Learn More

  • If you need assistance with a current project and would like to get a design and cost, please visit our Request a Design page.
  • To get in contact with a REGENESIS Technical Solutions Manager use our Contact Us form.

We got a few questions related to injection pressure, was this high or low pressure injections and also somewhat related. Could you remind me, what was the hydraulic conductivity of the glacial till?

In this case, the hydraulic conductivity varied, some across the site between 10 and the minus 4 and even 10 to the minus 5 in some locations. The injection pressures were higher in those tighter areas. We did get upwards of 50 psi in those locations. We have an internal standard to stay below 100 psi sustained, but we got nowhere near that in this case but 50 psi in some of the tighter areas and generally in the other area is about 20 to 25 psi. And a lot of these sites managing flows and pressures, we like to stay even down as low as 10 to 15 psi, but in this particular case, with the glacial tills, there was some additional pressures.

What technique do you use to target a specific horizon in the well?

I mean, we use direct push on a lot of these applications. So we’ll either push down a specific interval or rise up a specific interval to load chemical into a specific one two or three foot horizon. So we do it surgically. We do it slowly, again as low a flow as we can possibly get, at as lowest sustained pressure as we possibly can. So we get that contact time and we get that sustained scenario.

It looks like there is an inverse relationship with water levels versus benzene concentrations. How confident are you that you won’t have additional rebounds when the water levels change again?

And that’s a really good point and very, very common. I mean, we’re not talking about anything new here. That’s a pretty common phenomena we see at most every site. But I think our confidence lies in the fact that we’re getting a generous amount of injection chemical in contact with our mass. We know where it is. We’re not getting crazy in terms of our vertical injection intervals. We’re keeping it very concise and very sustained. And our rebound now is not as substantial as we saw it in the past. Again, we have risk-based standards here. So we don’t have to get to five micrograms per liter. For benzene, I’d be very concerned if that were the case, but because we have these risk-based scenarios and they’re much, much more generous, I think I’m pretty confident that we’re gonna get to those or very, very close and be able to close the site out.

Wouldn’t it be more efficient just to pick one technology and implement it hard? Why is the combined remedies approach in the best interest of your clients? And then another related question says, “This all sounds expensive. Can you touch on ballpark cost?

I’ll touch on the cost next. You know, this whole combined remedies thing, are there sites that can get away with a singular technology? Absolutely, you know, countless numbers of them. I just find that with combined remedies, you can take advantage of the best of each and every component of those remedies. And I think if you extrapolate out the costs, when you have a combined remedy like that, you wind up saving more money in the long term than you would if you went a singular remedy in and of itself. I think that’s been proven, especially in more recent presentations that I’ve observed. When you combine those remedies, you’re putting each particular approach in the best light, in the best scenario that you can possibly have to make that chemistry, that approach be as efficient as possible. You know, as far as cost goes, you know, products cost what they cost. So really, it comes around to efficiencies in the field, you know, the mobe cost, your actual injection time. I will pay more for an injection contractor who takes his time and talks and shares information and makes observation any day. So I would say that our injection events varied anywhere from about $40,000 per event to some of the larger ones, which were upwards of 75,000 per event, so expensive. You know, that’s a relative term. I look in terms of quality of effort and efficiency. It’s not too expensive if progress is made.

We have a couple questions relating to volumes. First one is please convert the volumes of chemical in gallons injected into the ground into pore volumes, was at one or two pore volumes of chemical injected? A related question, for each product injected, seems like over 100 gallons per point, is that right?

There were definitely over 100 gallons per point, somewhere upwards of 200 gallons per point depending upon the chemistry. You know, we try to approach a pore volume. There are certain sites where we really load the fluid and push upwards of multiple pore volumes. But a lot of these ISCO efforts, particularly PetroCleanze, we try to load that aggressively, so one pore volume, a pore and a half, pore volume and a half. A lot of times when an ISCO approach, we will load less than a pore volume. It just depends from site to site. But again, it’s the most fluid we can get in as efficiently as possible, given the respect of geology and hydrogeology on the site to get the most contact and that subject to change from event to event

A lot of questions also about the contaminants. One of them is what is your benzene cleanup level related to that? Does Iowa require analysis for trimethylbenzene, and if so, what were the results for this constituent? Another question says what were the results for MTBE, if there was a constituent or concern at all?

