govinfo:USCOURTS-ksd-6_23-cv-01218-4

IN THE UNITED STATES DISTRICT COURT 
FOR THE DISTRICT OF KANSAS 
 
FAYE BLACK et al., 
 
Plaintiffs, 
 
v. Case No. 23-1218-EFM-ADM 
 
UNION PACIFIC RAILROAD COMPANY, 
 
De
fendant. 
 
 
 
 
MEMORANDUM AND ORDER 
 In this Order, the Court considers two motions filed by Defendant Union Pacific Railroad 
Company (“Union Pacific”). Both motions arose in the context of Plaintiff Faye Black’s effort to 
certify a class for her claims th at Union Pacific is responsible for toxic chemical contamination 
underneath homes within Plaintiff’s proposed class area (“PCA”). 
The first Motion the Court will address is Union Pacific’s Federal Rule of Procedure 
12(b)(1) Motion to Dismiss Plaintiff’s claims for lack of standing (Doc. 218). Union Pacific argues 
that Plaintiff’s injury in fact is too speculative and disconnect ed from her requested remedy to 
confer Article III standing upon her and the potential class members. The second is Union Pacific’s 
Motion to Exclude Expert Testimony (Doc. 185). In that Motion, Union Pacific seeks to exclude 
Plaintiff’s five experts who offer testimony and re ports in support of her ef fort to certify a class 
action. For the reasons stated herein, the Court denies Union Pacific’s Motion to Dismiss and 
grants in part and denies in part its Motion to Exclude. 

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I. Factual and Procedural Background 
 Plaintiff brings this putativ e class action alleging that Un ion Pacific contaminated her 
property, exposing her and others similarly situated to toxic chemicals. Union Pacific owns and 
operates an industrial railroad site near 29th North and Grove Stre ets in Wichita, Kansas (the 
“Site”). In 1994, the City of Wichita discovered trichloroethylene (“TCE”)1 contamination in the 
groundwater near 21st North and Grove Streets. In 1995, the Kansas Department of Health and 
Environment (“KDHE”) began inve stigating the TCE c ontamination, eventually confirming that 
Union Pacific’s Site was the source of the contamination. 
In 2002, Union Pacific entered a consent order with KDHE to investigate the 
contamination. In 2003, KDHE and Union Pacific learned that the groundwater contamination 
plume extended 2.7 miles south of the Site. Pursuant to the consent order, and overseen by KDHE, 
Union Pacific has engaged in investigations, studies, and remediation measures since at least 2005. 
In September 2022, KDHE held its first public meeting to inform the community in 
Northeast Wichita about the contamination and public health risks. Plaintiff filed suit in October 
2023 and seeks to certify a class of persons who ow n residential homes within an area overlying 
TCE-contaminated groundwater. After Plaintiff filed an Amende d Complaint and Union Pacific 
filed a partial motion to dismiss, only four of Plaintiff’s claims remain: negligent remediation, 
continuing nuisance, continuing trespass, and viol ation of Kansas’s Discharge Statute, K.S.A. 
§ 65-6203. 
Plaintiff contends that the TCE contamination in the groundwater and soil beneath the PCA 
homes will volatize into vapor an d enter the indoor air of the PC A homes via a pr ocess called 
vapor intrusion. Plaintiff maintain s that this poses a health risk to her and the potential class 
 
1 TCE is chemical that has been commonly used as an industrial degreaser. It is a known carcinogen. 

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members. Accordingly, Plaintiff requests damages measured, in large part, by the cost of installing 
vapor intrusion mitigati on systems within the PCA homes. Plai ntiff designated five experts to 
support her claims: 
Dr. Richard Laton: Dr. Laton is a hydrologist, hydr ogeologist, and environmental 
contamination expert. He used historic groundwater sampling data from tests conducted by Union 
Pacific and KDHE to map where the TCE groundwat er contamination exceeds a value of 1.2 
micrograms per liter (µg/L). Dr. Laton’s plume map defines Plaintiff’s proposed class area 
(“PCA”). 
Mr. Frank Anastasi: Mr. Anastasi is a hydrogeologist and offers opinions about the 
location of the TCE contamination from the Site . Additionally, he opines that Union Pacific’s 
remediation measures have been negligent since 2003. 
Dr. Mark Kram: Dr. Kram is a hydrogeochemist. He offers an opinion that connects the 
TCE groundwater contamination valu e of 1.2 µg/L to a risk of TCE vapor intrusion into the 
overlying homes at a value of 0.48 micrograms per cubic meter (µg/m3). Based upon this risk, he 
opines that vapor intrusion mitigation systems should be installed at every home that overlies TCE 
groundwater contamination of 1.2 µg/L. 
Mr. Thomas Hatton: Mr. Hatton is a technical expert in the field of vapor intrusion 
mitigation. He offers cost estimates for installing vapor intr usion mitigation systems within two 
types of homes he identified in the PCA: si ngle-family, single-story ranch homes and single-
family, two-story residences. 
Dr. Richard Zabel: Dr. Zabel is an urban and real esta te economist. He offers a formula 
for determining the current market value of the properties within the PCA. 

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On September 30, 2025, Union Pacific filed its Motion to Exclude each of Plaintiff’s experts from 
the Court’s consideration of the issue of class certification. 
Union Pacific first raised the issue of standing in its memorandum opposing class 
certification. In her Amended Complaint, Plaintiff specifically requested judgment “for the loss of 
permanent and temporary or continuing property value, stigma, unjust enrichment, [and] the cost 
of prompt corrective action” to relieve the alleged injury to her and the potential class members. 2 
In her Motion to a Certify Class, however, Plaintiff did not seek class treatment of her request for 
diminution in value damages. 3 Union Pacific argued that, wit hout a diminution in value claim, 
Plaintiff lacks standing. 
On April 23–24, the Court held a hearing to address Union Pacific’s Motion to Exclude 
and Plaintiff’s Motion to Certify Class. The C ourt heard Union Pacific’ s standing argument but 
noted that Union Pacific had not made a motion to that end. The Court i nvited Union Pacific to 
file a Rule 12(b)(1) motion after the hearing; Union Pacific did on May 4, 2026. Plaintiff filed her 
response on May 14, 2026. Because the Court heard much of the arguments at the hearing, the 
Court did not grant Union Pacific an opportunity to file a reply specific to the Motion to Dismiss. 
Accordingly, the matters are fully briefed and ripe for the Court’s ruling. 
 
2 Doc. 54 at 31. 
3 See Doc. 186 at 46 (only listing property mitigation damages as appropriate for class-wide determination); 
see also Doc. 202 at 13 (noting in her reply that “Plaintiff and the class do not seek a decrease in property value at all, 
much less a decrease in valued due to the presence of indoor air exceedances.”). 

