In the 

United States Court of Appeals 

For the Seventh Circuit ____________________ 

Nos. 18-1918 & 18-2598 

WILLIAM LIEBHART & NANCY LIEBHART, 

Plaintiffs-Appellants, 

v.

SPX CORPORATION, TRC ENVIRONMENTAL CORPORATION, &

APOLLO DISMANTLING SERVICES, INC. 

Defendants-Appellees. 

____________________ 

Appeals from the United States District Court for the 

Western District of Wisconsin. 

No. 16-cv-700 — James D. Peterson, Chief Judge. 

____________________ 

ARGUED DECEMBER 4, 2018 — DECIDED MARCH 6, 2019 

____________________ 

Before BAUER, KANNE, and BRENNAN, Circuit Judges. 

KANNE, Circuit Judge. William and Nancy Liebhart together own three houses on the same block in Watertown, 

Wisconsin. Besides a few other houses, the rest of the block 

was previously occupied by an abandoned transformer factory, last owned by SPX Corporation. In 2014, SPX demolished the building with the assistance of TRC Environmental 

Corporation and Apollo Dismantling Services (collectively, 
2 Nos. 18-1918 & 18-2598 

“the defendants”). The Liebharts allege that dust and debris 

containing toxic chemicals migrated onto their properties, 

contaminating their yards and jeopardizing their health and 

the health of their tenants. 

The Liebharts sued under federal statutes authorizing private rights of action for environmental contamination. They 

also brought various state-law claims. Following discovery 

and the submission of expert witness reports, the district 

court denied the Liebharts’ motion for partial summary judgment and granted summary judgment to the defendants with 

costs. Although the district court adequately evaluated the expert witnesses and did not abuse its discretion in its procedural decisions, the court set the bar unnecessarily high for 

ȱěȱȱ ȱȱȱȱȱȱȱȬ

utes. For that reason, we vacate the district court’s judgment 

and remand for reconsideration. 

I. BACKGROUND

The factory dates to the 1920s and was used to manufacture various industrial equipment. Most relevant to our purpose, the factory manufactured power transformers containing polychlorinated biphenyls (PCBs), a carcinogenic chemical banned by the Environmental Protection Agency in 1979. 

See Polychlorinated Biphenyls (PCBs) Manufacturing, Processing, Distribution in Commerce, and Use Prohibitions, 44 

FǯȱǯȱřŗǰśŗŚȱǻ¢ȱřŗǰȱŗşŝşǼȱǻęȱȱŚŖȱǯǯǯȱpt. 761). 

The parties all agree that the facility has not manufactured or 

handled any items containing PCBs since 1971, and that it 

shut down completely in 2005. 

But even with all the products and manufacturing equipment removed, PCB contaminants remained in the facility. In 
Nos. 18-1918 & 18-2598 3

2009, SPX retained TRC and another company (not named as 

a defendant in this suit) to study the property and determine 

the extent and precise location of any PCB contamination. 

ȱȱ ȱ ȱ ȱȱĚȱȱ ȱ ¢ȱ

was generally contaminated, with concentrated amounts locatȱȱęȱȱȱȱǯ

Several years went by. In 2014, SPX decided to move ahead 

with the demolition, retaining Apollo to conduct the work 

and TRC to supervise the project. That November, the defendants timely proposed a self-implementing cleanup plan to the 

EPA, as required by 40 C.F.R. § 761.61(a). The trouble began 

as demolition commenced in January 2015. The Liebharts allege that Apollo demolished the building recklessly, failing to 

use appropriate safety methods to control the dust generated 

by demolition equipment. They assert that their properties 

 ȱȱȱǰȱȱ¢ȱĴȱȱof photos 

and videos of dust from the facility blowing toward their 

homes to support their allegation. 

ȱȱęȱȱȱ th the local government 

in February. They also collected a dust-covered sample of 

snow from their yard and placed it in a mason jar. Soon thereafter, a representative of the Wisconsin Department of Natural Resources (“DNR”) contacted the defendants about the 

Liebharts’ concerns. In April, TRC collected samples of the 

surface soil (roughly down to eight inches below ground) on 

both the industrial and residential properties. Sure enough, 

the properties tested positive for the presence of PCBs. In August, the Liebharts vacated the property on advice of their 

physician to avoid further exposure to the chemicals. Frustrated with the lack of action, William Liebhart had the snow 
4 Nos. 18-1918 & 18-2598 

sample tested for PCBs. Although the sample did, in fact, contain PCBs, the irregular manner of collection and storage 

spoiled the sample, and the laboratory declined to endorse the 

ȱ ȱ¢ȱęǯ

In September 2015ǰȱȱĴȱȱȱȱȱȱ

contamination to the DNR. In turn, the Liebharts sued in federal district court in October. The complaint sought injunctive 

relief under both the Resource Conservation and Recovery 

Act (RCRA), 42 U.S.C. § 6901 et seq., and the Toxic Substances 

Control Act (TSCA), 15 U.S.C. § 2601 et seq. In addition, the 

Liebharts brought a host of state-law claims under supplemental jurisdiction, including strict liability, negligence, tres-

ǰȱǰȱȱȱĚȱȱȱǯ

During discoveryǰȱȱȱĴȱȱȱȬ

ing for PCBs both in their yard and inside their home. They 

also underwent blood testing. Although the external surveys 

revealed a more comprehensive picture of the extent to which 

the soil on the Liebharts’ properties contained PCBs, the internal sampling and blood tests were both negative for contamination. The Liebharts later learned in October 2017 that 

the defendants allegedly buried some of the concrete remains 

on-site rather than removing them to a toxic waste dump as 

required by the EPA-approved clean-up plan. 

