## F I L E D United States Court of Appeals Tenth Circuit 

### MAY 26 2000 

### PATRICK FISHER Clerk PUBLISH UNITED STATES COURT OF APPEALS

TENTH CIRCUIT

TOSCO CORPORATION, a Nevada corporation, Plaintiff-Appellee,

v. KOCH INDUSTRIES, INC., as successor to Rock Island Oil & Refining Co., Inc., a Kansas corporati on, Defendant-Appellant, SUN COMPANY, INC., (R&M), a Pennsylvania, corporation; ALPHA OIL COMPANY, an Oklahoma corporation; RESOURCE RECOVERY COMPANY; ENERGY REALTY INTERNATIONAL, Defendants. No. 98-6209

Before BRORBY, McWILLIAMS and HENRY , Circuit Judges.

ORDER ON REHEARING Koch Industries, Inc. (“Koch”) has filed a petition for panel rehearing to clarify factual statements in Tosco Corp. v. Koch Indus., Inc. , ___ F.3d ___, 2000 WL 525915 (10th Cir., May 2, 2000), concerning the district court’s allocation of fifteen percent of past and future response costs at the Duncan, Oklahoma refinery to Koch. Specifically, Koch seeks to clar ify that the court did not-2-

allocate fifteen percent of the response costs to K och bases on the “relative Proportion of time Koch operated the Refinery,” Tosco , 2000 WL 525915 at *2, but rather, on the relative period during which the Refinery was operated while under Koch’s ownership. Upon consideration, the court grants the limited pe tition for rehearing. An amended opinion is attached to this order. Entered by the Court: WADE BRORBY United States Circuit Judge

## F I L E D United States Court of Appeals Tenth Circuit 

### MAY 26 2000 

### PATRICK FISHER Clerk PUBLISH UNITED STATES COURT OF APPEALS

TENTH CIRCUIT

TOSCO CORPORATION, a Nevada corporation, Plaintiff-Appellee,

v. KOCH INDUSTRIES, INC., as successor to Rock Island Oil & Refining Co., Inc., a Kansas corporati on, Defendant-Appellant, SUN COMPANY, INC., (R&M), a Pennsylvania, corporation; ALPHA OIL COMPANY, an Oklahoma corporation; RESOURCE RECOVERY COMPANY; ENERGY REALTY INTERNATIONAL, Defendants. No. 98-6209

Appeal from the United States District Court for the Western District of Oklahoma (D.C. No. CIV-95-556-M)
John J. Lyons (Kathleen O’Prey Truman of Latham & W atkins, Los Angeles, California, and Robert N. Barnes of Barnes, Smith, Lewis & McCutcheon, P.C., Oklahoma City, Oklahoma, with him on the brief) of Latham & Watkins, Los Angeles, California, for Plaintiff-Appellee. J. Kory Parkhurst (Thomas A. Loftus III of Koch Ind ustries, Inc., Wichita, Kansas, and J. William Conger of Hartzog, Conger & Cason, Oklahoma City, Oklahoma, with him on the briefs) of Koch Industrie s, Inc., Wichita, Kansas, for Defendant-Appellant.-2-

Before BRORBY, McWILLIAMS and HENRY , Circuit Judges.

BRORBY , Circuit Judge.

The United States District Court for the Western Di strict of Oklahoma entered judgment in favor of Plaintiff, Tosco Corpo ration (“Tosco”), on its Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”) and Oklahoma nuisance law claims againstDefendant, Koch Industries, Inc. (“Koch”). In so doing, the distri ct court declared Koch responsible for its fair share (fifteen percent) of all past and future response costs and damages Tosco incurred or will incur while inve stigating and remediating environmental contamination at the abandoned Duncan , Oklahoma oil refinery (“Refinery”). Koch appeals, claiming the district court (1) erred in determining Koch to be liable under CERCLA; (2) applied an inco rrect and inequitable cost allocation method; (3) erred in ruling Koch liable under Oklahoma nuisance law; (4) abused its discretion by admitting late-filed, untimely evidence; and (5) erred by not taking into consideration the settlement between Sun and Tosco. We consider each issue in turn, and affirm.-3- I. Factual Background Ownership History The Refinery sits on approximately four hundred acr es five miles south of Duncan, Oklahoma. Rock Island Refining Company bui lt the northern and eastern portions of the Refinery (approximately 160 acres) in the 1920s, and expanded and modified those portions during the 192 0s and 1930s. Rock Island Oil & Refining Company, an unrelated entity and Koc h’s predecessor company, purchased those portions of the Refinery as an ongo ing refining business in September 1946. Koch operated the northern and eas tern portions of the Refinery until December 1949, when it shut down operations.

