five-year review report for the crystal chemical …

FIVE-YEAR REVIEW REPORTFOR THE

CRYSTAL CHEMICAL COMPANY SITEHouston, Harris County, Texas

September 2005

Prepared for

U.S. ENVIRONMENTAL PROTECTION AGENCYREGION 6

DALLAS, TEXAS

Prepared by

TETRA TECH EM INC.Contract No. 68-W6-0037

Work Assignment No. 123-FRFE-0617

195605

FIVE-YEAR REVIEW

Crystal Chemical Company Site EPA ID#TXD990707010

Houston, Harris County, TX.

This memorandum documents EPA's approval of the second Five-Year Review Report forthe Crystal Chemical Company Site.

Summary of Five-Year Review Findings

The site's soil remedy called for on-site consolidation and capping of arsenic-contaminatedsoils. The constructed cap effectively contains contaminants by preventing infiltration of rainwaterand preventing direct contact with contaminated soils. Some minor erosion and rutting was observedon the cap during the site inspection.

The site's groundwater remedy called for pumping and treating the part of the arsenic plumeamenable to arsenic removal. The extracted ground water's average annual arsenic concentration hasvaried during the past five years from a high of 44.87 mg/L in 2002 to a low of 30.56 mg/L in 2005.The groundwater pump and treat system is operating and functioning as designed and modified. Thegroundwater remedy also called for the construction of a slurry wall around the remaining portion ofthe arsenic plume where it was determined that removal of the arsenic is technically impracticable.The construction of the slurry wall and accompanying ground water pressure relief system wascompleted in August 2003.

Ground water monitoring has been conducted on a regular basis from the 15-foot sand zone,the 35-foot sand zone, and the 100-foot sand zone to assess whether the arsenic-affected groundwater is being contained by the containment system and groundwater recovery system. In December2004, groundwater sampling of 100-foot sands did detect arsenic at a concentration of 0.327 mg/L inmonitoring well MW-32. This was the first time since the MW-32 well was installed in 1993 that thereported arsenic concentration was above the remedial goal of 0.050 mg/L. MW-32 was locatedwithin the footprint of the slurry wall and was unique among all other site wells in that when openedto the atmosphere, it would pull a vacuum. Cross-contamination between the 35-foot zone and the100-foot zone was the suspected source of the elevated arsenic concentrations reported at MW-32. April 2005, MW-32 was plugged and abandoned and a replacement well (MW-32A) was installedoutside the slurry wall. In May 2005, MW-32A was sampled and had an estimated arsenicconcentration of 0.0052 mg/L.

Deed recordation documents for the site and affected off-site properties were prepared byUnion Pacific Railroad (UPRR) using a recently completed boundary survey of the extent ofaffected ground water. The draft deed certification was sent on May 13, 2005, to the City ofHouston, an adjacent property owner, and is currently being reviewed by the City of Houston for itscomment and approval.

No community concerns were identified during the review.

Actions Needed

The minor erosion and rutting on the cap will be repaired. The site fence also requires someminor repairs. Groundwater monitoring will continue, as will efforts to place institutional controlson the site. While not required to ensure the site's protectiveness, but in an effort to increase thepotential for site redevelopment, UPRR will be evaluating alternatives to the current affected soilcontainment remedy. UPRR will also be evaluating alternative remedial methods to the currentpump and treat system (i.e., slurry wall, intermitted pumping, phyto-hydraulic control, etc.) topotentially reduce operation and maintenance costs for the site's groundwater treatment plant.

Determinations

I have determined that the selected soil and groundwater remedies for the Crystal ChemicalCompany site are protective of human health and the environment and will remain so provided thatthe action items identified in the Five-Year Review Report are addressed as described in theexecutive summary. Action items include maintaining the monofill cap and perimeter fence,continuing groundwater monitoring to determine if the groundwater pump and treat system andcontainment system are performing as designed, and recording the appropriate institutional controldocuments.