The parties prepared and Ĵȱȱȱȱȱ¡Ȭ

pert witnesses who were to testify at trial. Among those, three 

ȱȱȱȱǯȱǰȱȱȱĴȱ

a report by John Woodyard, a licensed professional engineer. 

His report included a description of standard methods used 

when demolishing PCB-contaminated buildings and an analysis of the purported ways in which the defendants deviated 

from those practices, thereby causing the contamination of the 
Nos. 18-1918 & 18-2598 5

residences. The Liebharts’ second expert was Dr. David Carpenter, a public health physician who opined on ways in 

which the Liebharts might have been exposed to PCBs and the 

ȱȱěȱȱȱ¡ǯȱ
ȱȱ

that “there is no ‘safe’ level of exposure to PCBs that does not 

increase the risk of disease.” Finally, the defendants submitted a report prepared by Dr. Russell Keenan, a toxicologist 

who analyzed the survey data and determined that it was impossible to determine whether the presence of PCBs on the 

Liebharts’ property was due to the recent demolition or to 

ěȱȱȱȱȱȱȱ. 

In December 2017, the Liebharts moved for partial summary judgment on the issue of causation, reserving the issue 

of damages for a jury trial. The defendants cross-moved for 

summary judgmentDzȱ ¢ȱ ȱęȱ ȱȱ ȱ¡ȱ ȱ

¢ȱȱě’ experts Woodyard and Carpenter under Fed. R. Evid. 702. In February 2018, after those motions 

were fully briefed to the court, the Liebharts sought leave to 

amend their complaint. In light of the information they obtained through discovery regarding the burial of concrete on 

the property, they intended to allege separate RCRA and 

TSCA violations and seek an enlargement of the proposed injunction to include removal of that material. 

The district court issued its decisions on March 30. First, 

the court granted in part the defendants’ motion to exclude 

the ě’ expert witness reports. The court explained that 

Woodyard’s report was “equivocal” as to the issue of causation; it hedged on whether the contaminants came from dem-

ȱ ȱ ȱ ěȱ ȱ ȱ ȱ ǯȱ See 

Liebhart v. SPX Corp., No. 16-cv-700-jdp, 2018 WL 1583296 at 
6 Nos. 18-1918 & 18-2598 

*3–4 (W.D. Wis. Mar. 30, 2018). Second, the report “overlook[ed] tȱȱęȱ” and failed to account 

for “obvious alternative explanations” in determining the 

cause of the contamination. Id. at *4 (quoting Fed. R. Evid. 702 

¢ȱĴ’s note to 2000 amendments). Finally, the 

court noted that Woodyard’s report depended on “unreliable 

or uninformative” evidence, including the Liebharts’ defec-

ȱ ȱǰȱ ȱĴȱȱȱȱȱȱ

clippings and a chromatogram that allegedly detected PCBs 

on the property. Id. at *4–5. For those reasons, the court excluded Woodyard’s report in its entirety. Id. at *5. 

ȱȱȱĴȱȱȱ¢ȱȱǯȱȬ

penter’s report, it struck Carpenter’s conclusion that “there is 

no ‘safe’ level of exposure to PCBs that does not increase the 

risk of disease” as unsupported by the medical studies he 

cited. Id. at *5. In doing so, the court pointed to the absence of 

PCBs inside the Liebharts’ home and in their blood, suggesting that the Liebharts had not actually been exposed to PCBs 

ȱȱȱȱȱěȱǯȱId. at 5–6. 

ȱȱ¡ȱ¢ȱěȱȱǰȱȱȱȱ

concluded that the Liebharts failed to present any admissible 

evidence to support their RCRA and TSCA claims. The remaining photos and videos certainly showed dust migrating 

onto the Liebharts’ property, but there was no reliable evidence proving that the dust contained PCBs. Given that any 

PCBs detected in the soil may have been there prior to the 

demolition, the lack of evidence doomed the Liebharts’ case. 

ȱȱȱȱ¢ȱȱȱȱě, 

granted summary judgment to the defendants on the federal 

claims, and dismissed the state-law claims without prejudice. 
Nos. 18-1918 & 18-2598 7

The district court also denied the Liebharts’ petition for 

leave to amend their complaint on two grounds. First, alt-

ȱȱȱ ȱȱȱěȱȱ

the factual basis for the new counts over a year ȱęȱȱ

initial complaint, it also noted that they took an additional 

four months thereafter to seek leave to amend. During that 

ȱ ǰȱ ȱ ȱ ȱ Ĵȱ ȱ ȱ

their motions for summary judgment, and the trial date was 

fast approaching. It found their petition untimely. Second, the 

district court determined that the new claims were futile under both statutes' advance-notice requirements. 

The ěȱ¢ȱ. Several months after 

the judgment, the clerk of the district court imposed costs on 

the Liebharts in the amount of $46,320.02. The Liebharts separately appealed that decision. We consolidated the two appeals and now consider them together. 

II. ANALYSIS

The ȱȱęȱȱȱȱǯȱǰȱ

they argue that the district court erred in excluding the opinions of expert witnesses Woodyard in full and Carpenter in 

part. As part of that argument, they allege that the district 

court failed to apply the same stringent standard to the defendants’ expert Keenan. Second, they contend that summary 

judgment was inappropriate because, even absent the testi-

¢ȱȱȱ¡ȱ ǰȱ¢ȱĴȱȱȬ

ȱȱęȱȱȱȱȱȱȱȱ

RCRA and TSCA. Third, they challenge the district court’s de-

ȱȱȱȱȱȱȱęȱ¢ have iden-

ęȱȱ’s state-approved clean-up plan. Fourth, they argue that the district court abused its discretion in denying 
8 Nos. 18-1918 & 18-2598 

leave to amend their complaint. Finally, they challenge the 

imposition of costs. 

