6 is 50% completed and will be finished in 2007. A surcharge is being placed on the foundation soil for spillbox #5. Construction of spillbox #5 is scheduled to be completed in 2008. Spillboxes 1 and 2 are in good shape they have settled less than a foot since there construction. Spillbox #3 is in better condition than 4,5 and 6 because it has only settled 5 feet in 20 years. Spillbox # 6 settled over 10 feet in 20 years. Spillboxes 1, 2, and 3 will still require replacement in the next few years because they are nearing there maximum design height. This slide also shows that we divided CI into 3 cells. This was done in 1983 to increase the soils ability to dry out. Soil is deposited into 1 cell per year. This allows the moisture in the other two cells to evaporate. As dredged material dries, it shrinks and takes less space. We believe dividing Craney Island into 3 cells has resulted in a 25% reduction in the volume displaced by the dredged material. We have started replacing the 20 year old spillboxes at Craney Island. Spillbox #4 was replaced in 2005. The replacement of the northern most spillbox #6 is 50% completed and will be finished in 2007. A surcharge is being placed on the foundation soil for spillbox #5. Construction of spillbox #5 is scheduled to be completed in 2008. Spillboxes 1 and 2 are in good shape they have settled less than a foot since there construction. Spillbox #3 is in better condition than 4,5 and 6 because it has only settled 5 feet in 20 years. Spillbox # 6 settled over 10 feet in 20 years. Spillboxes 1, 2, and 3 will still require replacement in the next few years because they are nearing there maximum design height. This slide also shows that we divided CI into 3 cells. This was done in 1983 to increase the soils ability to dry out. Soil is deposited into 1 cell per year. This allows the moisture in the other two cells to evaporate. As dredged material dries, it shrinks and takes less space. We believe dividing Craney Island into 3 cells has resulted in a 25% reduction in the volume displaced by the dredged material.

4. The inflow of dredged material on the eastern end of Craney Island has resulted in the east end being an average of 6 feet above the west end. The water flows 2 miles down the slope and is ponded on the western end. The weir in the spillway is then used to decant the top few inches of clear water from the settling pond and discharge it to the receiving waters. All dredged material placed at Craney Island is evaluated and permitted by the State and Federal regulatory agencies. This regulatory evaluation occurs well before any dredged material is placed at Craney Island. The regulatory permitting process thoroughly evaluates each project to determine whether the dredged material will comply with Clean Water Act requirements (i.e. water quality). There is nothing added to the dredged material and we decant it like fine wineThe inflow of dredged material on the eastern end of Craney Island has resulted in the east end being an average of 6 feet above the west end. The water flows 2 miles down the slope and is ponded on the western end. The weir in the spillway is then used to decant the top few inches of clear water from the settling pond and discharge it to the receiving waters. All dredged material placed at Craney Island is evaluated and permitted by the State and Federal regulatory agencies. This regulatory evaluation occurs well before any dredged material is placed at Craney Island. The regulatory permitting process thoroughly evaluates each project to determine whether the dredged material will comply with Clean Water Act requirements (i.e. water quality). There is nothing added to the dredged material and we decant it like fine wine

5. Dredged Material Placement Actual images of the processes at Craney Island. The inflow is 15% soil and 85% water. The soil settles out of the water on the 2 mile trip to the spillbox. The spillbox decants the top layer of clear water. The water travels down the corrugated pipes becoming oxygenated and is discharged on the west side of CI. Answer to foam question if asked The creation of foam in our waterways is a natural phenomena. It requires two conditions. There must be surfactants to reduce the surface tension of the water and there must be turbulence to entrain the air in the water creating foam. The surfactants are natural fatty acids which come from decomposing plants and are similar to the additives used in soap products. At Craney Island the air is entrained when the water splashes over the weir and cascades down the spillway and down the corrugated pipes. In a November 17 2007 article in the Daily Press Mark Ailling of VADEQ explains foam on the Appomattox River and is quoted as saying. �Foam is a common occurrence on our waterways after periods of heavy rain or flooding� Decaying leaves and other organic acids on the river lead to temporary foam� Actual images of the processes at Craney Island. The inflow is 15% soil and 85% water. The soil settles out of the water on the 2 mile trip to the spillbox. The spillbox decants the top layer of clear water. The water travels down the corrugated pipes becoming oxygenated and is discharged on the west side of CI. Answer to foam question if asked The creation of foam in our waterways is a natural phenomena. It requires two conditions. There must be surfactants to reduce the surface tension of the water and there must be turbulence to entrain the air in the water creating foam. The surfactants are natural fatty acids which come from decomposing plants and are similar to the additives used in soap products. At Craney Island the air is entrained when the water splashes over the weir and cascades down the spillway and down the corrugated pipes. In a November 17 2007 article in the Daily Press Mark Ailling of VADEQ explains foam on the Appomattox River and is quoted as saying. �Foam is a common occurrence on our waterways after periods of heavy rain or flooding� Decaying leaves and other organic acids on the river lead to temporary foam�

6. Craney Island Environmental Monitoring The purpose and function of Craney Island is to retain and to confine sediment that is removed from navigation channels and placed in Craney Island. How do we monitor how much sediment escapes Craney Island? Water discharged from Craney Island is tested for Total Suspended Solids (TSS) multiple times per day to document the amount (mass) of sediment leaving the island in each liter (volume) of water. The water quality monitoring program has been developed from recommendations and guidance provided by the USACE, Waterways Experiment Station (WES). What do the results of the Total Suspended Solids tests mean? TSS results provide the best overall indicator of the performance of the facility. It tells how efficient the facility is at retaining and confining the sediment. Studies and daily field monitoring demonstrate that Craney Island retains 99.89% of the dredged material placed into Craney Island. Pictures (left) Colorimeter, water quality device used to measure Total Suspended Solids at Craney Island. (right) Craney Island effluent sample on the left and tap water sample on the right. Picture is an example of the quality and clarity of water that is discharged from Craney Island. The purpose and function of Craney Island is to retain and to confine sediment that is removed from navigation channels and placed in Craney Island. How do we monitor how much sediment escapes Craney Island? Water discharged from Craney Island is tested for Total Suspended Solids (TSS) multiple times per day to document the amount (mass) of sediment leaving the island in each liter (volume) of water. The water quality monitoring program has been developed from recommendations and guidance provided by the USACE, Waterways Experiment Station (WES). What do the results of the Total Suspended Solids tests mean? TSS results provide the best overall indicator of the performance of the facility. It tells how efficient the facility is at retaining and confining the sediment. Studies and daily field monitoring demonstrate that Craney Island retains 99.89% of the dredged material placed into Craney Island. Pictures (left) Colorimeter, water quality device used to measure Total Suspended Solids at Craney Island. (right) Craney Island effluent sample on the left and tap water sample on the right. Picture is an example of the quality and clarity of water that is discharged from Craney Island.

7. Craney Island Environmental Monitoring We also apply the �common sense tests� to the discharge water by performing regular visual inspections of the water. Simply put, does the discharge water look cloudy? If the water appears cloudy then we stop the discharge of water to allow more time for the suspended sediments to settle out of the water column. Visual inspections and testing events are all documented by each contractor utilizing Craney Island. The inspections and testing provides real-time measurements and allows dredging contractors to take immediate action to manage or modify their operation. The ability for a contractor to have real-time results and the ability to take immediate action helps minimize impacts on the environment. Dredging contractors (i.e. Mike Haverty, Norfolk Dredging) who conduct similar operations on dredging projects all along the east coast have responded positively on the environmental monitoring required at Craney Island; stating that the testing protocols are very straight forward and help them manage their operations effectively and efficiently.We also apply the �common sense tests� to the discharge water by performing regular visual inspections of the water. Simply put, does the discharge water look cloudy? If the water appears cloudy then we stop the discharge of water to allow more time for the suspended sediments to settle out of the water column. Visual inspections and testing events are all documented by each contractor utilizing Craney Island. The inspections and testing provides real-time measurements and allows dredging contractors to take immediate action to manage or modify their operation. The ability for a contractor to have real-time results and the ability to take immediate action helps minimize impacts on the environment. Dredging contractors (i.e. Mike Haverty, Norfolk Dredging) who conduct similar operations on dredging projects all along the east coast have responded positively on the environmental monitoring required at Craney Island; stating that the testing protocols are very straight forward and help them manage their operations effectively and efficiently.

