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Our team of engineers, geologists, and inspectors allow us to provide you with a one-stop-shop for existing structure assessments whether you are evaluating a cracked slab, renovating an existing space, or designing and implementing an entire seismic retrofit. Our areas of expertise include:

  • Geotechnical Investigations (i.e., ASCE 41 Evaluation)
  • Site Specific Seismic Hazard Evaluations & Ground Motion Studies
  • Structural Material Inspections, Sampling and Testing (i.e., ASCE 41 Evaluation)
  • Forensic Investigations (e.g., Floor Level Surveys, Distress Inventories, Causation Reports)
  • Hazardous Materials Inspections, Sampling and Testing
  • Environmental Assessments, Investigations, and Remediations


Many evaluations of existing structures require an assessment of seismic and geologic site hazards.  Group Delta staff have performed both screening-level evaluations for risk assessments, as well as detailed field investigations and studies, including for site-specific surface fault ruptures, landslides, and slope failures. Our studies and investigations typically evaluate the potential for:

  • Strong ground shaking
  • Surface fault rupture
  • Liquefaction
  • Landslides and slope instabilities
  • Tsunamis, seiches and flooding


Structural assessments for building renovations or seismic retrofits (i.e., ASCE 41 Evaluation) may benefit from or may require in-situ assessment of the existing structural materials. Group Delta’s engineers and special inspectors are experienced in providing observations, inspections, field testing, field sampling, and in-house laboratory testing of existing structural building materials. Our innovative approaches to existing structure evaluations, including in-situ testing of steel, concrete and steel cutting capabilities, and dynamic concrete coring techniques allow us to save projects time and money by limiting our impact on the structure and the users. We have extensive experience providing structural material evaluations, including inspections, sampling, and field and laboratory testing of:

  • Reinforced Concrete (e.g., slabs, walls, columns, shallow foundations)
  • Structural Steel (e.g., HSS, I-beams)
  • Concrete Masonry Units (CMU)
  • Diaphragms & Connections (e.g., concrete filled metal decks, welds, bolts, gusset plates)


Our engineers, geologists, and field technicians have accumulated decades of experience in applied engineering and earth sciences. Group Delta provides building condition assessment investigations, forensic distress causation reports, insurance claim investigations, as well as document review and expert witness services in litigation cases. Our areas of expertise include the investigation of distress and extent of damages related to a variety of causes such as:

  • Water Intrusion and seepage
  • Surface and subsurface drainage
  • Soil settlement / soil expansion / soil creep
  • Slope failures, landslides, and mudflows
  • Tree roots
  • Vibrations
  • Earthquakes


Many older structures that require renovation or retrofit will contain hazardous materials. Our team can provide assistance in hazardous materials management, including design and inspections of abatements. Our environmental consultants can evaluate, sample, and test for the presence of asbestos, lead-based paint, mold, moisture, polychlorinated biphenyls, heavy metals, dust, sewage, bacteria, and can monitor indoor air quality and vapor intrusion. Our capabilities include:

  • Hazardous materials abatement design
  • Hazardous materials air monitoring
  • Inspections during remediation/abatement
  • Contractor oversight
  • Industrial hygiene
  • Visual inspections, air/surface/bulk sampling/ATP and laboratory analysis
  • Emergency response sampling and clearances for asbestos/lead and mold microbial consulting services
  • Final visual inspections and clearance sampling


Our environmental team consists of highly skilled environmental engineers, geologists, scientists, industrial hygienists, technicians, and support personnel specialized in their respective fields. We offer a broad range of services to meet the needs of our clients.  Our capabilities and services include:

  • Initial Site Assessments & Environmental Site Assessments (Phase I’s)
  • Site Investigations (Phase II’s)
  • Site Remediation (Phase III’s)
  • Construction Compliance Support
  • Stormwater/Water Quality Services
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