But there’s a larger issue looming in the background. The 

district court’s opinion operates under the assumption that 

ȱ ěs must demonstrate “an imminent and substantial danger with evidence of health problems they have 

¢ȱ ěǯ” Liebhart, 2018 WL 1583296 at *6. Relying 

primarily on Foster v. United States, 922 F. Supp. 642 (D.D.C. 

ŗşşŜǼǰȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ȱ ěǰȱ

holding that “it doesn’t follow necessarily that there is an imminent and substantial risk of harm simply because there is 

some amount of PCBs on the property.” Liebhart 2018 WL 

1583296 at *5. We review that question of law, which was the 

underlying basis for the award of summary judgment, de 

novo. Daugherty v. Harrington, 906 F.3d 606, 609 (7th Cir. 2018). 

A. RCRA Requires Only that Harm “May” Be Imminent 

ȱȱȱ ȱȱȱȱěȱȱȱȱ

make out a prima facie violation of RCRA has led to much discussion among the circuits. We have yet to tackle that issue 

head on, so the district court necessarily had to look elsewhere for guidance. Passed in 1976, “RCRA is a comprehensive environmental statute that empowers [the] EPA to regulate hazardous wastes from cradle to grave.” City of Chicago v. 

Envtl. Def. Fund, 511 U.S. 328, 331 (1994). The statute’s “primary purpose ... is to reduce the generation of hazardous 

waste and to ensure the proper treatment, storage, and disposal of that waste which is nonetheless generated, ‘so as to 

minimize the present and future threat to human health and 

the environment.’” Meghrig v. KFC Western, Inc., 516 U.S. 479, 

483 (1996) (quoting 42 U.S.C. § 6902(b)). 
Nos. 18-1918 & 18-2598 9

Although the EPA has the primary responsibility for enforcing the law, the statute, “like other environmental laws, 

... contains a citizen suit provision, § 6972, which permits private citizens to enforce its provisions in some circumstances.” 

Id. at 484. As relevant to this case, the statute provides that 

any person may commence a civil action on his own 

behalf ... against any person, ... including ... any 

past or present owner or operator of a treatment, 

storage, or disposal facility, who has contributed or 

who is contributing to the past or present handling, 

storage, treatment, transportation, or disposal of any 

solid or hazardous waste which may present an imminent and substantial endangerment to health or 

the environment. 

42 U.S.C. § 6972(a)(1)(B) (emphasis added). Notably, Congress amended the language in 1980 by substituting the 

phrase “may present” for the original 1976 wording “is presenting.” Maine People’s All. and Nat. Res. Def. Council v. 

Mallinckrodt, Inc., 471 F.3d 277, 287 (1st Cir. 2006) (citing Solid 

Waste Disposal Act of 1980, Pub. L. 96–482, § 25, 94 Stat. 2334, 

2348). The section authorizes district courts to grant injunctive 

relief and “order [a violator] to take such other action as may 

be necessary” to remediate the endangerment. Id.; see also Meghrig, 516 U.S. at 484 (“Under a plain reading of this remedial 

scheme, a private citizen suing under § 6972(a)(1)(B) could 

seek a mandatory injunction, i.e., one that orders a responsible 

party to ‘take action’ ¢ȱĴȱȱȱȱȱȱ

disposal of toxic waste, or a prohibitory injunction, i.e., one 

that ‘restrains’ a responsible party from further violating 

RCRA.”); Avondale Fed. Sav. Bank v. Amoco Oil Co., 170 F.3d 

692, 694 (7th Cir. 1999). 
10 Nos. 18-1918 & 18-2598 

The critical question in this case is how to determine 

whether alleged contamination “may present an imminent 

and substantial endangerment to health.” § 6972(a)(1)(b). We 

touched on this question only brĚ¢ȱȱAlbany Bank & Trust 

Co. v. Exxon Mobil Corp., 310 F.3d 969, 973 (7th Cir. 2002). 

ǰȱ ȱęȱ ȱ ȱȱ ȱ ȱprima facie RCRA 

claim: “a ěȱȱȱǻŗǼȱȱȱȱȱȬ

erated solid or hazardous waste, (2) that the defendant is contributing to or has contributed to the handling of this waste, 

and (3) that this waste may present an imminent and substantial danger to health or the environment.” Id. (citing Cox v. 

City of Dallas, 256 F.3d 281, 282 (5th Cir. 2001)). We then ob-

ǰȱȱȱęȱǰȱȱ“[i]mminence does 

not require an existing harm, only an ongoing threat of future 

harm.” Id. (citing Cox, 256 F.3d at 299). That is the extent of 

our circuit precedent on the “may present” language contained in § 6972(a)(1)(B). 

But our sister circuits have engaged with this question in 

ȱǯȱȱȱęȱȱȱȱȱǰ

the Third Circuit emphasized that the statute “enhanced the 

courts’ traditional equitable powers by authorizing the issuance of injunctions when there is but a risk of harm, a more 

lenient standard than the traditional requirement of threatened irreparable harm.” United States v. Price, 688 F.2d 204, 

211 (3d Cir. 1982). The court found the statutory language 

“unequivocal,” demonstrating that Congress “intended to 

ȱȱȱȱȱ¢ȱȱȱĜȱȬ

uitable relief to the extent necessary to eliminate” the risks 

posed by toxic waste. Id. at 213–14. 