8. This is an example of 21 of the 27 plus monitoring reports done on Craney Island. These reports have shown conclusively that Craney Island is highly efficient in removing dredged material solids and the effluent is a very high quality, meeting water quality standards. This is an example of 21 of the 27 plus monitoring reports done on Craney Island. These reports have shown conclusively that Craney Island is highly efficient in removing dredged material solids and the effluent is a very high quality, meeting water quality standards.

9. Craney Island Wildlife Norfolk District has received a �Take Pride in America Award� and we received the 1996 Jackson Abott Conservation Award, from the Virginia Society of Ornithology for our work with Professor Ruth Beck from William & Mary managing nesting shore birds. Craney Island is a well-known and popular bird area. We have visitation in excess of 2,000 people per year. Craney Island has one of the few established least tern colonies in the state of Virginia. Craney Island harbors tens of thousands of migrating birds annually; some of which are global migrants. Migrating birds stopover on Craney Island during their migration to �recharge� their batteries by feeding on the abundant aquatic insects that thrive within the containment cells. Bird species pictured: great egret (large birds) and snowy egret (small birds).Norfolk District has received a �Take Pride in America Award� and we received the 1996 Jackson Abott Conservation Award, from the Virginia Society of Ornithology for our work with Professor Ruth Beck from William & Mary managing nesting shore birds. Craney Island is a well-known and popular bird area. We have visitation in excess of 2,000 people per year. Craney Island has one of the few established least tern colonies in the state of Virginia. Craney Island harbors tens of thousands of migrating birds annually; some of which are global migrants. Migrating birds stopover on Craney Island during their migration to �recharge� their batteries by feeding on the abundant aquatic insects that thrive within the containment cells. Bird species pictured: great egret (large birds) and snowy egret (small birds).

10. Since Craney Island was constructed, it has received on average 4.8 Million CY of dredged material per year. The 2005 -2006 spike was due to the 50-foot inbound deepening and the APM Terminal. The 1988 spike was due to the 50-foot outbound deepening The spike in 1984 was due to completion of backlog work on the anchorages and Norfolk Harbor Channel Added info if needed: One unique feature of Craney Island is that the Corps charges a toll for use of the site. The new 2007 tolls will be $1.32 per CY direct pump. (This reimburses the treasury for all costs associated with Craney Island.) The rehandling basin charge is $6.75 per CY. The rehandling basin charge is the cost to pay for Craney Island, $1.32, plus $5.43to dredge the rehandling basin. Since Craney Island was constructed, it has received on average 4.8 Million CY of dredged material per year. The 2005 -2006 spike was due to the 50-foot inbound deepening and the APM Terminal. The 1988 spike was due to the 50-foot outbound deepening The spike in 1984 was due to completion of backlog work on the anchorages and Norfolk Harbor Channel Added info if needed: One unique feature of Craney Island is that the Corps charges a toll for use of the site. The new 2007 tolls will be $1.32 per CY direct pump. (This reimburses the treasury for all costs associated with Craney Island.) The rehandling basin charge is $6.75 per CY. The rehandling basin charge is the cost to pay for Craney Island, $1.32, plus $5.43to dredge the rehandling basin.

11. Craney Island has over 75 users; the ones in yellow are located here in Portsmouth. Norfolk Dredging Company recently estimated it would cost $10.66 per CY to dredge Norfolk Harbor and haul the material 40 miles to the Norfolk Ocean Disposal site. Norfolk Dredging�s current contract for dredging Norfolk Harbor and using Craney Island has a unit price of $4.52. Using this figure, the savings to the user of CI is an average of ($10.66 - $4.52)x4.8 MCY= $29,472,000 per year or $530,000,000 through 2025. One of the reasons APM Terminals located in Portsmouth was the availability of Craney Island as an economical dredged material placement site.Craney Island has over 75 users; the ones in yellow are located here in Portsmouth. Norfolk Dredging Company recently estimated it would cost $10.66 per CY to dredge Norfolk Harbor and haul the material 40 miles to the Norfolk Ocean Disposal site. Norfolk Dredging�s current contract for dredging Norfolk Harbor and using Craney Island has a unit price of $4.52. Using this figure, the savings to the user of CI is an average of ($10.66 - $4.52)x4.8 MCY= $29,472,000 per year or $530,000,000 through 2025. One of the reasons APM Terminals located in Portsmouth was the availability of Craney Island as an economical dredged material placement site.

