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  • Writer's picturetoddwhanna

EDS-ZVI and EDS-ER DPT Injection in San Mateo County, CA

We are thrilled to share the success of another completed project, targeting Trichloroethylene (TCE) contaminated groundwater at a project site in Eastern San Mateo County. Under the direction of a regional engineering firm, we injected a combination of Colloidal Micro Scale Zero-Valent Iron (EDS-ZVI) and Electron Donor Solution-Extended Release. (EDS-ER), both provided by Tersus Environmental. We also bioaugmented with KB-1 microbial culture provided by SiREM.

Geoprobe 7822DT

The direct push tooling was advanced using a Geoprobe 7822DT.

This project consisted of 68 direct push injection points located on two separate properties.

1.5 inch diameter Bottom-Up Injection Tool

The target treatment interval was between 5 to 15 feet below ground surface.

We utilized a bottom-up injection tool targeting 2.5-foot long treatment intervals.

Hand Clearing of DPT Point

As usual, each direct push injection point was hand cleared to 5 feet prior to advancing the Injection Tools.

Special care was used to keep the newly paved asphalt parking lot clean.


EDS-ZVI is a In Situ Chemical Reduction (ISCR) reagent.

EDS-ZVI consists of a less than 5-micron sulfonated Zero-Valent Iron in a colloidal suspension (mZVI)

The EDS-ZVI was delivered in 2,000 pound IBC Totes.


EDS-ER is a long-lasting electron donor. It is shipped as a 100% fermentable substrate concentrate, which cuts down on shipping costs, and reduced the containers required. When mixed with water, EDS-ER spontaneously transforms into an emulsified vegetable oil (EVO).

The EDS-ER was delivered in 2,100 pound IBC Totes.

Nutrimens Liquid

A small amount of Nutrimens Liquid was also added to the mixture. Nutrimens is an all-natural fermentation product.  Nutrimens provides reduced carbon and a wide array of beneficial vitamins, minerals, and metabolites to microbes for enhanced bioremediation. Nutrimens also aids in maintaining neutral pH.

KB-1 Culture Keg & Measurement Tube

KB-1 culture contains the highly effective Dehalococcoides species that is adept at performing reductive dechlorination, breaking down the chlorinated solvents and ultimately converting them into harmless ethene and chloride.

The KB-1 microbial culture doses were measured in our graduated tube, and injected in-line on our 10-point manifold.

Anaerobic Water Tanks

All mix water was made anaerobic onsite in our 1,000 gallon poly tanks with the use of Newman Zone OS oxygen scavenger.

Newman Zone OS is specially formulated to quickly remove dissolved oxygen from water and create the reducing conditions.

Water Quality Meter Display

Water quality readings were taken with a hand held Multiparameter Digital Water Quality Meter throughout the day, and before each tank was used to verify the water quality was in spec.

Typically we are looking for the DO: less than 0.2 milligrams/liter (mg/L), ORP: less than -75 mV, and pH: between 6.0 - 8.5

Onsite Set-Up

All reagent mixing and pumping was performed within one of our self-contained Injection Trailers.

As we are setting up at the beginning of a project, we always try set-up so we maximize safety and efficiency, while keeping things as tight possible to minimize the impact the existing tenant(s).

Mix Tank

For this project, our Injection Trailer was fitted with our custom built ChemGrout dual mixer set-up, with a 3x8 Double Action Piston Pump.

Even though the 3x8 pump is capable of injecting at high pressure, we rarely needed more than 25 psi of injection pressure.

Our self-contained injection trailers allow for us to easily manage the mixing and monitor the injection of up to 10 simultaneous injection points.

Our dedicated team, completed this project in 14 days, 1 day ahead of schedule, coming in under budget for our client. This project exemplifies Legacy Remediation's dedication to delivering effective and efficient field solutions, even in the most challenging environments. We are proud of our team's hard work and innovation, and we look forward to continuing to provide top-notch remediation services for our clients.

This post can also be viewed on our LinkedIn page. Follow Legacy Remediation on LinkedIn to stay up to date with all the cool things we are up to.

If you have any questions on this project, or if we can help support any of your current or upcoming projects, please contact us.


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