In June 1951, Koch leased the northern and eastern portions of the Refinery to Sunray DX Oil Corporation (“Sunray”), predecesso r-in-interest to Sun Company, Inc. (“Sun”). Sunray continued Koch’s ope ration under lease from June 1951 to September 1953. In September 1953, Su nray purchased the northern and eastern portions of the Refinery from Koch and combined those portions with the southern and western portions of the Refinery i t purchased in 1947 from the United States, Defense Plant Corporation, which hadutilized the southern and western portions to produce jet fuel during World W ar II. Sunray and its successors owned and operated the Refinery from 194 7 until 1980. Tosco-4-

purchased the Refinery from Sun in November 1980, and operated it for three years until June 1983. The Refinery has not been i n operation since that date.

Tosco sold the Refinery to Alpha Oil Company (“Alph a”) in April 1986. Alpha then sold certain waste areas of the Refinery to Resource Recovery Company (“Resource Recovery”) and the remaining are as to Energy Realty International (“Energy Realty”) in the summer of 19 86. Resource Recovery Company and Energy Realty International are the cur rent owners of the Refinery.

Refinery Operations Koch, Sun and Tosco each conducted oil refining ope rations at the Refinery. Koch manufactured gasoline, kerosene, di stillate, naphtha, range oil, fuel oils, and asphalt products at the Refinery. D uring Sun’s and Tosco’s ownership, the Refinery manufactured automotive gas oline, diesel fuel, aviation fuel, various grades of fuel oil, LP gas, petrochem ical feedstock, and petroleum coke. Koch’s asphalt plant was shutdown after Sunr ay built the coker in 1954.

Refinery operations, including those during Koch’s ownership and operation, generated various hazardous substances and wastes, including slop oil emulsion solids, heat exchanger bundle cleaning slu dge, API separator sludge,-5-

leaded tank bottoms, highly corrosive sludges, wast e waters, and petroleum hydrocarbon byproducts. Koch operated numerous unl ined waste ponds and pits, oil skimming ponds, sumps, settling ponds, cooling ponds, holding ponds, and drainage ditches, and an asphalt pit area and under ground pipeline for waste disposal. These areas are probable sources of unde rground contamination. The pollution caused by the Refinery’s various owners and operators commingled and cannot be separated.

Site Investigation and Remediation The Oklahoma Department of Environmental Quality (“ Department”) completed an environmental investigation of the Ref inery in 1994. The Department informed Tosco and Sun, as former owners of the Refinery, that further investigation and remedial action was neces sary and requested that Tosco and Sun conduct such activity jointly. Only Tosco entered into a Consent Agreement and Final Order with the Department, unde r which Tosco agreed to complete a remedial investigation and feasibility s tudy of the site, prepare a remedial design, and take certain interim remedial actions. Tosco has installed a cut-off wall and bank stabilization to remediate se eps of hydrocarbons and hazardous substances into Claridy Creek, and has op erated a system to recover hydrocarbons and other hazardous substances floatin g on the groundwater under-6-

the Refinery. At the time of trial, Tosco continue d to work with the Department to investigate the need for further, future correct ive actions. As of December 1, 1997, Tosco had incurred investigation and remediat ion costs of $755,868.23. Total costs are likely to exceed $2,000,000.

