New York v. SOLVENT CHEMICAL CO., INC.

MEMORANDUM OF DECISION

JOHN T. CURTIN, District Judge.

In this action, originally brought in 1983 by the State of New York against the Solvent Chemical Company, Inc. (“Solvent”), and its parent company, ICC Industries, Inc. (“ICC”), pursuant to the Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”), 42 U.S.C. § 9601 ,

et seq.,

the court conducted a non-jury trial on issues pertaining to the liability and equitable allocation of responsibility for costs incurred in remediating environmental contamination at Solvent’s property located at 3163 Buffalo Avenue in Niagara Falls, New York; adjacent property owned by the Olin Corporation (referred to as the “Olin Hot Spot” or simply, the “Hot Spot”); and Gill Creek, which flows through both Olin’s property and neighboring property owned by the E.I. du Pont de Nemours & Company (“DuPont”). The following constitutes the court’s findings of fact and conclusions of law with regard to these issues, in accordance with Rule 52 of the Federal Rules of Civil Procedure,

1

based on the trial testimony and exhibits (including designated deposition testimony of 24 witnesses not appearing at the trial), the parties’ post-trial submissions and arguments, and the court’s prior rulings.

I.

FACTUAL AND PROCEDURAL SUMMARY

A. The Three Neighboring Facilities

The geographical area of concern in this case involves relatively contiguous parcels of property comprising three chemical manufacturing plant sites located in the

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midst of a sprawling heavy industrial area along the northern shore of the Niagara River in the City of Niagara Falls. The court’s analysis begins with a brief description of the three sites and the historical operations conducted there.

1. The Solvent Site

Solvent’s property at 3163 Buffalo Avenue comprises 5.7 acres situated generally between the Olin chemical manufacturing plant site on the west, and the DuPont chemical manufacturing plant site on the east and south. It is bordered directly by Buffalo Avenue to the north, Adams Avenue to the south, DuPont Drive to the west, and a vacant parcel owned by DuPont to the east. Gill Creek, which flows from north to south through the Olin and DuPont plant sites, is located about 400 feet west of the 3163 Buffalo Avenue property

(see

December 1996 Record of Decision (“ROD”), Solvent Exhibit (“S-”) 1012).

The manufacturing facility at the 3163 Buffalo Avenue address was originally built and operated by DuPont during World War II under a contract with the United States government to make “impregnite,” a chemical compound developed to treat Army uniforms for protection against exposure to poison gas. The plant was reactivated between 1951 and 1953 by the Hooker Electrochemical Company for impregnite production during the Korean conflict. The City of Niagara Falls purchased the site in 1972 and sold it to Solvent

(id.).

Solvent operated the chemical manufacturing plant at 3163 Buffalo Avenue from approximately 1974 to 1978. Its primary business function was to purchase lower grades of mixed chlorinated benzene material from other manufacturers or suppliers and refine this material into commercial grade products, such as various technical and refined grades of chlorinated benzenes and zinc chloride solutions.

See State of New York v. Solvent Chemical Co., Inc.,

218 F.Supp.2d 319, 323-24 (W.D.N.Y.2002);

see also

S-6040. This process involved the handling, storage, production, and use of several chemicals including benzene, chlorobenzene (also referred to as “monochlorobenzene”), 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,4-trichlorobenzene, 1,2,3-trichlorobenzene, petroleum products containing toluene, xylenes, ethylbenzene, and benzene, and zinc (DuPont Exhibit (“D-”) 14, 213; Trial Transcript (“Tr.”) 9/26/07, Item 1423

2

at 109). Solid residues from the refining process were accumulated in steel drums and disposed of off-site by approved waste disposal contractors

(see

Item 1328 (3/24/06 Decision and Order) at 43-44;

see also

S-6052; Tr. 1423 at 24-26).

The Record Chemical Co., later known as Recochem, Inc., and its president, Joseph Kuchar, also operated the plant at the Solvent Site for a short period during the first three months of 1978 in order to ascertain the plant’s chlorinated benzene production capacity in anticipation of Recochem’s purchase of Solvent’s assets, which never materialized

(see

Item 1328 at pp. 68-69).

3

Between approximately 1980 and

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1983, two separate entities named Frontenac Environmental Services, Inc., leased a portion of the Site and used it as an unlicensed hazardous and industrial waste storage and transfer facility (D-14, p. 1-6). During that period of time, approximately 610,000 gallons of liquid chemical wastes, including chlorinated aliphatic solvents perchloroethene (“PCE”) (29,920 gals.), trichloroethene (“TCE”) (114,565 gals.), 1, 1, 1-trichloroethane (495 gals.), methylene chloride (1,100 gals.), chloroform, and carbon tetrachloride, as well as unspecified quantities of chlorinated and non-chlorinated waste products such as “halogenated solvents, electroplating sludge, spent pickle liquor, acid and caustic wastes, paint sludge, cyanides, etc.” (S-1012, p. 3), were managed or stored at the Site (D-91, 213; S-6053, 6054; Tr. 1423 at 26-27; Tr. 1425 at 61-63).

2. The Olin Site

Olin’s Niagara Falls facility, located directly west of the 3163 Buffalo Avenue property, consists of two plants: Plant 1, which comprises six acres located west of Chemical Road; and Plant 2, which comprises sixteen acres located between Chemical Road to the west and Gill Creek to the east (S^1113). The area of Plant 2 between Alundum Road to the west, Buffalo Avenue to the north, Adams Avenue to the south, and Gill Creek to the east, is known as the “ARGC Area.” Olin also owns the property between Gill Creek and DuPont Drive directly adjacent to the 3163 Buffalo Avenue Property (S-4121; Tr. 1430 at 51, 62; Tr. 1433 at 81). Gill Creek runs from north to south through the Olin property and the DuPont property directly to the south, and empties into the Niagara River (Olin Exhibit (“0-”) 431).

Olin or its predecessors have engaged in the production of various chemical products at the Niagara Falls facility continuously since 1897, with principal emphasis on electrolytic production of chlorine and caustic soda from sodium chloride (rock salt) using various modifications of the mercury cell/chlor-alkali process (0-223; S-4113; Tr. 1420 at 114, 121-22). Mercury cell operations historically took place at both Plants 1 and 2, but were confined to Plant 2 for the last 30 years of chlor-alkali production, which ceased entirely in 1991 (0-223).

Olin also manufactured the pesticide benzene hexachloride (“BHC”), also known as hexachlorocyclohexane, in the southern portion of the ARGC Area of Plant 2 from 1950 to 1956 (S-4121; Tr. 1413 at 30-31; Tr. 1430 at 52, 62-63). By-products of Olin’s BHC production included trichlorobenzene, pentachlorobenzene, and hexachlorobenzene (Tr. 1413 at 31-35, 39-41; Tr. 1430 at 119-123,136). During this six-year period of operation, Olin generated approximately 4.5 million pounds of BHC and 5.5 million pounds of trichlorobenzene annually (Tr. 1413 at 38-41; S-6045). Olin’s BHC production ended in 1956 when the manufacturing plant was destroyed in an explosion (S-4016; Tr. 1440 at 12-13).

3. The DuPont Site

From approximately 1896 to the present day, DuPont or its predecessors have owned and operated a chemical manufacturing facility situated on a 52-acre site located directly south of the Olin Site, and generally south and southwest of the Solvent Site (D-187; S-6014). During a 50-year period between 1925 and 1975, DuPont manufactured various chlorinated aliphatic compounds there (among other chemical products), including trichloroethene (“TCE”), tetrachloroethene (a/k/a perch loroethylene or “PCE”), cis-l,2-dichloroethane, chloroform, 1,1,2,2-tetrachlo-roethane (“1,1,2,2-TCA”), vinyl chloride, methylene chloride, and dichloroethene

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(Tr. 1413 at 16-17, 20-22; S-6039, 3024, 3025).

On November 28, 1989, DuPont entered into an Order on Consent with the New York State Department of Environmental Conservation (“DEC”) requiring DuPont to perform certain remedial activities at its facility so as to “eliminate or mitigate, to the greatest extent practicable, the release and migration of contaminants into the environment” (D-106, p. 2). On January 3, 1990, the DEC issued a Record of Decision (“ROD”) outlining the remedial action for the DuPont facility. This remedy consists of a series of pumping wells in the shallow groundwater zone running along an east-west axis of the DuPont facility south and west of the Solvent Site, and a production well on Olin’s property for control in the deeper groundwater zones west of Gill Creek

(see

S-3021 at 15;

see also

Tr. 1432 at 118-19; Tr. 1442 at 66). There is no control of groundwater in the deeper zones on the DuPont East Plant, located east of Gill Creek and south and southeast of the Solvent Site and the Hot Spot (Tr. 1432 at 118-19; Tr. 1442 at 66-67, 69).

B. Remedial Investigations at the Solvent Site

In 1978, Solvent entered into a contract to sell the 3163 Buffalo Avenue property to Newco Chemical Waste Systems, Inc.

(see

D-4). In November 1978, RECRA Research, Inc. (“RECRA”), an environmental consulting firm, conducted an environmental survey on behalf of Newco, finding chemical contamination present on the site “to an appreciable extent,” and describing the conditions “to be quite serious and are expected to necessitate yet undefined abatement activities” (D-l). The RECRA report further stated that, “Gill Creek, immediately adjacent to the Solvent Chemical Plant, is also suspected of being highly contaminated with chlorobenzenes, as well as storm sewer lines leading from the Solvent Chemical property and discharging into Gill Creek”

(id.).

In November 1979, Solvent and Newco retained environmental consultant Roy F. Weston to conduct an investigation of the conditions at the Site and to determine the need for any remedial measures

(see

D-4). In a report dated February 1980, Weston described benzene and chlorinated benzene groundwater contamination in the overburden and shallow bedrock in the southwest quadrant of the Site (S-1001, pp. 19, 22). Dichlorobenzenes had the highest groundwater concentrations, ranging from 8,000 to 24,975 ppb (parts per billion)

(id.

at Table 2-3).

Later in 1980, RECRA conducted a hydrogeological investigation of the Site on Solvent’s behalf “to expand on the work undertaken by Roy F. Weston, Inc., and to provide recommendations for remedial work to be performed, if deemed necessary” (S-1002, p. 1). In a Remedial Action Investigation Report dated December 3, 1980, RECRA confirmed the presence of elevated concentrations of benzenes and chlorinated benzenes in the soil and groundwater, as well as in the sewer lines passing beneath the site

(see id.

at pp. 67-72). RECRA recommended a number of remedial measures “to collect contaminated ground waters and provide reasonable containment of such ground water to the site proper”

(id.

at p. 73-78).

Upon receipt and review of this information, the DEC requested further investigation to determine the extent of groundwater contamination and the scope of remedial work to be performed at the Site. As a result, a Phase I Study was conducted in the spring of 1983, and a Phase II Study was conducted in the summer of 1984, to gather additional data and evaluate remedial alternatives for the Site. Both studies were performed for the DEC

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by Engineering Science, in association with Dames & Moore

(see

D-ll).

In 1985, the DEC listed the Solvent Site on the New York State Registry of Inactive Hazardous Waste Disposal Sites as Site No. 932096, designated as a class “2” site

4

(see

D-103, p. 3). At about the same time, the State also listed the DuPont Site on the Inactive Waste Disposal Site Registry as Site No. 932013, and the two Olin plants as Site Nos. 932051A and 932051 B

(see

D-103, p. 5).

Beginning in late 1989, the environmental consultant firm Ecology and Environment, Inc. (“E & E”), conducted a remedial investigation at the Solvent Site at the DEC’S request, pursuant to a stipulated cost-sharing agreement entered between Solvent, ICC, and DuPont (along with other third-party defendants) subsequent to the commencement of this action. In November 1990, E & E submitted a Remedial Investigation (“RI”) report to the DEC (S-1005). The DEC then requested additional investigation and, when the parties could not reach a cost-sharing agreement, engaged another environmental consultant firm, Malcolm Pirnie, to conduct a Supplemental Remedial Investigation (“SRI”) and prepare a Feasibility Study (“FS”). The SRI report was completed and approved by the DEC in July 1995 (S — 1009;

see also

D-14), and the FS report was completed and approved in February 1996 (S — 1010;

see also

Tr. 1442 at 18-19, 22).

In December 1996, after several years of additional site investigation and evaluation of remedial alternatives, the DEC issued the Solvent ROD outlining a detailed plan for the remedial action to be taken at the Site (S-1012). As explained in the Solvent ROD’s Declaration Statement, the DEC “selected an overburden containment remedy with a phased bedrock hydraulic control program for the Solvent Chemical site and associated groundwater” consisting of the following components:

1. Containment of highly contaminated soils on-site by placement of a permeable clean soil cover system.

2. Control and collection of contaminated overburden groundwater through construction and operation of an overburden (“A-zone”) collection system.

3. Installation of a phased bedrock hydraulic control system, including pumping wells installed and operated within the upper fractured bedrock (“B-zone”) to achieve hydraulic control over the highly contaminated groundwater found in the overburden and upper bedrock at both the 3163 Buffalo Avenue Property and in the vicinity of monitoring wells OBA-15A and OBA-3A located on Olin’s property (referred to as the “Olin Hot Spot”).

4. Treatment and disposal of pumped groundwater.

5. Implementation of a monitoring program to evaluate the effectiveness of the remedy.

6. Deed restrictions limiting future use of the Site.

See

S-1012, at pp.

i-ii

Solvent began the construction of the ROD-specified remedy at the Site in the fall of 1999 with the installation of a trench and pumping well system designed to collect groundwater from the A-Zone overburden soils both on the 3163 Buffalo Ave

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nue Property and at the Olin Hot Spot, followed by the installation of a series of pumping wells designed to collect groundwater from the fractured bedrock in the B-Zone both on the 3163 Buffalo Avenue Property and at the Hot Spot (Tr. 1422 at 31-36). All of the contaminated groundwater pumped by the system is pre-treated in the on-site pre-treatment system and then discharged to the Niagara Falls Publicly Owned Treatment Works (“POTW”) pursuant to a permit (Tr. 1422 at 54; Tr. 1442 at 53-54).

B-Zone aquifer testing began in the early spring of 2000, and continuous B-Zone pumping operations commenced in the spring/summer of 2002 (see Tr. 1442 at 71-79; Tr. 1413 at 63-64). As of June 30, 2007, Solvent had incurred $9,624,328 in connection with implementing the remedy for the Site and Hot Spot (Tr. 1422 at 106-07).

C. The Lawsuit

Meanwhile, in December 1983, the State of New York brought this action (referred to by the parties as

“Solvent

/”) against Solvent and ICC (among other settling defendants) pursuant to CERCLA and state statutory and common law seeking recovery of the costs incurred and expected to be incurred in responding to the release or threatened release of hazardous substances at or from the 3163 Buffalo Avenue Site

(see

Item 1; D-101). Beginning in June 1986, Solvent commenced a series of third-party contribution actions against more than 80 companies and individuals, including DuPont.

In April 1997, Solvent and ICC entered into separate consent decrees with the State, in which Solvent agreed to implement the remedial measures outlined in the ROD

(see

Item 655), and ICC agreed to guarantee Solvent’s performance (see Item 652). Also in April 1997, DuPont entered into a separate consent decree with the State, in which DuPont agreed to pay $216,250 of the $865,000 reimbursement to the State for the costs incurred in investigating conditions at the Solvent Site

(see

Item 657). In an order dated October 8, 1997, this court approved entry of the Solvent, ICC, and DuPont consent decrees, effectively terminating the State’s involvement in the litigation.

See State of New York v. Solvent Chemical Co.,

984 F.Supp. 160 (W.D.N.Y.1997).

In April 1998, Solvent filed a fifth amended third-party complaint (Item 746) seeking contribution pursuant to CERCLA from Olin and other third-party defendants for a share of the response costs Solvent has incurred and will continue to incur at the Site. Olin answered and asserted a counterclaim against Solvent, and filed a fourth-party complaint against ICC, seeking recovery of a portion of the response costs incurred in connection with the remediation of Gill Creek which Olin and DuPont conducted jointly in 1990-92

(see

Item 809). DuPont has not sought recovery from Solvent or ICC for any of the response costs it incurred in connection with the Gill Creek remediation.

In June 2001, after encountering the presence of chlorinated aliphatic compounds (including TCE, PCE, DCE, 1,1,2,2-TCA, vinyl chloride, and chloroform) at much higher levels than expected in the groundwater extracted during aquifer testing of the B-Zone pumping wells at the Site, Solvent commenced a new lawsuit (referred to by the parties as

“Solvent II

”) against DuPont for contribution pursuant to CERCLA § 113(f)(1) and the common law, seeking equitable allocation of response costs incurred as a result of the alleged migration of these substances from the DuPont facility.

Solvent II

was subsequently consolidated with this action for all purposes throughout trial and appeal.

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II.

THE TRIAL

Following extensive discovery, dispositive motion practice, resolution of Solvent’s claims against all parties but Olin and DuPont, and referral of the remaining claims to a magistrate judge for one final, unsuccessful attempt at settlement, a non-jury trial was held over the course of 19 days in September, October, and November 2007. The trial was conducted primarily by electronic presentation of over 1200 exhibits consisting of drawings, photographs, charts, maps, correspondence, deposition transcripts, and other documents introduced during the live testimony of ten witnesses. The court received the parties’ post-trial submissions and motions, and heard summations and argument on November 19, 20, and 21, 2008.

