Kathy Webb, P.G.

Senior Market Leader | Principal

Kathy Webb, who co-founded SynTerra (then known as The Fletcher Group) in 1992, has completed remedial investigations and regulatory compliance projects associated with Resource Conservation and Recovery Act (RCRA) facilities, state and federal Superfund sites, solid waste landfills, brownfield redevelopment, utility coal combustion residual (CCR) management units, and regulated industrial facilities. She has supported litigation as an expert witness related to chlorinated solvents, metals, and polychlorinated biphenyls (PCBs).

Kathy is known for her practical assessment strategy with the perspective of the client’s business objectives. She routinely evaluates groundwater corrective action systems for effectiveness and progress toward achieving compliance objectives. She has co-authored a trade journal paper with case studies of low-impact remedial strategies. Kathy is a licensed Professional Geologist in North Carolina and South Carolina.

Mark Taylor, P.G.

Principal

Mark has worked more than 40 years in natural-resource based industries. His expertise includes mine geology and mine engineering, hydrogeologic and geotechnical investigations, solid and hazardous waste management, and regulatory negotiations. He has published peer-reviewed papers about coal geology, ore geochemistry, mineralogy, and solid waste management. He is a leading expert in mining and environmental permitting for litigation support.

Mark is licensed as a Professional Geologist in South Carolina, Alabama, Arkansas, Georgia, Kentucky, Mississippi, North Carolina, and Washington. He serves on the boards of the Upstate Red Cross and Upstate Forever. He served on the South Carolina Board of Registration for Geologists for six years. Mark holds a Master’s degree in Geological Sciences from The University of Michigan and a Bachelor’s degree in Geological Science from Harvard University.

Andrea Kehn, P.E.

Vice President of Engineering | Principal

Andrea Kehn, leader of our Civil & Environmental Engineering Business Unit, has 28 years of experience in chemical manufacturing and environmental consulting. She leads and supervises staff professionals on multidisciplinary projects for a variety of industrial clients. Andrea’s vast experience and expertise includes: air quality construction and operating permitting; air quality modeling; air permit record-keeping and reporting; Oil Spill Prevention Control and Countermeasures (SPCC) and Storm Water Pollution Prevention Plans (SWPPP); NPDES permitting; water quality modeling; process safety management; risk management compliance and auditing; and RCRA compliance.

Andrea is registered as a Professional Engineer in South Carolina. She holds a Bachelor of Science degree in Chemical Engineering from Michigan Technological University.

Ruth Albright, P.E.

Vice President | Principal

Ruth has led projects for major industrial facilities throughout the Southeast and beyond. She built her knowledge of environmental regulations and their application to manufacturing operations while working for the second largest chemical manufacturing company in the United States. At SynTerra, she has expanded both her knowledge and reputation working for chemical manufacturing operations of all sizes. She has also worked extensively with other manufacturing operations, including pulp and paper, industrial equipment, pharmaceuticals, food, and automotive parts and assembly. Her experience includes air and wastewater permit compliance, solid and hazardous waste management, solid waste construction permitting, hazardous materials transportation, wastewater treatment systems, air pollution control equipment operations and maintenance, and ambient air monitoring systems.

Ruth is a professional engineer registered in South Carolina, North Carolina, Georgia, Florida, Virginia, Mississippi, Oklahoma, Michigan, Arkansas, and Kentucky. She is an active member of the South Carolina Chamber of Commerce Environmental Technical Committee and serves as the chair of the water subcommittee. She has previously served as the program and committee chair for the Greater Greenville Chamber of Commerce Environmental Affairs committee. She has a Bachelor’s degree in Chemical Engineering from Clemson University.

A Cost-Effective, Low-Impact Remedial Approach for Metals: Utilizing Phyto-Enhancement to Accelerate pH Adjustment of Shallow Groundwater

Blog

SynTerra to Present at WOCA 2026

Posted March 27, 2026

SynTerra will present a unique, low-cost, low-impact approach to metals remediation in shallow groundwater at a former industrial site located in the Atlantic Coastal Plain. The approach employs pH adjustment of groundwater using agricultural lime coupled with the use of daikon radish to augment lime contact time and to increase depth of soil augmentation. This method is designed to be a more sustainable, less resource-intensive, and less technically challenging remedial alternative with lower estimated overall costs.

The primary corrective action—source removal—has been completed. However, the oxidation of residual sulfide-bearing minerals has resulted in persistent low-pH groundwater, which increases the solubility and mobility of metal constituents of interests (COIs). While long-term natural attenuation is expected, low-pH conditions could persist for decades; therefore, an evaluation of remedial options was completed to accelerate COI attenuation mechanisms.

The selected remedy is the application of agricultural lime (CaCO₃) to the shallow subsurface to increase pH and buffering capacity in groundwater and unsaturated soil, thereby decreasing COI mobility and concentrations. Application dosage rates and details were developed following a baseline evaluation and analysis of subsurface soil conditions.

Although infiltrating rainwater will naturally carry the higher-pH water deeper into the water-bearing unit, SynTerra developed a simple, low-cost enhancement using daikon radish root channels (phyto-enhancement) to accelerate lime movement into the groundwater. This enhancement is expected to expedite the buffering capacity of the water-bearing unit and the time needed to decrease COI mobility. A robust monitoring well program is already established to track performance. The final assessment design, site characterization results, and lime application calculations will be presented, along with initial observations from the novel pilot study.