Over 30 Years of Providing Results Oriented Soil and Groundwater Remediation to Our Clients
- XDD Principals have been focused in the design and implementation of soil and groundwater remediation since subsurface remediation first gained traction in the early 1980’s
- Our reputation as remediation specialists within the industry drives our clients to seek out our services, especially at high profile or technically difficult sites
- See our case studies for a sampling of these successful projects.
- How Often Has XDD Met Project Goals? 97%
- Change Project Course to Avoid Costly Remedy: 52%
- Projects that Came to XDD with Previous Remedial Failures: 39%
The difference between the success or failure of a remedial application is often a result of understanding the interaction of the site specific geochemistry and biology with the proposed technology. XDD’s more than 16 years of experience in conducting bench scale treatability testing allows us to quickly and cost-effectively select the technology most certain to achieve the remedial goals based on site and client specific requirements.
Treatability Testing Benefits:
- Increased Certainty – The ability to identify undesirable outcomes and avoid technology failures prior to design and full-scale implementation
- Technology Selection – The flexibility to effectively evaluate multiple applicable technologies simultaneously
- Determine Reagent Quantities – An understanding of the type and quantity of reagent required to meet your site objectives. Under-dosing can result in additional unanticipated applications, while over-dosing is the equivalent to pumping capital down a well
- Cost Estimation – As reagent costs can make up a significant component of the full scale application costs, an understanding of the applicable reagents and costs can refine/confirm budget estimates
A small selection of our case studies can be found here.
Remedial Strategy Development
XDD’s process allows for a thorough analysis and determination of the most appropriate site remedy by drawing on XDD’s expertise in a wide range of remediation technologies as well as our sound understanding of risk assessment and state and federal regulatory requirements. XDD uses our on-site laboratory to complete in-depth technology evaluations to identify and avoid potential risks associated with soil and groundwater remediation applications.
In many cases, more than one remediation technology is required as part of an optimal strategy. Hybrid strategies can vary from simple source excavation and disposal with monitored natural attenuation for the groundwater plume to innovative applications of in situ chemical oxidation coupled with enhanced in situ bioremediation or biostimulation.
Remedial applications can be a significant expenditure toward achieving site goals. In the same way it is often advisable to get a second medical opinion for a major health care decision, it makes financial sense to have XDD conduct a second look. XDD regularly conducts peer reviews of site:
- Conceptual models
- Remedial strategies
- Bench or pilot testing results
Through our peer review and remedial strategy process, we often are able to avoid financial pitfalls and have been able to convince regulatory agencies to amend governing site documents.
XDD personnel have more than 35 years of remediation technology selection, design, and implementation experience, making our staff uniquely qualified to provide expert testimony.
These services include:
- XDD’s decades of experience and recent acquisition of BCI.
- Anaerobic and aerobic technologies for common and emerging contaminants.
- Microcosm Studies: XDD provides the ability to bench test several enhanced bioremediation technologies at once and can use either XDD’s in-house microorganisms for bioaugmentation or those naturally occurring in the site soil and groundwater.
- Design and Engineering: XDD has designed enhanced bioremediation projects using several different application strategies. Our in-depth understanding of in situ bioremediation remediation and enhancement methods allows us to recommend the optimal solution for each site.
- Implementation: XDD is renowned for our high quality implementation services with a stellar health and safety record.
In Situ Chemical Reduction
- Zero Valent Iron (ZVI)
- Bi-Metallic Particles
- Metal Sulfides
Monitored Natural Attenuation
- Less invasive, especially for site with existing activities or obstructions
- Uses existing subsurface processes such as biological/abiotic degradation, dispersion, dilution, and retardation to reduce risk.
- Relatively lower in cost when compared to other remedial technologies
XDD has been providing MNA evaluation and sampling services throughout our history, those services include:
- Conceptual model refinement
- Evaluation of fate and transport within groundwater and vapor phases
- Timeframe estimates relative to source zone properties
- Evaluation of existing MNA pathways, such as:
- Abiotic and biotic transformations
- Site investigations and analyses to determine the magnitude of MNA processes
In Situ Chemical Oxidation
Bench Scale Treatability Tests:
XDD provides one of the nation’s leading ISCO bench testing facilities.
XDD has designed a significant number of projects using several different application strategies including direct injection, pull-push, and re-circulation. Our in-depth understanding of each technology allows us to select the optimal chemistry for each site.
XDD is renowned for our high quality implementation services with a stellar health and safety record. We have successfully implemented ISCO to treat both large and small sites with numerous site-specific challenges including:
- Active/operational industrial facilities,
- Sensitive and restricted areas at government facilities,
- Busy commercial districts,
- Suburban neighborhoods requiring XDD to be off site daily before local schools let out,
- and many others.
XDD was among the first companies to apply activated persulfate and stabilized hydrogen peroxide. XDD regularly publishes book chapters, assists on guidance documents, presents at national conferences, and completes government funded field and bench studies. Our engineers and scientists have experience in the following oxidant systems:
- Iron-chelate activated
- Alkaline activated
- Naturally activated
- Hydrogen Peroxide
- Catalyzed Hydrogen Peroxide (e.g. Fenton’s Reagent)
- Stabilized Hydrogen Peroxide
- Acidified Hydrogen Peroxide
Air Sparging and Soil Vapor Extraction
XDD personnel have employed SVE technologies at hundreds of sites in the U.S., Europe, and Asia.
XDD staff helped pioneer these remedial technologies with the first U.S. application of air sparging in 1989 and later authored the American Petroleum Institute’s Air Sparging Guidance Document. Furthermore, XDD — working with the U.S. Environmental Protection Agency (EPA) — developed an SVE closure program for the Picillo Farm Superfund Site in Coventry, RI which subsequently served as the basis for the EPA’s national SVE site closure guidance document.
XDD has vast experience evaluating, designing, and implementing AS/SVE systems in conjunction with other technologies such as oxygen biosparging, bioventing, enhanced reductive dechlorination (ERD), biostimulation, and aerobic trench systems.
- Capital expenditures for other remedial technologies are significant relative to long-term operation and maintenance of an extraction system
- Subsurface conditions are not amenable to other in situ remedial technologies
- Sensitive receptors are located immediately downgradient of groundwater impacts
- Regulations require hydraulic capture
As XDD is not invested in pushing a singular in-situ remedial technology, we have designed, installed, and operated a number of remedial systems involving hydraulic capture. Tasks completed by XDD include:
- Superfund level groundwater and fate and transport modeling
- Well, conveyance, and equipment construction design and installation oversight
- Value engineering and design calculations to meet discharge permitting requirements
- Operation, maintenance, and monitoring services