Litigation History In June 1997, Tosco filed suit against Sun, Koch, A lpha, Resource Recovery and Energy Realty seeking contribution forpast and future investigation and remediation costs pursuant to CERCLA § 113, 42 U.S.C. § 9613, Oklahoma public nuisance law, and other statutes. Tosco als o sought relief against Sun for breach of contract and contractual declaratory reli ef, stemming from the purchase agreement through which Tosco purchased the Refinery from Sun. Sun settled all claims with Tosco in January 1998 after a one-day b ench trial on the contractual issues. The remaining CERCLA and nuisance claims a gainst Koch, Alpha, Resource Recovery and Energy Realty were tried to t he court in February 1998. Koch was the only defendant that appeared and defen ded these remaining claims, as Alpha, Resource Recovery, and Energy Realty eith er no longer exist or are insolvent.

In March 1998, the district court found Koch liable under CERCLA and-7-

Oklahoma public nuisance law and allocated nineteen percent of Tosco’s past and future response costs to Koch. In September 1998, the district court amended its judgment by reducing the allocation of costs to Koc h to fifteen percent, reflecting the relative period during which the Refinery was o perated while under Koch’s ownership. Koch appeals the amended judgment.

II. Analysis A. CERCLA Liability Pursuant to CERCLA’s contribution provision, 42 U.S .C. § 9613(f), Tosco is entitled to recover response costs from any pers on who is liable or potentially liable under CERCLA § 107(a), 42 U.S.C. § 9607(a). See United States v. Colorado & Eastern R.R. , 50 F.3d 1530, 1535-36 (10th Cir. 1995). Section 107 imposes strict liability on four classes of potenti ally responsible persons, including current and former owners and operators o f a facility or vessel involved in hazardous substance disposal, and persons who arranged for or accepted hazardous substances for disposal or transportation . 42 U.S.C. § 9607(a)(1)-(4). Prior owners or operators like Koch are responsible persons if they controlled the site “at the time of disposal” of a hazardous subst ance. Id. § 9607(a)(2). A “disposal” is “the discharge, deposit, injection, d umping, spilling, leaking, or placing of any ... hazardous waste into or on any l and or water so that such ...-8-

hazardous waste ... may enter the environment.” Id. § 6903(3). The plaintiff in a CERCLA response cost recovery action involving mult iple potentially responsible persons need not prove a specific causal link betwe en costs incurred and an individual responsible person’s waste. United States v. Alcan Aluminum Corp. , 964 F.2d 252, 264-66 (3d Cir. 1992). To establish liability under § 9613(f), it is sufficient for the plaintiff to establish a connect ion between a particular defendant and the incurred response costs vis à vis the defendant’s identification as a responsible person as defined in § 9607(a). See Control Data Corp. v. S.C.S.C. Corp. , 53 F.3d 930, 935 & n.8 (8th Cir. 1995); General Elec. Co. v. Litton Indus. Automation Sys., Inc. , 920 F.2d 1415, 1417-18 (8th Cir. 1990) (courts lo ok only to see if there has been a release or threatened re lease for which a defendant is responsible), cert. denied, 499 U.S. 937 (1991); c.f. Farmland Indus., Inc. v. Colorado & Eastern R.R. , 922 F.Supp. 437, 439-42 (D. Colo. 1996) (court ho lds § 9613(f) does not impose a separate causation elem ent – a prima facie case for contribution liability is established by proving li ability under § 9607); LouisianaPacific Corp. v. Beazer Materials & Serv., Inc., 811 F.Supp. 1421, 1426-30 (E.D. Cal. 1993) (statute does not impose a causation ele ment where defendant falls within one of four statutorily defined classes and there has been an actual release).1 Koch alleges the district court adopted Tosco’s p roposed findings of fact

verbatim, and for that reason we should review thos e findings “especially critically.” Having reviewed the record, we do notbelieve the district court mechanically adopted the prevailing party’s propose d findings without reasoned consideration. In any event, the clearly erroneous standard must still guide our review. See Everaard v. Hartford Accident & Indem. Co. , 842 F.2d 1186, 1193 (10th Cir. 1988).