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II. Legal Standards 
A. Federal Rule of Civil Procedure 12(b)(1) and Standing 
Under Rule 12(b)(1), a defendant may move to dismiss a claim for lack of subject-matter 
jurisdiction.4 Federal courts are courts of limited juri sdiction, and a presumption exists against 
exercising jurisdiction over a case. 5 The party asserting jurisdiction bears the burden of 
establishing its existence. 6 Thus, the Court may exercise jurisdiction only when specifically 
authorized to do so and must dismiss a claim if it becomes apparent at any stage of the proceedings 
that it lacks jurisdiction. 7 The party asserting jurisdiction has the burden of establishing subject 
matter jurisdiction.8 
Standing is a jurisdictional issue that is properly challenged via a Rule 12(b)(1) motion. 9 
Article III of the Constitution “confines the federal judicial power to the resolution of ‘Cases’ and 
‘Controversies.’”
10 To show that the Court has jurisdicti on over a case or cont roversy, a plaintiff 
must demonstrate that she has a pe rsonal stake—or standing—in the matter. 11 A plaintiff 
establishes standing by showing “(i) that he suffered an injury in fact that is concrete, 
particularized, and actual or imminent; (ii) that the injury was likely caused by the defendant; and 
 
4 Fed. R. Civ. P. 12(b)(1). 
5 See In re Syngenta AG MIR 162 Corn Litig., 61 F.4th 1126, 1170 (10th Cir. 2023) (citations omitted). 
6 Id. 
7 Siloam Springs Hotel, LLC v. Century Sur. Co., 906 F.3d 926, 931 (10th Cir. 2018). 
8 Port City Props. v. Union Pac. R.R. Co., 518 F.3d 1186, 1189 (10th Cir. 2008). 
9 Colo. Env’t Coal. v. Wenker, 353 F.3d 1221, 1227 (10th Cir. 2004). 
10 TransUnion LLC v. Ramirez, 594 U.S. 413, 423 (2021) (quoting U.S. CONST. art. III, § 2). 
11 Id. 

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(iii) that the injury would likely be redressed by j udicial relief.”12 If a plaintiff fails to show that 
he has suffered an injury caused by the defendant and amenable to judicial remedy, there is no 
case or controversy and the Court has no jurisdiction over the matter.13 
Generally, a Rule 12(b)(1) motion to dismiss ta kes one of two forms: a facial attack or a 
factual attack.14 “In addressing a facial attack, the district court must accept the allegations in the 
complaint as true.” 15 In a factual attack, the moving party do es not attack the sufficiency of the 
complaint but asserts that the Court lacks subject matter jurisdiction based on facts outside of the 
pleadings.16 In that instance, “a part y may go beyond allegations c ontained in the complaint and 
challenge the facts upon which subj ect matter jurisdiction depends.” 17 When reviewing a factual 
attack, the Court “may not presume the truthf ulness of the complaint’s factual allegations.” 18 
Rather, the Court has “wide discretion to allo w affidavits, other docu ments, and a limited 
evidentiary hearing to resolve di sputed jurisdictional facts under Rule 12(b)(1)” without needing 
to convert the motion to summary judgment.19 
B. Federal Rule of Evidence 702 and Motions to Exclude 
Rule 702 of the Federal Rules of Evidence governs the admissibility of opinion testimony 
from witnesses qualified as expe rts by their knowledge, skill, expe rience, training, or education. 
 
12 Id. (citing Lujan v. Defs. of Wildlife, 504 U.S. 555, 560–61 (1992)). 
13 Id. (citing Casillas v. Madison Ave. Assocs., Inc., 926 F.3d 329, 333 (7th Cir. 2019)). 
14 Holt v. United States, 46 F.3d 1000, 1002–03 (10th Cir. 1995). 
15 U.S. v. Rodriguez-Aguirre, 264 F.3d 1195, 1203 (10th Cir. 2001). 
16 Holt, 46 F.3d at 1003. 
17 Id. 
18 Id. 
19 Id. 

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Under Rule 702, expert opinion tes timony is admissible to assist th e trier-of-fact in matters of 
scientific, technical, or otherwise specialized knowledge provided that such testimony (1) is based 
upon sufficient facts or data, (2) is a product of reliable principles and methods, and (3) the witness 
applied the principles and methods reliably to the facts of the case. 20 As these requirements 
demonstrate, the court is charged as a gatekeeper to admit only expert testimony that is relevant 
and reliable.21 This Daubert analysis considers the proffered expert testimony in a flexible inquiry 
specific to the facts of the case at bar.22 
A Daubert analysis may be necessary when a plain tiff relies on expert opinions to certify 
a class under Federal Rule Civil Procedure 23 and demonstrate that Rule 23(a)’s requirements for 
numerosity, commonality, typicality, and adequacy are met. 23 But this need not be a full-fledged 
Daubert analysis because “as the parties remain engaged in merits discovery at the class 
certification stage, the information available to experts is limited.” 24 Accordingly, “any Daubert 
analysis performed by the court will focus prim arily on: (1) the knowledge, training, experience, 
and qualifications of the expert; and (2) the methodology relied on by the expert in formulating 
the challenged opinion.”25 In reviewing the latter, “[t]he focus . . . must be solely on principles and 
 
20 Fed. R. Evid. 702. 
21 See Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 589 (1993). 
22 Id. at 593; see also Kumho Tire Co ., Ltd. v. Carmichael , 526 U.S. 137, 150 (1999) (rejecting formulaic 
application of reliability factors discussed in Daubert because “[t]oo much depends upon the particular circumstances 
of the particular case at issue”). 
23 See In re EpiPen (Epinephrine Injection, USP) Mktg., Sales Pracs. & Antitrust Litig., 2019 WL 1569294, 
at *3 (D. Kan. Apr. 11, 2019) (“If, for instance, a plaintif f relies entirely on expert evid ence to satisfy a Rule 23(a) 
requirement for certification, a nearly full-fledged Daubert analysis may be appropriate.”). 
24 Id. at *4. 
25 Id.; see also In re Zurn Pex Plumbing Prods. Liab. Litig., 644 F.3d 604, 614 (8th Cir. 2011) (“We conclude 
that the district court did not err by conducting a focused Daubert analysis which scrutinized the reliability of the 
expert testimony in light of the criteria for class certification and the current state of the evidence.”). 

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methodology, not on the conclusions that they generate.”26 Furthermore, any conclusion regarding 
expert testimony reached at this stage “is subject to amendm ent for purposes of the class 
certification determination and is not finally dete rminative of the admissibility of the expert’s 
testimony at a trial on the merits.”27 
III. Analysis 
A. Standing 
Union Pacific challenges the injury in fact and redressability elements of Plaintiff’s 
purported standing. In doing so, Union Pacific asserts that its challenges are factual attacks. But a 
close look at Union Pacific’s arguments reveals that they are facial rather than factual attacks. To 
start, Union Pacific does not offer any factual ev idence to challenge Plaintiff’s allegations. Next, 
regarding Union Pacific’s challenge of Plaintiff’s injury in fact, Union Pacific asserts that 
Plaintiff’s injury is speculative, and therefore not suff icient to confer standing. And, as to the 
redressability argument, Union Pacific contends that Plaintiff’s requested remedy does not 
correspond to her injury. These arguments do not contest the factual premises upon which 
Plaintiff’s allegations rest. Rather, they presume Plaintiff’s facts and challenge the sufficiency of 
the allegations to confer standing. Accordingly, the Court considers Union Pacific’s arguments to 
be facial challenges and will accept Plaintif f’s non-conclusory allegations in her Amended 
Complaint claims as true.28 
 
26 Daubert, 509 U.S. at 595. 
27 In re EpiPen, 2020 WL 1164869, at *3 (citing Bill Barrett Corp. v. YMC Royalty Co., LP , 918 F.3d 760, 
770 (10th Cir. 2019)). 
28 See Rodriguez-Aguirre, 364 F.3d at 1203. Cf. Lujan, 504 U.S. at 561 (standing is assessed by “the manner 
and degree of evidence required at the successive stages of the litigation”); and Vallario v. Vandehey, 554 F.3d 1259, 
1265 (10th Cir. 2009) (“[A]t the clas s certification stage a district court mu st generally accept the substantive, non-
conclusory allegations of the complaint as true.”). 