In the subsequent decades, several other circuits adopted 

and further developed the same interpretation of § 6972. See 
Nos. 18-1918 & 18-2598 11

Mallinckrodt, 471 F.3d at 277; Dague v. City of Burlington, 935 

F.2d 1343, 1355–56 (2d Cir. 1991), rev’d in part on other grounds, 

502 U.S. 1071 (1992); Interfaith Cmty. Org. v. Honeywell Int’l, 

Inc., 399 F.3d 248 (3d Cir. 2005); United States v. Waste Indus., 

Inc., 734 F.2d 159, 165 (4th Cir. 1984) (rejecting the argument 

that “[§ 6972] was designed to control pollution only in emergency situations”); Cox, 256 F.3d at 299–301; Price v. United 

States Navy, 39 F.3d 1011, 1019 (9th Cir. 1994); Burlington N. 

and Santa Fe Ry. Co. v. Grant, 505 F.3d 1013, 1019–22 (10th Cir. 

2007); Parker v. Scrap Metal Processors, Inc., 386 F.3d 993, 1014–

15 (11th Cir. 2004). We now join those courts and explicitly 

embrace the core content of their interpretation. 

The district court therefore used an incorrect legal standard to evaluate the Liebharts’ argument that PCBs from the 

demolition may present an imminent and substantial danger 

to their health and that of their tenants. It did not cite any of 

the cases we listed above, but instead relied on a single district 

court decision from a circuit that has not yet addressed the 

issue. See Liebhart, 2018 WL 1583296 at *5 (quoting Foster, 922 

F. Supp. at 662 (“While there can be no question that the levels 

of contamination present at the Site may warrant future re-

ȱ ǰȱ ȱěȱ ȱ ȱ ȱ ȱ ȱ

risk of substantial or serious threatened harm, or some necessity for action.”)). 

That error undercuts several of the reasons the district 

court gave for rejecting the Liebharts’ RCRA claim. For example, the district court cursorily adopted a passing statement 

we made over twenty-ę years ago that “[t]he [EPA’s] accepted safe level of PCBs in the ȱȱę¢ȱȱȱ

million,” id. (quoting Cincinnati Ins. Co. v. Flanders Elec. Motor 
12 Nos. 18-1918 & 18-2598 

Serv., Inc., 40 F.3d 146, 148 (7th Cir. 1994)), to create a requirement that the Liebharts show that PCB contamination on their 

property met that threshold. But there is no requirement in 

ȱȱȱěȱȱȱ“a particular quantitative showing as a sine qua non for liability.” Interfaith, 399 F.3d at 260; see 

also Dague, 935 F.2d at 1356. Only one circuit has come to an 

arguably contrary conclusion. In Price v. United States Navy, 

818 F. Supp. 1323, 1325 (S.D. Cal. 1992), ě’d 39 F.3d 1011 (9th 

ǯȱŗşşŚǼǰȱȱȱȱȱȱěȱȱ ȱ

that “the level of contaminants [was] above levels that are considered acceptable by the State.” But as the Interfaith court 

noted, the Ninth Circuit’ȱ ȱ Ĝȱ ȱ ȱ

court’s judgment did not discuss that requirement. RCRA 

ȱ ȱ ȱ ȱ ěs demonstrate contamination 

above some agency-derived threshold level of concentration. 

399 F.3d at 260–61. It merely requires that they show that contaminants on the property are seriously dangerous to human 

health (or will be, given prolonged exposure over time). See 

Cox, 256 F.3d at 299–300 (“an endangerment is ‘substantial’ if 

it is ‘serious’” (quoting United States Navy, 39 F.3d at 1019)). 

That’s especially true when the standard is taken out of 

context. The district court relied on Cincinnati Ins. Co. to support its contention that contamination below the threshold 

ȱȱę¢ȱȱȱȱ(“ppm”) does not qualify as a 

regulatory violation, thereby contradicting Woodyard’s opinion regarding safe levels of PCBs and providing the grounds 

for excluding it. In that case, we evaluated whether an insurance company was required to indemnify its insured for damages arising out of PCB contamination at an industrial site. 

ȱȱȱęȱȱȱȱ¢ȱȱȱ

the Comprehensive Environmental Response, Compensation, 

and Liability Act of 1980 (CERCLA), 42 U.S.C. § 9601 et seq. In 
Nos. 18-1918 & 18-2598 13

that context, we noted that the contaminated site contained 

PCBs concentrated at levels up to 58,000 ppm, well above the 

EPA’ȱȱ¢ȱȱȱę¢ȱǯȱŚŖȱF.3d at 148 

(citing 40 C.F.R. § 761.60). 

ȱ ȱ ǰȱȱȱěȱ ¢ǰȱęȱȬ

trial equipment and other wastes contaminated at levels 

above ę¢ȱppm and requires special procedures for their storage and disposal. It does not unequivocally state that PCBs 

ȱȱȱ ȱȱę¢ȱȱȱȱȱȱ

exposure. Neither Cincinnati Ins. Co. nor the EPA regulation 

stand for the proposition that PCBs concentrated at forty-nine 

ppm on residential property do not present a substantial endangerment to the health of the residents. That is especially apparent when we consider that the same set of regulations distinguishes between low and high-occupancy areas and requires that, in high-occupancy areas, bulk PCB remediation 

waste, such as soil, be cleaned up to levels of concentration at 

or below one ppm. § 761.61(a)(4)(i)(A). Section ŝŜŗǯřȱęȱ

that the term “high-occupancy area” includes residences. See 

also § ŝŜŗǯŗŘřȱǻȱȱȱȱȱȱę¢ȱ

ppm or greater but emphasizing that “[t]he concentration of 

PCBs spilled is determined by the PCB concentration in the 

material spilled as opposed to the concentration of PCBs in 

the material onto which the PCBs were spilled”). “Proof of 

contamination in excess of [agency] standards may support a 

ęȱȱ¢ǰȱȱ¢ȱȱĜȱȱ¢ȱȱȱ

ǰȱȱȱȱȱȱ ȱęȱȱȱȬ

ute.” Interfaith, 399 F.3d at 261. 