-9- The district court concluded Koch was liable under CERCLA because (1) it “owned or operated” the Refinery, a facility as def ined by CERCLA, and (2) during its ownership and operation, Koch released o r disposed of hazardous substances, as defined by CERCLA. The court furthe r concluded Tosco had proven the required connection between Koch’s activ ities and the response costs Tosco incurred. According to the district court, K och failed to establish any of the CERCLA defenses. See 42 U.S.C. § 9607(b).

We review the district court’s conclusions of law d e novo, applying the same standard used by the district court in making its initial ruling. See Naimie v. Cytozyme Lab., Inc. , 174 F.3d 1104, 1108 (10th Cir. 1999); Olguin v. Lucero , 87 F.3d 401, 403 (10th Cir.), cert. denied, 519 U.S. 982 (1996). We review the district court’s fact findings for clear error. 1 Naimie , 174 F.3d at 1108. “‘A finding of fact is “clearly erroneous” if it is wit hout factual support in the record or if the appellate court, after reviewing all the evidence, is left with a definite-10-

and firm conviction that a mistake has been made.’” Manning v. United States , 146 F.3d 808, 812 (10th Cir. 1998) (quoting Cowles v. Dow Keith Oil & Gas,
Inc. , 752 F.2d 508, 511 (10th Cir. 1985)).

Koch claims Tosco failed to prove Koch actually dis carded a hazardous waste at the Refinery site. In particular, Koch ar gues the district court’s findings of fact numbers 18 through 45 are erroneous and uns upported by the record. We find ample record evidence to support the district court’s findings that Koch disposed of hazardous waste at the Refinery. CERC LA liability may be inferred from the totality of the circumstances; it need notbe proven by direct evidence. See United States v. Cello-Foil Prods., Inc. , 100 F.3d 1227, 1231-32 (6th Cir. 1996) (defining the scope of CERCLA liability under42 U.S.C. § 9607(a)(3)); United States v. Vertac Chem. Corp. , 46 F.3d 803, 808 (8th Cir. 1994) (determination of operator liability under 42 U.S.C . § 9607 (a)(2) is a factintensive inquiry requiring consideration of the to tality of circumstances), cert. denied, 515 U.S. 1158 (1995). This is especially true un der the circumstances presented in this case, as eyewitness testimony or other direct evidence concerning specific waste disposal practices at oil refineries during the 1940s – well before the enactment of environmental laws – i s rarely available. It is sufficient, therefore, that Tosco presented a wealt h of circumstantial evidence2As the district court found, and the record subst antiates, Koch’s refinery

operations, as well as operations conducted during the period when Koch leased the Refinery to Sunray, generated numerous hazardou s substances and wastes. Koch itself operated numerous unlined waste ponds and pits, oil skimming ponds, sumps, settling ponds, cooling ponds, holding ponds , and drainage ditches, and an asphalt pit area and underground pipelines for wast e disposal. In addition, numerous product and chemical spills and leaks occu rred from tanks, ditches, pipelines, process units and waste areas. All thes e areas are probable sources of underground contamination. Koch’s own documents in dicate Koch could not account for seven percent of its daily throughput, thus evidencing a large volume of materials, including liquid phase petroleum hydr ocarbons containing hazardous constituents, leaking from the process units into the environment.

-11- showing disposals of hazardous waste occurred at th e Refinery during Koch’s ownership or operation. 2 Indeed, given the evidence of record, reviewed in its entirety, Koch’s effort to discredit the evidence i n an attempt to avoid the broad scope of CERCLA liability is disingenuous.

Koch’s arguments concerning the lack of a nexus between any disposal activity conducted by Koch and the costs Tosco has incurred, and the application of the petroleum exclusion to wastes Koch discharge d at the Refinery, are equally meritless. As stated above, and for obvious reason s given the nature and history of the Refinery site, Tosco need not tie specific r esponse costs to hazardous waste identified as Koch’s, alone. Koch does not dispute it owned, operated or leased out a portion of the Refinery site between 1946 and 1953. Moreover, the record is replete with evidence Koch used unlined ditches, pits and ponds to dispose of3 The definition of “hazardous substance” specifica lly excludes material

that is “petroleum, including crude oil or any frac tion thereof which is not otherwise specifically listed or designated as a ha zardous substance.” 42 U.S.C. § 9601(14)(D).