CONCURRENCES:

SECOND FIVE-YEAR REVIEW FOR

CRYSTAL CHEMICAL COMPANY SITE

EPA ID No. TXD990707010

Chris G. VillarrealRemedial Project Manager, TX Section

Gustavo ChavarriaProject Management Section Chief

AnnepnsterCounse

^^ ^f*~r~^lanTA. Peycke

Chief, Regional-Counsel

John HepolaChief, AR/TX Branch

.\P^riela PhillipsDeputy Division Director, Superfun Division

Date:

Date:

Date:

Date:

Date:

Date:

CONTENTS

Section Page

ACRONYMS AND ABBREVIATIONS iii EXECUTIVE SUMMARY ES-1

1.0 INTRODUCTION 1 2.0 SITE CHRONOLOGY 2 3.0 BACKGROUND 2

3.1 PHYSICAL CHARACTERISTICS 2 3.2 LAND AND RESOURCE USE 7 3.3 HISTORY OF CONTAMINATION 7

4.0 REMEDIAL ACTION 9 4.1 SELECTED REMEDY 10 4.2 REMEDY IMPLEMENTATION 10

4.2.1 Soil Remedy 11 4.2.2 Groundwater Remedy 11

4.3 OPERATION AND MAINTENANCE 12 4.4 OPERATION AND MAINTENANCE COST 18

5.0 FIVE-YEAR REVIEW PROGRESS 19 6.0 FIVE-YEAR REVIEW PROCESS 19

6.1 ADMINISTRATIVE COMPONENTS 19 6.2 COMMUNITY INVOLVEMENT 20 6.3 SITE INSPECTION 20 6.4 LOCAL INTERVIEWS 21 6.5 ARAR REVIEW 21

6.5.1 Chemical-Specific ARARs 22 6.5.2 Location-Specific ARARs 23 6.5.3 Action-Specific ARARs 23

6.6 DATA REVIEW 23 6.6.1 GWTP 24 6.6.2 Groundwater Monitoring 25

7.0 TECHNICAL ASSESSMENT 27 8.0 ISSUES 28 9.0 RECOMMENDATIONS AND FOLLOW-UP ACTIONS 30 10.0 PROTECTIVENESS STATEMENT 30 11.0 NEXT REVIEW 30

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CONTENTS (Continued)

Appendices

A DOCUMENTS REVIEWED B SITE VISIT REPORT C PUBLIC NOTICE D SUMMARY OF GROUND WATER ELEVATION DATA E SUMMARY OF GROUNDWATER ANALYTICAL RESULTS

FIGURES

Figure Page

1 SITE LOCATION MAP 6 2 SITE LAYOUT MAP 8

TABLES

Table Page

1 CHRONOLOGY OF SITE EVENTS 3 2 GROUNDWATER MONITORING PLAN 18 3 ANNUAL OPERATION AND MAINTENANCE COSTS 19 4 GROUNDWATER RECOVERY AND DISCHARGE SUMMARY 24 5 GWTP INFLUENT ANALYTICAL DATA SUMMARY 25 6 ISSUES IDENTIFIED 29 7 RECOMMENDATIONS AND FOLLOW-UP ACTIONS 31