This is not to say that ȱȱěȱȱȱȱȱshow 

some bit of soil on their property that tests positive for PCBs 
14 Nos. 18-1918 & 18-2598 

above one ppm (or even above the purported lower Wisconsin DNR standard, which the defendants seem to have 

acknowledged in their state-approved clean-up plan). Of 

course, there must be accompanying evidence that establishes 

some connection between the existing contaminants and 

some imminent and substantial endangerment to health.1 But 

ȱ ȱ Ĵȱ ȱ ȱ ȱ ǰȱ ȱ ȱ

district court held the bar higher than necessary under 

RCRA’s standard. In criticizing expert witness Carpenter’s 

statement that “there is no ‘safe’ level of exposure to PCBs that 

does not increase the risk of disease,” the district court rejected Carpenter’s citation to studies showing the general 

risks of PCB exposure because “the Liebharts do not cite any 

evidence that they have been exposed to PCBs.” Liebhart, 2018 

WL 1583296 at *5. Moreover, the district court concluded that 

“[t]he Liebharts do not contend that they can prove an imminent and substantial danger with evidence of health problems 

¢ȱȱ¢ȱěǯ” Id. at *6. 

As we noted in Albany Bank, “[i]mminence does not require an existing harm, only an ongoing threat of future 

 

1 On appeal, the Liebharts contend that there is no separate requirement for expert witness testimony because the photos and videos they 

have submitted into evidence suffice to prove their RCRA claim. The defendants push back on that argument, insisting that many of the issues are 

beyond the competence of lay fact-finders and require the assistance of 

experts to address. See, e.g., C.W. ex rel. Wood v. Textron, Inc., 807 F.3d 827, 

838 (7th Cir. 2015) (“Given the complex nature of this case, ... [and w]ith 

no experts to prove causation ... the appellants cannot prove their toxictort case under [state] law.”) Because the district court did not make a factual finding as to whether this case is sufficient complex to require expert 

testimony, and because we remand for reconsideration of a separate legal 

issue, we need not reach that question today. 
Nos. 18-1918 & 18-2598 15

harm.” 310 F.3d at 973. Although the Supreme Court has instructed that “[a]n endangerment can only be ‘imminent’ if it 

‘threaten[s] to occur immediately,’” Meghrig, 516 U.S. at 485 

(quoting Webster’s New Int’l Dictionary of English Language

ŗŘŚśȱǻŘȱǯȱŗşřŚǼǼǰȱȱęȱȱȱ ȱȱȬ

ingly quoted the Ninth Circuit’s interpretation that the statutory term “implies that there must be a threat which is present 

now, although the impact of the threat may not be felt until 

later.” Id. at 486 (quoting United States Navy, 39 F.3d at 1019). 

We take that to mean that the Liebharts must show that there 

are PCBs currently on the property that have the potential to 

substantially threaten their health at some point in the future 

if they continue to occupy the premises and prolong their exposure. On remand, the district court should reevaluate its exclusion of Dr. Carpenter’s assertion regarding PCB safety under the standards we have outlined above and determine 

whether, if admissible, the report demonstrates that a substantial and imminent threat to the Liebharts’ health may be 

present. 

B. TSCA Likewise Requires No Heightened Showing

TSCA authorizes a separate, private cause of action allowing “any person [to] commence a civil action ... against any 

person ... who is alleged to be in violation of ... any rule 

promulgated under” the Act. 15 U.S.C. § 2619(a)(1). The EPA 

promulgated the PCB regulations in question pursuant to 

statutory authority under TSCA, designating PCBs as “hazardous waste” and controlling their manufacture, use, storage, and disposal. See 40 C.F.R. pt. 761. The Liebharts’ TSCA 

claim alleged that the defendants violated those regulations, 

thereby authorizing the district court to “restrain [the] violation.” § 2619(a). Unlike RCRA, which authorizes mandatory 
16 Nos. 18-1918 & 18-2598 

injunctions to compel remediation of previous violations, 

TSCA authorizes only prohibitory injunctions to stop ongoing 

violations. Id. The defendants argued that there was no longer 

an ongoing violation, as demolition was complete by the time 

ȱȱęȱȱǯ2 

 The purported violation was based on 40 C.F.R. § 761.123, 

which, as we noted above, regulates “spills” of PCB materials 

ȱȱȱȱę¢ȱǯȱ district court correctly noted that the Liebharts had not shown any evidence 

that any PCBs had been “spilled” onto their property (by 

means of dust migration) at that level of concentration, and it 

granted summary judgment to the defendants on that basis. 

But the district court seems to have overlooked the following sentence in the regulation, which directs that “[t]he concentration of PCBs spilled is determined by the PCB concentration in the material spilled as opposed to the concentration 

of the material onto which the PCBs were spilled.” Id. The 

Liebharts’ complaint seems to have alleged that the concrete 

Ěȱȱ ȱ ¢ǰȱ ȱȱ ȱȱȱȬ

ȱ ȱ ȱ ȱę¢-ppm threshold, was demolished 

and “spilled” onto the Liebharts’ property. By the plain text 

of the regulation, there is no need to show that contaminants 

on the Liebharts’ property are themselves concentrated above 

ę¢ȱȱȱȱȱȱȱȱȱ ȱȱȱ

of that spill met the criteria. On remand, the district court may 

again determine that there is no ongoing violation, but it must 

 

2 The district court determined that the Liebharts waived this claim 

by failing to engage the defendants’ argument that there was no “ongoing 

violation.” But the court chose to analyze the merits of the claim regardless 

of waiver and reached its conclusion on an alternative basis. We likewise 

set aside the issue of waiver to reach the district court’s merits analysis. 
Nos. 18-1918 & 18-2598 17

ęȱ ȱ  ȱ ȱ ȱ ȱ ȱ  ȱ

the meaning of § 761.123 ȱȱęȱ. 

