Senior Project Mananger
A Senior Principal, Mr. Tull has over 30 years of experience as a professional geologist. Mr. Tull graduated from Northeastern University with a B.S. in Geology and provides environmental consulting for commercial, industrial, institutional, municipal, state, and federal sectors. He provides client-oriented planning, cost sensitive investigation and technically-proven remediation incorporating cost-cap closure strategies for groundwater and soil clean-up programs; nationwide multi-site assessment packages for corporate acquisition, Department of Defense (DoD) and regulatory compliance. He provides clients with a broad base of technical, financial and program management for regulatory investigations, subsurface exploration, and design and implementation of remediation programs for petroleum, VOCs, metals and PFAS. Mr. Tull is a frequent public presenter and has been the point-person for six Public Involvement Plan (PIP) sites under the Massachusetts Contingency Plan. At the UMass Soils Conf in 2017 Mr. Tull presented the findings of a nation-wide PFAS investigation for over 70 Air Force and Air National Guard Bases highlighting findings in groundwater, sediment, surface water, and drainage systems. Prior to joining Wood, Mr. Tull taught environmental and investigative sciences under contract to the EPA and served as a consulting LSP for city and local boards such as the Quincy Department of Public Works and the Brookline Housing Authority.
Assessment of Stormwater as Primary Mechanism for Impact to Drinking Water
INTRO: PFAS Site Investigations at US military installations has led to the discovery of multiple PFAS release areas from the use of AFFF at FTAs, fire suppression systems, virgin and waste AFFF storage systems, equipment testing and AFFF transfer areas and specifically translocation of AFFF through infrastructure. Currently closures of drinking water supplies has been primarily attributed to PFAS transported with groundwater, however stormwater is also a mechanism of transport that can readily render drinking water sources unusable. USEPA has established drinking water public health advisories for two PFAS compounds at 70 ppt owing to the persistence, toxicity and bioaccumulation of these compounds. Findings from 125 AFFF release areas at multiple military installations confirms PFAS are persistent and migrate long distances in groundwater with no evidence of biological attenuation rendering groundwater discharge areas vulnerable. This study reviews surface water bodies leading from an airport, used by both military and civilian aircraft, to be the source from PFAS release areas to have closed a large reservoir. While PFAS has been detected in groundwater, the relative contribution from groundwater transport versus surface flow and subsurface stormwater flow is minimal and may be of no factor at all. Sediment, pore-water, and surface water downgradient from known release areas are consistently impacted by PFAS. Stormwater scouring and non-storm surface flow moves these releases to surface water receptors. This presentation provides early findings relative to the occurrence and distribution of PFAS in drains and conduits leading from and across the military side of a multiuse aircraft base. These conduits have impacted a stormwater retention basin that has in-turn fed a larger surface drinking water source resulting in an ongoing shutdown for over 3 years.
METHODS: Assessment of stormwater and surface water drainage has included auto-samplers, manual sampling, flow gauging, and data collected for volume and concentrations of PFAS. Statistical analysis of PFAS detections, including frequency and magnitude of detection on a compound-specific basis is performed. Results are correlated to sources both at the surface as well as impacted groundwater leaking into pipes.
RESULTS: Evaluation of this data set reveals PFAS transport via stormwater and non-storm surface water is useful in predicting impacts from AFFF release areas. Several emerging observations are made: the frequency of detection of PFAS associated with AFFF releases is high, typically well above 50% for common AFFF constituents; PFOS and other sulfonates comprise the majority of PFAS mass; the relative concentration of PFOS increases along the flow path, accumulates in sediment, and re-contaminates outgoing water from the retention basin; multiple transport pathways are evident; stormwater infrastructure is a short-circuit pathway. The relative concentrations of PFAS in environmental media provides clues regarding relative contribution from various transport pathways. How PFAS manifest in exposure pathway endpoints and what impact will they have on surface water drinking sources is beginning to be understood and will inform decision making in system improvements and capture and treatment.