240 Attend Why We Dredge Meeting in St. Louis Missouri
At the Western Dredging Association (WEDA) annual meeting June 8 through 11 approximately 240 people came from Brazil Canada Colombia England Germany the Republic of Ireland Mexico and the Netherlands as well as the United States to participate in the four-day event.
The theme of the meeting was Why We Dredge.
Held at the St. Louis Airport Marriott Hotel the event began with the one-day Texas A&M 39th annual Dredging Seminar followed by the WEDA program which consisted of multiple technical paper sessions social functions and a field trip to Tower Rock Stone’s limestone quarry in Ste. Genevieve Missouri.
Bill Hanson WEDA president welcomed the group and announced a meeting in Panama in March 2009 noting that the Panama Canal expansion is an incentive for U.S. ports to expand to accommodate the larger ships coming through the Canal.
He said he had surveyed the WEDA goals and objectives. In our meetings everyone has a story to tell he said. Meetings also provide a forum for technology transfer for discussing the problems of enhancement of the marine environment and for education for young people to encourage them to enter the dredging industry.
He introduced Lt. Col. Robert Bayham deputy commander of the St. Louis District of the Corps of Engineers who informed the group of the District’s $15 million per year dredging program on 300 miles of the Mississippi river 80 miles of the Illinois River and 30 miles of the Kaskaskia River aided by the Corps Dredge Potter a 32-inch dustpan dredge.
The Potter’s Captain Jim Pierce was present at the WEDA meeting.
Tower Rock Field Trip
On Tuesday afternoon June 10 Luhr Brothers sponsored a tour of their Tower Rock Stone Company at Ste. Genevieve Missouri Upper Mississippi River Mile 127. The quarry opened in 1972 and produces manufactured stone in a variety of standard sizes in addition to chemical lime which is produced on site.
The group travelled by bus to the site and Rodney Linker of Luhr Brothers described the quarry during the trip. At the site Ron Inman general manager of Tower Rock met the group at a high point that allowed a view of the entire operation. The riverfront quarry has a loading ramp where trucks transfer the product to barges. The plant produces 100 different sizes of manufactured rock as well as agricultural lime and chemical lime.
After a drive through the quarry where the group saw the crushing and separating operations they disembarked on another high spot opposite the rock face that would be blasted that day.
John Kiefer blasting supervisor answered questions prior to the blast which produced a huge dust plume and revealed a large pile of broken rock after it cleared several minutes later.
That evening a conference dinner and dance offered attendees the opportunity to socialize and where the presentations for Lifetime Achievement and Dredger of the Year were given to Mort Richardson and Judith Powers.
46 Technical Papers
The combined Texas A&M Seminar and WEDA Technical Conference included 46 papers under sessions entitled: Management of Contaminated Sediments Dredging Research Environmental Aspects of Dredging Dredging Studies and Projects Navigational Dredging Ashtabula River Remediation Contracts and Construction Management Dredging and Dewatering Survey and Data Management and Dredged Material Disposal. The final two sessions held concurrently were the WEDA Safety Commission Panel chaired by Tom Verna and the WEDA Environmental Commission Panel Making It Happen: Management of Dredged Material and Sediment in the Watershed chaired by Craig Vogt.
The award for best technical paper was sponsored by the Dredging Contractors of America. It was awarded to Douglas Clarke U.S. Army Engineer Research and Development Center and Dana Wilber Bowhead Information Technology for their paper Compliance Monitoring of Dredging Induced Turbidity: Defective Designs and Potential Solutions.
The second place award sponsored by WEDA went to Keith Mahoney Elio Paradise New York City Department of Environmental Protection; Robert DeLorenzo O’Brian and Gere Inc. and John De Rugeris CLE Engineers for CSO Sediment Removal in an Urban Tributary.
Sape Miedema Delft University of Technology The Netherlands received the third place award for A Sensitivity Analysis of the Production of Clamshells.
The WEDA Best Student Paper Award went to John Henriksen of Texas A&M University for Laboratory Near Field Turbidity Data for a Cutter Suction Dredging Operation.
This year for the first time awards were given for best displays in the exhibit area. Judges were Dr. Billy Edge of Texas A&M University and Marsha Cohen editor of Terra et Aqua magazine.
They chose Odom Hydrographic Systems as the most inviting warm and recepive booth and Hypack Inc. as the most technically educational booth. Both will receive a free 10 x 10-foot booth at WEDA 29 in Tempe Arizona June 14-17 2009.
The proceedings were provided on DVD edited by Robert E. Randall Ph.D. P.E. Ford Professor of Ocean and Civil Engineering and Director of the Center for Dredging Studies. The proceedings are CDS Report No. 509 published by the Center for Dredging Studies Ocean Engineering program Zachry Department of Civil Engineering Texas A&M University.
The 2009 WEDA 29 and Texas A&M 40th Dredging Seminar will be held at The Buttes Resort in Tempe Arizona Sunday June 14 through Wednesday June 17.
Abstract of Winning Paper
The abstract of the first place technical paper states: “Re-suspension of sediments during dredging and dredged material disposal operations continues to be a primary concern of regulatory agencies charged with the protection of environmental resources. Consequently almost all dredging projects incorporate some level of monitoring effort dedicated to measurement of sediment re-suspension. In the majority of cases turbidity is measured with optical sensors as expeditious indices of suspended sediment concentration. Results are interpreted with reference to specific water quality criteria and often within the context of allowable mixing zone dimensions. When criteria are exceeded regulatory responses are triggered ranging from collection of additional samples to modification or even cessation of the dredging operation.
“For numerous reasons the existing generic approach to compliance monitoring is frequently ineffective in both adaptively regulating dredging projects and ensuring true environmental protection. Turbidity is a relative index of water clarity that only has ecological relevance once it is related to an environmentally relevant parameter such as suspended sediment concentrations water clarity percent surface irradiance or sedimentation rate in the water body of interest. Failing these correlations turbidity criteria are based on speculation of thresholds that may result in negative biological impacts. Present day inconsistencies in turbidity standards across state regulatory agencies in the U.S. reflect the continued lack of specificity in knowledge of likely exposures and responses for diverse organisms.
“The perfunctory collection of few data at basically arbitrary spatial and temporal scales lacks sufficient statistical power to assess potential impacts in any meaningful way. Furthermore most commonly applied compliance sampling protocols seldom demonstrates any linkage between turbidity measures and detrimental biological response. Thus compliance monitoring creates a status quo in which effort is expended at many dredging projects without demonstrable protection of the environment. Wasteful ineffective compliance monitoring designs can be enhanced by taking advantage of technological advances as well as logical common sense-driven improvements in obtaining data that can be used adaptively.
“Re-invention of compliance monitoring can simply involve a combination of acoustic-based mapping of suspended sediment plume trajectories and collection of time series data at the locations of target resources of concern (e.g. hard bottom sea grass spawning habitats). The latter data can contribute to a project-independent database that would enable much improved management decisions regarding safe environmentally sound dredging projects.”