C. The District Court Should Reconsider the Remaining Issues 

on Remand

 ȱ ȱ  ȱ ȱ ęȱ ȱ standard ȱ ěȱ

must meet, we turn to the remaining procedural issues the 

Liebharts have asked to us to address. 

1. The District Court did not Abuse Its Discretion in Excluding 

Woodyard’s Testimony 

“The summary-judgment decision here turned [in large 

part] on the district court’s conclusion that [the] expert testimony was inadmissible. Whether the district court applied 

the appropriate legal framework for evaluating expert testimony is reviewed de novo, but the court’s choice of relevant 

factors within that framework and its ultimate conclusion as 

to admissibility are reviewed for abuse of discretion.” Lees v. 

Carthage College, 714 F.3d 516, 520 (7th Cir. 2013). When a district court is “[Ǿȱ ȱȱěȱȱ¡ȱęȱȬ

mony ... the trial judge must determine at the outset ... 

 ȱ ȱ ¡ȱ ȱ ȱ ȱ ¢ȱ ȱ ǻŗǼȱ ęȱ

knowledge that (2) will assist the trier of fact to understand or 

determine a fact in issue.” Daubert v. Merrell Dow Pharm., Inc., 

509 U.S. 579, 592 (1993). “The trial court must have ... latitude 

in deciding how to test an expert’s reliability.” Kumho Tire Co., 

Ltd. v. Carmichael, 526 U.S. 137, 152 (1999). 

The district court was well within its discretion to exclude 

the ěȱ¢ȱȱ¡ȱ ȱ¢ǯȱ¢ȱ

ȱȱȱȱěȱȱȱȱ ȱȱȬ

sue in the district court by failing to engage with the defendants’ arguments in their motion to strike the testimony, 
18 Nos. 18-1918 & 18-2598 

Woodyard’s analysis sěȱ ȱ ȱ ȱ Ě ȱ ȱ ȱ

from the way in which the parties have framed this lawsuit. 

ȱȱȱĚ¢ȱȱȱȱȱȱ“both sides 

assume that none of the defendants can be held liable for any 

PCB contamination on the Liebharts’ property that occurred 

before the demolition began, so the court will make the same 

assumption.” Liebhart, 2018 WL 1583296 at *1. That’s a curious 

choice. RCRA permits the Liebharts to obtain injunctive relief 

from the owner of the facility for any cognizable contamination, regardless of whether the PCBs migrated onto their 

property before or after the demolition occurred. See 42 U.S.C. 

§ 6972(a)(1)(B) (authorizing suit against “any person ... who 

has contributed ... to the past or present handling ... or disposal” of hazardous waste); see also Meghrig, 516 U.S. at 486 

(“RCRA contains no statute of limitations.”). 

But because the Liebharts restricted their claims to PCBs 

that allegedly migrated onto their property via the dust from 

the 2015 demolition, they necessarily excluded claims resulting from PCBs that may ȱĴȱȱȱ¢ȱȬ

ing the previous century. The district court correctly noted 

that Woodyard’s expert opinion could not distinguish between these two alternatives, as both sets of contaminants 

originated from the same source. There was even evidence 

showing that PCBs existed in the soil beneath the Liebharts’ 

asphalt driveway—Woodyard could not explain how that 

might have occurred as the result of dust blowing in the wind 

as opposed to seepage over the course of years before any 

demolition occurred. 

Perhaps the Liebharts decided to frame their claims in this 

way because they wanted to go after defendants TRC and 

Apollo, who would not be liable for what happened before 
Nos. 18-1918 & 18-2598 19

demolition. Or perhaps some element of their state-law 

claims, which we have not addressed, required them to constrict the scope. They did not explain their reasoning to us (or 

it seems, to the district court). But the distinction makes it difęȱ ȱ¢ȱ ȱȱȱǰȱȱ ȱȱȱȱ

“adequately account[] for obvious alternative explanations.” 

	ȱǯȱ
 Ĵ-Packard Co., 877 F.3d 771, 787 (7th Cir. 

2017). Viewed in this light, the district court was within its 

discretion to exclude the testimony as unreliable and unhelpful to the trier of fact. The district court may choose to rethink 

that evaluation on remand under the legal standards we outlined above, but it may well reach the same conclusion. 

2. The District Court Should Reconsider Its Denial of Injunctive 

Relief 

The district court denied injunctive relief to the Liebharts 

because the defendants had already agreed to a clean-up plan 

that had been approved by the Wisconsin DNR. We review 

that decision for an abuse of discretion. See AMI Int’l, Inc. v. 

Datacard Corp. 106 F.3d 1342, 1352 (7th Cir. 1997) (remanding 

grant of RCRA injunction). 

As we mentioned above, RCRA authorizes district courts 

to issue either mandatory or prohibitory injunctions, while 

TSCA authorizes only prohibitory injunctions. “[I]t is appropriate ‘to give great deference to the district court’s decision 

as to the precise equitable relief necessary in a particular 

case.’” Bowes v. Ind. Sec. of State, 837 F.3d 813, 817 (7th Cir. 

