A Graph that Makes You Go, Hmmm! - Remediation Products

Every so often, I come across data that makes me pause. Recently, while reading a Technical Bulletin, I encountered a simple graph showing bacterial population increases in an aquifer following product application. The graph was offered as a “line of evidence” supporting the product’s effectiveness (CAC, 2023).

However, when I examined the microbial counts, my initial thought was: Those numbers are ordinary.

To put things in context, I overlaid microbial count data from a site in Tennessee treated with a single application of RPI’s BOS 200+ onto the same graph. (See Graph 1.) For each quarter, the first two columns show the competitor’s data from Indiana; the second two show BOS 200+ data from Tennessee. Naturally, the sites differ in location and characteristics, and a variety of factors could influence the outcomes. Still, assuming the competitor is putting their best foot forward, the comparison seems fair.

At both sites, baseline microbial counts hover around 10⁶ cells/mL—a typical background level for the eastern United States. In petroleum-impacted groundwater, concentrations of 10⁷ cells/mL are often observed. A robust biostimulation effort should increase microbial populations 10 to 100 times above the impacted baseline. See, for example, Figure 16.11 (Noland and Winner, 2024). A jump from 10⁶ to over 10⁸ cells/mL is a reasonable benchmark for success in the Eastern U.S.

In that light, an increase from 10⁶ to 10⁷ isn’t exactly headline-worthy; it could just reflect natural variation in plume characteristics. On the other hand, the BOS 200+ data show microbial counts exceeding 10⁹ cells/mL by the second quarter post-application, levels that are then sustained for the duration of sampling.

That’s the kind of result that deserves attention.

So, yes—file this under: Things that make you go, Hmmm…

References

CAC, T.B. (2023). regenesis.com/wp-content/uploads/2019/12/Technical-Bulletin-Biodegradation-of-Contaminants-on-CAC-1-23-23-1.pdf Retrieved June 14, 2025.

Noland and Winner (2024). Activated Carbon Injection for In-Situ Remediation of Petroleum Hydrocarbons. In E. G. J. Garcia-Rincon, Advances in the Characterization and Remediation of Sites Contaminated with Petroleum Hydrocarbons (pp. 549-589). Cham, Switzerland: Springer.

Graph 1. Moving from left to right, the salmon and green columns are from a competitor’s Technical Bulletin. The burgundy and purple columns display bacterial count data after BOS 200+ treatment. The BOS 200+ data is 100-fold higher than that in the Technical Bulletin.

7th International Symposium on Bioremediation and Environmental Biotechnologies, June 23-26, 2025, Boston, MA

At this year’s Bioremediation Conference, RPI will be sharing a booth with AST Environmental. Come by booth 212 and say hello.

Platforms

Use of Adsorbent-Based Remediation Technologies to Limit Surface Water Impacts from Contaminated Groundwater (165) Tuesday 24^th, D Sessions, Black Bay Ballroom. Mike Mazzarese and Derek Pizarro

Application of a Modified Activated Carbon-Based Injectate to Manage and Remediate LNAPL (234) Wednesday 25^th, E Session, Black Bay Ballroom. Mile Mazzarese

Reductive Dechlorination with Concurrent Sequestration of PFAS and 1,4-Dioxane in a Large Commingled Plume at a Former Manufacturing Facility (377) Thursday 26^th, D Session, Black Bay Ballroom. Michael Mazzarese and Raymond Vaske

Mitigating LNAPL Migration to Adjacent Surface Water Bodies Using Regenerative PRBs (254), Thursday 26^th, B Sessions (Back Bay Ballroom A). Derek Pizarro and Nathan Thacker

Posters

Modeling Residual LNAPL and Impacts to Groundwater using a Kinetic Approach (Group 1, Poster Board #38) Tuesday, 24^th. Scott Noland

Accessing Difficult Geology for Characterization and Injection of Slurry Reactants (Group 1, Poster Board #77) Tuesday, 24^th. Derek Pizarro

The Single Application and Distribution of BOS 200® Activated Carbon Amendment, in Fine-Grained Geology, Resulted in BTEX & Naphthalene Concentration Decreases in Soils and Groundwater Leading to Regulatory Closure (Group 1, Poster Board #81) Tuesday, 24^th. Ed Winner

Enhancing Dehalococcoides Populations without Augmentation: Insights from Chlorinated Solvent-Contaminated Sites Treated with CAT 100 (Group 1, Poster Board #82) Tuesday, 24^th. Ed Winner

Using qHRSC Modeling and an Activated Carbon Injectate to Remediate a Complex Petroleum Hydrocarbon Plume Adjacent to Sensitive Receptors (Group 2, Poster Board #28) Wednesday, 25^th. Derek Pizarro

Pitfalls of Column Testing of Products Containing Activated Carbon (Group 2, Poster Board #53) Wednesday, 25^th. Scott Noland, Gabriele Giorgio Ceriani, and Diderik Goschel

An Examination of Physical Materials Used to Support Microbial Populations in Bioremediation: Impacts on Abundance, Diversity, and Sustainability (Group 2, Poster Board #94) Wednesday, 25^th. Ed Winner