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1. Injury in Fact 
“To establish injury in fact, a plaintiff must show that he or she suffered ‘an invasion of a 
legally protected interest’ that is ‘concrete an d particularized’ and ‘actual or imminent, not 
conjectural or hypothetical.’”29 In lodging its challenge to the inju ry in fact element of Plaintiff’s 
standing, Union Pacific shifts focus away from the TCE contamination in the groundwater and 
towards the two risks that Plaintiff associates with the TCE contamination beneath the PCA homes. 
Union Pacific then describes Plaintiff’s injury as a “risk of a risk” and insufficiently concrete. 
The first risk identified by Union Pacific is the risk of TCE vapor intruding into Plaintiff’s 
and the other PCA homeowners’ homes. Because Plaintiff offers no testing to confirm her or any 
other PCA home actually contains TCE vapor at tributable to Union Pacific’s groundwater 
contamination, Union Pacific contends that the ri sk of vapor intrusion is not supported by any 
evidence. The second risk that Union Pacific points to is the risk of cancer and other health issues 
from exposure to TCE-contaminated vapors. Union Pacific posits that Plaintiff’s allegations stack 
these risks upon each other, rendering the injury too speculative and attenuated from Union 
Pacific’s alleged wrongful conduct to constitute a concrete injury. 
But Union Pacific starts its argument halfway through Plaintiff’s allegations, skipping over 
the nature of Plaintiff’s claims. Plaintiff asserts that the TCE contamination beneath her home and 
the PCA homes is her injury in fact. Plaintiff has consistently maintained that she seeks redress for 
Union Pacific’s violation of her property rights. She contends that the risks identified by Union 
Pacific go to show damages caused by the physical presence of TCE underneath the PCA homes.30 
 
29 Spokeo, Inc. v. Robins, 578 U.S. 330, 339 (2016) (quoting Lujan, 504 U.S. at 560). 
30 Plaintiff also contends that these risks—vapor intrusion and the associated health concerns—are additional 
injuries. Indeed, “[a]n allegation of future injury may suffice if the threatened injury is ‘certainly impending,’ or there 
is a ‘substantial risk’ that the harm will occur.” Susan B. Anthony List v. Driehaus, 573 U.S. 149, 158 (2014). However, 

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Courts have found that both intangible and ta ngible injuries may satisfy the “concrete” 
requirement of the injury in fact inquiry. 31 Plaintiff styles the TCE contamination as an obvious 
“traditional tangible harm” that “has caused physical or monetary injury” amounting to a concrete 
injury. 32 Plaintiff maintains that the physical presence of TC E contamination in the groundwater 
and soil beneath her home is an “invasion of [her] legally protected [property] interest.”33 
This physical invasion is a concrete injury because it is “real” and not “abstract.”34 Just as 
“when one man placed his foot on another’s property, the property owner needed to show nothing 
more to establish a traditional case or controversy,”35 Plaintiff need not show anything more than 
the physical presence of the TCE beneath her home. Indeed, the physical presence of TCE 
underneath Plaintiff’s home in the groundwater and soil is the type of harm recognized by each of 
her four remaining claims: negligent remediation (explicitly tied to the non-removal of TCE 
contamination); continuing nuisance, continuing trespass, and violation of Kansas’s discharge 
statute. 
When starting from the beginning of Plaintiff’s allegations—namely at the assertion that 
the groundwater and soil beneath the PCA homes is contaminated with TCE from Union Pacific’s 
Site—Plaintiff’s four claims easily meet her burden of showing a concrete injury. Ironically, Union 
 
because her primary argument—that the TCE contamination violates her property rights—constitutes an injury in fact 
sufficient to confer standing, the Court need not address this argument. 
31 Id. at 340. 
32 Doc. 220 at 5 (citing TransUnion LLC, 594 U.S. at 425). 
33 Spokeo, 578 U.S. at 339. 
34 Id. at 341. 
35 Id. at 344 (Thomas, J., concurring). 

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Pacific’s next argument regardi ng redressability acknowledges that Plaintiff’s claimed injury is 
the presence of TCE in the groundwater. 
2. Redressability 
 Union Pacific asserts that the requested remedy—money to install vapor intrusion 
mitigation systems in the PCA homes—does not remedy the TCE contamination in the 
groundwater or soil. Because there is a mismatch between the reque sted remedy and the asserted 
harm, Union Pacific argues that Pl aintiff fails to meet her burden to show that her injury is 
redressable. Plaintiff clarifies that she does not seek to enjoin Union Pacific to install vapor 
intrusion mitigation systems—rather she seeks money damages measured by the cost of installing 
vapor intrusion mitigation systems in the PCA homes. 
Union Pacific cites Steel Company v. Citizens for a Better Environment
36 for the 
proposition that “[r]elief that does not remedy the injury suffered cannot bootstrap a plaintiff into 
federal court.”37 There, the plaintiff was an association of individuals interested in environmental 
protection, seeking to enforce a civil penalty agai nst the defendant for fail ing to timely report 
details about its use of toxic chemicals as required by statute. 38 But the plaintiff sought the court 
to impose a civil penalty upon the defendant—payable to the United States Treasury—rather than 
any money damages payable to plaintiff. 39 Because the plaintiff would receive nothing but the 
gratification that the law was enforced, the Supreme Court found this “psychic satisfaction” 
insufficient to satisfy the redressability requirement.40 
 
36 523 U.S. 83. 
37 Id. at 107. 
38 Id. at 86–87. 
39 Id. at 106. 
40 Id. at 107. 

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Plaintiff’s request is easily distinguished from the plaintiff’s request in Steel Company. She 
seeks damages payable to her and the class for the purpose of installing vapor intrusion mitigation 
systems. True, measuring those damages requires Plaintiff to prove that the risk of vapor intrusion 
and health effects are the result of Union Pacific’s TCE contamination of the soil and groundwater. 
Nonetheless, at this stage of the proceedings and considering Plaintiff’s allegations as true, they 
satisfy redressability because Plaintiff allege s that Union Pacific caused contamination and 
requests an award of money damages. 41 And even though Plaintiff’s requested remedy does not 
fully remedy the TCE contamination in the groundwater and soil, it at least partially remedies the 
harm caused by her claimed injury.42 
Plaintiff has sufficiently alle ged that her property rights we re violated when TCE from 
Union Pacific’s Site entered and remained upon Plaintiff’s and the PCA properties. Union Pacific 
does not challenge the second element of the standing inquiry related to causation. And Plaintiff’s 
request for money damages satisfie s the redressability element. As such, the Court finds that 
Plaintiff has standing to bring her claims. 
B. Motions to Exclude 
 Union Pacific seeks to exclude all five of Pl aintiff’s experts from the Court’s consideration 
of class certification. Th e Court will address Union Pacific’s ar guments with resp ect to each of 
Plaintiff’s five experts. 
 
