Amendments, also referred to as treatment materials, reactive materials, adsorptive or chemsorptive materials—are formulated to limit the movement and availability of Contaminants of Concern (COCs).
Amendments can be used in a wide range of settings or remedial designs, and will treat most common COCs. Amendments are available in various physical forms (i.e. powder vs. granular) and can be applied or used directly in some applications. However, amendments also tend to be expensive and are often diluted or mixed with other more inert materials (i.e. sand) for two reasons:
1. To create the desired dose or loading of amendments.
2. To effectively distribute amendments over a larger volume or area to improve contact time or residence time (i.e. greater likelihood that contaminants will come in contact with the amendments for a longer period of time).
All amendments require some amount of contact time to react or sorb the target contaminant. The issue of uniform distribution and thickness—or potential contact time—becomes paramount in designs that utilize these materials. Below is a graphic that highlights issues related to the design of a reactive layer in a sediment remediation application.
Uniform delivery of Amendments is a critical factor in the implementation of a design.
It is important to recognize the construction related challenges associated with handling and placement. To illustrate these challenges, tests were performed in our lab to evaluate material separation in a water column. Below are photos that illustrate the results of drop tests in 5-foot columns. More detailed description of the tests and results can be obtained by clicking the link below the photos (full test report).
Click here to review Test Report #15- Organoclay Drop Test
Click here to review Test Report #16- Activated Carbon Drop Test
AquaGate®+PAC: Bremerton Navy Base, WA
In-situ treatment was performed using a thin layer application of AquaGate+PAC 5%. Two presentations are available that provide extensive information regarding this installation and the positive results obtained.
AquaGate+Organoclay: East Branch, Grand Calumet River
This project is thought to be the largest application of Organoclay™ amendments in the reactive capping design ever implemented. Two different cap designs were successfully placed over 1.8 miles of river bottom. Loading of Organoclay ranged from approximately 7-21 lb/cf within the capping layer. The following graphics provide additional detail on the project, execution and quality control aspects.