What follows next is the court’s effort to summarize the parties’ presentation of the facts in order to provide a relatively coherent groundwork for making the findings and conclusions required by the Federal Rules.

A. Solvent’s Witnesses

1. Andrew H. Smyth

Mr. Smyth was retained by Solvent as its hydrogeological expert to determine the nature and possible sources of contamination at the Solvent Site and Gill Creek. As set forth in his curriculum vitae (S — 6013), Mr. Smyth has an M.S. in Geology from New Mexico State University and a B.A. in Geology from Ohio Wesleyan University. He has over 17 years of experience as an environmental consultant encompassing geologic and hydrologic site assessments and has numerous professional registrations as a geologist and environmental professional. He is currently employed by TRC, an environmental engineering and consulting firm in Lowell, Massachusetts (Tr. 1413 at 10-11).

In preparing his expert report, Mr. Smyth reviewed historical documents, investigative reports, regional and localized hydrogeological studies, well-monitoring data, and several other sources of information about the Site. He defined the term “NAPL” as nonaqueous phase liquid, which can be either lighter or heavier than water. Light nonaqueous phase liquids (or LNAPL), such as benzene, are generally lighter than water and tend to float on the water’s surface, while dense nonaqueous phase liquids (or DNAPL) are heavier than water and actually flow through the earth, often coming to rest on a low permeability medium like bedrock. NAPL contains higher concentrations of contamination than groundwater, in which the constituents tend to dissolve (Tr. 1413 at 12-16).

S-6023 is a diagram of the DuPont Site, showing the area where the chlorinated aliphatics PCE and TCE were manufactured. The diagram also indicates the location of a “tank heel cleanout” area where DuPont removed 4300 cubic yards of soil contaminated with chlorinated aliphatics at levels which were not present anywhere on the Solvent Site

(id.

at 16-18). Based on his analysis of pumping well data and historical information regarding contaminant levels in groundwater migrating from the DuPont Site, Mr. Smyth calculated that about 2 million pounds of chlorinated aliphatics have been removed from the DuPont Site. According to Smyth, this is a significant amount, but very small in comparison to the contamination still remaining in the DNAPL and soil at the DuPont Site (Tr. 1413 at 18-19).

S-6039 is a timeline Mr. Smyth created based on information obtained from a September 1989 report on an interim remediation program conducted at the DuPont Site which indicates various periods of operation during which chlorinated aliphatics

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were manufactured or used by DuPont (Tr. 1413 at 20-22).

S-6031 is a map of the Olin Site which depicts the location of mercury cell rooms, a BHC plant area where chlorinated benzenes were produced and used, and a bedrock injection well where hydrochloric acid was injected into the B-Zone bedrock. This map also depicts the Hot Spot area in the northeast corner of the Olin Site and process sewers that emptied into Gill Creek (Tr. 1413 at 22-28). S-4071 is a more detailed depiction of the network of sewers in the area of Gill Creek. The historical information available indicates discharges of various contaminants into Gill Creek through these sewers from Olin’s production facilities, but there is no sediment sampling data or water quality information to confirm amounts or concentrations (Tr. 1413 at 28-30). S-6041 shows Olin’s historical chemical production and use of chemicals at the Niagara Falls facility.

S-6033 is a process flow diagram created by Mr. Smyth depicting Olin’s BHC production operations at a facility located in the Plant 2 area near Gill Creek. This process, which took place for a limited time between 1950 and 1956, generated various chlorinated benzene materials. S-6030 and 6045 are process flow diagrams produced by Olin which depict a slightly different BHC production process than the one depicted in Mr. Smyth’s diagram (Tr. 1413 at 31-41).

S-6018 is a cross-section diagram entitled “Simplified Bedrock Geology and Fracture Zones,” taken from the Record of Decision for the DuPont Site. Mr. Smyth used it to identify the water-bearing overburden and bedrock zones underlying the Solvent, Olin, and DuPont Sites, identified during various hydrogeological studies conducted in the area. As depicted on the cross-section, the uppermost layer of consists of approximately 12 feet of overburden aquifer, followed by approximately 150 feet of bedrock referred to generally as Lockport Dolomite. The bedrock is divided into fracture zones identified at various depths by the letters A, B, C, CD, D, E, F, and, finally, J. The J-Zone represents the base of the Lockport formation, below which is shale (referred to as the Rochester Shale) (Tr. 1413 at 48-50).

S-6026 is a document taken from a regional groundwater assessment dated October 1992, performed on behalf of Olin and DuPont by Woodward-Clyde and Conestoga-Rovers consultants. It depicts groundwater elevations in the area of the Solvent, Olin, and DuPont Sites, along with some of the regional hydrogeological features influencing groundwater flow. Mr. Smyth identified the Falls Street Tunnel and South Side Interceptor sewer lines, which carry approximately 9 million gallons of water a day each in an east-to-west direction under city streets, and the Power Authority of the State of New York (“PAS-NY”) conduits, which carry water from the Niagara River north to the PASNY reservoir. He testified that this exhibit indicates a preferred groundwater flow path in the deeper bedrock zones (D-Zone and deeper) from the southwest to the northeast, with an arrow drawn directly from the DuPont Site, past the Olin BHC plant, under the Hot Spot, past the Solvent Site, and toward the exact location where the PASNY conduits intersect with the Falls Street Tunnel and South Side Interceptor sewer (Tr. 1413 at 50-54).

S-6022 depicts the same general flow path for groundwater in the Upper Lock-port Dolomite (B-, C-, and CD-Zones). This drawing indicates that groundwater in the upper zones flows from a high elevation point at the DuPont and Olin Sites, through the Solvent Site and the Hot Spot, and directly toward the intersection of the

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Falls Street Tunnel and the PASNY conduits. According to Mr. Smyth, this intersection “is a major ground water discharge point for a huge section of the Lockport dolomite. A lot of the water is trying to get to that point as fast as it can” (Tr. 1413 at 55).

S-6015 is a composite of information obtained from several different hydrogeological investigations, showing groundwater elevations in the A-Zone, which is the groundwater flow zone closest to the surface. The A-Zone includes both “saturated overburden” and the uppermost level of fractured, or “weathered,” bedrock (see Tr. 1415 at 16-21). S-6015 depicts a high groundwater level near the center of Olin Plant 1, with a flow direction toward the low water level northeast of the Solvent Site. According to Mr. Smyth, the elevation readings on this exhibit indicate that Gill Creek does not have an impact on the flow of groundwater through the A-Zone (Tr. 1413 at 56-61).

On cross-examination by Olin’s counsel, Mr. Smith gave the opinion that chlorinated benzenes could travel in the A-Zone groundwater from the Olin Site to the Hot Spot through or under Gill Creek (Tr. 1415 at 26-29).

S-6017 shows the same northeasterly flow of groundwater in the B-Zone, from a high point south and west of the Olin BHC plant area toward the Hot Spot and the Solvent Site. This information was obtained from a Woodward-Clyde Phase I study at the Olin Site, conducted in 1993 (before Solvent began its pumping program in 2002). Mr. Smyth testified that the elevations depicted on this exhibit indicate that neither the Buffalo Avenue sewer, running from east to west along the northern boundaries of the Solvent and Olin Sites, nor the DuPont Sewer, running from south to north parallel to and just to the east of Gill Creek, have any impact on the flow of groundwater in the B-Zone (Tr. 1413 at 62-65).

S-6068 is a potentiometric surface map of the same area depicting B-Zone groundwater elevations and flow based on combined data from Solvent and DuPont investigations conducted in December 2006. According to Mr. Smyth, this exhibit shows that under pumping conditions, groundwater flows from the high point in the B-Zone aquifer, located on the DuPont Site in the area of the facility at which chlorinated aliphatics (PCE and TCE) were produced, and travels to the northeast across Gill Creek and on to the Solvent Site (Tr. 1413 at 65-67).

S-6069 shows potentiometric surface readings in the B-Zone prior to commencement of pumping operations, and S-6070 shows potentiometric readings after 69 hours of B-Zone pumping at well PW-1, located in the southwest corner of the Site. Mr. Smyth testified that a comparison of these two exhibits shows that this high rate of pumping did not have much influence on the overall groundwater flow in the B-Zone aquifer at the Site, beyond a limited draw-down effect in an area of approximately 50 feet surrounding the pumping well (Tr. 1413 at 67-70).

Based on these several groundwater elevation and flow path exhibits, Mr. Smyth gave the opinion that groundwater in the A-Zone flows from the Olin Site to the east and northeast toward the Hot Spot and the Solvent Site, and in the B-Zone the groundwater flows to the northeast throughout the areas of interest at the three sites. The B-Zone flow is not impacted by the Buffalo Avenue sewer, but there is not enough information on the exhibits discussed to determine the impact of the DuPont Sewer (Tr. 1413 at 70-72).

On cross-examination by Olin’s counsel, Mr. Smyth testified that groundwater in

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the B-Zone flows primarily within the cracks and fissures in the bedrock between horizontal bedding planes, as well as in vertical fissures (Tr. 1415 at 18-21). He also testified that general hydrogeological principles regarding sewer lines as preferential pathways for groundwater flow would suggest that at least some of the groundwater from the Olin Site would travel north along the DuPont Sewer toward the Buffalo Avenue sewer and the wastewater treatment plant

{id.

at 30^40).

S-6075 shows the thickness of fill material and lacustrine (lake) sediments at the Solvent Site, indicating a fairly thick (six to ten feet) sequence of low permeability materials in the overburden which would impede the flow of spilled liquids into the bedrock and cause pooling of DNAPLs (Tr. 1413 at 73-74).

S-6019 is a bedrock elevation map of the entire three-site area, compiled from available well data with color-shaded areas indicating high-to-low elevation contours and computer-generated arrows indicating top of bedrock flow gradients. S-6071 is the same map without the elevation color shading but with the production facilities and buildings on the various sites highlighted. According to Mr. Smyth, the information on these exhibits shows that if NAPL was flowing along the top of bedrock, it would flow generally toward the Solvent Site (Tr. 1413 at 74-81). At the Olin Site, the arrows indicate that NAPL would flow from the location of the former BHC production plant south or southeast toward Gill Creek, and from the trichlorophenol and trichlorobenzene production areas north of the BHC plant toward the Hot Spot by traveling in fractures under Gill Creek (Tr. 1413 at 82-85).

On cross-examination, Oliris counsel pointed out that the arrows on these exhibits indicate a NAPL flow trend from northeast of the BHC plant to the south, in the opposite direction of the Hot Spot. Mr. Smyth testified that while there were several factors of influence in this particular area (such as a depression in the elevation of the bedrock under Gill Creek near the Adams Avenue bridge, and the nature of the media in the DuPont Sewer bedding), the general trend reflected by all of the parties’ bedrock data remained consistent, showing the highest elevation on the Olin Site sloping toward the lowest elevation on the Solvent site (Tr. 1517 at 22-25).

S-6027 is a map showing the location of groundwater monitoring wells in the entire three-site area. The vast majority of wells are located on the Solvent Site in the areas of tank farm, rail, and other operations, and there is also a dense network of wells at the Hot Spot. There are essentially no monitoring wells located in the areas of BHC and trichlorobenzene operations at the Olin Site, or in the areas of TCE and PCE operations at the DuPont Site. Mr. Smyth testified that if the object of well placement was to capture the highest potential sources of groundwater contamination without bias in the analytical data, the wells should be located directly in the area where the particular chemical production took place (Tr. 1413 at 85-88).

S-6036 shows soil sampling locations for the entire three-site area. The vast majority of soil samples have been taken from the Solvent Site, with a large number of dots indicating soil sampling in the areas of former site operations, as well as in the area of the Solvent 18-inch storm sewer which ran from north to south along the western boundary of the Solvent Site, then west through the lower portion of the Olin parking lot and emptied into Gill Creek. The map also shows sparse soil sampling in the areas of operations at both the Olin and DuPont Sites. In Mr. Smyth’s opinion, this results in bias in the analytical data regarding contamination levels in the

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soil, as the placement of monitoring wells did with respect to groundwater contamination (Tr. 1413 at 89-94).

Mr. Smyth testified that the purpose of installing monitoring wells is to characterize ambient groundwater concentration in the aquifer, unaffected by pumping activity. The area of characterization is limited to the flow path line that travels through the well under ambient conditions, resulting in a zone of influence of just a few inches-essentially, the width of the sand pack around the well. A pumping well pulls in water from a greater diameter, giving a composite sample of flow paths in a much broader area of the aquifer. Because groundwater generally flows downward from the upper to lower water-bearing zones of the bedrock, a monitoring well screened in the B-Zone will have very little information about the C-Zone, whereas a pumping well in the B-Zone could conceivably pull water from the C-Zone through vertical fractures in the bedrock. In Mr. Smyth’s opinion, pumping well data presents a better characterization of the overall quality of groundwater in the region than does monitoring well data (Tr. 1413 at 94-97).

On cross-examination, Mr. Smyth agreed with Olin’s counsel that monitoring well data is of value because it represents the movement of contaminants through the aquifer at a specific location over time. A pumping well, which draws water from a much larger area than a monitoring well, can actually change the hydraulic regime of groundwater by pulling in contaminants from sources outside the normal flow path. In fact, the very purpose of a pumping well is to aid the cleanup objective by capturing the highest concentration of contaminants from as large an area of the site as possible. In Mr. Smyth’s opinion, pumping well data presents a more representative picture of the contaminants in the aquifer of interest because monitor well data does not reflect the movement of groundwater through the fractured bedrock (Tr. 1415 at 60-64).

S-6021 is a graph prepared by Mr. Smyth as a summary of chlorinated aliphatics and chlorinated benzenes removed from the groundwater in the three-site area, beginning in 1940 when Olin began operation of its production wells, and continuing to approximately the time of trial. The graph shows a steady rise in the amount of chlorinated aliphatics being removed, with a noticeable upward turn beginning in 1991, when DuPont began operation of its shallow recovery well system; continuing in 1997 when Olin began operation of its shallow recovery well system; and a further spike in 2002, when Solvent began operation of its B-Zone pumping well system. The graph also shows chlorinated benzene removal at a very low rate throughout the entire period, with a slight increase in 2002 upon commencement of the Solvent pumping operations. According to Mr. Smyth, this exhibit represents the disparity between the large amounts of chlorinated aliphatics, as opposed to the much smaller amounts of chlorinated benzenes, being recovered by the pumping systems at the various sites (Tr. 1413 at 100-04).

S-6043 is a map of the three-site area taken from a regional groundwater assessment performed in 1992 by Woodward-Clyde and Conestoga Rovers Consultants, showing various levels of chlorinated aliphatic contamination. According to Mr. Smyth, this exhibit shows widespread groundwater contamination over the entire area of study as the result of DuPont’s chlorinated aliphatic production (Tr. 1413 at 104-06).

S-6038 is a map of the entire study area, prepared by Mr. Smyth from monitoring well results, showing 1,1,2,2-tetrachloroe-

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thane concentrations in the B-Zone groundwater. The highest concentrations emanate from the area of DuPont’s TCE and PCE manufacturing facilities, spreading to various locations in the Olin and Solvent Sites. TCE and PCE can be considered tracer chemicals for DuPont since, among the three companies, only DuPont manufactured these chemicals. According to Mr. Smyth, this exhibit shows that DuPont is the source of the chlorinated aliphatic contamination found at the Hot Spot and the Solvent Site (Tr. 1413 at 107-13).

On cross-examination, DuPont’s counsel asked Mr. Smyth about D-240, which is a copy of a 1977 report by the International Trade Commission listing Hooker Chemicals & Plastics Corp. as the only manufacturer of 1,1,2,2-TCA in the United States at that time (Tr. 1420 at 16-17). He explained on redirect examination that the Hooker facility is located to the east of the Solvent Site, and there is no groundwater contour map or other evidence to suggest that materials from the Hooker facility could have migrated to the wells at the Solvent Site and Hot Spot (Tr. 1420 at 53-54).

S-6025 is a graph and associated pie chart prepared by Mr. Smyth based on combined data obtained from the pumping wells at the Solvent Site and Hot Spot, showing average concentrations of contaminants extracted from the groundwater, divided by USEPA maximum contaminant levels. As demonstrated by the graph and pie chart, chlorinated aliphatics (TCE, PCE and vinyl chloride) represent the overwhelming majority of contaminants found in the water pumped at the Site and Hot Spot (Tr. 1413 at 113-17).

S-6037 is a graph and associated pie chart, prepared from the same data as S-6025, showing straight concentrations of contaminants pumped from the wells at the Solvent Site and Hot Spot. As in the prior exhibits, the highest concentrations are chlorinated aliphatics. The pie chart suggests that chlorinated aliphatics represent about 65% of the contaminants extracted by the Solvent pumping wells (Tr. 1413 at 118-22).