41 Diamond Alt. Energy, LLC v. EPA , 606 U.S. 100, 111 (2025) (holding that when “a defendant’s action 
causes an injury . . . awarding damages for the action will typically redress that injury.” (citation and internal quotation 
marks omitted)). 
42 Uzuegbunam v. Preczewski, 592 U.S. 279, 291 (2021) (“[T]he ability to effectuate a partial remedy satisfies 
the redressability requirement.” (citation and internal quotation marks omitted)). 

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1. Dr. Laton 
Dr. Laton is an expert in hydrology, hydrogeology, environmental contamination, and site 
contamination investigations. Union Pacific does not challenge Dr. Laton’s qualifications. Plaintiff 
relies on Dr. Laton to define the PCA by mapping the contours of the groundwater contamination 
plume at which TCE concentration is at or above 1.2 µg/L. Uni on Pacific challenges Dr. Laton’s 
opinion on several grounds. 
a. Use of 1.2 µg/L 
Union Pacific first argues that Dr. Laton’s use of the number 1.2 µg/L as a threshold value 
is unreliable because it is based upon unverified assumptions. Union Pacific posits that Dr. Laton 
did not come up with the 1.2 µg /L number. In his report, Dr . Laton acknowledges that the 
significance of 1.2 µg/L groundwater contamination is tied to the risk of vapor intrusion. Plaintiff 
does not dispute that Dr. Laton did not independently arrive at the 1.2 µg/L value and agrees that 
Dr. Kram instructed Dr. Lat on to use this as the thres hold number to map the plume. An expert 
may permissibly “rely on th e opinions of another e xpert if they inform or contribute to his own 
independent conclusions.”43 As more fully discussed in the discussion of Union Pacific’s challenge 
to Dr. Kram, it cannot be said that this value lacks scientific support. Accordingly, Union Pacific’s 
concerns with Dr. Laton’s use of the value 1.2 µg/L to map the contamination plume goes to 
weight, not admissibility, and provides no basis to exclude Dr. Laton’s opinion.44 
 
43 Ash Grove Cement Co. v. Emps. Ins. Of Wausau, 246 F.R.D. 656, 661 (D. Kan. 2007). 
44 In re Urethane Antitrust Litig., 768 F.3d 1245, 1263 (10th Cir. 2014) (“[A] district court must admit expert 
testimony as long as it is based on a reliable methodology. It is then for the jury to evaluate the reliability of the 
underlying data, assumption, and conclusion.”). 

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b. Well-Depth and Other Potential Sources 
Next, Union Pacific argues that Dr. Laton did not account for di fferentiating factors 
affecting testing samples. First, Union Pacific asserts that Dr. Laton did not account for the 
differences in the depth of we ll samples and the various soil types within the PCA. These 
variables—soil type and depth—affect the TCE in the groundwater’s ability to reach the surface 
after volatizing. Dr. Laton explai ns in his report that contamin ation is subject to spatial 
variability—meaning the depth of the contamination may change with seasonal and other factors 
affecting the groundwater level. This is a co ncept acknowledged by one of Union Pacific’s 
consultants.45 To account for this vertical variability, Dr . Laton used test sa mples irrespective of 
the well-depth to capture the full extent of the plume. 46 Union Pacific also argues that Dr. Laton 
did not sufficiently account for other potential so urces of TCE—specifically, dry cleaners and a 
nearby industrial corrid or. But both of these arguments—tha t the depth of the contamination 
affects the risk of vapor intrusion and that there may be other sources of contamination—go more 
to the causation element of Plaintiff’s claims rather than to issues related to class certification. As 
such, this is not a basis to exclude Dr. Lat on’s opinion from the Court’s consideration of the 
certification issue. 
c. Concerns Addressed by Dr. Laton’s New Map 
Union Pacific presented two arguments agains t Dr. Laton’s map that the Court addressed 
in detail at the hearing: Dr. Laton’s use of “historic maximums” and his inclusion of “non-detect” 
test results in his plume map. After the hearing, Dr. Laton significantly revised his plume map in 
 
45 See Doc. 187-2 (quoting Arcadis, one of Union Pacific’ s consultants, as stating “TCE observed in the 
shallow monitoring wells in the southern three-fourths of the plume is not likely to have migrated directly from the 
source zone. Instead, the shallow zones were likely cross-contaminated by diffusion from the lower zone or by upward 
smearing of contamination when groundwater elevations rose during natural fluctuations of recharge.”). 
46 Doc. 187-8 at 33–34. 

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response to the Court’s expressed concern and Union Pacific’s arguments.47 Nevertheless, because 
other experts relied upon Dr. Lat on’s original plume map to form their opinions, the Court will 
address all of Union Pacific’s arguments in its motion to exclude Dr. Laton. 
i. Historic Maximums 
To map the contamination plume, Dr. La ton reviewed and relied upon groundwater 
sampling tests from dozens of monitoring wells and one-time grab sa mples in and around the 
expected plume area. These samp les have been taken at various times since 1991. In his initial 
map, Dr. Laton considered the “historic maximu m” from each well, meaning Dr. Laton took the 
highest value of TCE concentra tion reported over this more than 30-year testing period for any 
given well or sample. For example, in 2005, one monitoring well reported TCE contamination at 
a value of 5.9 µg/L; however, samples from that same well taken between 2010 and 2023 detected 
no TCE. But because the 5.9 µg/L value was the “historic maximum” from this monitoring well, 
Dr. Laton used this number rather than the more recent test data. 
Union Pacific asserts that a map of the plume using this method does not reflect the current 
plume but rather creates a “phant om plume.” This phantom plume masks the impact of remedial 
measures taken by Union Pacific over the years. Plaintiff responds that Dr. Laton’s method is 
consistent with the practice of hydrogeolog ic plume mapping and EP A guidance. Dr. Laton 
justifies the use of historic data by pointing out that groundwater systems are dynamic, and that 
fluctuations make it possible for a well sample to not detect TCE one day and for that same well 
to subsequently return a positive test for TCE. When asked about the source of this method during 
his deposition, however, Dr. Lat on could cite no au thority for using th e historic maximum. 48 
 
47 Doc. 217. 
48 Doc. 196-1 at 88–89. 

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Rather, he merely stated that he has seen it employed and has used it before, but could not provide 
specific authority for this proposition.49 Aside from another case in which Dr. Laton’s use of this 
historical maximum approach was found to be “arguably” accepted in his field, Plaintiff provides 
no other evidence that this is an accepted method.50 The Court considers this to be an ipse dixit—
nothing more than Dr. Laton’s statement that this is a legitimate method of mapping a 
contamination plume.51 
The Court’s concern with Dr. Laton’s use of historic maximums is enhanced by the specific 
facts here. It is undisputed that Union Pacific, at the direction of KDHE, has been engaged in 
significant remediation activities at the Site since at least 2005. It de fies logic to use test samples 
that predate that remediation activity by 14 years to map the current groundwater plume. This 
concern becomes even more pronounced considering one of Plaintiff’s claims is that Union Pacific 
has been negligent in re mediating the contamination. To map th e area in which Plaintiff alleges 
that Union Pacific has been negligent in remediating by plotting the value of tests predating Union 
Pacific’s remedial efforts is temporally and logically irreconcilable. As such, the Court expressed 
significant concern with the reliability of Dr. La ton’s use of historic maximum levels of TCE 
contamination over the last 30 years. 
 
