–Forwarded Message Attachment–
Subject: Monthly update for Sellers Auto / Artist Studio petroleum cleanup site 489201547 / 489201548 (twenty second update- September 2, 2008)
Date: Tue, 2 Sep 2008 10:15:57 -0400
CC: Carlos.Gonzalez2@ocfl.net; Renee.Parker@ocfl.net; JRWebster@r-kidproperties.com; email@example.com; firstname.lastname@example.org; AQuaid@argusconsulting.com
I would like to take this opportunity to give you our twenty second monthly update on the project.
The next quarterly report is due October 2, 2008, but we expect it will be available sooner. A response to our last comment letter was due from Arugus on August 29th and from my conversation with Robert Horton last week, it has already been sent in. Late last week I received an electronic copy of the milestone tables, which I will summarize below. With the exception of the response to comments report, which I will probably see this afternoon, there are currently no reports in house for the County to review. The next full quarterly report should cover a period that spans from mid April to late July 2008 (GW sampling was performed on July 23rd and will be summarized below).
I had expected we would be able to stop using the oxidizer by now. From a recent conversation with Robert, he would be getting the air sampling data back from the lab by now, so it is possible we are approximately 30 days (my estimate) from being able to turn it off. I will send you a separate update on that when I find out the exact date we may discontinue the oxidizer. The last data we got to analyze indicated we would have to keep it on, but when this new data and recommendation are received I will expedite the review and email the consultant permission to discontinue use of the oxidizer. After it is turned off, the rest of the system will remain on and the oxidizer will be moved to another site (in Brevard County). Also, the propane tank will be removed.
General System Status:
We have had some issues this quarter related to the transfer pump and high water level in the infiltration gallery which I ask Argus to detail in their upcoming report. We suspect that our upcoming approval in response to Argus’ request the use a chemical solution (AN-310FG, a food grade sequestrant) will address this. Also, we have had some torrential rains that have probably caused the infiltration gallery to reach its maximum tolerance of water. I don’t believe this will be a continued problem. In the meantime, I think the best Argus can do to address the backpressure issue is to change the liquid phase carbon (granular activated carbon) and to clean the trays in the air stripper often enough that colloidal fouling won’t cause the transfer pump to fail to keep up with the water. Focused treatment in the area of MW-5 is still needed. This may include the installation of one or more treatment points there.
GW recovery portion:
Since no report has been submitted to document focused treatment (the 24 multiphase extraction wells), we are not able to report on which of the treatment wells will be turned off and which will remain in operation. As stated in previous updates, we believe that the use of focused treatment to hone in on the areas with the most contamination is the best approach as some of the key wells have cleaned up and other ones remain above GCTLs. The area to focus on is the area near MW-5. So far, I don’t have data that shows focused treatment has commenced.
The soil vapor extraction portion:
As stated in the last update, the focused treatment (Vapor recovery) may apply on this portion of the system as well, and may be independent of the focused treatment of groundwater recovery.
This update includes the milestone data from the July 23, 2008 groundwater sampling event. All performance measurement key monitoring wells (AW-3, AW-7, AW-11, AW-22, AW-24, and MW-5) are meeting milestones.
- AW-11, AW-22, and AW-24 have completely cleaned up – met Groundwater Cleanup Target Levels (GCTL).
- AW-3 and AW-7 have almost met GCTL . These wells are close to being cleaned up, with the levels of contaminants lower than they have ever been. AW-3 is only 2 ug/L over the GCTL for benzene and AW-7 is only 34 ug/L over the GCTL for the total xylenes.
- MW-5 is meeting milestones but there is still a lot of room for improvement. The lighter molecular weight contaminants (Benzene and Toluene) aren’t decreasing in a linear or exponential fashion. While the are meeting milestones, these wells have had lower concentrations before. The heavier of the volatile constituents are decreasing in a linear fashion and are lower than they have been. Still this well represents the highest concentrations we have on the site.
- AW-10 is another well (though not currently a performance measurement key well) that will need to be addressed because this well has levels of contaminants similar to MW-5. This well is near MW-5 located near the former Sellers Auto side of the project.
I look forward to giving you the next update on October 1, 2008. Please feel free to call me anytime if you need additional information or have any questions.
Damon Taylor, CFEA, LEP
Orange County Environmental Protection Division
Petroleum Cleanup Team
800 N. Mercy Drive, Suite 4, Orlando, FL 32808
Voice (407) 836-1480, Fax (407) 836-1417