EXHIBITS

Exhibit

A SITE VISIT PHOTOGRAPHS B SITE INVESTIGATION CHECKLIST C SURVEYS

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ACRONYMS AND ABBREVIATIONS

§ SectionARAR Applicable or relevant and appropriate requirement bgs Below ground surfaceCERCLA Comprehensive Environmental Response, Compensation, and Liability Act COC Contaminant of Concern COH City of HoustonCWA Clean Water ActEPA U.S. Environmental Protection Agency Region 6 FS Feasibility study GWTP Groundwater treatment plant mg/kg Milligrams per kilogram mg/L Milligrams per literNCP National Oil and Hazardous Substances Pollution Contingency PlanNPDES National Pollution Discharge Elimination SystemNPL National Priorities List O&M Operation and maintenancePOTW Publicly Owned Treatment WorksPRP Potentially responsible partyPRS Pressure release system RA Remedial action RAO Remedial action objective RCRA Resource Conservation and Recovery Act RD Remedial design RI Remedial investigation ROD Record of Decision Southern Pacific Southern Pacific Transportation CompanyTCEQ Texas Commission on Environmental QualityTNRCC Texas Natural Resource Conservation Commission Tetra Tech Tetra Tech EM Inc.UPRR Union Pacific Railroad Company yd3 Cubic yard

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EXECUTIVE SUMMARY

The U.S. Environmental Protection Agency Region 6 (EPA) has conducted the second five-yearreview of the remedial action (RA) implemented at the Crystal Chemical Company (CrystalChemical) site. The purpose of this five-year review was to determine whether the selected remedyfor the site continues to protect human health and the environment. This review was conducted fromJune 2005 to August 2005, and its findings and conclusions are documented in this report. The firstfive-year review of the RA was completed in September 2000. The second five-year review periodextended from 2000 to 2005.

Several documents were reviewed as part of this five-year review: (1) groundwater monitoringanalytical data for the 15-foot zone, 35-foot zone, and 100-foot zone; (2) monitor well groundwaterelevation data for the 15-foot zone, 35-foot zone, and 100-foot zone; (3) groundwater analytical datafor groundwater treatment plant (GWTP) influent and effluent; (4) groundwater recovery anddischarge volume data for GWTP; and (5) operation and maintenance inspection summaries.

The Crystal Chemical site was listed on the National Priorities List (NPL) in September 1983. EPAsigned the Record of Decision (ROD) that addressed soil and groundwater contamination onSeptember 27, 1990. Due to the unavailability of the technology for the selected soil remedy, EPAissued a ROD Amendment on September 16, 1992. During the course of implementation of theselected groundwater remedy, EPA determined the restoration of the groundwater was technicallyimpracticable for portions of the site. As a result, EPA issued an Explanation of SignificantDifferences on March 19, 1997. The remedial action objectives (RAO), selected remedy, andimplementation status for the soil and ground water at the Crystal Chemical site are discussed below.

Soil Contamination The selected soil remedy in the September 27, 1990 ROD called for the excavation of off-site soilscontaminated with arsenic, treatment of soils using an innovative treatment technology (in-situvitrification), and capping of the entire site after the soil treatment had been completed. Due to theunavailability of the technology, EPA selected a new soil remedy consisting of soil consolidationand capping in the ROD amendment issued on September 16, 1992. The soil consolidation andcapping remedy was completed in September 1995.

The ROD amendment described the on-site and off-site soil remedy as follows:

1) Resampling off-site areas previously identified as contaminated with arsenic in orderto identify all off-site soils with arsenic concentrations exceeding 30 milligrams perkilogram (mg/kg).

2) Excavation of approximately 55,000 cubic yards (yd3) of off-site soils with arsenicconcentrations exceeding 30 mg/kg. Backfill off-site excavated areas to previouslyexisting grades.

3) Placement of excavated soils into a monofill on the Crystal Chemical site.

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4) Installation of a multilayer low permeability cap over the entire Crystal Chemical siteafter excavated off-site soils have been placed on-site.

EPA determined that this soil remedy is protective of human health and the environment, attainsfederal and state requirements that are applicable or relevant and appropriate, is cost-effectivecompared to equally environmentally protective alternatives, and utilizes permanent solutions andalternative treatment technologies to the maximum extent practicable.

Groundwater Contamination The selected groundwater remedy in the September 27, 1990 ROD called for the extraction andtreatment of arsenic contaminated ground water. The remediation goal specified in the 1990 RODfor the affected groundwater zones is 0.050 milligrams per liter (mg/L), the maximum contaminantlevel (MCL) for arsenic. The 1990 ROD also included several contingency measures that could beimplemented if an extraction and treatment system could not attain the groundwater remediationgoal.