49 Id. 
50 See Behar v. Northrop Grumman Corp. , 2026 WL 413398, at *5 (C.D. Cal. Feb. 4, 2026) (“The use of 
‘historical maximum concentrations’ is (arguably) an accepted method in Dr. Laton’s field as a conservative technique 
to capture all possible exposure.”). Although the Central District of California Court accepted this argument, a review 
of the plaintiffs’ memorandum in opposition to the exclusion of Dr. Laton in that case reveals that plaintiffs only cited 
Dr. Laton himself for the proposition that historical maximum concentrations are accepted in the hydrogeology field 
and did not cite any other authority. See Pls.’ Opposition to Defs.’ Northrop Grumman Corp.’s Notice of Mot. & Mot. 
to Exclude the Ops. of Pls.’ Expert Dr. Richard Laton, Behar v. Northrop Grumman Corp., 2026 WL 413398 (C.D. 
Cal. Feb. 4, 2026), 2025 WL 3676893. 
51 Ipse dixit translates as “he himself said it” and is defined as “[s]omething asserted but not proved.” Ipse 
Dixit, Black’s Law Dictionary (12th ed. 2024). 

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Plaintiff subsequently filed a map revised by Dr. Laton that only takes account of the 
maximum value of well samples since 2023. This si gnificant revision allays the Court’s concern 
with the reliability of Dr. Laton’s map. 
ii. Non-Detects 
Before addressing Dr. Laton’s use of “non-de tect” values, the concept of a “non-detect” 
warrants a brief description. Due to instrument and resource limitations, any test for particles in a 
sample has a detection limit. A detection limit is the smallest qua ntity of particles for which a 
given test can confidently provide a reading. A “non-detect” is a test result that is lower than the 
detection limit for the given test. For example, if a test has a detection limit of 5 µg/L, that test’s 
results can only state with confidence a reading of 5 µg/L or greater. A result of 4.99 µg/L or lower 
would be considered a “non-detect ” because it falls below the test ’s detection limi t. Some tests 
have high detection limits, and some tests have low detection limits. 
In his initial plume map, when Dr. Laton came across a “non-detect,” he assigned a value 
of half the detection limit to that reading. He th en incorporated this substituted value—half the 
test’s detection limit—into his plume map. For exampl e, if a test had a dete ction limit of 5 µg/L 
and the sample returned a “non-detect,” Dr. Laton considered that the sample would have reported 
2.5 µg/L. He then incorporated the substituted value of 2.5 µg/L into his plume map. 
Plaintiff does not dispute that Dr. Laton employed this method. Instead, Plaintiff contends 
that this is a standard, conservative use of non-detect values and that it is a method commonly used 
by hydrogeologists. Plaintiff cites the EPA’s 2009 Statistical Analysis of Groundwater Monitoring 
Data at RCRA Facilities: Unified Guidance (“Unified Guidance”) for this proposition. 52 A review 
 
52 ENVTL. PROT. AGENCY, S TATISTICAL ANALYSIS OF GROUNDWATER MONITORING DATA AT RCRA 
FACILITIES: UNIFIED GUIDANCE (2009). 

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of the Unified Guidance confirms that this method is called simple substitutio n and that it is a 
statistically appropriate manner of handli ng non-detects in cer tain circumstances. 53 But it also 
reveals that the circumstances under which the Unified Guidance suggest s non-detect readings 
should be substituted with a numerical value are not present here. 
The Unified Guidance identifies three scenarios in which simple substitution should be 
used to handle non-detects. The first circumstance in which simple substitution is appropriate is 
“[w]hen the sample size is too small to do anything else.”54 This is when there are only a handful 
of samples to analyze.55 Here, the first circumstance is not present because there are over 30 years 
of testing samples from dozens of wells. The second circumstance is “[w]hen non-detects comprise 
no more than 10–15% of the total sample.”56 It is not clear what the ratio of non-detect samples to 
confident readings were, but a review of the map in which Dr. Laton identifies which samples had 
non-detect values shows that th ere are almost certainly more than 10–15% non-detects when 
compared to the total sample size.57 Thus, the second circumstance is not present either. The third 
circumstance is “[w]hen non-detects are generated by a different physical process than the detected 
values, and thus represent a distinct statistical distribution.”58 This is most often used by assigning 
a zero value to the non-detect sample. 59 The third circumstance is not present here because Dr. 
 
53 Id. at 15-3. 
54 Id. at 15-5. 
55 Id. 
56 Id. 
57 See Doc. 187-8 at 68. 
58 UNIFIED GUIDANCE at 15-6. 
59 Id. 

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Laton did not do this in his initial map, rather he attached a substituted positive value for the non-
detects rather than a zero. 
In all other cases, the Unified Guidance reco mmends complicated mathematical formulas 
to handle non-detect values. 60 Because the circumstances in which the Unified Guidance would 
recommend using simple substitu tion are not present he re, the Court indicated that it had grave 
concerns over Dr. Laton’s simple substitution of half the detection limit for non-detect test results 
in his plume map. But Dr. Laton’s new map assigns a value of zero to non-detect testing samples. 
This significant revision allays the Court’s concerns with Dr. Laton’s map.61 
Because Dr. Laton’s revised map addresses the Court’s reliability concerns and the Court 
has found Union Pacific’s other arguments to exclude Dr. Lat on unpersuasive, Dr. Laton’s 
testimony and opinions will not be excluded fro m the Court’s consideration of the class 
certification issue.62 
2. Dr. Kram 
Dr. Kram is a hydrogeochemist. He holds a Ph.D. in Environmental Science and a master’s 
degree in Geology. He has over 40 years of ex perience assessing groundw ater contamination, 
subsurface vapor migration, and vapor intrusion. Union Pacific does not challenge Dr. Kram’s 
qualifications. Dr. Kram opines that the TCE gr oundwater plume origina ting from the Site is 
widespread and extends beneath thousands of residential properties in the PCA. Dr. Kram further 
 
60 See id. at 15-3–15-24. 
61 Union Pacific’s Response to Dr. Laton’s new map takes issue with Dr. Laton’s continued incorporation of 
non-detect well samples. However, Dr. Laton assigns a zero value to the non-detect well samples which is an 
appropriate method of handling non-detect samples and explicitly contemplated by the Unified Guidance. U NIFIED 
GUIDANCE at 15-6. 
62 Union Pacific expressed concern over the fact that it did not receive some of the parameters supporting Dr. 
Laton’s new map, rendering his new map method untestable. Plaintiff responds that Dr. Laton’s new map employed 
a simple linear interpolation method rather than the co mplicated methods Union Pacifi c suggests. As such, Union 
Pacific’s argument here is no basis to exclude Dr. Laton’s new map. 