-12- hazardous waste at the site. The evidence indicate s those wastes migrated from the ditches, pits and ponds, through the soil and i nto the groundwater, and thus are a probable source of groundwater contamination. The record further reveals the Department has identified additional areas for investigation and possible remediation, including the Refinery’s northern peri meter which Koch owned for seven years, as well as waste management units Kochis known to have operated. This evidence is more than sufficient to identify K och as a responsible person under 42 U.S.C. § 9607, and thus, demonstrate a con nection between Koch’s operations and waste handling practices at the Refi nery and the resulting hazardous waste contamination the Department identi fied and Tosco has and will continue to remediate. See Control Data Corp. , 53 F.3d at 935 n.8.

The record similarly supports the district court’s finding that hazardous wastes have commingled with the petroleum products in the soil and floating on the groundwater beneath the refinery, thus renderin g the CERCLA petroleum exclusion 3 inapplicable. It is well known refineries generat e hazardous wastes in addition to petroleum products. See Cose v. Getty Oil Co. , 4 F.3d 700, 707-094The hazardous substances present in seep and soil samples from the

Refinery include heavy metals, chromium, napthalene s and phenols, dissolved benzene, toluene, ethyl benzene and xylene, chromiu m, arsenic, barium, cobalt, lead, nickel, and benadium.

-13- (9th Cir. 1993) (crude oil tank bottoms are not “pe troleum” and therefore not subject to CERCLA’s exclusion); United States v. Western Processing Co. , 761 F.Supp. 713, 721 (W.D. Wash. 1991) (EPA presumes wa stes from the interior of a tank that held a petroleum product are hazardous); see also 40 C.F.R. §§ 261.31, 261.32 (listed, hydrocarbon-based hazardous wastes relating to refineries include API separator waste, slop oil emulsion solids, and wastewater sludge). Congress intended that the petroleum exclusion address oil s pills, not releases of oil which has become infused with hazardous substances. See Alcan Aluminum , 964 F.2d at 266-67 (citing S.Rep. No. 848, 96th Cong., 2d Sess. 30-31 (1980)). Consequently, “‘EPA does not consider materials such as waste oil to which listed CERCLA substances have been added to be within the petrole um exclusion.’” Id. at 266 (quoting 50 Fed. Reg. 13,460 (1985)). Sampling res ults and expert testimony confirm that certain soil at the Refinery, as well as the petroleum plume in the groundwater aquifer beneath the Refinery, contains a mixture of petroleum and hazardous wastes generated and disposed from numero us sources at the Refinery. 4 The petroleum exclusion requires Koch to controvertTosco’s evidence concerning the hazardous composition of the petrole um product in the soils or5 In any CERCLA case, once the plaintiff alleges a release or threatened

release of hazardous substances, which Tosco has al leged and supported with evidence here, the party asserting the benefit of t he petroleum exclusion bears the burden of proof on that issue. See Organic Chem. Site PRP Group v. Total Petroleum Inc. , 58 F.Supp.2d 755, 763 (W.D.Mich. 1999) (because p etroleum exclusion is an exception to a statutory prohibitio n, the defendant bears the burden of showing the exclusion applies). For the reasons discussed above, Koch’s assertion Tosco failed to establish the rele ase of a hazardous substance and therefore Koch bears no burden to demonstrate the applicability of the petroleum exclusion is wrong.

6Indeed, Koch’s own expert conceded he performed n o testing to show unadulterated petroleum was the only contaminant in the ground water plume. Moreover, he could not opine that hazardous waste g enerated by Koch did not commingle with petroleum products.

7Koch’s emphasis on the presence of petroleum prod uct and past efforts to monitor and recover petroleum product from the grou nd water beneath the Refinery is of no relevance. It simply does not re but the fact hazardous substances are commingled with the petroleum produc ts, thus rendering the petroleum exclusion inapplicable.