S-6024 is a pie chart comparison of chlorinated aliphatic and chlorinated benzene groundwater contamination, based on pumped well data from various reports on the groundwater remediation systems being operated at each of the Sites. According to the pie charts, chlorinated aliphatics represent 100% of the contaminant load at DuPont. At Olin and at the Hot Spot, chlorinated benzenes represent only a very small percentage (approximately 3-4%) of the contaminant load. At 3163 Buffalo Avenue, chlorinated benzenes represent approximately 98% of the contaminant load in the shallow trench (A-Zone), and chlorinated aliphatics represent approximately 70% of the contaminants being pumped from the B-Zone wells. The combined B-Zone influent, including both the Hot Spot and the 3163 Buffalo Avenue property, is approximately 60% chlorinated aliphatics and 40% chlorinated benzenes. In Mr. Smyth’s opinion, this information shows that the contaminants being pumped from the Olin Site are the same as the contaminants being pumped from the Hot Spot. The Solvent Site proper has a lot more chlorinated benzenes, but the overwhelming majority of contaminants being pumped from the B-Zone groundwater consists of chlorinated aliphatics (Tr. 1413 at 122-26).

S-6067 contains pie charts comparing the ratios of trichloroethene and tetrachloroethane (the two most prevalent chlorinated aliphatics) found in the pumped well data at each of the three sites. The comparison shows that the ratios are very similar, indicating that the chlorinated aliphatic contamination at all three sites is

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coming from the same source (Tr. 1413 at 126-27).

S-6042 is a pie chart comparison of the contaminants detected in the A-Zone shallow trench system at the 3163 Buffalo Avenue property. This system consists of three trenches installed down to the bedrock along the northern, western, and southern (including a portion of the southeastern) boundaries of the property to intercept the shallow groundwater in the overburden soils. The pie chart comparison shows that approximately 99% of the contaminants collected in the south and west trenches are chlorinated benzenes, while about 25% of the contaminants collected in the north trench are chlorinated aliphatics attributed to drum storage during the Frontenac periods of operation (Tr. 1413 at 127-30).

S-6028 is a summary of NAPL data for the three sites, compiled by Mr. Smyth from several site investigation and analytical data reports, showing the presence of NAPL associated with chlorinated aliphatics, chlorinated benzenes, and BHC throughout the study area on a widespread basis. Mr. Smyth testified that the NAPL associated with BHC is traceable to Olin, and the NAPL associated with chlorinated aliphatics is traceable to DuPont (Tr. 1413 at 130-139). He also testified on cross-examination by DuPont’s counsel that, as stated in the SRI

(see

D-14 at p. 5-5), a quantitative assessment of contaminant loading based on NAPL migration would be difficult if not impossible due to several unknown factors, such as the unreported quantities of NAPL and the variable physical characteristics of the overburden and fractured bedrock (Tr. 1417 at 155-56).

S-6044 is a map of the study area showing total chlorobenzene and chlorotoluene concentrations in the B-, C- and D-Zone groundwater. According to Mr. Smyth, this exhibit shows two large plumes joining together, one caused by the Solvent facility and one caused by the Olin facility (Tr. 1413 at 139-40).

S-6032 shows monitor well results for perchlorate in the B-Zone groundwater. Mr. Smyth used perchlorate as a tracer to show that there is a flow path from Olin’s hypochlorite production areas west of Gill Creek to the Hot Spot wells located east of Gill Creek, which indicated elevated concentrations of perchlorate (Tr. 1413 at 140-43). On cross-examination, Mr. Smyth explained that Olin did not manufacture perchlorate, but it was a “decomposition product” of hypochlorite (Tr. 1417 at 28). His opinion that there was a groundwater flow path from Olin’s hypochlorite production facility to the Hot Spot, and that Olin was the source of not only perchlorate but all of the chlorinated benzenes detected at the Hot Spot, was based primarily on samples taken on one occasion in June 2007 from two of the six B-Zone monitoring wells showing concentrations of perchlorate .above detection limits (Tr. 1417 at 30-34;

see also

0-608). He did not check to determine the groundwater impact of the long (over 60-year) history of perchlorate manufacturing operations at the nearby Occidental Chemical facility (Tr. 1417 at 37-43;

see also

0-404, 605, 607 and 623). He testified that Occidental would be an unlikely source of the perchlorate detected at the Hot Spot because of its location, which the existing documentation shows as downgradient in all of the groundwater flow zones (Tr. 1420 at 65-67).

S-6035 contains pie charts showing the relative proportion of chlorobenzene, dichlorobenzene, and trichlorobenzene materials detected in the groundwater influent from pumped wells at the Solvent and Olin Sites. According to Mr. Smyth, the pie charts show a close similarity in the proportions of materials being pumped at the

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Olin wells and the Hot Spot wells, indicating that the chlorobenzenes found at the Hot Spot came from the Olin facility (Tr. 1413 at 143-46).

On cross-examination, Mr. Smyth testified that the data represented on this exhibit was obtained by averaging the results from two pumping wells at the Hot Spot, one screened in the A-Zone and one screened in the B-Zone. Since each zone has different gradient and media characteristics, and each carries different concentrations of contaminants, a pie chart showing the average of sampling results taken from the two zones presents a completely different picture than a pie chart showing sampling results from each (Tr. 1415 at 49-56).

S-6046 is a map of Gill Creek and adjacent areas showing the location of downstream sediment samples taken during remediation activities in the late 1980s and early 1990s, along with a pie chart showing the makeup of the sampling results. Approximately 75% of the materials detected were PCBs associated with the DuPont facility, with approximately 5% attributed to chlorinated benzenes and the remaining 20% split between chlorinated aliphatics and BHC materials (Tr. 1413 at 146-47).

S-6048 contains pie charts comparing the results of sediment samples taken from Gill Creek near Adams Avenue, along with the results of soil samples taken from the Olin Site and from the Solvent Site during removal of the 18-inch storm sewer. According to Mr. Smyth, this comparison indicates that the sediment samples taken from the creek are composed of approximately 70% trichlorobenzenes, associated with the Olin Site (Tr. 1413 at 147-52). This comparison did not include available data based on sediment samples obtained from inside the sewer itself, which indicated the presence of very high levels of chlorinated benzenes, including trichlorobenzenes (Tr. 1417 at 59-63). Mr. Smyth explained that he did not use this information because of the different environmental media for samples taken from the soil and samples taken from inside a pipe, and there was no available data from the Olin Site to allow for a reasonable comparison (Tr. 1420 at 74-75).

During cross-examination, Olin’s counsel showed Mr. Smyth three separate tables from the 1995 Malcolm Pirnie SRI indicating the presence of trichlorobenzenes at very high levels in both the soil and groundwater at the Solvent Site. Specifically, 0-602 is a soil boring summary table showing concentrations of 1,2,3-trichloro-benzene at 640,000 ppb, and 1,2,4-trichlo-robenzene at 290,000 ppb, detected at a depth of between six and eight feet in the southwest portion of the Site where a tank farm was located and chlorinated benzene processing operations took place

(see

O-613). Mr. Smyth agreed that these are high concentrations, and that the 18-inch storm sewer provided a potential pathway for contaminants released from this area to find their way into Gill Creek (Tr. 1415 at 65-70). Mr. Smyth also agreed that the high levels of NAPL concentrations detected in the soil at these operational areas of the Solvent Site are associated with several documented surface releases and spills

(see

0^149), and that these areas generally drained into the 18-inch sewer (Tr. 1417 at 45-48).

0-603 is a groundwater contaminant data summary based on samples taken from A-Zone monitoring wells showing a maximum level of 24,000 ppb 1,2,4-trichlo-robenzenes detected at MW-4A, located in the northwest corner of the Solvent Site— just across DuPont Drive from the Hot Spot and monitoring well OBA-3A (Tr. 1415 at 70-71;

see also

0-615). 0-601 is a groundwater contaminant data summary based on samples taken from B-Zone

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monitoring wells showing a maximum level of 47,000 ppb 1,2,4-trichlorobenzenes detected at MW-2B, located in the southwest corner of the Solvent Site where product was loaded and unloaded from railroad cars (Tr. 1415 at 71-76).

S-6047 is an allocation summary listing the contaminants found in the Gill Creek sediments. It was compiled by Mr. Smyth from the various studies performed in connection with the Olin/DuPont cleanup efforts in the late 1980s and early 1990s. The contaminants are given an allocation rating based on an assessment of “chemical harm” and “prevalence” under three separate DEC toxicity standards: 1985 Surface Water Criteria, 1999 Sediment Criteria — Human Exposure, and 1999 Sediment Criteria — Benthic Aquatic Toxicity. Under all three criteria, the overwhelming allocation percentages are attributed to PCB 1248, alpha-BHC, and beta-BHC, which are traceable to DuPont and Olin (Tr. 1413 at 152-55).

S-6020 is an allocation summary listing the contaminants found in the soil at the Solvent Site, compiled by Mr. Smyth from the various site investigation reports. He assessed a “weighted impact” for each contaminant based on its prevalence and average concentration as compared to DEC cleanup criteria, and then normalized the weighted impacts to add up to 100% as a means of rating each contaminant against the other. Zinc was rated first, with an assessed allocation of 22.54%, followed by mercury (21.93%), 1,2,4-trichlorobenzene (13.77%), benzene (9.06%), 1,2-dichloro-benzene (4.10%), and other chlorinated benzenes, metals, and chemicals. S-6020A is the full list of contaminants found in the soil for which Mr. Smyth performed this allocation calculation (Tr. 1413 at 155-59).

S-6066 is Mr. Smyth’s allocation analysis for contaminants detected in the groundwater at the Solvent Site and Hot Spot, using pumped well (as opposed to monitoring well) data from the Solvent and Olin sites. As he did with soil contaminants, Mr. Smyth assessed a weighted impact for each groundwater contaminant, divided into two categories: aromatics, allocated at 44.5%, and aliphatics, allocated at 55.5%. According to Mr. Smyth, using a weighted risk factor as opposed to straight volumetric division of harm resulted in a 10% decrease in the allocation percentage for aliphatics (Tr. 1413 at 160-62).

On cross-examination by DuPont’s counsel, Mr. Smyth testified that he used pumped well data for the years 2002-04 in calculating the allocation percentages reported on S-6066. He was then shown D-222, prepared by DuPont’s expert, Dr. Faust, using B-Zone monitoring well data for the years 2004-06. This data reports concentrations and prevalence of chlorinated benzenes and other aromatic contaminants at 92.5%, and chlorinated aliphatics at 7.5% — significantly different than the allocation percentages reported on S-6066. Mr. Smyth explained that the monitoring well data used for this analysis represents a fraction of the contamination being intercepted by the pumping wells (Tr. 1420 at 40-46).

S-6016 is a table showing Mr. Smyth’s assessment of contaminants detected in the shallow trench system at the Solvent Site. According to Mr. Smyth, this analysis shows that chlorinated aliphatics account for only a small amount of the contaminants being intercepted by the trench system (Tr. 1413 at 162-65).

S-6065 is a summary of groundwater flow readings showing the total gallons of water removed from the shallow overburden (approximately 2.9 million gals.), Solvent Site bedrock (42.4 million gals.), and Hot Spot (43.3 million gals.) wells between March 24, 2003 and December 23, 2005 (Tr. 1413 at 165-66).

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S-6006 is a map of the three-site area showing mercury concentrations in the soil. The exhibit indicates a high level concentration of mercury in the southwest corner of the Solvent Site. In Mr. Smyth’s opinion, this was most likely caused by an accumulation of surface materials at the Solvent storm sewer (Tr. 1413 at 166-68).

S-6072 contains two bar charts, one showing pumping data collected by TRC at the Hot Spot and the other showing pumping data from the Olin shallow groundwater remediation system located in the proximity of the BHC plant west of Gill Creek. According to Mr. Smyth, a comparison of the two charts shows very similar concentrations of contaminants being pumped at the two locations (Tr. 1413 at 168-71).

S-6074 is a compilation of the two previous charts with a third bar chart showing concentrations of contaminants detected in the DuPont groundwater remediation system influent. According to Mr. Smyth, a comparison of these charts shows the similarity of the chemicals being detected in the influents at all three sites. He testified that the general groundwater containment and control systems deployed at all three sites are very similar, and that the Solvent system can be expected to remain in operation for hundreds of years due to the high level of contamination at the site (Tr. 1413 at 172-76).

Mr. Smyth testified that, based on his review of the pumping data, 94% of the contaminants detected in the pumped wells at the Hot Spot are chlorinated aliphatics associated with DuPont. At the Solvent Site proper, as well as in the combined treatment system, chlorinated aliphatics make up the majority of the chemicals being pumped. According to Mr. Smyth, the presence of chlorinated aliphatics in the aquifer impacts the remediation of the site by lengthening the time for any natural bioremediation, leaching out of NAPLs, and eventual shutdown of the treatment system. He testified that if the system was treating chlorinated benzenes alone, it would be able to reduce contaminant levels to meet the standards for discharge to the Niagara Falls water treatment plant, and shutdown of the site treatment system, much sooner. In addition, the Solvent ROD requires Solvent to evaluate the impact of the treatment system on the concentrations of contaminants in the deeper bedrock zones. If the DEC finds the impact insufficient, it could require deeper wells and expanded pumping which, given the permeability of the deeper zones at the Site, would be likely to result in increased concentrations of chlorinated aliphatics in proportion to chlorinated benzenes (Tr. 1415 at 4-11).

2. Gary T. Hunt

Mr. Hunt is a Qualified Environmental Professional, currently employed by TRC. His area of expertise pertinent to this case is the impact on the environment of emissions of toxic air pollutants from stationary sources. He was retained by Solvent to investigate and report on the potential sources of mercury found in the soils at the Solvent Site (Tr. 1420 at 91-93).

He began his analysis by reviewing the available soil sampling data and documentation on the historical uses of the property since the inception of chemical production there in the early 1940s, finding no indication of activities that would account for the pervasive and widespread mercury contamination in the soils at the Site. His investigation of off-site sources revealed that Olin had operated a chlor-alkali production (“CAP”) facility to the west and upwind of the Solvent Site, which the open literature confirmed was a potential major source of mercury emissions. Based upon his review of the available data, historical

*377

documents, peer-reviewed literature, deposition transcripts, results of air emissions dispersion modeling, and several other sources of information

(see

S-6080), Mr. Hunt reached the conclusion that the mercury found in the soils at the Solvent Site can be attributed to emissions from the Olin CAP (Tr. 1420 at 95-102).

S-6081 is a summary of the mercury detected in 21 soil samples collected at the Solvent Site in the 1990s. According to Mr. Hunt, this exhibit confirms the pervasive nature of the mercury contamination at the Site, at concentrations well above accepted background levels for urban soils in the United States

(see

S-6082). S-6006 is a contour map of the three-site area of study showing mercury soil concentrations as represented in the available soil data. Specifically, with respect to the Solvent Site, this exhibit shows the areas of concentrations of mercury as reported in the 21 soil samples represented on S-6081. According to Mr. Hunt, such pervasive contamination is unusual for a parcel of that size, particularly where there is no history of mercury use on the property. He identified Olin as the likely source, given the history of mercury use at its chlor-alkali production facility from 1897 through the early 1990s

(see

S-6041, 6083), the upwind location of the Olin facility as indicated by the “five year wind rose” represented on S-6006, and the lack of any information regarding mercury use at the DuPont Site (Tr. 1420 at 102-20).

Mr. Hunt explained his understanding of the chlor-alkali cell process, which involved the use of mercury to function essentially as an electrode in the electrolytic production of chlorine, caustic soda, and other products. The mercury was not consumed and would generally remain in the cell to be re-used in the process, but it commonly escaped into the environment as a vented gas, as a component of the “brine mud” waste product periodically removed from the cell, as the result of volatilization due to spills, or through other fugitive releases

(see, e.g.,

S-4086). Industry awareness of these problems eventually led to regulatory initiatives, resulting in the adoption in 1973 of national emission standards to specifically address mercury handling issues at chlor-alkali production facilities (Tr. 1420 at 122-32).

Mr. Hunt discussed several other documents which he relied upon in reaching his conclusions about the source of the mercury contamination at the Solvent Site. Figure 3 from the October 1988 Woodward-Clyde Olin Site Groundwater Assessment (0-243) shows the location of five mercury cell rooms at the Olin Site. Mr. Hunt testified that four cell rooms, containing a total of more than 2000 production cells, operated for a period of approximately 60 years, and a fifth cell room containing 58 cells operated for a period of approximately 30 years. According to Mr. Hunt, these operations resulted in the release of a significant amount of mercury into the atmosphere and environment in the area of the Olin Site. For example, Figure 31 from O-243 shows mercury concentrations detected at elevated levels in soil borings in the area of Olin Plant 2, where three of the five cell rooms were located (Tr. 1420 at 134-42).

S-4112 is an internal Olin memorandum dated August 14, 1991, entitled “Environmental Status of Niagara Falls Plantsite.” The authorship is not indicated on the memorandum itself, but Mr. Hunt identified the author as a Mr. Brown. The memorandum discusses several issues related to the anticipated partial or complete shutdown of the Olin Niagara Falls facility, including the cost of corrective action to address contaminated soils resulting from the mercury cell chlor-alkali operations (Tr. 1420 at 142-43).

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S-4113 is a February 1992 Woodward-Clyde RCRA Investigation Interim Report for the Olin Site, discussing at section 9.1.1 the evidence of widespread mercury contamination characteristic of emissions occurring over nearly 100 years of mercury cell operations at the Olin facility. S-4117 is the Woodward-Clyde Phase I Corrective Measures Study for the Olin Site, dated November 1993. Figure 4-1 depicts the soil management area, including the areas of both Plants 1 and 2 which contained the chlor-alkali cell rooms. According to Mr. Hunt, the remedial measures taken by Olin included some type of cover or cap of the soil management area (Tr. 1420 at 143-48).