During the course of the design for the groundwater remedy, EPA and the Texas Natural ResourceConservation Commission (TNRCC) (now the Texas Commission on Environmental Quality[TCEQ]) determined that restoration of the ground water was technically impracticable for portionsof the Crystal Chemical Site. Therefore, EPA determined that the applicable or relevant andappropriate requirement (ARAR) for groundwater restoration to the MCL of 0.050 mg/L for arsenicshould be waived and a slurry wall should be constructed around the portions of the site wheregroundwater cannot be restored. The extraction and treatment of arsenic-contaminated ground waterremained the selected remedy for the remainder of the site as specified in the 1990 ROD. Thedecision to waive the groundwater ARAR and construct the slurry wall is documented in theExplanation of Significant Differences dated March 1997.

EPA determined that this groundwater remedy is protective of human health and the environment,attains federal and state requirements that are applicable or relevant and appropriate, is cost-effectivecompared to equally environmentally protective alternatives, and utilizes permanent solutions andalternative treatment technologies to the maximum extent practicable.

Second Five-Year Review

The second five-year review focused on data obtained during annual inspections conducted at theCrystal Chemical site. This review included the groundwater monitoring activities, groundwaterrecovery and treatment activities, groundwater containment activities, and general monofillmaintenance performed from September 2000 through May 2005. Based on this review, the selectedremedy is performing as intended.

The following issues were noted:

1. Minor erosion on monofill - Areas with minor erosion were noted on the northernand western side slopes of the monofill.

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2. Rutting of monofill surface cover - Ruts in the grass surface cover were observed ina few areas on the northeast corner of the monofill. The ruts appeared to be caused bythe lawn maintenance vehicles that mowed the grass cover the week before the sitevisit.

3. Minor fence and gate maintenance - Minor fence and gate damage was observed atthe entrance gate to the 12.5-acre northern tract of land where the northern andeastern slurry wall segments are located.

4. Minor erosion at northern property - Minor erosion was observed under the fenceat the southeast corner of the 12.5-acre tract. A gap approximately 1.5 feet by 1 footin area was observed below the fence in this area.

5. Rainwater ponding within vaults - The quarterly inspection reports for late 2004and early 2005 note that rainwater appeared to be ponding and infiltrating into thecleanout/leak detection vaults of the pressure release system (PRS). Repairs weremade to the seals at all six vaults in February and May 2005. During the site visit,approximately 6 inches of standing water was observed in Vault #1. According toAdolfo Cepeda, of Hatch Mott MacDonald (HMM), no rainwater infiltration has beenobserved since the repairs in February and May 2005. Mr. Cepeda stated that not allthe infiltrated water was removed from the vaults during the repair activities and thatthe standing water was remnant of the ground water that infiltrated prior to therepairs.

6. Leaf debris on drainage outlet - Leaf debris was noted over the drainage outlet onthe western side of the monofill.

7. Corroded pipe in GWTP - The sludge decant pipe from the clarifier in the GWTP iscorroded.

8. Deed recordation - According to the November 1994 "Remedial Action Operationand Maintenance Plan," UPRR is required to record a notation on the deed or anyinstrument normally examined during a title search, which will allow any potentialbuyer to be made aware of site conditions. Deed recordation documents for the siteand off-site properties have been prepared using a recent boundary survey of theextent of the affect ground water. According to Michael Wisniowiecki ofConestoga-Rovers & Associates (CRA), the documents have been reviewed andapproved by all off-site property owners with the exception of the City of Houston(COH). The COH is currently reviewing the deed recordation documents and thedeed recordation will be completed upon approval by the COH.

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The following actions are needed in response to these issues:

1. Continue to monitor the areas of the monofill experiencing minor erosion, and reseedwhen appropriate to prevent impact upon the monofill and slurry wall.