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opines that Union Pacific’s inves tigation and remediation efforts have not adequately addressed 
vapor intrusion risk. Finally, he offers that the time and resource li mitations required to test each 
home in the PCA outweigh the cost of implementing preemptive mitigation measures in each 
home. Dr. Kram’s opinions go to commonality, typicality, and predominance as they establish a 
common risk of harm. 
 Union Pacific lodges three overarching challe nges to Dr. Kram’s opinion. First, Union 
Pacific contends that Dr. Kram uses the wrong standard when he relies on EPA screening levels. 
Second, Union Pacific asserts th at Dr. Kram’s recommendation that preemptive mitigation is 
required is inconsistent with the applicable standa rds. Finally, Union Pacific takes issue with Dr. 
Kram’s estimation of the cost of vapor intrusion mitigation. 
a. Use of EPA Screening Levels 
Dr. Kram opines that ev ery property overlying the 1.2 μg/L isoconcentration contour is 
“more likely than not threatened by toxic chemicals via the vapor intrusion pathway and has been 
for decades.”
63 Dr. Kram relies upon the OSWER Technical Guide fo r Assessing and Mitigating 
the Vapor Intrusion Pathway from Subs urface Vapor Sources to Indoor Air (“OSWER”). 64 He 
does a back-calculati on using the EPA’s TCE c ontamination indoor-air ri sk screening value of 
0.48 µg/m3 and the EPA’s default groundwater-to-indoor air attenuation factor (which accounts 
for the diminishing concentration of TCE as it moves from the groundwater, through the soil and 
other barriers, and into the indoor air of a home overlying that contaminated groundwater). Using 
these numbers, Dr. Kram back-calculates that when the TCE value in groundwater is at or exceeds 
 
63 Doc. 199-1 at 68. 
64 OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE, ENVTL. PROT. AGENCY, OSWER TECHNICAL GUIDE 
FOR ASSESSING AND MITIGATING THE VAPOR INTRUSION PATHWAY FROM SUBSURFACE VAPOR SOURCES TO INDOOR 
AIR (2015) [hereinafter OSWER]. 

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1.2 µg/L, one can expect that an overlying hom e will have a TCE con centration of 0.48µg/m3 in 
the indoor air. 
Union Pacific seeks exclusion of this opinion for several reasons: (1) the 0.48 µg/ m3 value 
is based upon EPA guidance and is lower than what KDHE has used; (2) the 0.48µg/m3 value only 
represents a “screening” level rather than an “action” level; (3) Dr. Kram relies upon Dr. Laton’s 
map without verifying Dr. Laton’s methodology; and (4) Dr. Kram failed to account for variability 
in individual homes. The Court will address each argument in turn. 
First, Union Pacific argues that because KDHE is overseeing the remediation of the Site, 
Dr. Kram should have used KDHE’s risk screening levels instead of the EPA’s. Union Pacific and 
KDHE have been using the indoor-air risk screening level of 2.09 µg/m 3 rather than the EPA’s 
lower value of 0.48 µg/ m3. Plaintiff responds that KDHE standards are not dispositive of the issues 
between private parties and are not to be used as the standard for due care. Daubert does not require 
the Court to resolve which of two competing standards are better suited for use. Rather, the Court 
must evaluate whether an opinion is based upon reliable principles. Union Pacific does not contend 
that the EPA’s screening levels are scientifically invalid—merely that KDHE’s standards are better 
suited to assess Union Pacific’s culpability. This is not a serious challenge to Dr. Kram’s 
methodology, rather it is a demand that Dr. Kram use Union Pacific’s preferred data and methods. 
As such, it is no reason to exclude Dr. Kram’s opinion. 
Second, Union Pacific points out that the EPA guidance Dr. Kram relies upon is a 
“screening” level that recommends more testing, rather than an “action” level that would warrant 
implementing mitigation measures. Union Pacific flags Dr. Kram’s opinion that mitigation 
measures be implemented as inconsistent with the EPA guidance he cites. But Dr. Kram arrives at 
this conclusion after considering that it would be more cost effective to implement mitigation 

-22- 
measures at all homes now rather than to engage in a lengt hy testing process. Contrary to what 
Union Pacific contends—that Dr. Kram skipped the “testing” st ep and jumped straight to 
recommending mitigation—Dr. Kram considered the cost of testing and c oncluded that it would 
be more economically feasible to mitigate. As such, Dr. Kram’s opinion does not suffer from the 
analytical gap that Union Pacific perceives.65 
Third, Union Pacific argues that Dr. Kram relies on the flawed mapping work of Dr. Laton 
and his reliance is misplaced because he did not understand Dr. Laton’s methods. Plaintiff does 
not dispute that Dr. Kram relied upon Dr. Laton’s in itial map to arrive at this conclusion. In a 
deposition, Dr. Kram stated that he did not read Dr. Laton’s report and was unaware of Dr. Laton’s 
methodologies. This is concerning because “one expert may not rely on another expert’s opinion 
if the first expert is unfam iliar with the met hods and reasons supporting the second.” 66 Plaintiff 
responds that this is of no conc ern because Dr. Kram is not disclo sed to testify to the location of 
the plume itself (where the groundwater exceeds 1.2 µg/L). But Dr. Kram provides an opinion that 
“every occupied residentia l building on these 2,319 parcels”—i dentified by Dr. Laton’s initial 
plume map—is a candidate for preemptive mitigation. 67 Dr. Kram’s identific ation of a definite 
number of homes in the PC A, indicates that he does opine as to the loca tion of the groundwater 
plume. Accordingly, to the extent Dr. Kram identifies a definite number of homes currently at risk 
for vapor intrusion, this opinion is excluded be cause he impermissibly relied upon Dr. Laton’s 
initial map without verifying the report and because Dr. Laton’s initial map was problematic.68 
 
65 See Gen. Elec. Co. v. Joiner , 522 U.S. 136, 146 (1997) (“Trained experts commonly extrapolate from 
existing data”). 
66 Assessment Techs. Inst., LLC v. Parkes, 2021 WL 2530977, at * (D. Kan. Jun. 21, 2021) (citation omitted). 
67 Doc. 199-1 at 42 (emphasis added). 
68 This is distinct from Dr. Kram’s opinion regarding the effect 1.2 µg/L groundwater contamination has on 
an overlying home, generally. 