Mr. Hunt described the steps taken by TRC to determine the potential impact of mercury emissions associated with Olin’s chlor-alkali production activity on the soils at the 3163 Buffalo Avenue property. The principal analytic tool was an atmospheric dispersion modeling process using a computer program known as the Industrial Source Complex Model. The input parameters were based on available source identification information, mercury emission rates for cell room number five, meteorological data, representative ambient background levels for mercury in the air and soils in the study area, studies of environmental impacts at other chlor-alkali plants, and other pertinent data. The modeling program was run by TRC meteorologist John McCutcheon, and the results were plotted as predictive annual averages for mercury concentrations in both the atmosphere (see S — 6011) and soils (see S-6009). Based on these results, Mr. Hunt concluded that Olin’s chlor-alkali production was the most likely source of the mercury found in the soils at the 3163 Buffalo property (see Tr. 1420 at 148-56; Tr. 1421 at 2-43).

On cross-examination, Mr. Hunt agreed that the modeling results for soil deposition indicated that the highest concentrations of mercury would occur on the northwest portion of the Solvent Site, whereas the actual results of soil sampling showed the highest concentrations occurring in the southwestern portion of the Site. He explained that the purpose of the modeling was to determine if Olin’s CAP could account for the overall presence of mercury at the Solvent Site, not to predict where the highest concentrations might be found (Tr. 1421 at 101-08).

Mr. Hunt testified that TRC also performed a dispersion modeling analysis to determine the possible impact on Solvent Site soils of chlor-alkali production at the Occidental plant, located to the east and upwind of the Solvent Site. Due to the limited availability of chlor-alkali production and sampling data from Occidental, TRC used the input parameters from the Olin model, essentially placing Olin’s cell room five at the most likely location of Occidental’s CAP. The results of the modeling, as depicted on S-6010, indicate that Occidental’s mercury emissions had a limited ambient impact on the Solvent Site, estimated to be less than 10% of the impact of Olin’s chlor-alkali production (Tr. 1421 at 43-51). Mr. Hunt also testified that there was no information available for his review to substantiate the theory that contaminated fill material might have been a significant source of the mercury concentrations detected at the Solvent Site (Tr. 1421 at 51-54).

3. Paul Hughes

Mr. Hughes is the Project Manager in charge of the design and implementation of the remediation activity at the Solvent Site, as required by the December 1996 Solvent ROD (see S — 1012) and the October 1997 Solvent Consent Decree (see D-103).

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He was initially hired as a subcontractor by AIG Environmental Management, Inc., to provide design services for the remedy. He eventually became employed by TRC, which was the firm retained directly by Solvent to perform construction, operations, maintenance, and monitoring services at the Site (Tr. 1422 at 8-12).

S-1012 is the declaration statement from the Solvent ROD summarizing the seven major elements of the remedy being implemented at the Solvent Site and Hot Spot. The first element is described as containment of highly contaminated soils onsite with a clean cover system, which Mr. Hughes explained was implemented by installing a 12-ineh-thiek, generally clean soil cover across the entire site to prevent direct contact with contaminated soils, and to prevent migration due to wind or surface water erosion. The second element, control and collection of contaminated overburden groundwater, refers to construction and operation of a system to drain and collect the water from the overburden materials for treatment and disposition. The third element, phased bedrock hydraulic system for control of contaminated bedrock groundwater, refers to construction and operation of a series of pumping wells in the B-Zone, which is the upper transmissive zone of bedrock at the Site. The fourth element, monitoring and evaluation of B-Zone and lower bedrock groundwater, refers to ongoing monitoring of groundwater by elevation and quality measurements to evaluate the effectiveness of the pumping system. The fifth element refers to treatment and disposal of the pumped water, which involves pretreatment of the collected groundwater and discharge to the Niagara Falls POTW. The sixth element refers to the long-term monitoring program for the remedy. Mr. Hughes was not involved with the seventh and final element, which refers to deed restrictions to prevent future uses of the property incompatible with the remedy (Tr. 1422 at 12-16).

Mr. Hughes testified that AIG was responsible for the initial design of the remedial plan, negotiating access to the property, and other activities outlined on S-2023. The first site activity undertaken by TRC involved baseline groundwater monitoring at the 3163 Buffalo Avenue property in late 1997 to collect data and evaluate the status of the existing monitoring wells. TRC sought access to Olin’s property at that time to perform baseline monitoring at the Hot Spot, but was denied (Tr. 1422 at 17-20;

see also

S — 1081).

S-1022 is a letter from AIG to the DEC dated May 12, 1998, reporting the results of a pump test conducted by TRC in March 1998 at PW-2B, located in the northwest corner of the 3163 Buffalo Avenue property. The purpose of the test was to obtain preliminary site-specific information about how the B-Zone aquifer would respond to the stress of pumping activity. As indicated in the correspondence to the DEC, groundwater samples taken during test pumping showed decreasing levels of site-specific contaminants (benzenes and chlorobenzenes), as expected. However, the samples also showed unexpected increased levels of non-site-specific contaminants, including TCE, PCE, and BHC. According to the test report, sampling after one hour of pumping at a rate of 60 GPM (60 gallons per minute) indicated a ratio of 35% site-specific contaminants to 65% non-site-specific contaminants. After 20-plus hours of pumping, the ratio was 10% site-specific to 90% non-site-specific contaminants detected. As identified in the test report, the non-site-specific compounds were primarily chlorinated aliphatics (Tr. 1422 at 21-28).

Mr. Hughes testified that TRC also conducted a preliminary subsurface investiga

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tion of the 18-inch storm sewer running from the 3163 Buffalo Avenue property to Gill Creek to determine the scope of the sewer remediation project. According to Mr. Hughes, soil sampling at a variety of locations along the sewer line detected chlorinated benzenes and some inorganic compounds, but the soil contamination was deemed non-pervasive, and the remedial design was limited to the area of the sewer line and bedding (Tr. 1422 at 28-30).

To determine the placement of the pumping wells to be used in the groundwater remedy at the Solvent Site, Mr. Hughes reviewed the hydrogeological studies represented in the Solvent ROD, which indicated a general groundwater flow from south to north, influenced by man-made features to the north and northeast. Based on this information, Mr. Hughes determined that the hydraulic control required by the ROD would be most efficiently achieved by placing the wells along the northern property boundary. This remedial design was submitted to, and approved by, the DEC (Tr. 1422 at 30-32).

Construction of the remedy began in October 1999 with the installation of the overburden collection trench and pumping wells (also referred to as “production” or “extraction” wells). A plan view of the Site and the Hot Spot area (S-1057, JFM1070529)

5

shows the A-Zone collection trench and well system as built. The system was designed to manipulate the groundwater flow in order to eliminate offsite migration. Once the system was in place, additional aquifer testing was performed during the winter of 2000 to gather hydraulic control data at newly installed production wells along the collection trench in the Hot Spot area (PW-3B and 4B) and in the northern part of the 3163 Buffalo Street property (PW-5B and 6B) (Tr. 1422 at 32-36).

The next major construction event was the remediation of the 18-inch sewer, which took place in the summer of 2000. S-1057 (JFM1070534) is a drawing of the sewer remediation area, representing the different categories of remedial activity, including complete removal of the sewer and contaminated soils, where possible, and in-place closure and abandonment of the sewer in certain places where removal was not an option. The excavated soils were stockpiled on the Solvent Site, along with the soils excavated during construction of the A-Zone trench. Subsequent soil samples sent to the DEC confirmed satisfactory remediation of the predominant contaminants of concern (Tr. 1422 at 37-40).

The next step was construction of the soil cover by first establishing subcover grades for proper drainage, utilizing the soils stockpiled from the storm sewer remediation and A-Zone trench excavation. A geotextile vapor barrier was then installed, followed by 12 inches of clean fill over the entire site. Other surface elements included construction of a building housing the equipment to be used for pretreating the water for eventual discharge to the POTW and, finally, access roads and fencing (Tr. 1422 at 41-47;

see

S-1032). Mr. Hughes testified on cross-examination by DuPont’s counsel that using the heavily contaminated excavated soils for subcover grading added chlorinated benzene materials to the property, to be flushed into the groundwater over time (Tr. 1422 at 193).

On cross-examination by Olin’s counsel, Mr. Hughes testified that he was unaware

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of any information suggesting that any entity other than Solvent was responsible for the chlorobenzenes found in the soils at the Site. He has worked on hundreds of environmental remediations and has never encountered higher concentrations of chlorobenzenes than those detected in the soils at the Solvent Site (Tr. 1422 at 121-22). However, he also testified that this was the first site he had ever worked on where the facility was in the business of manufacturing chlorinated benzenes (Tr. 1425 at 111-12). He was shown 0-445, which is a map of the Site taken from the 1995 Malcolm Pirnie SRI representing the extent of NAPL either observed or suspected to be present in the soils along the 18-inch sewer line and other areas of the 3163 Buffalo Avenue property where historical chemical handling operations took place. He was also shown OA149, which depicts the location of reported chemical spills in relation to the detected or suspected presence of NAPL at the Site. He generally agreed that the NAPL found at several locations along the sewer line in both the soil and inside the sewer itself was associated with chlorinated benzene contamination, and that the sewer drained areas of the Solvent Site directly into Gill Creek (Tr. 1422 at 120-38).

0-319 is a letter from the DEC to Michael Plumb of TRC, dated January 16, 2003, in which the DEC acknowledges the completion of all major remedial construction activities at the Solvent Site. By letter dated May 16, 2003, TRC transmitted its Final Engineering Report and Engineer’s Certification

(see

S-1057, JFM107054142), which were approved by the DEC in July 2003

(see

S-1059, 1060; Tr. 1422 at 47-50).

S-1065 is a transmittal letter and excerpts from the Performance Monitoring Plan for the Solvent Site, submitted to the DEC by TRC in June 2004. As outlined in a summary at Table 3-1 of this report, and as testified to by Mr. Hughes, these activities included monitoring the performance and integrity of the clean soil cover to ensure that it continued to contain contaminated soils; measuring the water levels in the collection trench and surrounding soil to determine whether the A-Zone groundwater was migrating to the trench; measuring water levels in the production and observation wells to determine the effectiveness of hydraulic control of contaminated groundwater in the B-Zone; water quality sampling of B-Zone and deeper monitoring wells; and water quality sampling of pumped and pretreated groundwater for discharge to the POTW, including submission of quarterly self-monitoring reports to the DEC, to ensure compliance with the discharge permit. The DEC approved the performance monitoring plan in July 2004, marking the completion of remedial construction and start-up activities and the beginning of operation, monitoring, and maintenance (“O, M

&

M”) activities (Tr. 1422 at 50-56;

see

S-1083, JFM1076174-75).

Mr. Hughes testified that the remedy ultimately approved for the Site differed in a number of ways from the original design. The major modification involved a shift away from “formation grouting” or a “grout curtain,” explained as a process for plugging up groundwater flow in the bedrock aquifer to reduce the amount of pumped water necessary to effect hydraulic control. Implementing this option would not have eliminated the need for pumping wells because the grout curtain would not address the horizontal flow of water entering the site from above. A grout curtain was also considered and rejected as an option for the Hot Spot, due to din’s concerns about the need for further hydrogeological study. Ultimately, the decision not to utilize a grout curtain at the 3163 Buffalo Avenue property was

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based on the aquifer testing program data, which indicated that more than half of the water produced by the pumping wells would be coming from Hot Spot wells PW-3B and PW-4B, located outside the grouted area (Tr. 1422 at 56-68;

see

S-1032, 2023,1040,1048, 1081; 0-312).

Mr. Hughes testified that the expected flow rate for groundwater pumping to attain the hydraulic control indicated in the Solvent ROD was estimated at a range from 175 to 225 GPM

(see

S-1012), and the conceptual design flow rate was estimated at 200 GPM. These estimates represented the combined total of the pumping rates of all B-Zone wells and A-Zone wells

(see

S-1045). However, a number of problems related to contaminant loading were encountered while operating the wells and pretreatment system during the “start up-prove out” period in late 2001 and early 2002, requiring the eventual modification of the flow rates to meet the limits of the POTW permit. As reported to the DEC in a letter dated March 29, 2002 (S — 3038), sampling of groundwater influent at wells PW-2B and PW-4B revealed substantially elevated levels of chlorinated aliphatics, while site-specific indicator compounds

(ie.,

chlorinated benzenes) were being detected within design criteria. TRC proposed a six-month study, during which the wells would be pumped at reduced rates in order to get a better understanding of how contaminant concentrations responded to different pumping rates over time. This proposal was approved by the DEC

(see

S-1083, JFM1069577-78), and the pumping wells began continuous operation in May 2002 (Tr. 1422 at 68-78).

S-1083 (JFM1069572-73) is a monthly progress report dated June 14, 2002, indicating that continuous operation of the groundwater extraction and pretreatment system began in May at a reduced pumping rate of 40 to 50 GPM. Individual well sampling and discharge sampling identified continued exceedences of discharge permit limits for chlorinated aliphatics, leading to discussions between representatives from Solvent and the POTW regarding temporary modification of the permit to allow the system to operate at pumping rates sufficient to demonstrate the hydraulic control required by the Solvent ROD. As testified to by Mr. Hughes, the monthly progress reports for June and July 2002 reflect that the predominant contaminants of concern associated with Solvent’s historical activity at the Site did not impede operation of the extraction and pretreatment system within permit limits (Tr. 1422 at 79-83).

S-3039 is a letter from TRC to the DEC dated October 21, 2002, summarizing issues for discussion at a meeting scheduled for the end of the six-month study period. As discussed in this letter, the overall pumping well flow rate was gradually increased during this period from a low of 40-50 GPM to a high of 120 GPM, and high concentrations of chlorinated aliphatics continued to be detected in the groundwater extracted at PW-2B and PW-4B. Mr. Hughes testified that, at the urging of the POTW, TRC investigated possible sources of the chlorinated aliphatics causing the discharge permit violations. The investigation identified the lower zones of fractured bedrock beneath the East Plant area of the DuPont facility, where historic TCE and PCE operations were located, as one possible source. As reported in the October 21 letter, there was no active groundwater remediation system in place at the DuPont Site to address the documented presence of groundwater contamination and DNAPL containing chlorinated aliphatic compounds (Tr. 1422 at 83-91).

The meeting between TRC and the DEC took place on October 24, 2002. As indicated in TRC’s monthly report for No

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vember 2002 (S-1083, JFM1069562), the DEC found the evidence regarding the source of the chlorinated aliphatic contamination to be compelling, and indicated its intent to encourage DuPont to engage in discussions with Solvent to address the problem. However, Solvent was advised that it remained responsible for fulfilling its Consent Decree obligations. As Mr. Hughes testified, the Solvent ROD required Solvent to pump and treat whatever contaminants are found in the water in order to attain hydraulic control of the Site, and the system in place was incapable of extracting only the chlorinated benzene contamination due to the inseparability of the dissolved contaminants in the groundwater (Tr. 1422 at 91-93).

S-3040 is a letter dated November 25, 2002, from Michael Hinton of the DEC to Paul Mazerski at DuPont Environmental Remediation Services requesting that DuPont immediately undertake an evaluation of options to address the off-site migration of contaminants from DuPont’s East Plant which the DEC had determined were adversely affecting the operation and performance of the remedial system in place at the adjacent Solvent Site. Mr. Hughes testified that he did not know whether DuPont ever responded to this letter (Tr. 1422 at 93-95).

0-317 is a letter from TRC to Albert Zaepfl, Industrial Monitoring Coordinator for the Niagara Falls POTW, requesting a permanent modification of the discharge permit. The POTW approved the modification in December 2002, allowing Solvent to operate its pump and treat system at 80 GPM without additional permit violations

(see

S-1083, JFM1069558). Mr. Hughes testified that this is the approximate overall rate at which the B-Zone system currently operates, and that the DEC approved the degree of hydraulic control achieved at this flow rate for the entire Site (Tr. 1422 at 95-101, 103-05;

see also

0-321; S-1083, JFM 1075232-33).

In June 2003, the POTW made a further modification to the permit to allow for the discharge of T-cyanide and BHC, which had been detected in recent verification samples

(see

S — 1065; Tr. 1422 at 102-03).

In March 2004, the DEC advised Solvent that it had reviewed the results of a continuous 24-hour B-Zone bedrock groundwater level monitoring event conducted in December 2003, which presented data from routine pumping as well as static conditions after a week-long shutdown for system maintenance. Based on this review, the DEC found sufficient hydraulic control of the bedrock groundwater at the Solvent property and the Olin Hot Spot to justify using the 24-hour monitoring event data as baseline hydraulic conditions for long-term performance monitoring (Tr. 1422 at 105-06;

see also

S-1062, 1064).

S-6064 is a summary of the costs incurred by Solvent as of June 30, 2007 for remediation of the 3163 Buffalo Avenue property and the Hot Spot, broken down on a chronological basis. S-6063 is a summary of the remediation costs incurred per task, along with future costs of operation, monitoring, and maintenance projected over a 30-year period. Mr. Hughes explained the general nature of the activities performed for each category of costs listed, and testified that in his opinion the operation, monitoring, and maintenance period is likely to last longer than 30 years (Tr. 1422 at 107-18).