2. Instruct lawn maintenance crew to be careful during lawn maintenance activities toprevent rutting of monofill grass surface cover.

3. Repair damage to fencing at the front gate and fence at the 12.5-acre northern tract.

4. Place fill material under the southeast corner of the fence at the 12.5-acre northernproperty where an approximately 1.5-feet by 1-foot gap exists under the fencing.

5. Continue to inspect cleanout/leak detection vaults to assess whether or not rainwaterinfiltration is occurring, and conduct additional repairs if needed to preventgroundwater infiltration. Vacuum and/or evaporate all standing water in vaults.

6. Leaf debris over drainage outlets should be removed during routine mowingactivities.

7. Replace corroded sludge decant pipe from the clarifier in the GWTP.

8. Continue to communicate with COH during their review of the deed recordationdocuments. Complete deed recordation upon approval of all parties.

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Five-Year Review Summary Form

SITE IDENTIFICATION

Site Name (from WasteLAN): Crystal Chemical Company

EPA ID (from WasteLAN): TXD 990707010

Region: 6 State: TX City/County: Houston/Harris County

SITE STATUS

NPL Status: [X] Final D Deleted D Other (specify)

Remediation Status (choose all that apply): I I Under Construction

|~1 Complete

Operating

Multiple OUs?* IE! YES D NO Construction Completion Date:

Contaminated soil remedy- Sept. 1995Ground water treatment plant - Nov. 1996Ground water treatment plant modifications - May 1998Eastern and Northern portion of slurry wall - June 2002PRS complete except under Westpark - Oct. 2002Final segment of PRS under Westpark- August 2003

Has site been put into reuse? D YES |EI NO

REVIEW STATUS

Reviewing Agency: [>3 EPA [U State CJ Tribe dl Other Federal Agency

Author Name: Chris Villarreal

Author Title: Remedial Project Manager Author Affiliation: EPA Region 6

Review Period:** 9/2000 to 5/2005

Date(s) of Site Inspection: 07/29/2005

Type of Review: Statutory

Policy D Post-SARA D Pre-SARA D NPL-Removal only

Non-NPL Remedial Action Site Q NPL State/Tribe-lead

Regional Discretion

Review Number: H3 1 (first) £<] 2 (second) HH 3 (third) Q Other (specify).

Triggering Action:

l~~l Actual RA On-site Construction at OU

I I Construction Completion

D Other (specify)

Actual RA Start

Previous Five-Year Review Report

Triggering Action Date: 09/2000

Due Date (Five Years After Triggering Action Date): 09/2005

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* "OU" refers to operable unit.

** The review period refers to the period during which the five-year review was conducted.Issues:

1. Minor erosion on monofill - Areas with minor erosion were noted on the northern andwestern side slopes of the monofill.

2. Rutting of monofill surface cover - Ruts in the grass surface cover were observed in afew areas on the northeast corner of the monofill. The ruts appeared to be caused by thelawn maintenance vehicles that mowed the grass cover the week before the site visit.

3. Minor fence and gate maintenance - Minor fence and gate damage was observed at theentrance gate to the 12.5-acre northern tract of land where the northern and eastern slurrywall segments are located.

4. Minor erosion at northern property - Minor erosion was observed under the fence at thesoutheast corner of the 12.5-acre northern tract. A gap approximately 1.5-feet by 1-foot inarea was observed below the fence in this area.

5. Rainwater ponding within vaults -The quarterly inspection reports for late 2004 andearly 2005, note that rainwater appeared to be ponding and infiltrating into thecleanout/leak detection vaults of the PRS. Repairs were made to the seals at all six vaultsin February and May 2005. During the site visit, approximately 6 inches of standing waterwas observed in Vault #1. According to Adolfo Cepeda of Hatch Mott MacDonald(HMM), no rainwater infiltration has been observed since the repairs in February and May2005. Mr. Cepeda stated that not all the infiltrated water was removed from the vaultsduring the repair activities and that the standing water was remnant of the ground waterthat infiltrated prior to the repairs.