12. Section 148 of PL 94-587: Sec 148. �Chief of Engineers, shall . . . Extend the capacity and useful life of dredged material disposal areas such that the need for new dredged material disposal areas is kept to a minimum.� The Water Resource Development Act of 1976 authorized the Corps to extend the life of Craney Island. We have managed Craney Island to maximize its life by dewatering the dredged material and strengthening the foundation soil beneath the exterior dikes. We will continue to use innovative engineering methods to extend the life of CI.The Water Resource Development Act of 1976 authorized the Corps to extend the life of Craney Island. We have managed Craney Island to maximize its life by dewatering the dredged material and strengthening the foundation soil beneath the exterior dikes. We will continue to use innovative engineering methods to extend the life of CI.

13. CI was not easy to construct. Up to 100 feet of soft marine clays and silts deposited in a prehistoric riverbed underlie Craney Island. Intensive management and innovation has been required to build it, maintain it, and increase its storage volume. To build Craney Island, we had to construct a foundation with thin layers of sand so our dikes wouldn't disappear in the soft, unconsolidated material. Even today, we must build dikes relatively slowly. This slide depicts dike configuration based on recommendations by WES. This is the current condition at Craney Island.CI was not easy to construct. Up to 100 feet of soft marine clays and silts deposited in a prehistoric riverbed underlie Craney Island. Intensive management and innovation has been required to build it, maintain it, and increase its storage volume. To build Craney Island, we had to construct a foundation with thin layers of sand so our dikes wouldn't disappear in the soft, unconsolidated material. Even today, we must build dikes relatively slowly. This slide depicts dike configuration based on recommendations by WES. This is the current condition at Craney Island.

14. Based on the analysis, the west dikes can be raised to 50 feet MLLW without additional modifications to the surface or geometry of the dike. Results of the 2001 slope stability reportfor west dike construction The principle concern for dike height is the underlying foundation soils. Based on slope stability analysis and considering the improved strength of underlying clays, it was determined that the dike could be raised in increments to a maximum elevation of 50 feet by the year 2015 while maintaining a minimum acceptable safety factor of 1.3 for the slope stability. Dike raising above 50 feet would need additional modifications to the surface or geometry to achieve the minimum acceptable safety factor of 1.3. HOWEVER, WITH THE CURRENT INFLOWS, THE DIKE WILL NOT NEED TO BE RAISED TO AN ELEVATION OF 50 FEET UNTIL THE YEAR 2025. The dike raisings cannot be immediate. The factor of safety is a function of the time-rate behavior of the increase in strength of the clays from the decrease in pore water pressures. Results of the 2001 slope stability reportfor west dike construction The principle concern for dike height is the underlying foundation soils. Based on slope stability analysis and considering the improved strength of underlying clays, it was determined that the dike could be raised in increments to a maximum elevation of 50 feet by the year 2015 while maintaining a minimum acceptable safety factor of 1.3 for the slope stability. Dike raising above 50 feet would need additional modifications to the surface or geometry to achieve the minimum acceptable safety factor of 1.3. HOWEVER, WITH THE CURRENT INFLOWS, THE DIKE WILL NOT NEED TO BE RAISED TO AN ELEVATION OF 50 FEET UNTIL THE YEAR 2025. The dike raisings cannot be immediate. The factor of safety is a function of the time-rate behavior of the increase in strength of the clays from the decrease in pore water pressures.

15. The photo in the top left shows the existing western shore of Craney Island, as seen from the location on Rivershore Road shown in the bottom photo. The photo on the top right simulates the view after the western dike has been raised to 50 feet. The photo in the top left shows the existing western shore of Craney Island, as seen from the location on Rivershore Road shown in the bottom photo. The photo on the top right simulates the view after the western dike has been raised to 50 feet.