-14- floating on the groundwater beneath the refinery. 5 Koch presents no such evidence, 6 and thus, has failed to demonstrate its entitlemen t to the exclusion. 7 For all these reasons, we affirm the district court ’s conclusion Koch is obligated to contribute to investigation and remediation cost s incurred at the Refinery pursuant to 42 U.S.C. § 9613(f).

B. Contribution Allocation CERCLA authorizes a district court to allocate CERC LA response costs-15-

among the liable parties using any equitable factor s it deems appropriate. 42 U.S.C. § 9613(f). See also FMC Corp. v. Aero Indus., Inc. , 998 F.2d 842, 846 (10th Cir. 1993). We review the district court’s c ontribution allocation for abuse of discretion. FMC Corp. , 998 F.2d at 847.

Koch complains the district court erred by allocati ng remediation costs based solely on the duration of Refinery operations under Koch’s ownership relative to the thirty-seven-year period between 19 46 and 1983. Rather than allocate Koch a fifteen percent share based on the relative period during which the Refinery was operated while under Koch’s owners hip, Koch argues the district court should have based Koch’s fair share on the re lative productive capability of each responsible party and the alleged fact Koch di sposed of much of its Refinery waste off-site. Other equitable factors Koch claim s the district court failed to consider when making its allocation determination i nclude the total number of potentially responsible parties, the relative acrea ge controlled by each party (Koch operated on only 160 acres), and the fact that duri ng a portion of Koch’s ownership, Sun actually operated the Refinery underlease from Koch. In the end, Koch claims it should be responsible for no more th an 1.5% of the total response
costs.-16-

In balancing the equities in light of the totality of the circumstances, see FMC Corp. , 998 F.2d at 847, the district court first determi ned the pollution caused by the various Refinery owners and operators has commingled and cannot be separated. The court then found Koch operated w aste areas in eleven out of thirty, or thirty-seven percent, of the identified solid waste management areas at the Refinery. The court noted that waste disposal practices improved in the years subsequent to Koch’s ownership and operation of the Refinery, and found it more probable than not there was a greater infiltration of contaminants into soils during Koch’s operation and ownership than during subseque nt years – equitable factors weighing against Koch. Finally, the court cited th e absence of any evidence that the amount of waste disposed to the environment was substantially different during Koch’s ownership, a period of seven years (o r fifteen percent of the Refinery’s operational life). Record evidence exis ts to support each of these findings, which placed Koch’s fair share in the ran ge of fifteen to thirty-seven percent. Accordingly, we cannot say the court abus ed its discretion by rejecting Koch’s proposed 1.5% allocation, and instead allocating fifteen percent of the total response costs to Koch.

C. Nuisance Liability In addition to holding Koch liable for a share of r esponse costs under-17-

CERCLA, the district court also held Koch liable fo r damages to Tosco under Oklahoma public nuisance law. Koch claims the dist rict court erred because “[t]he unrefuted evidence establishes that no claim for statutory nuisance exists.” Koch further argues Tosco’s nuisance claim is barre d under Oklahoma’s two-year statute of limitations, and Tosco did not suffer a “special injury,” as required to maintain an action for public nuisance. We address each argument in turn.

Koch first attempts to avoid liability under state law by characterizing the alleged nuisance as the existence of petroleum seep s into Claridy Creek, not the presence of petroleum hydrocarbons in the groundwat er under the Refinery. According to Koch, it therefore cannot be liable be cause “there is no evidence that seeps of petroleum hydrocarbons, which constitute the claimed nuisance, occurred during Koch’s ownership or operation of it s portion of the Refinery.” The evidence as Koch relates it “establishes that t he petroleum hydrocarbon seeps were first observed in the early 1970s by Sun and that those seeps were abated by Sun’s installation and operation of the petroleum hydrocarbon recovery system.” Only later was the abatement discontinued and did t he seeps recur. In sum, Koch denies it ever committed any unlawful acts or faile d to perform any duties required by the law in effect at the time it owned and operated the Refinery, which acts or omitted duties caused the alleged nui sance. We disagree.-18-