6. Leaf debris on drainage outlet - Leaf debris was noted over the drainage outlet on thewestern side of the monofill.

7. Corroded pipe in GWTP - The sludge decant pipe from the clarifier in the GWTP iscorroded.

8. Deed recordation - According to the November 1994 "Remedial Action Operation andMaintenance Plan" UPR is required to record a notation on the deed or any instrumentnormally examined during a title search, which will allow any potential buyer to be madeaware of site conditions. Deed recordation documents for the site and off-site propertieshave been prepared using a recent boundary survey of the extent of the affect groundwater. According to Michael Wisniowiecki of Conestoga-Rovers & Associates (CRA), thedocuments have been reviewed and approved by all off-site property owners with theexception of the COH. The COH is currently reviewing the deed recordation documentsand the deed recordation will be completed upon approval by the COH.

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Recommendations and Follow-up Actions:

1. Continue to monitor the areas of the mono fill experiencing minor erosion, andreseed when appropriate to prevent impact upon the monofill and slurry wall.

2. Instruct lawn maintenance crew to be careful during lawn maintenance activities toprevent rutting of monofill grass surface cover.

3. Repair damage to fencing at the front gate and fence at the 12.5-acre northern tract.

4. Place fill material under the southeast corner of the fence at the 12.5 acre northernproperty where an approximately 1.5-feet by 1-foot gap exists under the fencing.

5. Continue to inspect cleanout/leak detection vaults to access whether or not rainwaterinfiltration is occurring, and conduct additional repairs if needed to preventgroundwater infiltration. Vacuum and/or evaporate all standing water in vaults.

6. Leaf debris over drainage outlets should be removed during routine mowingactivities.

7. Replace corroded sludge decant pipe from the clarifier in the GWTP.

8. Continue to communicate with COH during their review of the deed recordationdocuments. Complete deed recordation upon approval of all parties.

Protectiveness Statement:

The remedial action for soil and groundwater at the Crystal Chemical site is protective of human healthand the environment. Since both media are protective, the remedy for the site is protective of humanhealth and the environment.

Long-Term Protectiveness:

This second five-year review indicates that the selected remedies appear to be performing as intended,and are protective of human health and the environment. For the soil remedy to be protective in thelong term, the monofill should continue to be inspected and operated and maintained in accordancewith approved plans. For the groundwater remedy to be protective in the long term, the GWTP andslurry wall/PRS should continue to be inspected and operated and maintained in accordance withapproved plans. Additionally, the groundwater monitor wells in the current network will need tocontinue being monitored. Groundwater samples will need to continue being collected and analyzedfor arsenic as specified by the Groundwater Monitoring Plan dated December 12, 2003.

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1.0 INTRODUCTION

The U.S. Environmental Protection Agency Region 6 (EPA), with assistance from Tetra Tech EMInc. (Tetra Tech), and Union Pacific Railroad Company (UPRR), conducted the second five-yearreview of the remedial action (RA) implemented at the Crystal Chemical site in Houston, Texas. Thepurpose of a five-year review is to determine whether the remedy at a site is protective of humanhealth and the environment.

The five-year review process is required by federal statute. EPA must implement five-year reviewsconsistent with the Comprehensive Environmental Response, Compensation, and Liability Act(CERCLA) and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).CERCLA Section (§) 121(c), as amended, states the following:

If the President selects a remedial action that results in any hazardous substances,pollutants, or contaminants remaining at the site, the President shall review such remedialaction no less often than each five years after the initiation of such remedial action to assurethat human health and the environment are being protected by the remedial action beingimplemented.

NCP § 300.430(f)(4)(ii) states the following:

If a remedial action is selected that results in hazardous substances, pollutants, orcontaminants remaining at the site above levels that allow for unlimited use and unrestrictedexposure, the lead agency shall review such action no less often than every five years afterthe initiation of the selected remedial action.