2016) (quoting Gjersten v. Bd. Of Election Com’rs for City of Chicago, 791 F.2d 472, 479 (7th Cir. 1986)). That is especially true 

 ȱȱěȱȱȱ¢ȱǰȱ ȱ“im-

ȱęȱȱȱȱȱȱȱȬ

ful consideration of the intrusiveness of the ordered act, as 
20 Nos. 18-1918 & 18-2598 

 ȱȱȱĜȱȱ¢ȱȱȱin supervising 

the enjoined party’s compliance with the court’s order.” Kartman v. State Farm Mut. Auto. Ins. Co., 634 F.3d 883, 892 (7th Cir. 

2011). 

Considering SPX’s decision to formulate a clean-up plan 

and obtain approval from the state agency, the district court 

determined that there was no need for separate, federally-supervised remediation. It reached that conclusion even while 

assuming that the defendants were in violation of either 

RCRA or TSCA, despite the fact it found no such violation. 

Other courts have determined that the existence of a parallel 

plan of remediation supervised by the state does not necessarily prevent a federal district court from granting an injunc-

ȱȱȱęȱ ȱȱ¢’ȱȱ ȱȱĜȱ ȱ

remedy the violation of federal law. See, e.g., Interfaith, 399 

F.3d at 264–68. On the other hand, the same courts have also 

upheld denials of injunctions in similar situations when the 

ȱ ȱ ęȱ ȱ ȱ ȱ ȱȱ ȱ ȱ ȱ

task. See Trinity Indus., Inc. v. Chicago Bridge & Iron Co., 735 

F.3d 131, 139–40 (3d Cir. 2013) (distinguishing Interfaith). We 

recently reached the same conclusion. See LAJIM, LLC v. Gen. 

Elec. Co., No. 18-1522, 2019 WL 1011021, at *4–11 (7th Cir. Mar. 

4, 2019) (“[T]he district court correctly held that it has discretion to award injunctive relief under the RCRA and is not re-

ȱȱȱȱȱȱęȱȱ¢ǰ” particularly 

in light of ongoing relief supervised by a state environmental 

agency). 

Here, the district court determined that SPX’s existing 

ȱ  ȱ Ĝ and that the Liebharts had not “identif[ied] any way that SPX’ȱȱǽ ǾȱęȱȱǽǾȱ
Nos. 18-1918 & 18-2598 21

federal law.” Liebhart, 2018 WL 1583296 at *7. We agree. Although the Liebharts point to certain statistical sampling requirements outlined in 40 C.F.R. § 761.125 and contend that 

SPX’s existing plan fails to meet those requirements, the district court noted that SPX’s plan includes further sampling of 

the soil on the Liebharts’ property. It emphasized that “the 

Liebharts do not otherwise explain why SPX’s proposed sampling scheme is substantively inadequate.” Liebhart, 2018 WL 

1583296 at *7. We see no evidence that compels us to contra-

ȱȱȱęǯ

However, in light of the legal standards we outlined 

above, we ask the district court to reconsider its decision to 

deny injunctive relief on remand. Because the bar for establishing an imminent and substantial danger is lower than the 

district court believed when evaluating the request for an injunction, it would be prudent to reassess whether the DNRapproved plan adequately remedies harms that may come 

within RCRA’s scope. See LAJIM, 2019 WL 1011021 at *6 

(“[Ǿȱȱȱęȱȱȱȱȱȱȱȱȱ

imminent and substantial danger, it will usually be the case 

that injunctive relief is warranted. But that is not always the 

case.”) ǻȱȱȱȱĴǼǯ

3. The District Court did not Abuse Its Discretion in Denying 

Leave to Amend the Complaint. 

We review a denial of leave to amend a complaint for 

abuse of discretion. Life Plans, Inc. v. Sec. Life of Denver Ins. Co., 

800 F.3d 343, 357 (7th Cir. 2015). District courts are to “freely 

give leave [to amend] when justice so requires.” Fed. R. Civ. 

P. 15(a)(2). “The Supreme Court has interpreted this rule to 

require a district court to allow amendment unless there is a 

good reason—futility, undue delay, undue prejudice, or bad 
22 Nos. 18-1918 & 18-2598 

faith—for denying leave to amend.” Life Plans, 800 F.3d at 357 

(citing Foman v. Davis, 371 U.S. 178, 182 (1962)). The district 

ȱȱȱȱęȱ ȱȱȱȱȱȱȱ

denial: futility and undue delay. While we disagree with the 

¢ȱ¢ǰȱ ȱȱ ȱȱęȱȱȱ¢ȱ

and decline to reverse. 

We begin with the question of futility. Both statutes contain advance-ȱȱȱ£ȱěȱȱ

ȱ ȱ ȱ ęȱ ȱ ȱ ȱ ǯȱ ¢ȱ ȱ

ȱěȱȱ¢ȱȱȱ60–90 ¢ȱȱȱȱęȬ

ing the complaint. 42 U.S.C. § 6972(b)(2); 15 U.S.C. 

§ 2619(b)(1)(A). But the district court chose to apply the re-

ȱȱ¢ȱȱȱęȱȱȱǰȱȱȱȱ

any subsequent amendments that sought to add new RCRA 

or TSCA counts. Although the Liebharts complied with the 

ȱȱȱęȱȱȱȱȱȱ

2016, they gave no new notice to the EPA before ęȱ ȱ

leave to amend in February 2018. The district court held that, 

because the prior notice did not contain any mention of bur-

ȱȱȱȱȱ¢ǰȱȱ ȱĜȱȱȱȱ

EPA to the particular violation the Liebharts sought to include 

in the amended complaint. 

The notice provisions serve two purposes. “First, notice allows Government agencies to take responsibility for enforcing environmental regulations, thus obviating the need for 

citizen suits. ... Second, notice gives the alleged violator ‘an 

opportunity to bring itself into complete compliance with the 

Act[s] and thus likewise render unnecessary a citizen suit.’” 