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Fourth, Union Pacific asserts that Dr. Kr am failed to account for the individual 
characteristics in individual PCA homes affe cting TCE’s pathway fro m groundwater to vapor 
intrusion. Union Pacific cites se veral lines of Dr. Kram’s depos ition testimony in which he 
acknowledges that variables in individual hom es, like HVAC or plumbing systems, should be 
taken account. Union Pacific seems to assert that Dr. Kram’s recognition of individual 
characteristics in homes affecting vapor intrusion is inconsistent with his broader opinion that all 
homes overlying the 1.2 µg/L TCE groundwater contamination are at risk for vapor intrusion. But 
it is clear from the cited portions of the deposition that Dr. Kr am merely acknowledges that the 
referenced variables affect the cost of mitigation—not the risk of vapor intrusion.69 As such, Union 
Pacific’s argument here is unpersuasive. 
b. Preemptive Mitigation 
Union Pacific argues that Dr. Kram’s opinion that preemptiv e mitigation is required is 
unreliable because (1) it is inconsistent with the level of risk and the guidance he cites; and (2) it 
relies upon baseless estimates for costs of furt her testing. Neither basi s warrants excluding Dr. 
Kram’s opinion on preemptive mitigation. 
Union Pacific argues that Dr . Kram’s preemptive mitigation recommendation is not 
supported by the OSWER guidance he cites. Plaintiff, however, cites a scenario from the OSWER 
guidance that contemplates offering pr eemptive mitigation in stead of testing. 70 Accordingly, 
Union Pacific’s argument that Dr. Kram’s opin ion is inconsistent w ith this guidance is 
unpersuasive. Union Pacific’s ot her points rehash arguments pr eviously presented drawing a 
distinction between EPA screening and action levels and insisting upon the use of KDHE 
 
69 Doc. 199-2 at 108–09. 
70 OSWER at 138 (“[I]t may be determined to use a [preemptive mitigation] approach to offer mitigation 
systems to all buildings within a specified area of subsurface contamination.”). 

-24- 
standards. For the same reasons discussed a bove, these arguments do not warrant excluding Dr. 
Kram’s testimony. 
Union Pacific’s second argument—that Dr. Kram’s mitigation opinion relies upon baseless 
estimates—is also unpersuasive. Dr. Kram’s opinion relies upon a comparison between the cost of 
determining the reasonable ma ximum exposure (“RME”) for each home against the cost of 
preemptive mitigation measures. According to Dr. Kram and th e OSWER guidance he cites, 
accurately determining the RME is a lengthy and costly process because testing must account for 
spatial and temporal factors affecting indoor air concentration of TCE in a given home. 71 From 
this Dr. Kram concludes that pr eemptive mitigation is more cost effective. Union Pacific asserts 
that calculating the RME usi ng Dr. Kram’s method is not th e exclusive method of conducting 
indoor air testing. Once again, however, although Union Pacific would prefer Dr. Kram use 
another standard, it cannot be sa id the Dr. Kram’s opinion lacks sc ientific validity. As such, this 
is no basis to exclude Dr. Kram’s opinion. 
c. Dr. Kram’s Cost Estimate for Vapor Intrusion Mitigation 
Lastly, Union Pacific argues that Dr. Kram’s estimate of mit igation costs is unreliable 
because it is based upon insufficient facts and data. Plaintiff responds that she does not rely upon 
Dr. Kram’s estimate of damages for class certification. Because Dr . Kram’s opinion here is not 
relevant to class certification, the Court will not conduct a Daubert analysis of this particular 
issue.72 
 
71 Id. at 88 (“Several rounds of sampling are recommended to develop an understanding of temporal 
variability to ensure that final risk management decision s are based upon a consideration of a reasonable maximum 
vapor intrusion condition.”). 
72 In re EpiPen, 2019 WL 1569294, at *4 (“A district court, thus, should apply ‘a focused Daubert analysis 
which scrutinize[s] the reliability of the expert testimony in light of the criteria for class certification and the current 
state of the evidence.’”(quoting In re Zurn, 644 F.3d at 614)). 

-25- 
3. Mr. Anastasi 
Mr. Anastasi is a hydrogeologist with more than 40 years of experience studying and 
working on projects to remediat e soil, groundwater, and sediment contamination at industrial 
facilities. Union Pacific does not challenge Mr. Anastasi’s qualifications. Mr. Anastasi’s opinions 
relate to the location of the plume (going to commonality, typicality, and predominance) and Union 
Pacific’s negligent remediation e fforts (going to Plaintiff’s neg ligent remediation claim). Union 
Pacific presents two challenges to Mr. Anastasi’s opinions: (1) that he does not provide an opinion 
independent of Dr. Laton’s and (2) his opinion regarding Union Pacific’s remediation measures is 
irrelevant. 
a. Mr. Anastasi’s Reliance upon Dr. Laton 
 Mr. Anastasi reviewed and re lied upon Dr. Laton’s initial ma p to arrive at his opinions. 
From his review, Mr. Anastasi offers that “it is more likely than not, accounting for the dynamics 
of the plume, that TCE contaminated ground water is present beneath the entire area encompassed 
by [Dr. Laton’s] 1.2 ug/L TCE contour.”73 Union Pacific challenges Mr. Anastasi’s opinion as not 
an independent opinion, but mere ly a repackaged version of Dr . Laton’s initial map. Plaintiff 
responds that Mr. Anastasi did not rely solely on Dr. Laton’s map, but that he also reviewed 
historical site reports, data from the investigation of the Site, and the subsurface hydrogeology and 
geology. Plaintiff contends that Mr. Anastasi then compared that data to Dr. Laton’s map to form 
his opinion that every home in the plume identified by Dr. Lat on sits above a 1.2 µg/L TCE 
groundwater contamination. 
 The Court agrees that, at r oot, Mr. Anastasi’s opinion is a tautology of Dr. Laton’s report. 
But as discussed above, Dr. Laton’s initial map pr esented issues that caused the Court concern—
 
73 Doc. 198-1 at 15. 

-26- 
so much so that Dr. Laton significantly revised his map of the plume. And although Mr. Anastasi 
may have reviewed other data, he does not provide an independent plume map. Rather, his opinion 
is contingent upon the contours that Dr. Laton assigned to the plum e in his initial map. As such, 
Mr. Anastasi’s opinion is inextricably tied to issues that the Court found to be problematic and to 
a map that has since been revised. The Court must find that Mr. Anastasi’s opinion is irrelevant at 
best and exclude Mr. Anastasi’s first opinion regarding the PCA from its consideration of the class 
certification issue. 
b. Mr. Anastasi’s Negligent Remediation Opinion 
Union Pacific asserts that Mr. Anastasi’s second opinion regarding Union Pacific’s 
remediation efforts is irrelevant to class certification. Mr. Anastasi opines that the remedial actions 
undertaken by Union Pacific have been, and continue to be, inadequate to remediate the TCE in 
the groundwater underneath the PCA. Plaintiff responds that Mr. Anastasi’s opinion regarding the 
remediation goes to liability and supports the predominance and commonality elements of the class 
certification question. Further, Pl aintiff contends that Mr. Anas tasi’s opinion establishes that 
Union Pacific engaged in a common course of conduct applicable to all potential class members. 
Union Pacific presents no other ground to exclude Mr. Anastasi’s opinion. Of significant note, one 
of Plaintiff’s claims for which she seeks class certification is negligent remediation—a matter 
directly addressed by Mr. Anas tasi’s second opinion. Accordingl y, the Court finds that Mr. 
Anastasi’s opinion regarding Union Pacific’s reme diation efforts is relevant to the commonality 
and predominance elements of class certification and will consider it at this stage. 
4. Mr. Hatton 
Mr. Hatton is one of the nation’s foremost experts in designing and installing mitigation 
systems in homes and commercial spaces to reduce vapor intrusion from manufacturing chemicals 

