Lenox , Arthur J

From: Gerard Abrams [GAbrams@dtsc.ca.gov]Sent: Friday, November 15, 2002 4:18 PMTo: arthur.j.lenox@boeing .comSubject: Re: Core Hole 1 Pump Test Update

Art :Thanks for your note . The changes are OK with me . Let me pass this information by Stephen Baxter since he has more

experience in the groundwater treatment issues . I'll get back to you .Thanks,

G

>> > "Lenox, Arthur J" <arthur .j .lenox@boeing .com> 11/15/02 12 :52PM >>>

> Gerard ,> As we discussed during our telephone conversation on Wednesday, November> 6th 2002, we are experiencing technical difficulties commencing the long

> term hydraulic pumping test at Core Hole #1 (C-1) . The C-1 pumping test

> is being conducted in accordance with the DTSC approved CFOU Field

> Investigation work plan, dated October 2000 .> The first groundwater sample from C- 1 was collected on July 9, 2002 to

> determine the type of treatment that would be appropriate for th e

> groundwater . Based on this analysis, it was determined that solvents ,

> trichloroethylene (TCE), and 1,1,1-trichloroethane (TCA), and 1,4 dioxane> were present at concentrations of 2000 ug/L, 4 .8 ug/L, and 98 ug/L ,

> respectively . In addition to these compounds, perchlorate was reported at

> 130 ug/L . All of these compounds, with the exception of perchlorate, are

> capable of being treated in the UV/Peroxidation units .> The perchlorate on the other hand did present a treatment problem because> it is not treated/removed by the UV/Peroxidation treatment . Therefore, we> installed two ion exchange resin vessels piped in series at the wellhead

> to remove the perchlorate . In addition, we installed a secondary> containment structure (wired with high level alarms) around the canisters> and wellhead to collect well water in the event of a water leak from the> resin vessels and associated piping .

> The system installation was completed in October 2002 and a short-term> trial pumping test was conducted on October 17th to verify all equipment> was in proper operating condition . The system was switched on for about> an hour varying the pumping rate from 15 to 56 GPM . Groundwater samples> were collected at the pumping rate of -- 30 GPM and analyzed for th e

> chlorinated solvents and perchlorate . The sample results showed a major> change in groundwater quality compared to the first sample collected on

> July 9, 2002 . The original perchlorate concentration of 130 ug/L ha d

> decreased and was not detected (reporting limit of 4 ug/L) and the TCE> concentration had increased from 2,000 ug/L to 31,000 ug/L . The

> UV/Peroxidation unit reduced the 31,000 ug/L TCE concentration to 23 ug/L .

> A few other chlorinated solvents were detected ranging from 1 .7 to 44

1

>:ug/L . These low concentrations prompted us to look for ways to improv e> the system to attain complete treatment . As a result, we installed a new> hydrogen peroxide pump to enhance treatment performance .

> A second trial pumping test ("step test" with Seckington onsite) was> conducted on October 23 and the groundwater quality again change d

> significantly . Perchlorate concentrations were again not detected> (reporting limit of 4 ug/L) and TCE concentration at the wellhead was

> 4,500 ug/L at 9 :30 AM (@ - 20 GPM) and increased to 15,000 ug/L (@ -55> GPM) in the 12 :30 PM sample . 1,4-dioxane concentrations ranged from

> approximately 300 to 450 ug/L . A sample of the treated effluent from the> UV/Peroxidation treatment unit was collected at 12 :30 PM corresponding> with the 15,000 ug/L influent concentration . This sample showed> approximately 700 ug/L of TCE in the treated effluent with concentrations

> of 1,4-dioxane being reduced to approximately one half the influent

> values . A total of -10,600 gallons were pumped during this test . The> effluent water flowed in a storm drain along the Area 1 road to SWMU 4 .16

> R-1 Pond, where it was contained .

> We reviewed these results and conclude that the most likely reason for the> substandard treatment resulted from the variablity of the influen t> concentrations that overwelmed the UV-Peroxide treatment system capacity .

> Consequently, we plan on adding activated carbon vessels to the influent> of the UV/Peroxidation treatment system to reduce the VOC loading on the> UV-Peroxide unit to enable full treatment of VOCs and 1,4 dioxane . In

> addition, the perchlorate resin canisters will continue to be used t o

> address the perchlorate . The resin canisters will be moved from the well> head to the effluent side of the UV-Peroxide treatment system . Please> confirm with an email that these changes are acceptable .

> Thanks, Art

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