Fwd_ Modeling & PCE SourcesFrom:Reisch, Scott H.
To:Greg Pohll
Cc:Ivo Bergsohn
Subject:Fwd: Modeling & PCE Sources
Date:Thursday, April 13, 2017 6:34:46 AM
Attachments:LRWQCB Memorandum Regarding PCE Contamination at Campora Gas Site 1997.pdfATT00001.htmGW Sample Locations.pdfATT00002.htmHogan Lovells 8 Sept 2016 response letter excerpts.pdfATT00003.htm
Sorry I left you off yesterday's correction.
Sent from my iPhone
Begin forwarded message:
From: "Reisch, Scott H." <scott.reisch@hoganlovells.com>To: "Ivo Bergsohn (Ibergsohn@stpud.dst.ca.us)" <Ibergsohn@stpud.dst.ca.us>,"gregory.blount@troutmansanders.com"
<gregory.blount@troutmansanders.com>Cc: "Nick M. Billings Esq. (nick.billings@aimco.com)"
<nick.billings@aimco.com>, "Paul B. Hoffey (phoffey@ekiconsult.com)"<phoffey@ekiconsult.com>, "asafford@ekiconsult.com"
<asafford@ekiconsult.com>, "Vera Nelson (vhnelson@ekiconsult.com)"<vhnelson@ekiconsult.com>, "Kyle Flory (kflory@pesenv.com)"
<kflory@pesenv.com>, "Bras, Alejandro Luis (ABras@mofo.com)"<ABras@mofo.com>Subject: FW: Modeling & PCE Sources
Ivo/Greg:
Sorry, I omitted one of the attachments in my prior email. Here is it again with
everything attached. Regards, Scott
From: Reisch, Scott H. Sent: Wednesday, April 12, 2017 3:30 PMTo: Ivo Bergsohn (Ibergsohn@stpud.dst.ca.us); Greg Pohll (Greg.Pohll@dri.edu)Cc: Nick M. Billings Esq. (nick.billings@aimco.com); Peter.Cappel@aimco.com;asafford@ekiconsult.com; Paul B. Hoffey (phoffey@ekiconsult.com); Vera Nelson(vhnelson@ekiconsult.com); Bras, Alejandro Luis (ABras@mofo.com); Kyle Flory
(kflory@pesenv.com)Subject: Modeling & PCE Sources
Ivo and Greg,
Thank you for including us in the meeting last week. We found it very helpful. Below
are our comments on the email submitted by Greg last Friday (4/7/17), as well as some
preliminary reactions and questions regarding last week’s model presentation. As
noted below, we think a meeting in Lake Tahoe to discuss some of these issues is
warranted.
1) The map provided in the 4/7/17 email does not include all of the potential PCE
sources sites that we identified in our review of publicly-available files and
other sources. On September 8, 2016, Hogan Lovells (counsel to Fox Capital)
submitted a letter to the Water Board that described the results of our review.
The Hogan Lovells letter was provided to you previously and is available on
Drop Box. Selected pages from that letter that pertain to potential off-Site
sources are attached to this email.
Because of continuing concern that these possible sources have not been
adequately investigated, last month Fox Capital notified the Water Board, by
email that Fox and Seven Springs jointly plan to implement a groundwater
investigation in the South Y Area. As shown on the attached map (which has
been slightly revised from the one provided last month), a number of planned
groundwater samples are to be located just downgradient of suspected source
sites, including the former Lampson/Sierra dry cleaners site, as well as
upgradient of the LTLW site to look for PCE that may be migrating onto the
LTLW site from off-site areas to the south, including the Shop Street/Industrial
Avenue area, which has been targeted by the Water Board as a potential
source area for PCE contamination. Regarding upgradient sources, PCE has not
only been detected in groundwater at the Tahoe Asphalt site (Industrial Avenue
Well #4), but also at the Campora Propane Gas site at 1640 Shop Street. In a
memorandum prepared by the Water Board, dated December 12, 1997 (see
attached), it was reported that PCE was detected in a groundwater sample
collected from the Campora site at a concentration of 24 ppb. The source for
the PCE was never identified. We intend to complete the off-Site groundwater
investigation as soon as weather conditions and permitting allows. This
additional groundwater data, as well as subsurface lithology information that
we plan to collect, would certainly be useful in running your remedial action
alternatives simulations.
2) The location of the Redwood Oil site is incorrectly identified on your map. The
Redwood Oil site is actually located at the southeast corner of the intersection
of Dunlap Drive and Eloise Avenue. We understand that the Water Board has
encouraged you to remove Redwood Oil from your map. Our experts do not
agree and will address that point, as well as the TCI site, in a separate email to
all stakeholders.
3) Our consultants have a number of preliminary questions and requests for
additional information on the groundwater and transport model that was
presented at the April 5th meeting:
a. Please provide groundwater flow calibration data including simulated vs.measured head within the refined model area.
b. What are the units for the y-axis identifying the PCE concentration ofmodeled source recharge that is included on the slide identified as “PCEsources”? Also what is the recharge rate at the source that was used, thearea over which the source recharge occurred, and the resulting PCEconcentration in the groundwater within the cells directly beneath the
recharge area in the 1st 2nd, 3rd and 4th layers within model over thecalibration period?
c. What is the PCE concentration scale utilized to show the modeling results inthe videos, as it is not readable in the presentation?
d. Was Groundwater Vistas used to enter the data into Modflow andMT3D? If so, can the original input files be provided?
e. What are the simulated PCE concentrations relative to observedconcentrations for the calibration period from 1970 to 2016 for the TataLane Wells 1, 2, 3 and 4, the Julie Lane Well, South Y Well, LBWC4.
f. Can you provide references for the effective porosity used within themodel?
g. Please provide a copy of the paper referenced as Benson, 2001.
h. Please identify units for transverse dispersivity and vertical dispersivitypresented on presentation slide identified as “transport parameters.”
Given the complexity of the model, the fact that critical information has not yet been
shared with SSLP and Fox, and the fact that additional groundwater data on PCE
sources in the South Y will be available in short order, we ask that you postpone your
April 14 deadline for commenting on the model. We certainly understand your desire
to move this process along. The fact that our clients have committed to voluntarily
spend thousands of dollars to investigate other sources of contamination – something
the Water Board should have done long ago -- shows that we share your goal. The
April 14 deadline does not afford enough time for thoughtful review and input and we
are concerned that rushing this process now will result in a flawed model, a waste of
resources, and ultimately, further delays. We hope you will reconsider.
We would like to meet with you in Lake Tahoe to discuss these issues and would
propose April 19 as the meeting date. Please let us know if that date works for you.
Thank you,
Scott Reisch (counsel to Fox Capital) & Alejandro Bras (counsel to Seven Springs)
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