Your Coal Ash Dewatering Resource

Lately, there have been numerous workshops with presentations that focus on CCR water management. Griffin has a wide range of dewatering experience including the installation of deep well, wellpoint and eductor dewatering systems.  We’d like to provide some additional information on eductor dewatering systems as eductors are not normally discussed during these water management presentations.  Griffin has extensive experience with eductor dewatering systems, and eductors provide several advantages when working with very low permeability materials such as coal ash.

Eductor Advantages:

  • Effective in soil stabilization by applying a high vacuum to fine grained soils
  • Not limited in vacuum lift as in wellpoint systems
  • Can lower water table as much as 90+ feet from the top of excavations
  • Cost effective when compared to deep wells where close spacing is necessary because of stratification and/or low permeable soils
  • Low maintenance

Eductor Systems are generally used in areas where the soils have a low permeability. They are especially well suited for deep excavations with stratified soils. The eductors are installed at relatively close spacing similar to the array in wellpoint systems. Griffin has experience with several drilling methods for installation including hollow stem auger, rotary wash, and sonic drilling.

Here are some key success factors for effective coal ash dewatering:

  • Field permeability testing of ash in situ
  • Proper engineering analysis of permeability, flow conditions and expected drawdown
  • Dewatering system pilot tests to determine the permeability of the ash and the variability of conditions throughout the project site
    • Griffin has experience designing and completing ash dewatering pilot studies to assist with the final dewatering system design
  • Proper design and application of dewatering methods including wellpoint, eductor and deep well systems
  • Preventing recharge from aquifers or runoff
  • Effective filtration/treatment of discharged water

Once the coal ash dewatering has begun, the next step required is to treat that water to remove any contaminants that prevent compliance with the site discharge requirements. Griffin has the ability to treat Selenium, which joins Iron and Arsenic as some of the most common contaminants found. Griffin’s water treatment division has worked on projects throughout the country and has designed systems capable of treating over 1,200 gpm.

For more information about coal ash dewatering and water treatment click here.

For more information about Griffin’s water treatment services click here.