Stratus personnel were responsible for designing a site testing strategy, preparing work plans and site investigation reports (submitted to the State Regional Water Quality Control Board – the lead oversight agency), and preparing a removal action plan for a property containing high pH industrial waste materials that have impacted groundwater quality in the project vicinity.  The property is part of a larger industrial mineral processing plant that operated from the late 1800s to approximately 1970, and received the waste materials that were subsequently buried by layers of soil and road base surfacing materials.  Stratus personnel were also responsible for coordinating site investigation activities and equipment, and field testing of soil and groundwater pH in samples collected from soil borings and test trenches as well as coordinating laboratory sample analyses.

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Project challenges included assessing impacts from adjacent properties also containing the high pH materials that are under separate mitigation plans, evaluating groundwater depths and flow paths, and developing possible remedial measures to assure separation between the waste materials and groundwater.  The preferred alternative remedial measure was determined to be removal of the highly impacted material for off-site disposal, and soil mixing with overburden backfill materials to lower the resultant pH in the final backfill soil.