Horizontal Drilling Advancements and Installation using Vertebrae Wells™ for Site Assessment University Consortium for Field-Focused Groundwater Research, University of Guelph and G 360 , Guelph, ON June 4-6, 2019 Eric D. Arenberg, P.G., EN Rx Horizo izonta ntal l Nest Nested ed Wel ell l Sys ystem ems s
Horizontal System Advantages in Sampling and Remediation Client concerns over business Overhead obstructions or disruption at active sites, subsurface utility issues neighbor issues or site security (powerlines, water, sewer, (military and industrial). gas and fiber optics etc.). Physical limitations related to the built environment or natural terrain
Single horizontal units are very susceptible to preferential flow path influences.
TM Model Vertebrae • Nested wells (segment well systems) are discrete, using grout- based isolation, and each well screen has a riser to the surface, with multiplicity of well screens in a single bore. • Assessment and treatment is independent of preferential flow. HDD Boring Grout Well Screen Grout Wells Individually Plumbed to Surface Well Screen
Vertebrae TM Subsurface Model Nested wells minimize complications
Vertebrae TM Nested Horizontal Wells Investigation • Sample soil gas and groundwater Assessment Pinpoint • Sparge gas and/or inject liquid reagents Remediation • Extract soil gas and/or liquids
Filling Data Gaps • Particularly important when confronted with site access issues given the built environment.
Assessment of Data Gaps • Often the data gap is in the area of highest concentration.
Assessment of Data Gaps • Sampling nested wells identified 400% more contamination. • Note how the data supports how the wells are effectively isolated. • Even better grouts being tested to ensure longevity.
Total Halogenated Volatile Organic Compounds 89 HVOCs in ppb Groundwater Sample Location BDL 41 4820 BDL BDL BEFORE
Total Halogenated Volatile Organic Compounds HVOCs in ppb - NS = not sampled Segment (23) 1547 CSM indicated shallow mass was 7 times more NS 4 NS 247 NS 3 NS 267 47 NS 591 257 NS 56 18300 4450 705 7774 4450 24100 NS 1469 AFTER
Site Remediation • Vertebrae™ Well Systems are used for • Reagents that drive oxidative / reductive remediation • Air, ozone and bio sparging • SVE and VI mitigation. • Pump and Treat • PRBs • The segmented configuration allows the engineer to maximize efficiency by adapting to plume dynamics.
A Complex Problem - Impacts under tanks, adjacent roadway and parking lot - Resistant adjacent property owners - 25 Vertebrae TM Wells installed for treatment - First application made. Shading indicates relative intensity of dosage - A very important feature of a nested / segmented well system is that it offers unique flexibility not found in conventional horizontal well applications.
A Complex Problem - Subsequent assessment indicated a recalcitrant area toward the rear of the plume, requiring further treatment - Adjustments were made with simple reproportioning of the treatment scheme to match the plume dynamics. - Engineer is able to precisely control the treatment in real time.
AS/SVE Remediation AS Segments (29) SVE Segments (19)
AS Segments (29) SVE Segments (19)
AS Segments (29) SVE Segments (19)
Horizontal to Vertical Ratio (H2V:R) Currently working with 1 to 11 after Laton (2019), as a function of site area. Also, other H to V Ratios from the literature are: 1-30 (Parmentier & Klemovich, 1996); 1-11 (Wilson, Kaback and Oakley, 1990); 5-10 (Karlsson, 1993); 1-8 (Fileccia, 2015.
Use Considerations ⚫ Hi gh Resolution Site Characterization (HRSC) produces vertical profiles with varying degrees of “granularity.” Vertebrae TM Well Systems add a dimension to the process. With horizontal assessment we are able, in essence, to create the field of what we are calling High Resolution Contaminant Distribution (HRCD). ⚫ Reduce cost, on a case by case basis, relative to using vertical well systems. ⚫ Compliance criteria in parts per trillion, for polyfluoronated alkylsubstances (PFAS), has created serious sampling concerns. We are working towards certifying Vertebrae TM Well Systems that are certified free of PFAS for relevant projects or simply to protect environments where PFAS might otherwise be introduced via conventional operations.
Additional Applications ⚫ Vertebrae TM Well Systems can be factored into permeable reactive barrier (PRB) designs, both to explore the best transect for placement and to provide a safety factor for more treatment should the PRB underperform. ⚫ There are other applications for Vertebrae TM Well Systems, worthy of exploration, including but not limited to: – Landfills – Sediment-Groundwater Interface – Vapor Intrusion, as an extraction process, with emphasis on access issues. – Sensor-enabled leak detection of hydrocarbons or brine under storage tanks.
Summary Vertebrae TM Well Systems • Next Generation Site Assessment – More Complete CSM • High Resolution Contaminant Distribution • Next Generation in Remediation – Precise Control • In Progress: • PFAS-Free Systems • Horizontal to Vertical Assessment Modeling and Costing • Improved Grout Chemistry
Questions? Erik R. Piatt CEO Direct (877) 747-3679 piatt@enrxinc.com Next Gen Site Investigation & www.enrxinc.com Remediation Technology
Recommend
More recommend