So first and foremost, MTBE was not a constituent of concern at this site, although I got a variety of MTBE sites going on right now and in this particular chemistry in association with particularly the PersulfOx. You know, as far as Iowa, they have these risk-based standards. Our goal right now is 1,100 micrograms per liter for benzene based on our current risk scenario. There are higher standards, there are lower standards depending upon the risk scenario, the exposure scenario, your proximity to utility corridors. You know, those sort of things impact the overall target level for a given site. Dane, can you repeat the question one more time? I think I’m missing an element of it.

There was one of Iowa specifically. Does Iowa require analysis for trimethylbenzene, and if so, what were the results of this constituent?

Yeah, that was the one I missed. Not specifically on this site, although we do get specific requests from our regulators from site to site, but that was again not an issue on this site.

You mentioned that you prefer bottom-upward injection based on experience at this site, is this the general case for most of your sites?

I would say that we do do more bottom-up injection than top-down, although I have no specific preference. I just found that with the way these chemistries work in a lot of scenarios that the bottom-up injection works better for us in terms of daylighting, but there are other sites where we’ve had just splendid results with top-down. So I think a lot of that comes into play when you’re planning the site and you’re in conversation with your injection contractor in your direct push company, getting their experience and the benefit of their knowledge as well. I think that’s critically important

During high vacuum extraction events after injection, how is the volume of free product recovery measured?

Yeah, volume is measured on-site. Our particular vendor gave us a particular estimate as they remove the product back to their facility for disposal. So they gave us a quantity as they separated out the total liquid that resided within their vac truck and brought it back to their facility. That’s where we got the designation of how much product was removed

You mentioned how you often use RegenOx as a front-end to bio, is this for the oxidation, the desorption, bioavailability, and oxygen kick or some other reason?

Yeah, we’ve closed countless sites with the comment, especially here in Southern California with RegenOx part A specifically and ORCA advanced. The purpose of the RegenOx part A is, “Hey, I’ll gladly take whatever direct oxidation I can get, although I don’t expect a tremendous amount based on how we load it, but I do expect a tremendous amount of desorption based on the alkalinity of the chemical as well as just how efficient it is at scrubbing the soil particles.” So we use it as a soil scrubber, and that has proven the play out time and time again as a much better mechanism for us and just going in directly with either RegenOx or ORCA

Video Transcription

Dane: Hello, and welcome everyone. My name is Dane Menke. I am the Digital Marketing Manager here at REGENESIS and Land Science. Before we get started with the webinar today, I have just a couple of administrative items to cover. Since we’re trying to limit our time to an hour, today’s presentation will be conducted with the audience audio settings on mute. This will minimize unwanted background noise from the large number of participants joining us today. If you have a question, we encourage you to ask it using the question feature located on the webinar panel. We’ll collect your questions and do our best to answer them at the end of the presentation. If we do not address your question, we’ll make an effort to follow up with you after the webinar. We are recording this webinar and a link to the recording will be emailed to you once it is available. In order to continue to sponsor events that are of value and worthy of your time, we will be sending out a brief survey following the webinar to get your feedback.

Today’s webinar will focus on a case study for a petroleum hydrocarbon impacted site where a sequence of in situ remediation technologies from REGENESIS was applied to address residual, sorbed, and dissolved phase constituents. With that, I’d like to introduce our presenter for today. We are pleased to have with us Mr. Jack Sheldon, Senior Remediation Specialist at Antea Group. Mr. Sheldon is a remediation expert with over 34 years of industry experience. He has specialized in the field application of various types of bioremediation and chemical oxidation and reduction systems with personal involvement in 22 first type remediation projects in their respective states. He has completed remediation projects in all 50 states and several locations abroad. All right, that concludes our introduction. So now I will hand things over to Jack Sheldon to get us started.

Jack: Thank you, Dane, for that kind introduction, and thank you to REGENESIS for hosting this kickoff webinar for January 2017. And thank you to all of you who are joining today from around the country, and we’re glad that you can attend. My hope is here today to have a succinct presentation so that we have a generous amount of time at the end to answer questions, and I look forward to the Q&A that often is as good as the content, just hearing what others are thinking and responding to those questions as they come along. So, with that, I’ll kick it off. A tale of two ISCO chemistries, ISCO being in situ chemical oxidation, for those of you who are not acquainted with that term, for enhancing free product recovery and shrinking a dissolved-phase plume.