Dredging Specialists Takes Aquatic Remediation to the Next Level.

The introduction of the Dredging Specialists Aquatic Remediation System [ARS] has raised the bar and takes aquatic remediation to the next level. 

In the past aquatic remediation projects were done with a hydraulic dredge to excavate the material and a belt press or plate press to dewater the material.  This method has many problems.

1) Problems With Hydraulic Dredges.

a) Continual plugging of the dredge pump with oversize debris.  A dredge pump will pass a 4 to 6 inch spherical object.  However, a 10-inch long stick can jam in the eye of the impeller.  A few sticks, boards, metal objects, leaves, cattails, and you have a plugged pump.  The only way to remove a plug from a dredge pump is by hand.  This puts people in contact with muddy, sloppy, contaminated material.  Contaminated material is slopped all over the deck of the dredge, back in the water and in boats, as it is transferred to shore. 

b) Typically, small auger dredges are used.  With their single straight traverse cable, the laws of physics prevent them from maintaining a cut adjacent to a prior cut.  Therefore, they have very poor bottom clean up. 

c) The auger head pushes contaminated material around the ends and over the top of the auger.  This places contaminated material back in areas that have been cleaned.

d) One minute the dredge may be pumping dirty water, and the next minute it will be pumping peanut butter type material with 40% solids.  A dredge also has a vastly changing flow rate.  With the continual changes in percent solids and flow rates, the proper dosage of polymer required to make a flocculent cannot be consistently attained.  Polymer in a hydraulic dredge pipeline is nothing more than a placebo. 

e) The low percent solids cause an excessive volume of slurry to dewater in presses.

2) Problems With Belt Presses And Plate Presses:

a) Presses will not dewater material that is larger than 1/4 inch.  Material larger than 1/4 inch will hold belt press belts apart and prevent dewatering.  Even sand in the piston pumps, used with plate presses, will cause a hydraulic lock that will break pistons, connecting rods, and crankshafts.

b) Separating material larger than 1/4-inch can be very difficult and sometimes impossible.  Shaker screens continually plug with leaves, sticks, and rocks.  Cleaning them requires shutdown and manual or water jet cleaning.  This puts people in contact with the contaminated material. You end up with a large amount of > 1/4 inch material that the presses will not take.   This material is still full of water.  This causes another huge dewatering problem with no effective method or equipment available.

c) Polymer: A belt press requires polymer to make a flocculent.  Polymer is not effective when put in the dredge pipeline.  Material from the dredge must go to frac-tanks with mixers to equalize the percent solids.  Polymer is injected in the pipeline from the frac-tank to the belt press.

Several years ago, two technologies were developed that have proven to provide better cleanup, lower costs, shorter project time, and are more environmental and user friendly than a dredge and presses.

1) The Cable Arm Bucket has been proven and is the most widely accepted tool for excavation of contaminated aquatic material.

a) Has better clean up, compared to a hydraulic dredge or any other bucket dredge.

b) Less turbidity than hydraulic dredges.

c) Will handle debris much larger than a hydraulic dredge. 

d) People do not come in contact with contaminated material.

e) To learn more about the Cable Arm Bucket, go to www.cablearm.com

2) Geo-Bags:  To learn more about Geo-Bags, go to  http://geotecassociates.com

a) Typically, material is pumped into Geo-Bags.  They will accept any size material that will pass through the pump.  Typically, 4 to 6 inches.

b) Total project costs are less than when using presses for dewatering.

c) People do not come in contact with contaminated material.

d) Shaker screens are not used.  No second sloppy product from shaker screens that is difficult to dewater.  No downtime, cleaning shaker screens. 

e) No mechanical equipment to break down. or wear out.

f) Do not require polymer.  We have run tests and proven this to be true and can explain why.

However, up to now the Cable Arm Bucket and Geo-Bags could not be used together.  Dredging Specialists has developed the missing pieces that make the Cable Arm bucket work with Geo Bags.  The modules that Dredging Specialists have added to make the Aquatic Remediation System [ARS] are: Click Here to see the process flow chart for the details of how these modules work.

Chart Item 2: Barge Mounted Debris Separation & Cleaning Module.

Chart Item 3: Twenty Five Yard Debris Container on a Barge.

Chart Item 4: Barge Mounted Pumping Module.

The use of recycled water from the containment pond is a key to the success of the ARS and has the following advantages.

1) Substantially decreases the volume of contaminated water to treat.

2) Permits using as much water as needed for the separation and cleaning jets and for pumping the
<4-inch material, without adding any additional water that would need to be treated. 

The Aquatic Remediation System couples together proven technologies that will lower costs, shorten project completion time, provide exceptional cleanup, not spread contamination, and are user friendly. 

The Aquatic Remediation System [ARS] is an upgrade of a system Dredging Specialists built and successfully used on the White Lake Super Fund project in Montague, MI. in 2003.  For more details about how the ARS can benefit you, contact Don Searles at 217-259-2229.  To learn more about Dredging Specialists, go to www.dredgingspecialists.com