Produce Permeable Reactive Barrier (PRB) media through blending predetermined quantities of pea gravel, limestone, sand, compost and zero valent iron (ZVI).
Remove spent existing PRB wall media, and replace new PRB wall media, through caisson drilling.
Two types of wall media were produced: M1 and M2. The production of wall media, through blending of the wall media elements (pea gravel, compost, sand, ZVI, limestone) was strictly controlled, from a QA/QC point of view, requiring care / attention of all involved. Blending was undertaken through the use of excavators enabling
efficient blending but requiring great care.
The lower portion of the PRB wall is made up of M1 with the upper portion M2. The media was placed within the caisson, once the spent wall media / native material was removed, and great care was taken the ensure media was placed in such a fashion to minimize media element separation, and ensure that media was placed at design depths.