-27- 
or naturally occurring radon. Un ion Pacific does not challenge Mr. Hatton’s quali fications. Mr. 
Hatton opines that there are two categories of homes within the PCA, and he provides cost 
estimates to install vapor intrusion mitigati on systems in both types of homes. Mr. Hatton’s 
opinions go to commonality, typicality, and predominance as he provides an estimate of the cost 
of mitigation measures. Union Pacific presents two main arguments against Mr. Hatton’s opinions. 
First, Union Pacific asserts that Mr. Hatton’s opini on that Plaintiff’s property is representative of 
other residential properties is based upon insufficient facts and data. Second, Union Pacific argues 
that Mr. Hatton did not follow a recognized me thodology to estimate the costs of mitigation 
systems. 
a. Types of Homes in the PCA 
Mr. Hatton opines that there are two types of houses within the PCA: single-family single-
story ranch homes and single-family two-story residences. Union Pacific challenges this opinion 
by asserting that (1) Mr. Hatton only did a drive-through observation of less than half the homes 
within the PCA, and (2) Mr. Hatton did not review property tax records even though he stated he 
did so in his report. The Court will address each argument in turn. 
Union Pacific argues that Mr. Hatton’s investigation of the types of homes in the class area 
was insufficient because he only entered two homes and otherwise merely drove around the PCA. 
Union Pacific points out that Mr. Hatton did not do a close inspection of the vast majority of the 
PCA homes. To formulate his estimate for the cost of installing mitigation systems, however, the 
most pertinent factor distinguishing these ho mes is whether the home has a crawlspace or a 
basement.
74 Mr. Hatton accounts for any other individual characteristics by allowing for a margin 
 
74 Doc. 197-1, at 4. 

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of error in his estimates of be tween 4–5%. Here, Union Pacific is aware of the nature of Mr. 
Hatton’s investigation and can effectively cross-examine him on this matter. 75 
Union Pacific next argues that Mr. Hatton’ s opinion is unreliable because his report 
indicates that he reviewed government records, but Union Pacific asserts that Mr. Hatton testified 
in a deposition that he did not review these records. A review of the deposition transcript indicates 
that Mr. Hatton testified that one of his team members assist ing in writing the report likely 
reviewed the records. 76 The Court finds that this percei ved inconsistency is a matter more 
appropriately handled on cross-examination. 
b. Mr. Hatton’s Mitigation Cost Estimates 
Mr. Hatton provides estimates for the cost of designing, installing, operating, and 
maintaining mitigation systems in the two types of homes within the PCA. He estimates that the 
cost of diagnosing and designing mitigatio n systems will range between $7,900 and $9,100. He 
estimates that installing the mitigation systems will range between $21,000 and $28,000. Finally, 
he estimates that operations, maintenance, and monitoring costs will be between $8,100 to $8,900 
for the first year and between $2,000 and $2,300 annually after that. Union Pacific presents three 
arguments for excluding these estimates. Firs t, Mr. Hatton did not follow his own detailed 
methodology for estimating mitigation costs. Second, Mr. Hatton’s estimates are based upon 
unsupported assumptions and data. Third, Mr. Hatton acknowledges that his estimates will not be 
consistent with the actual remediation costs. The Court will address each in turn. 
 
75 White Oak Glob. Advisors LLC v. Weder, 2020 WL 8677761, at *3 (W.D. Okla. Apr. 10, 2020) (“Where 
an expert witness offers testimony based upon incomplete information, his testimony is nevertheless admissible if the 
inadequacies are known to the defendant in order to thoroughly cross-examine the witness.” (internal quotations marks 
and citations omitted)). 
76 Doc. 197-2 at 124–25. 

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Union Pacific asserts that Mr. Hatton agrees that mitigation systems require detailed, 
property-specific methodology to diagnose, desi gn, and implement. To gene rate his estimates, 
however, Mr. Hatton did not conduct the detailed analysis required to arrive at a reliable estimate. 
Union Pacific argues that Mr. Hatton’s estimation is inherently unreliable for this reason. Plaintiff 
responds that Union Pacific misunderstands Mr . Hatton’s opinion. Mr. Hatton agrees that the 
detailed assessment must be done, however, it does not need to be done yet. According to Plaintiff, 
Mr. Hatton’s estimate bakes in the detailed design phase of the mitigation systems and that his 4–
5% margin of error accounts for differences in construction and design. A review of Mr. Hatton’s 
report indicates that his estima tes account for a “diagnose” and “design” phase accounting for 
between $7,900 and $9,100. As such, Union Pacific’s argument that Mr. Hatton did not follow his 
own methodology by accounting for a detailed diagnose and design phase is unpersuasive. 
Next, Union Pacific argues that Mr. Hatt on’s cost estimates ar e based upon unsupported 
assumptions and data that is not provided in his expert report. Union Pacific asserts that Mr. Hatton 
relied upon cost estimates s upplied by a colleague, and that Mr. Hatton did not retain his 
colleague’s source cost es timates. Plaintiff responds, and Union Pacific does not dispute, that it 
did not file a discovery motion for this material and elected not to depose Mr. Hatton’s colleague. 
Union Pacific’s argument here is a discovery concern disguised as a Daubert challenge. As such, 
the Court declines to entertain this argument. 
Finally, Union Pacific argues that Mr. Hatton admits that actual costs will not be consistent 
with his estimates. This argument repeats Union Pacific’s initial concern that Mr. Hatton did not 
account for individual characteri stics in PCA homes. As discu ssed above, however, Mr. Hatton 
provided that his estimates may vary by 4–5%. Any further concerns Union Pacific may have may 
be explored on cross-examination. 

-30- 
In sum, none of Union Pacifi c’s arguments for excluding Mr . Hatton are persuasive, and 
the Court declines to exclude Mr. Hatton’s testimony from its cons ideration of whether a class 
should be certified. 
5. Dr. Zabel 
Dr. Zabel is an urban and real estate economis t. Dr. Zabel was retained to estimate the 
property values of the PCA homes to rebut any claim that mitigation costs exceed the value of the 
PCA properties. During the hearing, the partie s agreed that Dr. Zabel’s proffered rebuttal 
testimony is not relevant to the issue of class certification. B ecause Union Pacific’s motion to 
exclude Dr. Zabel’s testimony is tied to the issue of class ce rtification, and the parties agree that 
Dr. Zabel is not relevant for th at purpose, the Court will not consider his opinion for class 
certification purposes. 
6. Motions to Exclude Summary 
 For the purposes of determini ng class certification the Cour t will consider Dr. Laton’s 
revised map; Dr. Kram’s opini on, except as to the area of the PCA; Dr. Anastasi’s opinion 
regarding Union Pacific’s negl igence in remediating the contamination; and Mr. Hatton’s 
opinions. The Court will not consider Dr. Zabel’s opinions for class certification. 
IT IS THEREFORE ORDERED that the Union Pacific’s Motion to Dismiss (Doc. 218) 
is DENIED. 
 

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IT IS FURTHER ORDERED that the Union Pacific’s Motion to Exclude Plaintiff’s 
Experts (Doc. 185) is GRANTED in part and DENIED in part. 
IT IS SO ORDERED. 
 Dated this 4th day of June 2026. 
 
 
 E R I C F . M E L G R E N 
 U N I T E D S T A T E S D I S T R I C T J U D G E 

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