16. Green elevation line represents the height of Craney Island from the years 1957 to 2007. The orange elevation line represents the future elevation of Craney Island for the years 2007 until 2025 without improvement of soil strength. The orange dashed line represents possible future elevation from 2025 until Craney Island is no longer needed as a placement site for dredged material. This will require the use of existing and new technologies to strengthen the soils beneath Craney Island. Green elevation line represents the height of Craney Island from the years 1957 to 2007. The orange elevation line represents the future elevation of Craney Island for the years 2007 until 2025 without improvement of soil strength. The orange dashed line represents possible future elevation from 2025 until Craney Island is no longer needed as a placement site for dredged material. This will require the use of existing and new technologies to strengthen the soils beneath Craney Island.

17. Craney Island Dredged Material Management Area The Norfolk District has investigated and implemented innovative and cost effective methods of increasing the useful life of Craney Island. We will continue to use our best scientists and engineers to safely extend the life of Craney Island. Added info if needed: Strip drains inside CI: will reduce the volume of existing dredged material and underlying soils and allow more space for new dredged material. Westside berm: Will reinforce the western dikes foundation and allow it to be raised past 50 feet. South Cell only: The soils under the south cell are stronger than the center and northern cells so the south cell can be in use longer than the other cells.The Norfolk District has investigated and implemented innovative and cost effective methods of increasing the useful life of Craney Island. We will continue to use our best scientists and engineers to safely extend the life of Craney Island. Added info if needed: Strip drains inside CI: will reduce the volume of existing dredged material and underlying soils and allow more space for new dredged material. Westside berm: Will reinforce the western dikes foundation and allow it to be raised past 50 feet. South Cell only: The soils under the south cell are stronger than the center and northern cells so the south cell can be in use longer than the other cells.

18. Picture depicts dike configuration with dike raised to elevation 50 feet. Based on slope stability analysis and considering the improved strength of underlying clays (as a result of the strip drains), it was determined that the dike could be raised in increments to a maximum elevation of 50 feet by the year 2015 while maintaining a minimum acceptable safety factor of 1.3 for the slope stability. HOWEVER, WITH THE CURRENT INFLOWS, THE DIKE WILL NOT NEED TO BE RAISED TO AN ELEVATION OF 50 FEET UNTIL THE YEAR 2025. Any additional raise in dike height will require modification to the surface geometry or subsurface conditions. For instance, the construction of a 150 foot wide earthen berm along the western edge of the dike would allow the dike height to be raised to elevation 60 feet. Picture depicts dike configuration with dike raised to elevation 50 feet. Based on slope stability analysis and considering the improved strength of underlying clays (as a result of the strip drains), it was determined that the dike could be raised in increments to a maximum elevation of 50 feet by the year 2015 while maintaining a minimum acceptable safety factor of 1.3 for the slope stability. HOWEVER, WITH THE CURRENT INFLOWS, THE DIKE WILL NOT NEED TO BE RAISED TO AN ELEVATION OF 50 FEET UNTIL THE YEAR 2025. Any additional raise in dike height will require modification to the surface geometry or subsurface conditions. For instance, the construction of a 150 foot wide earthen berm along the western edge of the dike would allow the dike height to be raised to elevation 60 feet.

19. Craney Island subsides at a rate of 5 feet every ten years. The top 100 feet of soil is very soft dredged material and marine clays. If you constructed a structure on 100 foot piles, the soil and any utilities would continue to subside and eventually separate from the structure. THE ABOVE INFORMATION APPLIES TO THE INTERIOR AS WELL AS ALONG THE PERIMETER DIKE AREA.Craney Island subsides at a rate of 5 feet every ten years. The top 100 feet of soil is very soft dredged material and marine clays. If you constructed a structure on 100 foot piles, the soil and any utilities would continue to subside and eventually separate from the structure. THE ABOVE INFORMATION APPLIES TO THE INTERIOR AS WELL AS ALONG THE PERIMETER DIKE AREA.