First, Koch cites no legal authority or factual evi dence to support its claim that seeps of polluted groundwater into Claridy Cre ek constitute a public nuisance, but the presence of hydrocarbons in the g roundwater does not. We fail to see how the Oklahoma Department of Environmental Quality’s reference to the seeps as a public nuisance in any way limits legal liability to that particular aspect of the nuisance. The pollution of any Oklahoma wat ers, including groundwater, has been prohibited by state statute since the earl y 1900s – well before Koch’s waste disposal activity at the Refinery. As illust rated above, there is ample record evidence establishing Koch disposed of hazar dous wastes that have percolated through the soils and into the groundwat er beneath the Refinery. The groundwater is hydrologically connected to the Cree k as evidenced by the seeps. Consequently, Koch’s denial of any unlawful activity vis à vis water pollution and the public nuisance stemming therefrom rings hollow

.

We also reject Koch’s argument Tosco’s nuisance cla im is barred by a twoyear statute of limitations. While the statute of limitations on private nuisance claims under Oklahoma law is two years, see N.C. Corff Partnership, Ltd. v. OXY USA, Inc. , 929 P.2d 288, 293 (Okla. App. Div. 4 1996), Okla. Stat. tit. 50, § 7 provides: “No lapse of time can legalize a public nuisance amounting to an actual obstruction of public right.” Concluding, as we have here, that the pollution of-19-

Oklahoma waters constitutes a public nuisance underOklahoma law, the district court of the Western District of Oklahoma, in Fischer v. Atlantic Richfield Co. , 774 F.Supp. 616 (W.D. Okla. 1989), applied Okla. St at. tit. 50, § 7 to disallow the two-year statute of limitations as a defense agains t a plaintiff seeking pollution abatement or the costs of abatement. Id. at 619. We see no reason to reject this existing interpretation of Oklahoma law.

Finally, we agree with the District Court Tosco ade quately proved it suffered a “special injury” sufficient to maintain a cause of action under Okla. Stat. tit. 50, § 10 by establishing it has borne th e entire cost of investigation and remediation at the Refinery. See Westwood Pharm., Inc. v. National Fuel Gas Distrib. Corp., 737 F.Supp. 1272, 1281 (W.D.N.Y. 1990) (holding th at if Westwood can establish it has incurred response cos ts consistent with the National Contingency Plan, those costs will be suff icient to meet the special injury criterion for bringing a public-nuisance act ion).

D. Evidence Koch asserts the district court “abused its discret ion by admitting the results of scientific tests that Tosco conducted af ter the discovery cut-off and disclosed to Koch, for the first time, after the pr etrial conference, on the eve of-20-

trial.” The specific evidence to which Koch object s is data from soil and groundwater sampling conducted in December 1997 as part of the remedial investigation and feasibility study performed pursu ant to Tosco’s consent agreement with Oklahoma Department of Environmental Quality. Koch claims it was unfairly prejudiced by the introduction of this sampling data because it was unable to conduct additional discovery prior to tri al.

We will not disturb the district court’s evidentiary ruling unless we have a definite and firm conviction the court made a clearerror of judgment or exceeded the bounds of permissible choice under the circumst ances. McEwen v. City of
Norman , 926 F.2d 1539, 1553-54 (10th Cir. 1991). Moreove r, in bench trials “questions raised relative to the admission or excl usion of evidence ... become relatively unimportant,” because the rules of evide nce are “intended primarily for the purpose of withdrawing from the jury matter whi ch might improperly sway the verdict.” United States v. Norman T. , 129 F.3d 1099, 1107 (10th Cir. 1997) (quotation marks and citations omitted), cert. denied, 523 U.S.1031 (1998). Where, as here, a case is tried before the court wi thout a jury, we presume on appeal the court considered only competent evidence and disregarded any incompetent evidence. Id.-21-