4. James Kohanek

Mr. Kohanek is Vice President of Tech Law, Inc., located in Chantilly, VA. He has a Bachelor of Science degree from Saint John’s University in Collegeville, MN, a Master’s degree in chemistry from San Diego State University, and a Juris Doctor degree from Capital University

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Law School. His professional experience includes five years of working in the chemical industry, five years of working on Superfund cases as senior enforcement counsel for the USEPA in Washington, DC, and more than twenty years in the private sector performing a wide variety of roles as consultant, mediator, arbitrator, and court-appointed expert in cases involving the allocation of the costs of environmental remediation (Tr. 1423 at 2-5;

see

S-6049). He has no field experience in the areas of environmental engineering, geology, hydrology, hydrogeology, groundwater monitoring, or the movement of contaminants in the environment (Tr. 1423 at 98-100).

Mr. Kohanek was retained by Solvent to develop a methodology for the court to utilize in allocating the remediation costs at issue in this case. His methodology and proposal include all settling and non-settling potentially responsible parties, and all three areas of concern — the 3163 Buffalo Avenue property (including issues regarding soils, overburden groundwater, and bedrock groundwater), the Hot Spot (primarily involving bedrock groundwater), and Gill Creek (involving sediment issues) (Tr. 1423 at 5-8).

Mr. Kohanek testified that when he performs an allocation, there are three primary considerations: first, to determine the harm caused by the contaminants of concern; second, to determine the sources of the contamination causing the harm; and third, to determine the relative contribution of each source. To assist in this task, he relies on Tech Law staff for assistance in organizing the testimonial and documentary information, and often looks to outside organizations for technical expertise. In this ease, he also relied heavily on the technical information provided by Andrew Smyth and Gary Hunt from TRC, essentially adopting their findings with respect to the sources of the contaminants causing the harm at the areas of concern (Tr. 1423 at 8-11).

S-6051 is a color-coded map representing Mr. Kohanek’s attempt to identify the general locations of the 3163 Buffalo Avenue property where Solvent handled materials containing contaminants of concern. He explained his understanding that Solvent’s operations included manufacturing chlorinated benzenes from the reaction of benzene and chlorine, as well as bringing in waste chlorinated benzene materials for reprocessing into useable product. As indicated by this map, chlorinated benzenes were handled in several areas of the property. Mr. Kohanek’s review of the historical information, remedial investigation reports, and prior testimony revealed that Solvent was not a highly sophisticated chemical company, at least during the early days of its operation, and many spills and other releases of these materials occurred at the Site (Tr. 1423 at 11-14).

S-6054 depicts the general location of Frontenac’s material handling operations at the Site. Mr. Kohanek testified that Frontenac was basically a storage company which handled a wide variety of chemical wastes, including TCE and PCE. Most of the material was transported to the facility in drums, which were stored for short periods in buildings, parking lots, and other areas of the Site and transported back out again. There was little available information regarding Frontenac’s raw material handling, spills, ruptures of containers, or other releases indicating any major cause for concern (Tr. 1423 at 14-17).

As part of his work identifying potential sources of the contamination at the Solvent Site, Mr. Kohanek also reviewed the available historical documents, remedial investigation reports, and testimony pertaining to operations at the adjoining Olin and Du

*385

Pont facilities, which indicated the occurrence of events resulting in major releases of contaminants. These events included the 1956 explosion at Olin’s BHC facility, Oliris mercury cell operations, and DuPont’s TCE and PCE production (Tr. 1423 at 17-19).

S-6050 is a chart Mr. Kohanek prepared entitled “Allocation Parties,” listing the entities identified as owners or operators of the facility at 3163 Buffalo Avenue and the “Adjoining Migrating Facilities.” The chart also indicates which of these entities might be responsible for the chlorinated benzenes, chlorinated aliphatics, metals, and other contaminants of concern detected at the Solvent Site (Tr. 1423 at 19-24).

S-6052 lists the “Arrangers” who transported chlorinated benzene waste material to Solvent during the years of its operation. The chart indicates the volume of chlorinated benzene waste assigned to each arranger, measured against the total volume of chlorinated benzene waste brought into the facility during Solvent’s operation, to determine individual arranger shares by percentage. S-6053 presents the same type of volumetric waste-in information for arranger parties during the Frontenac period of operation of the Site, based on shipping records, manifests, deposition testimony, and other available data. This list does not indicate arranger shares by percentage (Tr. 1423 at 24-27).

S-6055 is a chart summarizing the first two steps of the allocation framework employed by Mr. Kohanek to assign relative contribution percentage shares for the contamination of the on-site soils at the 3163 Buffalo Avenue property. The first step involved assigning a contribution share for each of the contaminants of concern (representing the percentage of the total harm to the soils caused by each contaminant), based on the quantitative information and risk-weighted allocation calculations provided by Mr. Smyth

(see

S-6020A). Mr. Kohanek added up the percentages assigned to the individual contaminants detected in the soils and arrived at contribution shares of 38.72% for chlorinated benzenes, 0.01% for chlorinated aliphatics, 22.54% for zinc, 21.93% for mercury, and 16.80% for other mixed wastes not directly attributable to any specific source (Tr. 1423 at 27-32).

The second step involved Mr. Kohanek’s attempt to ascribe weighted percentage shares to the identified sources of these contaminants. The sources are listed as follows: Solvent Chemical; Recochem, Inc.; FES I (referring to Frontenac’s operation of the Site between 1/80-3/81, under ownership of Laidlaw Transportation Co.); FES II (Frontenac’s operation of the Site between 4/81-8/83, under ownership of George Lodick); Conrail (operator of railroad services at the Site); Bema (Canadian company related to Frontenac); and Corigan Sanoian (owner of 3163 Buffalo Ave. from 1983-1999). Based on the percentages of harm to the soil ascribed to the specific contaminants of concern reported in step one, as weighted against the extent of related site operations by each owner/operator, Mr. Kohanek assigned relative contribution shares of 59.07% to Solvent, 19.74% to Olin, and the remainder (totaling 21.19%) to the other identified sources. DuPont was assessed no contribution share for harm to the soils (Tr. 1423 at 32-39).

S-6055.2 illustrates Mr. Kohanek’s calculations at step three, involving assignment of shares between owner-operators (responsible for the handling of materials at the Site) and arrangers (responsible for shipping wastes to the Site). S-6055.3 illustrates Mr. Kohanek’s calculations at step four involving assignment of adjusted shares for individual arrangers during the FES I and FES II periods of operation.

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S-6055.4 shows the assignment of adjusted shares for individual arrangers during the Solvenf/Recochem period of operation. According to Mr. Kohanek, these calculations represent classic allocation work dealing with distribution of contribution shares among parties based on volumetric data (Tr. 1423 at 40-45).

S-6056 illustrates Mr. Kohanek’s calculations for assignment of contribution shares for contamination of the overburden (A-Zone) groundwater at the 3163 Buffalo Avenue property. Following the same step-by-step framework as he did for soils, he first ascribed relative shares to the contaminants of concern, assigning chlorinated benzenes a 97.3% contaminant contribution share, and chlorinated aliphatics a 2.87% share. The chlorinated aliphatic shares were broken down further as 2.17% ascribed to the north trench, and 0.70% ascribed to the south and west trenches. At step two, he assigned the relative contribution shares to the identified sources of the contaminants based upon their operations, resulting in the following total contribution share percentages for A-Zone groundwater contamination: Solvent = 89.36%; Recochem = 5.83%; FES II = 2.17%; Conrail = 1.94%; and DuPont = 0.70%. At steps three and four, Mr. Kohanek assigned percentage shares among owner/operators and arrangers based on the degree of their involvement with the contaminants detected in the A-Zone groundwater

(see

S-6056.2). S-6061 is an allocation summary listing the results of these calculations (Tr. 1423 at 47-64).

Mr. Kohanek testified that the same framework was used to develop contribution shares for the B-Zone bedrock groundwater contamination at 3163 Buffalo Avenue and the Hot Spot. S-6057.1 illustrates Mr. Kohanek’s calculations for 3163 Buffalo Avenue. At step one, he assigned contaminant contribution shares of 31.61% for chlorinated benzenes, and 68.39% for chlorinated aliphatics. At step two, based on the sampling data and hydrogeological information provided by Mr. Smyth, Mr. Kohanek assigned Solvent a 92% contribution share for the chlorinated benzene contamination, and DuPont a 98% share for the chlorinated aliphatic contamination. He then distributed the relative contaminant shares among the identified sources, including owner/operators and arrangers, based on the degree of their involvement with the contaminants detected in the B-Zone groundwater. As a result of these calculations, Mr. Kohanek assigned contribution shares of 67.02% to DuPont and 0.63% to Olin, with the remaining 32.35% assigned to Solvent and its related owner/operators and arrangers

(see

S-6057, 6061, 6078; Tr. 1423 at 64-79).

Using the same framework to determine contribution share percentages for bedrock groundwater contamination at the Hot Spot, Mr. Kohanek assigned chlorinated benzenes a relative contaminant share of 6.48%, and chlorinated aliphatics a relative contaminant share of 93.52%, distributed among the sources as follows: DuPont, 93.52%; Olin, 6.35%; Solvent and its related owner/operators and arrangers, 0.13%

(see

S-6059, 6061, 6078; Tr. 1423 at 79-86).

S-6060 illustrates steps one and two of Mr. Kohanek’s framework for allocating the costs of the Gill Creek remediation. Step one involved assigning relative contribution shares to the various contaminants found in the creek sediment samples, based on the data summary provided by Mr. Smyth

(see

S-6047), which resulted in average contribution shares of 0.44% for chlorinated benzenes and 99.56% for all other contaminants. Step two involved comparing the chemical composition of the chlorinated benzenes found in the creek

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sediment samples, storm sewer samples, and Olin plant soil samples, and assigning contribution shares as between Solvent (40%) and Olin (60%), the two identified sources of the chlorinated benzene contamination. When redistributed based on the average contaminant share of 0.44% for chlorinated benzenes, the result was an assignment of a 0.18% contribution share to Solvent and a 0.26% contribution share to Olin for the costs associated with cleanup of the chlorinated benzenes detected in the Gill Creek sediments (S — 6060; Tr. 1423 at 90-97).

On cross-examination by DuPont’s counsel, Mr. Kohanek testified that this overall allocation methodology did not take into account the variations in contaminant loadings that might occur over time as the result of remedial activity (Tr. 1425 at 60-61).

B. Olin’s Witnesses

1. Kelly McIntosh

6

Mr. McIntosh is an environmental engineer, currently employed by Geomatrix Consultants. He has a Bachelor of Science degree in biology from Penn State University, a Master’s degree in hydrology from the University of New Hampshire, and a Ph.D. from the University of Delaware. He was hired by Woodward-Clyde in 1984, and gained knowledge of the soil and groundwater in the areas of concern in this case through his work on several projects for both DuPont and Olin involving operations at their Niagara Falls facilities. He was transferred to Western New York in 1989 to work as project manager for the groundwater investigations, corrective measure studies, and remediation activities that took place at Olin’s Niagara Falls plant. He was directly involved with the remedial activities at Gill Creek in the 1990s, and was Olin’s on-site representative during the remediation of Solvent’s 18-inch storm sewer in 2000. He also served as project manager for both DuPont and Olin in connection with the development of the 1992 Woodward-Clyde/Conestoga Rovers regional groundwater assessment (Tr. 1430 at 3-13).

Mr. McIntosh testified that he was aware of a prior remediation effort at Gill Creek in 1980 which addressed only certain portions of the creek and was ineffective in removing the contaminated sediments in the area of the Adams Street Bridge. S-4519 is the March 1991 Consent Decree between the State, Olin, and DuPont dealing with the further remediation of Gill Creek, and S-4527 is the March 1992 Gill Creek ROD which outlined the procedures for implementing the selected remedy. As indicated in the ROD, the creek was divided into three primary areas of concern — Area 1, the farthest downstream section of the creek extending from the Staub Road overpass to the Niagara River; Area 2D, the downstream area from just south of Adams Avenue to Staub Road; and Area 3, encompassing the area in the general location of the Adams Avenue Bridge. The remedial plan for Area 3 involved the construction of dams to dewater the sediments before excavation, with seepages of groundwater into the excavation zone to be controlled by collection, on-site pretreatment, and discharge to the

*388

POTW

(see

S-4527, Fig. 2; Tr. 1430 at 15-20).

0-469A is a 1990 aerial photograph depicting Gill Creek between Buffalo Avenue and the Adams Avenue Bridge, along with the Olin plant parking lot and the Solvent Chemical Site. Also depicted on this exhibit is the Solvent 18-inch storm sewer, which extended from the northwest corner of the Solvent Site southward along the entire western boundary, and then from the southwest corner westward along the southern boundary of the Olin parking lot, finally emptying into Gill Creek at the diversion dam located to the north of the Adams Avenue Bridge (Tr. 1430 at 21-23).

Mr. McIntosh testified that his investigatory work involved collecting sediment samples in Area 3, revealing levels of chlorinated benzenes which exceeded State cleanup goals by orders of magnitude, meaning hundreds or thousands of times higher than recommended levels. As he walked through the creek bed, he observed NAPL being transmitted up through the water column to form an oily sheath on the surface. His recommendation was removal of the sediments from the creek bed in Area 3. This recommendation was ultimately adopted by the DEC in the Gill Creek ROD (Tr. 1430 at 23-28).

The design and engineering of the Gill Creek remedy was an extensive process involving hydrogeologie analysis, a complex treatment program, and a multi-phase diversion dam construction procedure — as well as deconstruction of the dams and restoration of the normal flow of the creek. Diversion dams were built on the north side of Buffalo Avenue to divert the creek waters into the City of Niagara Falls diversion sewer, and on the southern end of the creek at the Niagara River. Additional dams were built to the north and south of Adams Avenue to divert and collect groundwater seepage for treatment (Tr. 1430 at 28-34).

Mr. McIntosh was involved in oversight, inspection, and certification of the excavation work performed in Area 3. He testified that the bulk of the sediments were removed, using a small “Bobcat” excavator, followed by hand removal, and then high-pressure spraying of the top of bedrock sediments. The spray water was collected and sent to the treatment facility, along with fluid that was found seeping from the creek bank on the southwest side of the Adams Avenue Bridge abutment. A sample of the seep fluid sent for analysis revealed NAPL containing chlorinated benzenes, which triggered further excavation of creek bank soils, installation of monitoring wells, and other measures to determine whether the seeps were traceable to soil or groundwater contamination at the Olin Site. 0-604 is the December 1993 Gill Creek Remediation Project Final Report, prepared by Mr. McIntosh. He reported that no additional seeps were observed during this investigation of the dewatered western creek bank, which led him to conclude that the likely source of the NAPL was not the Olin Site soils but rather the outfall of the Solvent 18-inch storm sewer located on the east bank of the creek, north of the Adams Avenue Bridge (Tr. 1430 at 34^3).

On cross-examination by Solvent’s counsel, Mr. McIntosh was shown S-4530, which is an Olin interoffice memorandum dated October 7, 1992 discussing the sampling results for the NAPL seep taken from the west bank of the creek in Area 3. He agreed with Solvent’s counsel that the highest concentration reported in this sample was alpha BHC, indicating that the NAPL contained a lot of solid BHC which could not be diluted to liquid form in the environment. He also agreed that the high concentration of BHC, combined with

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reported high levels of trichlorobenzenes, indicated that the NAPL could have come from the Olin facility (Tr. 1432 at 20-23).

Mr. McIntosh testified that he was also the project manager for the remediation of the Olin Site, which took place between 1989 and 1995. He was responsible for the design of the site investigation and remedy, including development of several work plans, writing the RCRA Facility Investigation (“RFI”) Report and Corrective Measures Study (“CMS”), and certifying the results to the DEC. His investigatory work included soil and groundwater sampling in the area located between Alundum Road and Gill Creek (the “ARGC” area), which revealed contamination related to Olin’s production of BHC from chlorinated benzenes (Tr. 1430 at 45-53).

0-234 is a segment of the Phase II Corrective Measures Study for the Olin Site, dated March 1995. Mr. McIntosh testified that the purpose of the study was to evaluate the results of the RFI and to propose a remedy for cleaning up the site. He reported that the groundwater flow patterns at the site are strongly influenced by man-made passageways and the Olin production wells. In the A-Zone, the groundwater flows radially from a bedrock high point beneath Plant 2. There is some minor discharge to Gill Creek from the A-Zone, with the remainder of the flow being intercepted by the DuPont Sewer, which is a deep sanitary sewer running south to north along the east bank of the creek. Mr. McIntosh concluded that if any A-Zone groundwater somehow flowed from the ARGC area to the east or northeast under Gill Creek, it would be intercepted by the DuPont Sewer and sewer bedding and would flow north to the Buffalo Avenue sewer. In the B-Zone, monitoring well results indicate that the groundwater flows north towards Buffalo Avenue, or to the Olin production wells via leakage to the C-Zone. The Buffalo Avenue sewer sits in a trench blasted into the bedrock, fully penetrating the A- and B-Zones, and acts as a conduit carrying groundwater toward the POTW. Based on his review of all available information regarding hydro-geologic conditions at the Olin Site, Mr. McIntosh concluded that the groundwater in the B-Zone beneath the ARGC area west of Gill Creek generally flows north toward the Buffalo Avenue sewer and is discharged to the sewer or sewer bedding toward the POTW (Tr. 1430 at 57-68).

