Gregory S. Noblet, P.E., Principal, (510) 834-4747 ext. 13, Download Vcard

Mr. Noblet is a California professional engineer with more than 18 years of technical consulting experience in site characterization, vapor intrusion evaluation, emissions estimation, dispersion modeling, and health risk assessment.

He has designed numerous subsurface site investigations to characterize impacts to soil, groundwater, and soil gas. He specializes in emissions estimation and dispersion modeling to evaluate impacts to offsite receptors; and in vapor intrusion assesments, where multiple lines of evidence must be considered in evaluating indoor air sampling results. He has worked with several analytical laboratories to develop helium shrouds and soil gas sampling trains compliant with the Cal/EPA Soil Gas Advisory. One of Mr. Noblet's current interests is incremental sampling methodology, a potentially much more powerful soil sampling methodology than traditional discrete soil sampling. 

Representative Project Experience

Municipal Waste Transfer Station, San Carlos, California

At an industrial facility where historical fuel releases had resulted in hydrocarbon impacts to soil, groundwater, and soil gas, Mr. Noblet conducted statistical analyses of groundwater monitoring results to demonstrate the containment plume in groundwater was stable and decreasing. Mr. Noblet designed a subsurface investigation to delineate the vertical extent of soil impacts and thereby close a key data gap in the conceptual site model. Mr. Nobel designed and implemented an indoor air quality investigation to collect indoor air, outdoor air, and sub-slab soil gas samples, and conducted a multiple-lines-of-evidence evaluation which demonstrated that significant vapor intrusion was not occurring at the site. Mr. Noblet authored a Closure Request which made the case for site closure under the State Water Board's Low-Threat Underground Storage Tank Case Closure Policy. The request was approved upon first submittal and the site was thusly closed.

Various Redevelopment Projects, City and County of San Francisco

Mr. Noblet has assisted numerous redevelopment projects comply with the San Francisco-specific requirements, including Article 22A (the Maher Ordinance), Article 22B (the dust ordinance), and the Mission Bay Risk Management Plan. He has planned and implemented subsurface site investigations, developed construction Stormwater Pollution Prevention Plans (SWPPPs) and site-specific Environmental Health and Safety Plans, and developed and implemented site-specific Dust Control Plans including dust monitoring programs. Most recently, Mr. Noblet has evaluated project sites in the context of Article 38, a proposed regulation that would require enhanced ventilation systems for sensitive receptor projects located in a "Hotspot Zone," or a "Potential Roadway Exposure Zone."

Mixed-used Redevelopment, Former US Navy Facility, Alameda, California

Mr. Noblet provides technical expertise to a large mixed-used redevelopment project that overlies a plume of groundwater contamination by benzene and naphthalene. Under DTSC oversight, Mr. Noblet conducted site-specific vapor intrusion modeling analyses to quantify potential vapor intrusion risks using both soil gas and groundwater data. Mr. Noblet authored a human health risk assessment (HRA) and co-authored a feasibility study (FS), remedial action plan (RAP) and remedial design and implementation plan (RDIP). Mr. Noblet also provided technical assistance with evaluation of methane concentration and pressure data, resulting in DTSC's concurrence that methane mitigation measures are not warranted at the site, despite high concentrations of methane in soil gas at some sampling locations.

Air Sampling during Removal Actions

For numerous large-scale remedial excavations, Mr. Noblet designed air monitoring and air sampling programs for the protection of offsite populations. Mr. Noblet developed site-specific risk-based screening levels for evaluation of fenceline air sampling results, and developed action levels for evaluation of real-time measurements of dust and total VOCs. Mr. Noblet performed dispersion modeling to predict exposure point concentrations at the actual locations of offsite receptors.


M.S., Civil and Environmental Engineering, University of California Berkeley. 1993
B.S., Civil Engineering, University of Connecticut. 1992