Koch fails to overcome that presumption or demonstr ate any abuse of discretion or prejudice. The sampling evidence Koc h complains of was scheduled and conducted as part of Tosco’s ongoing remedial i nvestigation and feasibility study at the Refinery. The record indicates Koch w as aware no later than November 1997 Tosco would be conducting sampling inDecember 1997, after the discovery cut-off, and Tosco intended to present th e results of such testing in the trial. Koch never requested to observe the samplin g, take its own samples, or split any samples collected. Instead, Koch filed amotion in limine to exclude the sampling data the end of January 1998, after the co urt’s deadline for filing such motions, in part on the ground Tosco allegedly deni ed then co-defendant Sun’s request for split samples. Yet, Koch makes no show ing it had access to or otherwise was relying on any split samples Sun might obtain. Koch makes no claim Tosco failed to produce the data as soon as i t became available. More important, Koch makes no showing the data is unreli able or Koch was denied an adequate opportunity to cross-examine witnesses at trial concerning the December 1997 data. Under these circumstances, we affirm th e district court’s evidentiary ruling.

E. Previous Settlement Koch argues the district court “erred by not taking into consideration the-22-

fact of the Sun/Tosco settlement in connection with Koch’s liability to Tosco.” According to Koch, the district court was obligatedto conduct a “fairness hearing” on the amount of that settlement so that K och, as a non-settling defendant, could be credited with the amount of the settlement. Otherwise, Koch claims Tosco will realize a windfall by recovering more than it is entitled to in contribution ( i.e. , more than the investigation and remediation costs Tosco has or will incur).

Koch’s argument is factually flawed and without leg al support. The record makes clear the district court allocated liability for past and future response costs proportionately among the responsible parties – exp ressly as to Koch and implicitly as to Sun and Tosco – thus avoiding maki ng Koch responsible for more than its fair share. Sun opted to settle its liabi lity for a fixed amount in order to avoid the uncertainty of unknown future costs. Koc h chose not to settle for a fixed amount. We believe where, as here, a respons ible party chooses to go to trial and future response costs are likely to be in curred, but the exact amount remains unknown, a judgment on proportional liabili ty is an appropriate remedy. See Kelley v. E.I. DuPont de Nemours & Co. , 17 F.3d 836, 844-45 (6th Cir. 1994) (a declaration of liability is appropriate even if future costs are somewhat speculative). In other words, the district court w as not obligated to fix an amount8We note in the context of settlement with the EPA pursuant to 42 U.S.C.

§ 9613(f)(2), courts consistently have rejected anyright to a fair share hearing prior to judicial approval of the settlement. See Boomgaarden & Breer, supra , at 107-08 & note 171.

-23- of Koch’s liability based on the Sun/Tosco settleme nt. As noted above, the district court acted well within its discretion by allocating Koch’s proportionate share of liability based on Koch’s relative duratio n of Refinery ownership and control – a factor unique to Koch and unaffected by a settlement between other responsible parties. Moreover, the majority of cou rts deciding contribution suits between private parties under 42 U.S.C. § 9613(f)(1 ) (as contrasted from suits or settlements with the government under 42 U.S.C. § 9 613(f)(2)), have applied the Uniform Comparative Fault Act to reduce a nonsettli ng party’s liability by the amount of the settling parties’ liability, not the settlement amount. Lynnette Boomgaarden & Charles Breer, Surveying the Superfund Settlement Dilemma , 27 Land & Water L.Rev. 84, 109-12 & note 189 (1992). Koch cites no persuasive legal authority to the contrary, no authority for i ts proposition the district court was obligated to conduct a “fairness hearing” on th e terms of the Sun/Tosco settlement, 8 and no evidence Tosco will enjoy a windfall. Koch ’s assertion Tosco may receive double recovery is pure speculation. C onsequently, we will not overturn the district court’s judgment on this grou nd.-24- III. Conclusion For all the foregoing reasons, the district court’s judgment imposing contribution liability on Koch under CERCLA and Okl ahoma law is AFFIRMED

. Tosco’s request for attorney fees and costs pursuant to 28 U.S.C. § 1912 and Fed. R. App. P. 38 and 39 is denied.