Hallstrom v. Tillamook Cty., 493 U.S. 20, 29 (1989) (quoting 

	 ¢ȱȱęǰȱ ǯȱǯȱȱ¢ȱǯǰȱ ǯ, 484 
Nos. 18-1918 & 18-2598 23

U.S. 49, 60 (1987)). The district court’s decision to require no-

ȱ ȱ ȱ ȱ ȱ ȱ ȱ ęȱ ȱpurposeǯȱ¢ȱȱȱȱȱĴȱȱȱȱȬ

plaint, the EPA had been on notice of alleged PCB contamination at the SPX property for over two years—and it had declined to get involved. Moreover, it was unlikely that the defendants would resolve the alleged violation to avoid being 

sued when they were already in the midst of an extended law-

ȱ ȱ ȱ ȱ ěǯȱSee AM Int’l, 106 F.3d at 1351 

(“[T]he delay period is designed to allow a [defendant] a period in which to clean up its act and avoid litigation. [This defendant] was clearly not interested in using the delay period 

to resolve the dispute without going to court.”); see also Dague, 

935 F.2d at 1351 (“There is no need to maintain a window of 

opportunity for the government to take the lead enforcement 

role ...  ȱȱ£ǰȱȱȱȱȱĴ¢ȱǰȱȱ

already lawfully assumed the lead role in bringing a ... claim 

against the same facility.”) (quoting Dague v. City of Burlington, 733 F. Supp. 23, 26 (D. Vt. 1990)). When the original notice 

is “Ĝ¢ȱęȱȱȱȱȱȱǽȱȱ

agency] about what it is doing wrong, so that it will know 

what corrective actions will avert a lawsuit,” Atl. States Legal 

Found., Inc. v. Stroh Die Casting Co., 116 F.3d 814, 819 (7th Cir. 

1994), there is no need to require a second round of advance 

notice for an amended complaint in the same litigation. 

But an error in the futility analysis alone does not necessarily constitute an abuse of discretion on the whole. In addition to futility, the district court cited undue delay and prejudice in its decision to deny leave to amend. “[D]elay by itself 

ȱ¢ȱȱĜȱȱȱ¢ȱȱȱȱȱ

to amend. Delay must be coupled with some other reason. 

Typically, that reason ... is prejudice to the non-moving 
24 Nos. 18-1918 & 18-2598 

party.” Dubicz v. Commonwealth Edison Co., 377 F.3d 787, 793 

(7th Cir. 2004). The district court cited the Liebharts’ admission that they learned of the possible burial of contaminated 

concrete on the SPX property on October 11, 2017 but failed 

to seek leave to amend their complaint until February 22, 

2018. During that more than four-month period, the parties 

Ĵȱȱȱȱ-motions for summary judgment, and by February, trial was only three months away. The 

ȱȱȱęȱȱȱ¢ǯ

In response, the Liebharts contend that there was no un-

ȱȱȱȱDZȱ¢ȱȱȱ¢ȱęȱȱ

ǰȱęȱ  of discovery still remained. We disagree. 

While the district court’s explanation of prejudice was fairly 

short, even if the district court had failed ȱȱȱęȬ

ing of prejudice altogether, we might still “Ĝȱȱ

that ‘the prejudice that would result from such amendment 

was apparent.’” Park v. City of Chicago, 297 F.3d 606, 613 (7th 

Cir. 2002) (quoting Feldman v. Am. Mem’l Life Ins. Co., 196 F.3d 

783, 793 (7th Cir. 1999)). In Parkǰȱ ȱ ěȱ  ȱ ¡ȱ

months to move for leave to amend a complaint after she 

knew (or should have known) of the additional alleged violation. Id. Because trial was approaching, we concluded that the 

district court was well within its discretion to deny leave. Id.; 

see also Perrian v. O’Grady, 958 F.2d 192, 194–95 (7th Cir. 1992) 

(“Because substantive amendments shortly before trial serve 

to defeat the public’s interest in speedy resolution of legal disputes, ‘[a] district court judge is entitled, in such circum-

ǰȱȱȱȱ ȱȱě’s amendment.’” (quoting 

Campbell v. Ingersoll Mill. Mach. Co., 893 F.2d 925, 927 (7th Cir. 

1990)) ǻȱȱĴǼ). 
Nos. 18-1918 & 18-2598 25

On the contrary, in Life Plans, we found no undue delay 

 ȱȱěȱ¢ȱȱȱȱȱȱȱ

ten days after learning of the factual basis for its new count 

during discovery. 800 F.3d at 358. The Liebharts delayed more 

than four months in the same circumstances. Although discovery was ongoing at the time of the Liebharts’ motion, the 

parties had already briefed their dispositive motions, and the 

district court was preparing its summary-judgment order that 

would ultimately dispose of the case. We therefore cannot say 

that denial of leave for undue delay and prejudice was an 

abuse of the district court’s discretion. Of course, the district 

court may permit an amendment on remand if the interests of 

justice so require. 

III. CONCLUSION

Although the district court properly exercised its discretion on the various evidentiary and procedural issues the 

ěȱȱaised, its analysis on the merits was narrower 

than the statutes demand. It may reach the same conclusions 

on reconsideration, but the parties should have another opportunity to litigate whether a substantial and imminent endangerment to health exists in this case under the standards 

we have outlined. We therefore VACATE the order of the district court and REMAND for further proceedings consistent 

with this opinion.3

 

3 The Liebharts also challenge the taxation of costs against them by the 

clerk of the district court. Because we vacate the district court’s judgment, 

we assume that the imposition of costs is automatically vacated and so do 

not reach that issue. The clerk of the district court is free to reassess costs 

on remand as the case proceeds.