Mr. McIntosh testified that the groundwater remedy he proposed for the Olin Site consisted of two components — a soil management plan and a groundwater treatment system. The soil management component involved paving certain areas of exposed soil to prevent direct human contact. The groundwater component of the remedy involved the installation of a series of passive relief and extraction wells to recover contaminated groundwater for treatment and to prevent offsite migration. The passive relief wells were designed by Mr. McIntosh to create a connection between the A- and B-Zones in order to increase the influence of the extraction wells, which did the actual pumping of B-Zone groundwater. Mr. McIntosh testified that based on his review of the extraction well data for the initial three or four years of operation, the system was maintaining satisfactory hydraulic control, meaning that it was successful in intercepting the groundwater in the ARGC area for collection and treatment (Tr. 1430 at 68-73).

On cross-examination by Solvent’s counsel, Mr. McIntosh was shown a series of communications which took place between Olin and the DEC in 1994-95, commenting on Woodward-Clyde’s proposed RFI and CMS and chronicling the DEC’S ongoing disagreement with Olin’s characterization

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of the extent of groundwater contamination attributable to Olin’s historical operations in the ARGC area

(see

S-4118, 4119, 4124A, 4125). In a letter dated June 5, 1995, the DEC indicated that while the contamination detected in the monitoring wells in the area of the Hot Spot may be associated with the Solvent Site, it remained convinced that some of the contamination is attributable to Olin, and that the presence of substantial concentrations of BHC is difficult to attribute to a source other than Olin

(see

S — 4126; Tr. 1432 at 92-109).

Mr. McIntosh also testified on cross-examination that, based on his experience as project manager for remedial activities at the Olin Site and his prior experience with conditions at the DuPont Site, he became aware of the extensive chlorinated aliphatic contamination at the DuPont facility and the migration of chlorinated aliphatics from the DuPont Site to the Olin Site. He stated in his expert report

(see

note 6 infra) that a plume of chlorinated aliphatics extended from the DuPont Site to encompass areas of both the Olin and Solvent Sites, and that there is no containment or recovery system in place to prevent migration of contaminated groundwater from DuPont to the Olin Site and the Hot Spot in the B-Zone and deeper. As a result, he ruled out Olin as a source of the chlorinated aliphatics being captured by Solvent’s groundwater recovery and treatment system, and expressed the opinion that all of those chlorinated aliphatics were migrating from the DuPont Site (Tr. 1432 at 117-22).

On cross-examination by DuPont’s counsel, Mr. McIntosh was shown D-213, which is a list of some of the chemicals and chemical waste products handled at the Solvent facility during the period of Solvent’s processing operations and Frontenac’s waste storage and management operations. This list was prepared by DuPont based on the historical records, and as reflected in Mr. Kohanek’s expert report. The list contains a number of chlorinated aliphatics, including PCE, TCE, 1,1,1 — trichloroethane, methylene chloride, and chloroform. Mr. McIntosh was also shown D-91, which is an exhibit from Mr. Kohanek’s report identifying the locations where Frontenac conducted its TCE and PCE handling operations. Mr. McIntosh testified that when he prepared his report on the source of the chlorinated aliphatics detected in Solvent’s pump and treat system, he was not aware that Frontenac had handled these materials in these locations during the period of its waste management operations at the Site (Tr. 1450 at 136^14).

D-259 is a map prepared by Mr. McIntosh showing the location of monitoring wells at Olin Plant 2 and the Solvent Site. Samples taken from OBA-24B, -25B, and -26B located in the southwest quadrant of the Olin parking lot, as reported in a draft Supplemental Groundwater Investigation Report dated September 1999, indicated low or non-detect levels of chlorinated aliphatics

(see

D-260). D-192 shows the location of additional B-Zone pumping wells OBA-30B, -25B, and -29B installed by DuPont along Adams Avenue, which also reported low or non-detect levels of chlorinated aliphatics

(see

D-261). D-238 is a figure taken from Solvent’s monitoring report for the first quarter of 2007, showing the location of the A- and B-Zone wells and sampling results. D-257 is a reproduction of S^4156, which is a compilation of data obtained by subpoena from Olin’s consultant, MACTEC, reporting the results of a pump test conducted in July 2001 at wells SRW-1 and SRW-2, located in the ARGC area of the Olin Site where historical BHC production and trichlorophenol operations took place. Mr. McIntosh agreed that none of these sampling results supports his theory of a chlorinated alip

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hatic plume in the B-Zone migrating from the DuPont Site toward the Hot Spot (Tr. 1450 at 144-62).

Mr. McIntosh was also Olin’s on-site representative during TRC’s remediation of the Solvent 18-inch Sewer in the summer of 2000. The project manager for TRC was Todd Majer. Representatives of the DEC were also present during certain portions of the remedial activity. The work involved removal of the sewer line everywhere it could be accessed, but there were sections of the sewer line that could not be removed because of surface impediments, electrical grids, or gas lines. These sections were flushed out with a high pressure wash and filled with grout or cement. Mr. McIntosh testified that he observed NAPL in the flushed water, as well as in the pipe itself, in the wells, and along the entire length of the sewer line excavation (Tr. 1430 at 73-81).

0-302 is Todd Majer’s log book for the 18-inch Sewer removal project. At 10:45 a.m. on July 20, 2000, as TRC was in the process of flushing out the sewer pipe, Mr. Majer noted the presence of “free product,” or NAPL, floating on top of the water in the excavated area. Several other log entries note the presence of NAPL observed in the excavation area, in test pits, and flowing from concrete encasements around the sewer pipe. At some locations, TRC used a foam spray to suppress the odors caused by vaporization of the volatile organics exposed during the excavation (Tr. 1430 at 83-86).

0-631 is a drawing depicting TRC’s 18-inch storm sewer remediation activity in the southern portion of Olin’s east property, and showing the location of confirmatory soil samples. Samples SS-09 and SS-10 were taken along the wall of the excavation just to the west of the electrical substation, one of the areas where the sewer line was cleaned and left in place rather than removed. 0-247 reports the soil sample results showing detections of barium, copper, lead, mercury, and zinc. O-477 is a map of the Olin and Solvent Sites showing the location and results of soil samples taken in the area of the sewer excavation. Sample number SDKRM71400-1 was taken by Mr. McIntosh from inside the sewer pipe at a point approximately 30 feet from the end of the pipe outfall at Gill Creek, showing a total chlorinated benzene concentration of 22,-300,000 ppb. SD-0612-AK-01 was taken from inside the pipe about five feet in from the end at the Gill Creek outfall, showing a total chlorinated benzene concentration of 26,000,000 ppb (Tr. 1430 at 87-97).

Mr. McIntosh testified that he conducted a video survey of the Solvent 18-inch sewer in the area of monitoring well OBA-10A, near the intersection of the Solvent and DuPont sewers. The video showed that the 18-inch sewer pipe had been breached at that location. As noted by Mr. Majer in his log book, Mr. Hinton from the DEC suggested that the DNAPL detected at OBA-10A might be due to the breach in the 18-inch pipe. Mr. McIntosh did not observe NAPL in the area of the breach, but he did observe it coming out of the pipe when it was being cleaned (Tr. 1430 at 97-101).

Mr. McIntosh agreed with the statement in TRC’s April 2003 final engineering report

(see

0-625) that much of the overburden surrounding the 18-inch storm sewer consisted of urban fill material, and that the elevated concentrations of inorganic compounds were related to the fill as opposed to releases originating from the sewer (Tr. 1430 at 102-04).

On cross-examination by Solvent’s counsel, Mr. McIntosh was shown S-4071, which is a drawing of abandoned and existing sewer lines at Olin Niagara Plant 2, dated October 1982. The drawing depicts

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three plugged sewer lines, along with several connecting sewer lines, leading to Gill Creek from various buildings in the ARCG area. He was also shown S-4001, documenting spillages of benzene and other product loss during Olin’s BHC production operations; 0-419, which is an aerial photograph of the ARGC area shortly after the 1956 explosion at the BHC plant; and S^1500, which is an Olin internal memorandum discussing groundwater seepage from the BHC plant. Mr. McIntosh agreed with Solvent’s counsel that all of these circumstances could have contributed to the chlorinated benzene contamination found in the Gill Creek sediments. He also agreed that Olin and DuPont were primarily responsible for the elevated concentrations of BHC, PCBs, chlorinated aliphatics, mercury, and other materials detected in the Gill Creek sediments and identified in the Gill Creek ROD as the contaminants of concern necessitating the remedy (Tr. 1430 at 110-38).

S^4507 is Woodward-Clyde’s Gill Creek Sediment Study Report, completed in April 1989. Mr. McIntosh was the Project Scientist on this study. As noted in this report, the primary area of concern for the sediment study was the mouth of Gill Creek, designated as Area 1, where PCBs, chlorobenzene compounds, hexachlorobutadiene, and mercury were detected in the sediments. Figure 3-1 from the sediment study (Bates No. DUP15469) indicates that the vast majority of sediment sampling undertaken during this study was performed in Area 1, with only one set of samples taken in Area 3, at the Adams Street bridge. According to Mr. McIntosh, the sediment study focused on the mouth area of the creek because he assumed that the previous remediation of Gill Creek in 1981 took care of the upstream sediments, and the NAPL problems that later arose in Area 3 took him by surprise (Tr. 1430 at 1384Í8).

Table 5-1 from the sediment study (Bates No. DUP15387) is a list of indicator chemicals, representing the contaminants detected in the Gill Creek sediments with the greatest potential for environmental impact. The list contains several volatile compounds and PCBs associated with DuPont’s operations, as well as hexachlorobenzene, hexachlorobutadiene, pentachlorobenzene, and mercury, all associated with Olin’s BHC production. There are no chlorinated benzenes associated with Solvent’s operations on the list. Mr. McIntosh testified that hexachlorobenzene is the most toxic of the chlorobenzene compounds (Tr. 1430 at 148-55).

S-6085 is a listing of the results of Gill Creek Area 3 sediment samples taken in connection with the sediment studies performed in April 1989 and December 1990. Mr. McIntosh agreed with Solvent’s counsel that this listing shows that BHC in pure concentration accounted for 79.45% of the contamination in the Area 3 sediments (Tr. 1432 at 12-16).

S-4534 is the Gill Creek Remediation Final Report, dated December 1993, which describes the components of the remedy performed by Woodward-Clyde. The Report states that the majority of the excavated sediments were transported to permitted landfills for disposal, with the exception of a small volume of sediment from Area 3 which had to be incinerated due to elevated levels of gamma-BHC (Tr. 1432 at 25-28).

Table 6-1 of S-4534 is a listing of the estimated volumes of sediments to be removed, as compared to the volumes of the sediments that were actually removed, from the various areas of Gill Creek. Mr. McIntosh agreed with Solvent’s counsel that the volume of Area 3 sediments removed and disposed of (230 cubic yards) represents approximately 2.9% of the total

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volume of sediments removed and disposed of (8,020 cubic yards) (Tr. 1432 at 36-37).

2. William Hall

Mr. Hall is the Chief Executive Officer of NewFields Companies, an environmental engineering and consulting firm. He has been an environmental engineer and consultant for 33 years. He received a Bachelor of Science degree in civil engineering from Georgia Tech in 1974 and worked for over 20 years for Dames

&

Moore on environmental projects internationally and domestically. He has worked on over 100 CERCLA sites and was the principal engineer on 7 Superfund sites from the initiation of remedial investigation to closure. A critical component of his work involves determination of the “fate and transport” of contaminants, described by Mr. Hall as addressing what happens to a contaminant once it is released into the environment. He also defined the term “preferred pathway” as a feature in the environment that will alter the direction of the transport of a contami

nant

— e.g., as when groundwater finds its way to a creek or a sewer (Tr. 1433 at 2-10;

see also

0-630).

Mr. Hall testified that his general strategy in determining fate and transport as an allocation approach involves a very heavy focus on the data collected at the site which can be measured, quantified, and verified. He assembles a searchable electronic database containing all of the hard data that can be extracted from the field reports, site investigations, design reports, engineering data on surface and subsurface features, aerial photography, and other sources of quantifiable information obtained at the site over an extended period of time.

7

The data is accessed by using standardized computer software programs, such as Access and Art Map. He also considers the nature of the remedial activity and how it affects the fate and transport of the contaminants (Tr. 1433 at 10-14).

0-403 is a summary of the environmental data accumulated for the Solvent and Olin Site database, identified by type of matrix (or environmental media), number of locations, number of samples, and number of results. For example, for the matrix identified as “total groundwater,” there are listed 293 well locations, 1586 samples, and 52,535 results. According to Mr. Hall, this summary points out the need for an electronic database to effectively manage the large amount of accumulated information, and to prevent “cherry-picking” only the data supporting a particular hypothesis or conclusion. By way of illustration, Mr. Hall explained how he accessed the soil boring analysis data reported on Table 4-2 of the Malcolm Pirnie Supplemental Remedial Investigation Report for the Solvent Site (0-602) to create 0-614, which is an aerial photograph of the Solvent Site depicting various locations where concentrations of 1,2,4-trichloroben-zene have been detected in the soil (Tr. 1433 at 21 — 45).

0-444 is a 1978 aerial photograph of the Solvent Site, the Olin East Property, and a portion of Gill Creek. Also depicted on this exhibit are the DuPont sewer, the Buffalo Avenue sewer, and the Solvent 18-inch sewer. 0-432 is a 2002 aerial photograph depicting the areas where the remedial activities at issue in this action took place: the Hot Spot, the Solvent Site, the Solvent 18-inch sewer, and Gill Creek at the Adams Avenue Bridge. Mr. Hall testified that he was engaged by Olin to formulate an opinion regarding the fate and transport of the contaminants found at

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each of these remedial areas (Tr. 1433 at 45-48).

0-439 depicts the elements of the groundwater recovery system installed by TRC at the Solvent Site and the Hot Spot, including the extraction wells, interceptor trenches, piping, and onsite treatment facility. In the Hot Spot area there are two extraction wells completed into the B-Zone, along with an A-Zone interceptor trench and piping that carries the recovered water to the pre-treatment plant. Extraction wells, piping, and recovery trenches were also installed around the northern, western, and southern perimeters of the Solvent Site. According to Mr. Hall, this system was installed to maintain hydraulic control by preventing further migration of contaminated groundwater from the Solvent property and Hot Spot areas. His fate and transport analysis included examination of the sampling data obtained from this pump and treat system, as well from monitoring wells previously installed by Olin, to determine both the spatial distribution and the temporal characteristics of the contaminants — where they came from and where they went, and how they changed over time relative to the different features at the sites (Tr. 1433 at 48-52).

0-452 is a pie chart comparison of chlorinated benzene concentrations detected in groundwater samples from wells screened in the A-Zone on either side of Gill Creek. Each pie represents the total chlorinated benzene concentration detected at a particular location, divided into relative percentages of mono-, di-, and trichlorobenzenes, to demonstrate how the various contaminants have been distributed between the two areas. For example, the samples obtained from the A-Zone at monitoring well MW-4A, located in the northwest corner of the Solvent Site, contained approximately 55% trichlorobenzenes and 45% dichlorobenzenes. According to Mr. Hall, the ratios reported on this exhibit reveal a pattern of contamination indicating that the materials found in the A-Zone at the Hot Spot look more like the materials detected in the A-Zone at the Solvent Site than those detected at the Olin Site (Tr. 1433 at 52-56).

0-407 is a pie chart comparison of comparison of the average chlorinated benzene concentrations detected in all of the samples from all of the wells screened in the A- and B-Zones during the year 1998. Mr. Hall testified that this exhibit is an example of one of the various ways he looked at the data accumulated over many years in order to determine whether his conceptual model presents an accurate picture of the pattern of contamination at the Site. The averages from 1998 are important because they represent the middle of three significant time periods: before groundwater pumping took place, after pumping began at Olin in 1997, and after pumping began at Solvent in 2002. The pie charts on 0-407 represent that during 1998, the wells in the Hot Spot area were detecting predominantly mono- and dichlorobenzenes in the A- and B-Zone groundwater, which are the constituents associated with operations at the Solvent Site. The Hot Spot wells show very small concentrations of trichlorobenzenes, the constituents associated with operations at the Olin Site (Tr. 1433 at 57-60).

0-408 depicts the average chlorinated benzene concentrations detected in the A- and B-Zone wells during the year 2004. The presence of more pie charts indicates that there were more wells being sampled in 2004, after Solvent began operation of its pump and treat remediation system. The comparison of pie charts represented on this exhibit indicates that while more trichlorobenzenes were being detected at the Hot Spot in 2004, that area was still

*395

dominated by mono- and dichlorobenzenes (Tr. 1433 at 60-61).

0-445 is the figure taken from the 1995 Malcolm Pirnie SRI, presented during Mr. Hughes’ testimony, which identifies the areas of the 3163 Buffalo Avenue property where NAPL was observed or suspected to be present in the soils. This includes virtually the entire border with Olin East, as well as most of the southern half of the Solvent property, in the areas where loading and unloading of chemicals from rail cars and trucks took place

(see

0-448). Mr. Hall testified that loading operations are the dominant mechanism for releasing large quantities of contaminated material into the environment. He also testified that when NAPL or DNAPL show up in a boring log, it indicates extensive concentrations of oily, sludge-like material in free phase, before dilution. As depicted in these exhibits, NAPL was detected in several areas in the northwest corner of the Solvent Site, approximately 130 feet from Hot Spot pumping well PW-4 (Tr. 1433 at 61-66).

