Advanced Data Acquisition
In addition to basic site characterization activities that are common in the environmental industry, development of modern conceptual site models (CSMs) demands rigorous data collection methods to obtain certain critical site parameters. H2A’s scientists and field staff possess the knowledge and experience to efficiently, accurately, and precisely collect advanced site characterization data to maximize reliability of the CSM. The corresponding improvements to CSM quality and resolution improve risk evaluation and ultimately, remedy success.
Based on our experience performing LNAPL transmissivity testing, developing the ASTM standard for estimation of LNAPL transmissivity, and remediation optimization, H2A scientists recognized a need for a field portable, intrinsically safe, multi-phase flow meter capable of meeting the accuracy and precision requirements of the ASTM standard. As a result, we developed the patent pending H2A hydrocarbon and water knockout (H2AWK) precision flow meter, capable of operating via suction pumping, vacuum extraction, or pressurized air systems. Testing with the H2AWK yields more reliable leading, progress, and lagging remediation metrics by improving the accuracy of:
- Short term NAPL recovery rate measurements during LNAPL transmissivity baildown, slug, and manual skimming testing;
- Short term NAPL/water ratios and production rates during LNAPL transmissivity ratio testing; and
- Instantaneous LNAPL/water ratios and production rates to manage and optimize active remediation systems and calculate ongoing LNAPL transmissivity values to generate rate transient and expected ultimate recovery decline curves on an individual well or plume-wide basis.
LNAPL Transmissivity Testing
LNAPL transmissivity is a powerful metric for LNAPL hydraulic recoverability. H2A was involved in the development of ASTM standard E2856-11 for estimation of LNAPL transmissivity. We continue to develop improved methods and equipment to measure LNAPL transmissivity, and to understand and evaluate inherent variability, scale issues, and trend significance over time, at the individual well and plume-wide scales. Field testing for LNAPL transmissivity can be highly complex, particularly in fluctuating groundwater or preferential pathway environments. H2A’s scientists and field personnel possess the theoretical knowledge and practical experience to ensure successful testing under a wide variety of complicating field conditions. LNAPL transmissivity test methodologies that H2A has successfully implemented include:
- Baildown/slug testing
- Manual skimming testing
- Ratio testing
- Recovery data analysis from skimming, vacuum-enhanced skimming, total fluids pumping, and multi-phase extraction remediation systems
- Tracer testing
H2A’s scientists, engineers, and remediation technicians possess many years of experience designing, procuring, permitting, installing, operating, maintaining, optimizing, and evaluating progress to closure of multiple remediation technologies on behalf of clients ranging from consulting engineering firms to government agencies and responsible parties. In addition, H2A owns and operates a fleet of portable, self-contained, pilot testing and mobile remediation systems. Consequently, we intimately understand the need for reliable and detailed operational, hydraulic, pneumatic, and other critical system parameters to maximize operational uptime and remediation effectiveness, thereby minimizing time to closure.
Pilot testing provides critical remediation technology selection and design data, but is often performed without an understanding of the comprehensive data and CSM elements that can be determined by a properly designed and implemented pilot test. H2A’s experience and expertise in all facets of the remediation process, as well as our custom designed pilot testing and remediation system fleet operational experience, allow us to maximize the quality and comprehensiveness of pilot testing performance and data collection. In many cases our proprietary technologies and testing expertise provide critical data not often developed. Pilot testing technologies H2A can provide include:
H2A’s pilot testing systems are capable of testing multiple hydraulic and pneumatic remediation technologies, and are particularly beneficial in remote or restricted locations since they are completely self-contained. Typical tests include step tests and/or sustainable production tests of soil vapor extraction, multi-phase extraction, air sparging, NAPL skimming, and total fluids pumping, as well as other technologies.
Each test is designed to yield comprehensive hydraulic and pneumatic design parameters for recoverability of contaminants of concern from all phases for a given hydrogeologic setting. Our ability to adapt testing protocols to conditions observed in the field, coupled with the expertise necessary to capture precisely accurate test data, result in consistently successful and comprehensive pilot tests.