Soil Assessments

Our senior staff has performed soil remediation projects in 18 states in accordance with differing state and federal regulatory requirements.  The geology and soil included coastal plain sediment, piedmont and mountain saprolite, competent igneous and metamorphic rocks, marine-deposited limestone, shale and sandstones including basin and range sediments.  Contaminates remediated include nutrients, metals, petroleum hydrocarbons, volatile organic compounds (VOC’s), and semi-volatile compounds.

Duncklee & Dunham has designed, built, and installed soil-remediation systems that include air-sparge and soil-vapor-extraction systems, multi-phase extraction for soil components of petroleum hydrocarbons and VOC’s, injection and soil blending of chemical oxidants (hydrogen peroxide, Fenton’s Reagent, potassium and sodium permanganate, sodium persulfate, and slow release oxygen compounds), and biological enhancers (carbon sources such as molasses, sodium lactate, or emulsified vegetable oils) for in-situ remediation, and fixation of contaminants in soil.

Prior to remediation-system design, Dunckle & Dunham conducts geochemical evaluations to determine the ability of soil to absorb and decelerate contamination migration with respect to target compounds in the soil.  We conduct treatability bench tests to select the best remediation product based on soil characteristics and contaminate properties.  Small-scale field pilot studies are used to evaluate delivery methods and dosage rates.  When the regulatory cleanup standard is more strict than site-specifc conditions require, we may use the Synthetic Precipitation Leaching Procedure (SPLP) to determine the actual level necessary to be protective of the groundwater utilizing the soil’s ability to absorb and curtail contaminants.

We also use conventional methods and innovative methods such as field test kits, cone penetrometer testing (CPT), and mobile analytical laboratory testing. Sample-collection devices include many varieties of direct-push equipment, drilling rigs, and manual sampling equipment.  Field-screening methods with immunoassay kits have been used for releases of pesticides, PCBs, and petroleum hydrocarbons to provide real-time information to field teams while equipment is in the field.  This results in in better targeting of contaminated areas with drilling rigs, soil borings, and sampling crews.  Assessment costs are lowered overall. More effective remediation at a lower cost is also a benefit of this approach.