0-449 shows the same image with numbers added to indicate the location of several reported chemical spills at the Solvent Site

(see

0X450), which correspond to the loading and tank farm areas where NAPL was present. Also depicted on this exhibit is the 18-inch sewer, which runs along the western boundary of the Site and drains into Gill Creek. According to Mr. Hall, his review of the available environmental reports indicates that the southwest quadrant of the

Site

— ie., the area with the greatest concentration of NAPL — drained into the 18-inch sewer (Tr. 1433 at 66-68).

0-613 depicts various locations at the Solvent Site where concentrations of 1,2,3-trichlorobenzene have been detected in the soil. 0-614, presented earlier, shows detections of 1,2,4-trichlorobenzene. Mr. Hall testified that these exhibits indicate the presence of trichlorobenzenes at the Solvent Site sufficient to have an impact on groundwater. He explained the industry rule of reference that a detection of greater than 1% of the solubility limit concentration of any particular chemical indicates the potential for the presence of NAPL or DNAPL. As represented on 0-617, NAPL was detected at several locations along the Solvent/Olin border, and in the chemical handling areas of the Solvent Site, at levels greater than 10% of the solubility limit for trichlorobenzene. According to Mr. Hall, this indicates an ample source of TCB across the entire Solvent Site and negates the use of TCB as a tracer chemical for Olin (Tr. 1433 at TOTS).

0-446 depicts monochlorobenzene detections in the A- and B-Zone groundwater at various sampling locations across the Solvent Site and the Olin East property. According to Mr. Hall, these detections show levels of greater than 10% solubility at several areas of the Solvent Site, concentrated primarily in the southwest corner and along the 18-inch sewer, while there are no detections at these levels in the Hot Spot area (Tr. 1433 at 74-75).

Mr. Hall gave the opinion, based on the information in the environmental reports and the data that has been gathered at the Olin and Solvent Sites, that Gill Creek and the DuPont sewer act in combination as a barrier to the flow of groundwater from the Olin plant site toward the Hot Spot. He agreed with the conclusions stated in the March 1995 Malcom Pirnie Corrective Measures Study with respect to the flow of groundwater from the ARGC area, and explained his understanding of those conclusions in greater detail. For example, he agreed that Gill Creek penetrates the upper portion of the A-Zone, meaning the bottom of the creek is essentially down to the bedrock, and the water moving along

*396

the top of bedrock is moving into the Creek. He also agreed with the conclusion that the DuPont sewer fully penetrates the A-Zone and potentially acts as a preferential conduit for groundwater flow. He explained his understanding that the DuPont sewer trench and the pipe itself are installed down into the rock, and water flowing across the bedrock from the A-Zone that is not picked up by Gill Creek would be likely to travel along the cut-out trench or leak into the deteriorated sewer pipe. The CMS also concluded that the Buffalo Avenue sewer fully penetrates the A- and B-Zones on the west side of Gill Creek, meaning that this sewer line acts as an open conduit to transmit groundwater from the A-Zone down into the B-Zone, and into the sewer pipe and trench. Mr. Hall also agreed that the Buffalo Avenue sewer likely receives groundwater discharge west of Gill Creek due to the deteriorated condition of the sewer line, and field testing has confirmed that the hydraulic gradient of the B-Zone is toward the sewer except during periods of high flow (Tr. 1433 at 76-85;

see

0-234).

0-646 is a cross-section drawing showing Mr. Hall’s rendition of the vertical relationships between the subsurface features in the area where the Buffalo Avenue sewer passes under Gill Creek and intersects with the DuPont sewer. The drawing also depicts three monitoring wells at that location: BH-1 and OBA-15A, completed in the A-Zone, and OBA-15B, completed in the B-Zone. Data taken from the Conestoga Rovers CMS indicate groundwater elevations. According to Mr. Hall, this depiction shows that the A-Zone groundwater flowing west to east from the Olin plant site toward the Hot Spot would pass down Gill Creek, and any water passing through the creek would sink down toward the bottom of the DuPont sewer. He testified that, based on information obtained from his review of the available environmental studies and reports, Gill Creek discharges about 2 million gallons of water per day into the Niagara River, due largely to the decrease in the river’s water level during operation of the power plant intakes. Contaminants dissolved in the groundwater flowing through the overburden into the creek on the west side would be flushed down the creek and into the river and would not flow across or through the creek and into the groundwater in the overburden on the east side (Tr. 1433 at 85-93).

Mr. Hall testified that there has only been one occasion during the course of the investigations at the Olin and Solvent Sites when synoptic, or simultaneous, groundwater elevation testing took place at both sites. This was in June 1994, when groundwater level data was collected synoptically at multiple wells in the vicinity of the Hot Spot. The event was coordinated through cooperation between Olin and the DEC, which was investigating the Solvent Site at the time. Water levels were obtained at monitoring wells by physical measurements of the distance from the ground surface to the top of the water in the well. According to Mr. Hall, synoptic testing provides a clearer understanding of groundwater flow because the elevations change depending on existing hydraulic

conditions

— e.g., during a drought or after a very wet period — and actual field measurements provide better elevation information than computer-generated contour maps because the data points for the contours might not account for subsurface features, such as Gill Creek or the DuPont sewer (Tr. 1433 at 93-97).

S-6015, the A-Zone composite groundwater elevation contour map relied on by Mr. Smyth, was generated from data obtained from several different studies undertaken at widely varying times. According to Mr. Hall, this map is meaningless

*397

with regard to determining how groundwater actually flows subject to changing hydrological conditions in a particular area. 0-685 was generated by Mr. Hall using S-6015 as a base, but adding data from the June 1994 testing to show that the groundwater elevations represented on the composite contour map do not match the actual synoptic measurements. For example, while Mr. Smyth’s contour map depicts a groundwater flow direction from the high water level at the Olin Site toward the low water level northeast of the Solvent Site, with no impact at Gill Creek, the June 1994 data shows a groundwater surface elevation at Hot Spot monitoring well OBA-15A, which is nearly five feet lower than the elevation reported at MW-4A in the northwest corner of the Solvent Site. According to Mr. Hall, this data indicates that a contaminant dissolved in the A-Zone groundwater at the northwest corner of the Solvent Site would flow toward the Hot Spot and Gill Creek (Tr. 1433 at 97-102).

Mr. Hall gave his opinion that because the Buffalo Avenue sewer penetrates into the bedrock in both the A- and B-Zones, it acts as a large drain causing the groundwater in the area of the Olin facility west of Gill Creek to flow to the north. This opinion was based on data reported in the March 1995 CMS (0-234), which was generated by a pump test to obtain information about the hydraulic characteristics of the aquifer. 0-412 is a drawing of a larger cross-section view showing the subsurface features beneath the ARGC area of the Olin Site, the Hot Spot, and the Solvent Site. The pump test was conducted in the ARGC area at two wells — OBA-2B, located immediately adjacent to Buffalo Avenue, and OBA-16B, located to the southeast

(see

0-413). 0-415 is a drawing of a cross-section view of the Olin Site subsurface down into the C-Zone, looking from west to east at Alundum Road. Depicted on the left (north) is the installation trench and the two sewers comprising the Buffalo Avenue sewer system. 0BA-2B is depicted just to the right (south) of the sewers, and 0BA-16B is depicted further to the right. Both wells show collecting screens completed through the B-Zone into the C-Zone. The wells were fitted with transducers to measure water pressure, which was converted to elevation levels and charted on a time line (Tr. 1433 at 103-13).

On January 19, 1995, OBA-2B had a groundwater elevation reading of 558.2 ft., and OBA-16B had a groundwater elevation reading of 558.4 ft., indicating a northward gradient toward the Buffalo Avenue sewer. Then, on the morning of January 20, heavy rainfall began which caused a steady rise of the pressure in the wells and in the sewers, measured as a rise in groundwater elevation to a maximum of 560.9 feet at OBA-2B, and 561.75 feet in OBA-16B

(see

0-416). The rain stopped at 10:00 a.m., and the measurements recorded an almost immediate drop in groundwater elevation levels

(see

0-417). Within 48 hours of the rainfall event, the levels had returned to normal

(see

0-418). According to Mr. Hall, this series of field measurements shows the Buffalo Avenue sewer to be a hydraulic control which drains the B-Zone northward in the vicinity of the Olin plant (Tr. 1433 at 113-18).

Mr. Hall testified that he also examined the available sampling data from three discrete periods of time: before any groundwater pumping took place, after Olin began its pumping operations, and after Solvent began its pumping operations. 0-636 shows the Hot Spot area and the location of five monitoring wells in the vicinity: OBA-17AB, located on the west bank of Gill Creek in the ARGC area of the Olin Site; OBA-15A, located on the western side of the Hot Spot area; OBA-

*398

3A and 0BA-3B, located next to each other on the eastern side of the Hot Spot area; and MW-4A, located in the northwestern corner of the Solvent Site. 0-637 reports the percentages of total chlorinated benzenes represented by trichlorobenzene (TCB) detected in the groundwater at these wells at various times prior to 1996, when Olin began to operate its pumping wells, as follows: 0BA-17AB = 48% TCB; 0BA-15A = 4% TCB; OBA-3B = 2%; 0BA-5A = 5%; MW-4A = 54%. 0-638 reports the combined total of monochlorobenzenes (MCB) and dichlorobenzenes (DCB) detected at these wells, as follows: 0BA-17AB = 2,590 ppb; OBA-15A = 15,800 ppb; OBA-3B = 18,-740 ppb; OBA-5A = 25,300 ppb; MW-4A = 20,340 ppb. According to Mr. Hall, these results show that before any pumping operations began at the Hot Spot, the concentrations of chlorinated benzenes in the groundwater were greater closer to the Solvent Site, indicating a downward gradient from Solvent to the Hot Spot, and that the smaller concentrations of chlorinated benzenes at OBA-17AB could not be the source of the higher concentrations of chlorinated benzenes detected at Hot Spot wells OBA-15A, OBA-3A, and OBA-3B, on the other side of Gill Creek and the DuPont Sewer (Tr. 1433 at 118— 27).

0-639 depicts chlorinated benzene ratios in November 1998, after pumping began at the Olin Site. Passive relief wells PR-3 and PR-4, completed into the B-Zone in the ARGC area of the Olin Site near the west bank of Gill Creek, reported TCB concentrations at 1600 ppb and 300 ppb, respectively. Moving toward the east, Hot Spot monitoring wells OBA-15A and OBA-3A reported concentrations of MCBs and DCBs, but no TCBs. OBA-3B reported a TCB concentration of 220 ppb, represented on a pie chart as approximately 20% of the total chlorinated benzene detection. Then, at MW-4A in the northwest corner of the Solvent Site, a TCB concentration of 24,000 ppb was reported, represented on a pie chart as approximately 55% of the total chlorinated benzene detection. According to Mr. Hall, these results indicate that the highest concentrations of TCBs are at the Solvent Site, and that the TCBs detected at the Hot Spot are coming from Solvent, not from Olin (Tr. 1433 at 127-30).

0-640 shows the location of four pumping wells in operation at the Olin and Solvent Sites as of 2002. Olin well RW-3 is located in the ARGC area near the west bank of Gill Creek. Solvent wells PW-3B and PW-4B are located in the Hot Spot area, and Solvent well PW-2B is located in the northwest corner of the Solvent Site. 0-641 shows total TCB concentrations detected in the A- and B-Zone groundwater at these wells during synoptic testing in May and June 2002, as follows: RW-3 = 61 ppb; PW-3B = 1,400 ppb; PW-4B = 1,400 ppb; and PW-2B = 12,900 ppb. Based on this data, Mr. Hall stated his opinion that pumping wells PW-3B and - 4B are pulling the TCBs from the Solvent Site toward the Hot Spot, and that all three gradients — hydraulic, mass, and concentration — support his conceptual model which points to Solvent, not Olin, as the source of chlorinated benzenes in the groundwater being pumped from the Hot Spot (Tr. 1433 at 133-34; 145-49).

0-652 contains pie charts showing the ratios of chlorinated benzene concentrations detected at monitoring wells in the Hot Spot area during the June 1994 synoptic testing, along with groundwater elevation readings at certain wells. Also depicted are the DuPont and Buffalo Avenue sewer lines. According to Mr. Hall, this data shows that any contaminants traveling in the A-Zone groundwater from the Olin Site which might make their way

*399

through or under Gill Creek into the DuPont sewer bedding would be carried to the north, rather than to the east toward the Hot Spot. This is confirmed by the pie charts, which show that no TCBs were detected at wells OBA-13A and 13B, located to the north of Buffalo Avenue, with lower groundwater elevation readings than at OBA-15A, located to the south (Tr. 1433 at 150-54).

S-6072 is the bar chart comparison of pumping data collected at the Hot Spot and the Olin wells which, according to Mr. Smyth, showed that very similar concentrations of contaminants were being pumped at the two locations. Mr. Hall testified that, upon closer examination, it appeared that the concentration parameters on the two charts had been shuffled to create the similarity. 0-634 is a bar chart comparison representing just the constituents associated with Olin and Solvent detected at these wells, without showing the chlorinated aliphatics associated with DuPont. According to Mr. Hall, this comparison shows that there is no correlation at all between the water being pumped at the two sites (Tr. 1433 at 155-61).

On cross-examination, Mr. Hall was shown S^1562, which is a bar chart representing a combination of the two sets of data represented on S-6072. Mr. Hall explained that while the chart appears to have a good visual correlation, the data represented primarily shows that aliphatics are being detected at high levels at both the Hot Spot and the Olin Site. These detections are not indicator parameters for any transport of contaminants from Olin to the Hot Spot (Tr. 1440 at 101-04).

Mr. Hall testified that Mr. Smyth’s identification of perchlorate as a tracer to show a flow path from the Olin Site to the Hot Spot wells was unreliable because the information depicted on S-6032 with respect to the presence of perchlorate in the B-Zone groundwater was based on two minimal detections from one sampling event, and because historical documentation revealed that Occidental Chemical, and its precursors Oldbury Electrochemical and Hooker Chemical, manufactured perchlorate at a facility to the east of the Solvent Site for approximately 67 years (Tr. 1434 at 11-19;

see also

0-605, 606, 607, 608, 623).

0-493 shows the location of the groundwater treatment system at the Olin Site. There are six pumping (or extraction) wells completed in the B-Zone, and four passive relief wells which are drilled into the bedrock to passively allow contaminated water to drain into the B-Zone where the extraction wells are pumping. The primary purpose of the Olin system is to provide hydraulic containment within the boundaries of the site, and to treat the contaminated groundwater pumped. According to Mr. Hall, the environmental data and reports generated since the system began operating indicate that hydraulic control has been achieved, and groundwater is not crossing the boundary of the containment system (Tr. 1434 at 19-21).

Based on his review and analysis of all relevant data, Mr. Hall stated his conclusion that the chlorinated benzenes detected in the groundwater at the Hot Spot are coming from the Solvent Site, not from the Olin Site. Gill Creek and the DuPont sewer are acting as hydraulic barriers to the flow of groundwater in the A-Zone. In the B-Zone, the groundwater flow at the Olin Site is due north toward the Buffalo Avenue sewer. Finally, the sampling data confirms that the isomers of chlorinated benzenes detected at the Hot Spot are more closely associated with the contaminants found at the Solvent Site than those found at the Olin Site (Tr. 1434 at 21-23;

see

0-494).

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Turning to Gill Creek, Mr. Hall was first shown 0-469A, depicting the remedial area of Gill Creek at the Adams Avenue Bridge, referred to as Area 3. Also depicted is the Solvent 18-inch storm sewer which is shown emptying into the creek just north of the bridge. He was also shown 0-445, which is the figure taken from the 1995 Malcolm Pirnie SRI depicting the areas of the Solvent Site where NAPL was observed or suspected to be present in the soils, as well as 0-449, identifying the reported chemical spills at the Site. Mr. Hall testified that these were the tank farm and loading dock areas, and that surface liquids in these operational areas would drain into the 18-inch storm sewer by means of rainfall events or other discharges and be carried toward Gill Creek (Tr. 1434 at 23-28).

0-613 and 614 depict the areas of the Solvent Site where high levels of trichlorobenzenes were detected in the soils, which correlate with the areas where NAPL was observed. Mr. Hall testified that these exhibits indicate a significant source of trichlorobenzenes at the Solvent Site, with the 18-inch sewer providing a pathway for discharge of chlorinated benzene materials to Gill Creek. These materials would be expected to accumulate in the sediments downstream of the Adams Avenue Bridge (Tr. 1434 at 23-32).

0-428 contains pie charts indicating the relative concentration of chlorinated benzene isomers detected in the soils, sewer pipe, and creek bed sediments during the remediation of Area 3 and the Solvent 18-inch storm sewer. 0-651 depicts the sampling locations for the data utilized by Mr. Smyth in his analysis of the likely source of the contamination found in the Area 3 sediments, along with two samples that were taken from the sludge in the sewer pipe (see 0-650). 0-649 is a bar chart prepared by Mr. Hall indicating the relative percentages of the total chlorinated benzenes and trichlorobenzenes detected in the samples taken from the Olin Site, the 18-inch sewer pipe, and the creek bank at the sewer outfall and downstream. According to Mr. Hall, this data shows that the levels of chlorinated benzenes detected in the downstream creek sediments more closely match the levels detected in the sewer pipe than the levels detected in the Olin Site soils (Tr. 1434 at 32-40).

Mr. Hall testified that Mr. Smyth’s pie charts depicted on S-6048 comparing the composition of chlorinated benzene materials detected in the Area 3 sediments and the soils at the Olin and Solvent Sites are based on a simple average of percentages, which fails to account for the actual mass of chlorobenzenes represented in the sampling data. By contrast, 0-656 contains pie charts using the same data, but scaled to represent the relative mass of the contaminants detected at the various locations. The large pie chart representing the average mass of chlorinated benzenes detected in the in-pipe sewer samples, referred to by counsel as the “death star,” is many times larger than the pie chart representing the average mass of contaminants detected in the soil samples taken from the Olin plant (Tr. 1434 at 40-45).

On cross-examination by Solvent’s counsel, Mr. Hall explained that the purpose of 0-656 was to show that the data relied on by Mr. Smyth to produce S-6048 did not establish a connection between Olin and Gill Creek Area 3, and that the process of averaging the percentages of chlorinated benzene concentrations detected at the various locations did not account for an apparent active source of contamination immediately adjacent to the Area 3 remediation. He agreed with Solvent’s counsel that the BHC and chlorobenzene concentrations detected in the Gill Creek sediments are much higher than the BHC and

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chlorobenzene concentrations detected in the Olin soil borings (Tr. 1440 at 29-34).

Mr. Hall explained that he did not perform a risk assessment to determine the relative risk of the various chemicals found in the Area 3 sediments because each class of contaminants alone was sufficient to cause the sediments to be removed. He gave his opinion that the bulk of the chlorobenzene contamination detected in the Area 3 sediments originated from the Solvent 18-inch sewer. The concentration levels of chlorinated benzenes in the sediments were 150 times greater than the cleanup levels established by the DEC for the Solvent Site. Based on these findings, Mr. Hall stated that Solvent should be allocated 50% of the costs incurred by Olin for the remediation of Gill Creek at Area 3 (Tr. 1434 at 46-54).

On cross-examination by Solvent’s counsel, Mr. Hall testified that he considered the historical evidence regarding Olin’s BHC production (including the use and storage of trichlorobenzenes), the existence of sewers which drained into Gill Creek before they were plugged, and the explosion at the plant in 1956 which deposited a large amount of BHC material into the creek. He also reviewed the Gill Creek ROD, which identified BHC as the major contaminant of concern at Area 3 and identified chlorobenzenes at generally below detection limits. Mr. Hall explained his understanding that BHC entering the creek in solid form would have settled into the sediments, and any chlorinated benzenes that might have been deposited into the creek as a result of Olin’s BHC operations, or the explosion, would have long since dissolved in the creek waters and washed downstream

(see

Tr. 1434 at 70-119;

see also

Tr. 1440 at 3-29).

With respect to the soil remedy at the Solvent Site, Mr. Hall testified that the permeable cap alternative was chosen to allow water to continue to infiltrate the soils and enhance the movement of contaminants out of the soils. The pump-and-treat component of the remedy was designed to treat chlorobenzenes, not mercury. 0-467 is a bar graph comparison of the relative mass of organic contaminants versus mercury detected in shallow soil borings taken at a depth of less than five feet, indicating that mercury represents 0.5% of the contaminants detected in the Solvent soils, while organics — ie., chlorinated benzenes — represent 99.5%. He testified that upon examination of the boring logs, aerial photography, environmental reports, and other information in the record, he determined that an extensive amount of fill material exists at the Solvent Site which would be expected to contain a component of background or anthropogenic mercury. He also identified Occidental Chemical’s chlor-alkali facility to the east of the Solvent Site as another potential source of the mercury detected in the Solvent soils (Tr. 1434 at 54-60).

In his approach to allocating responsibility for the contaminated soils, Mr. Hall first determined the average concentration of each chemical found in the soils, then generated a ratio relative to either the cleanup standard or background value for that chemical, adjusted based on the area where the chemical was detected. 0-464 contains the calculations Mr. Hall performed to determine a risk factor for each of the soil contaminants, arriving at an allocation percentage representing the relative contribution of mercury as 16.03% of the need for remediation of the Solvent Site soils. Mr. Smyth used a similar approach to arrive at an allocation percentage of 21.93% for mercury (Tr. 1434 at 60-63).

The next step was to determine how much of the permeable cap consisted of soils relocated from other areas. Accord

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ing to Mr. Hall, this step was necessary because much of the material used for the cap was attributable to other remedial activity, such as the 18-inch sewer remediation and the Hot Spot trenches, and had nothing to do with mercury contamination. 0-463 contains Mr. Hall’s calculations of relative volumes of waste material and engineered cover material, resulting in the estimate that 55.6% of the cap consists of waste material and 43.6% of the cap consists of cover material. He then multiplied the cover material percentage (.436) by the mercury risk factor percentage (.1603), resulting in the conclusion that 6.9% of the soil remediation costs are attributable to mercury contamination (Tr. 1434 at 63-67;

see

0-427).

The final step of Mr. Hall’s soil allocation calculation was to divide this percentage among the three identified potential sources of the mercury contamination: Solvent, Olin, and Occidental. He determined that in the absence of any specific data or other information about where the mercury came from, it was appropriate to distribute the responsibility equally among these three sources. Dividing by three his calculated percentage (6.9%) of the soil remedy attributable to mercury contamination, Mr. Hall concluded that Olin should be allocated 2.3% of the cost of the soil remedy at the Solvent Site (Tr. 1434 at 68-69).

3. Kirk Winges

Mr. Winges is an air quality scientist employed by Geomatrix Inc., and environmental consulting firm located in Lynwood, Washington. He described his expertise as concerning the transport and dispersion of air pollutants in the atmosphere from release to deposition. He has been involved in air quality investigations for over 30 years, and has dealt with the emission and deposition of mercury on several occasions. His work involves a process known as air modeling, which he described as a computerized method for analyzing what happens to pollutants once they are released into the atmosphere (Tr. 1441 at 65-69).

Mr. Winges testified that he was retained by Olin to review the report of Solvent’s air emissions expert, Gary Hunt, and to determine whether Mr. Hunt’s opinion as to the source of the mercury contamination at the Solvent Site was based upon sound scientific principles. According to Mr. Winges, there were several problems with Mr. Hunt’s conclusion that the only possible explanation for the mercury found in the Solvent soils was airborne deposition of emissions from the Olin facility. For one thing, the concentrations of mercury detected in the Solvent soils do not follow the typical pattern of airborne deposition of pollutants from a single source. 0-484 depicts the location of the soil samples collected at the Solvent and Olin Sites. There are several incidences where high concentrations of mercury were detected in the same area as low concentrations, indicating a rapid gradient which cannot be explained by aerial deposition (Tr. 1441 at 74-86).

Mr. Winges testified that he performed a regression analysis to compare the actual soil sampling data with Mr. Hunt’s air model predictions, and found no correlation between the mercury concentration values predicted and the actual concentrations detected. He then looked at other possible sources for the mercury, including the Occidental Chemical chlor-alkali facility located to the south and east of the Solvent and Olin Sites. He testified that while there was insufficient information regarding the exact location of Occidental’s chlor-alkali plant and other factors pertinent to a precise modeling analysis of the impact of Occidental’s mercury emissions,

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the available information — including the windrose suggesting a predominant wind direction from the southwest to the northeast (S — 6003)—indicated that if there was airborne deposition of mercury at the Solvent Site traceable to Olin, there would be airborne deposition of mercury at Solvent traceable to Occidental as well (Tr. 1441 at 86-97).

Mr. Winges also reviewed the available information regarding the placement of fill material at the Solvent Site. He was shown the RECRA Remedial Action Investigation Report dated December 3, 1980 (0-241), which indicates that much of the Solvent Site was once marsh area which was subsequently filled with a heterogeneous mixture of silt, cinders, brick fragments, wood, and other miscellaneous materials. Mr. Winges testified that the co-location of mercury with barium, lead, zinc, and other inorganics not associated with chlor-alkali production suggests that these contaminants came to the Solvent Site via the same mechanism, more likely the placement of fill material than aerial deposition (Tr. 1441 at 97-110).

On cross-examination, Solvent’s counsel showed Mr. Winges historical aerial photographs indicating various periods of building construction, addition of railroad tracks and facilities, and other activities likely to create soil disturbances at the Solvent Site (0-404, 405). Mr. Winges agreed that these disturbances might account for some of the differences in the levels of contaminants detected in the soils, but not to the degree reflected in the sampling data (Tr. 1441 at 135 — 43).

4. James Brown

Mr. Brown was employed by the Olin Corporation for almost 40 years. From approximately 1990 until his retirement in May 2007, his focus was in the area of environmental remediation. He was directly involved in the remediation of Gill Creek, undertaken jointly with DuPont in 1992. His primary role was as environmental representative for Olin, with responsibility for liaison with the DEC and DuPont in the negotiation, execution, and implementation of the consent order, work plans, cost-sharing agreement, and various other aspects of the Gill Creek project (Tr. 1450 at 2-9).

Mr. Brown testified that in 1981, Olin and DuPont had independently performed remediation work on those portions of Gill Creek that ran through their respective properties. Subsequently, DEC contacted DuPont to address PCB contamination detected in the sediments at the mouth of Gill Creek during continuing work in the Niagara River. Further remedial investigations revealed the presence of additional contaminants traceable to both DuPont and Olin, including mercury, BHC, chlorobenzenes, and chlorinated aliphatics. According to Mr. Brown, the concentration levels detected for any one of these contaminants would have necessitated the chosen remedy, which involved removal of all contaminated sediments in four designated areas of the creek: Area 1, encompassing the mouth of Gill Creek between the Robert Moses Parkway and the confluence of the Niagara River; Area 2, encompassing the predominant length of Gill Creek which was remediated in 1981; Area 3, which is the area in the vicinity of the Adams Avenue bridge; and Area 4, encompassing the near shore of the Niagara River (Tr. 1450 at 9-15).

0-669 is a copy of the cost-sharing agreement entered by Olin and DuPont in September 1991. Mr. Brown testified that the purpose of the agreement was to establish responsibility for the various tasks of the remediation and the percentages of costs to be paid by Olin and DuPont, and to set up an operating committee with

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voting rights to address any changes in the scope of the work or cost-sharing percentages necessitated by circumstances encountered in the field. The initial overall percentages were set at 40% for Olin and 60% DuPont, but the final adjusted percentages were approximately 44% for Olin and 56% for DuPont. Mr. Brown explained that he did not adopt the proposal submitted by Blaine Butaud, a member of Olin’s environmental staff, that Olin pay a maximum of only 2%, because Mr. Butaud’s approach was based entirely on the relative toxicity of the constituents detected in the sediments without taking into account the need to maintain the business relationship between Olin and DuPont (Tr. 1450 at 17-20).

Mr. Brown testified that during the course of the remediation, he became aware of the 18-inch storm sewer connection with the Solvent Site. Samples taken from the sewer indicated elevated levels of chlorobenzenes of the same type found on the Olin Site. However, no effort was made to include Solvent in the cost-sharing agreement because there was no apparent viable financial entity operating the Solvent Site, and Olin and DuPont had a common interest in cooperating with the DEC to clean up the creek while maintaining their ongoing plant operations (Tr. 1450 at 26-28).

0-667 is a summary chart listing by task the common costs incurred by Olin to investigate and remediate Gill Creek. Mr. Brown explained that certain costs were considered to be “common” because they were expended to remediate the contaminated creek sediments regardless of the source of contamination. He testified at some length about each of the tasks listed and amounts spent by Olin: Design = $435,220; Creek Diversion = $1,236,770; Contract and Project Administration = $578,821; Water Treatment = $1,417,810; General Items = $404,996; Health and Safety = $6,381; Sales Taxes, Phase I = $184,680; Sales Taxes, Phase III = $24,332; Area 3 Seeps = $7,165; Seven-son Incentive = $152,924; Total = $4,467,099. According to Mr. Brown, these costs were reasonable and necessary to accomplish this complex project in a manner consistent with DEC oversight and the terms of the consent order. He also testified that Olin spent a total of just over $7 million for the Gill Creek remediation, leaving approximately $2.5 million not included as common costs. These additional amounts were spent on such tasks as conducting the remedial investigation and risk assessments; excavation, removal and disposal of creek sediments; and relocating two sewer outfalls (Tr. 1450 at 30-43).

C. DuPont’s Witnessesl

1. Jeffrey Konsella

Mr. Konsella is employed by the DEC as a project engineer with responsibility for overseeing the investigation and remediation of inactive hazardous waste sites in New York State. He described the State program as New York’s version of the federal program under CERCLA, which gives the DEC authority to investigate and oversee remediation of sites identified as posing a significant threat to human health or the environment. He has been the project manager for the DEC at the Solvent Site since 1993 (Tr. 1442 at 6-10).

D-124 is a copy of the Solvent Site’s listing page on the web-based version of the DEC’S registry of inactive hazardous waste sites, containing information about the Solvent Site as of October 30, 2006. The wastes disposed of at the Site are identified on the registry page as zinc, lead, benzene, mono-, di-, and trichlorobenzenes, all in unknown quantities. D-199 is DEC’S Technical and Administrative Guid

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anee Memorandum (“TAGM”) 4030, described by Mr. Konsella as a guidance document for the selection of remedies at hazardous waste disposal sites in New York. It was used for guidance in selecting the remedy at the Solvent Site. Mr. Konsella explained that under the State’s program, the DEC acts as lead agency with ultimate responsibility for decision-making with regard to remediation of a hazardous waste site, with input from the State Department of Health to safeguard the human health aspects of the remediation. Occasionally, the USEPA becomes involved on a case-by-case basis, but the EPA did not take an active role in the Solvent Site remediation (Tr. 1442 at 11-14).

Mr. Konsella testified that one of the early steps in the remedy selection process is to identify the applicable standards for determining the appropriate remedial work to be performed at the site. The federal standards are known as “ARARs” (Applicable or Relevant and Appropriate Requirements), and in New York State the standards are referred to as “SCGs” (Standards, Criteria and Guidance). D-24 is an EPA guidance document entitled “Guidance for Evaluating the Technical Impracticability of Ground-Water Restoration,” which Mr. Konsella explained was relied upon in the remedy selection process after a determination was made to waive otherwise applicable SCGs (Tr. 1442 at 14-16).

D-12 is a copy of the table of contents for the November 1990 Remedial Investigation report for the Solvent Site, undertaken by a group of potentially responsible parties to characterize the nature and extent of the contamination. Mr. Konsella testified that the DEC considered this to be a good first step, but more work needed to be done to perform a full remedial investigation and feasibility study. When the PRP group declined to complete the work, the State engaged Malcom Pirnie to conduct a supplemental remedial investigation and full feasibility study. D-14 is Volume I of Malcom Pirnie’s Supplemental Remedial Investigation Report, finalized in July 1995. Mr. Konsella was the project manager who oversaw the SRI, reviewed and modified the work plan, and reviewed and approved the SRI Report on behalf of DEC. As summarized by Mr. Konsella, the SRI Report concluded that the overburden soil and bedrock groundwater at the Solvent Site were contaminated by chlorinated benzenes and metals. D-16 is an excerpt from the report finalized in June 1995 of a study performed by Malcolm Pirnie, again under Mr. Konsella’s oversight, to determine the technical feasibility and cost of the various remedial alternatives being considered for the Solvent Site, which concluded that the presence of organic contaminants required on-site groundwater treatment (Tr. 1442 at 16-22).

D-17 is the table of contents for the Feasibility Study performed by Malcolm Pirnie on behalf of the DEC, dated February 1996. Mr. Konsella testified that the purpose of a feasibility study is to screen the appropriate remedial technologies to develop a remedial plan to deal with site-wide contamination. Table 2-6 from this study reports the volume and areal extent of soil contamination at the Site, indicating that the overburden materials down to a depth of 7.5 feet contained widespread organic and inorganic contamination. According to Mr. Konsella, the primary objective of the inactive hazardous waste site program is to achieve a cleanup remedy whenever possible, but in this situation the high concentrations of both organic and inorganic contaminants in the overburden made a cleanup alternative technically impracticable (Tr. 1442 at 22-26).

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D-23 is a feasibility study supplement dated July 1996, principally authored by Mr. Konsella, which discussed additional remedial alternatives to address the high levels of contamination in the Solvent soils in order to achieve SCGs for groundwater both on-site and off-site. One of the additional alternatives was a permeable soil cover combined with a collection system

to

allow infiltration as a method of enhancing capture and control of the contaminants in the overburden. The feasibility study supplement also discussed a phased approach to B-Zone groundwater control, which recognized that the majority of the contaminants at the site would be transmitted to the groundwater flowing within the fractured B-Zone bedrock. The phased approach was intended to achieve containment and control of the overburden and B-Zone groundwater, and to monitor the effect of the containment and control system on the lower bedrock zones. The supplement also discussed the DEC’s rationale for not requiring further off-site groundwater remediation, based on the technical impracticability presented by the man-made utilities located north of Buffalo Avenu

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