Because hazardous substances, pollutants, or contaminants remain at the Crystal Chemical siteabove levels that allow for unlimited use and unrestricted exposure, a five-year review is required.

The period addressed by this five-year review for the Crystal Chemical site extended from 2000 to2005. The triggering action for this review was the completion of the first five-year review inSeptember 2000. The second five-year review was conducted from June to August 2005, and itsmethods, findings, conclusions, and recommendations are documented in this report.

This report documents the five-year review for the Crystal Chemical site by providing the followinginformation: site chronology (Section 2.0), background information (Section 3.0), an overview of theEPA RA (Section 4.0), five-year review progress (Section 5.0), the five-year review process(Section 6.0), technical assessment of the site (Section 7.0), issues identified (Section 8.0), andrecommendations and follow-up activities (Section 9.0). The report also provides a protectivenessstatement (Section 10.0) and discusses the next review (Section 11.0). Appendix A provides a list ofdocuments reviewed, and Appendix B is the site visit report. The public notice is provided inAppendix C, a summary table of ground water elevation data is provided in Appendix D, and asummary table of ground water analytical data is provided in Appendix E.

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2.0 SITE CHRONOLOGY

A chronology of site events for the Crystal Chemical site is provided in Table 1. Additionalhistorical information for the site is available on line at: http://www.epa.gov/earthlr6/6sf/pdffiles/0603555.pdf (EPA 2005).

3.0 BACKGROUND

This section discusses the site's physical characteristics, land and resource use near the site, thehistory of site contamination, the initial response to the site, and the basis for the response.

3.1 PHYSICAL CHARACTERISTICS

The Crystal Chemical site is located at 10985 Westpark Drive (formerly 3502 Rogerdale Road), insouthwest Houston, Harris County, Texas (see Figure 1). The site is approximately 6.8 acres. Thesite is bounded on the west by the Harris County Flood Control District (HCFCD) ditch numberDl24-00-00, on the north by Westpark Drive and a 12.5-acre tract of land owned by UPRR, on theeast by a 5-acre tract owned by UPR, and on the south by a 3.8-acre tract of land owned by UPRRand vacant land owned by Shearton Development. The site is located in a mixed use commercial,light industry, and residential area.

Soils at the site are poorly drained and consist primarily of silty clay and sandy clay. Surface watersthat enter the flood control channel flow south and are discharged into Brays Bayou approximately 1mile south of the site. Brays Bayou drains into the Houston Ship Channel, which terminates atGalveston Bay. Two shallow groundwater sand zones are located under the site at approximately 15feet and 35 feet below ground surface (bgs). A third water-bearing zone is located under the site atapproximately 100 feet bgs. A clay confining layer is located beneath the 35-foot zone that reducesthe potential for vertical migration between the 35-foot zone and the 100-foot zone and deeperwater-bearing zones. The 15-foot zone is discontinuous and is generally present along WestparkDrive. The 35-foot zone and 100-foot zone are continuous at and in the vicinity of the site. In the35-foot sand zone, ground water at the site flows toward the northeast at an approximate gradient of0.013 foot/foot. South of the monofill, in the 35-foot sand zone, ground water flows to thesouth/southwest at an approximate gradient of 0.012 foot/foot. In the 100-foot sand zone, groundwater flow is toward the north/northeast at a gradient of approximately 0.0008 foot/foot.

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TABLE 1 CHRONOLOGY OF SITE EVENTS

CRYSTAL CHEMICAL COMPANY- HOUSTON, TEXAS Date Event

1968 Crystal Chemical began production of arsenical, phenolic, and amine-based herbicides.

June 1976 Flooding occurred at the site, causing runoff from process and material storage areas.

1977 Harris County Flood Control ditch no. D 124-00-00 was constructed along the westernportion of the site.

December 1977 TDWR cited operation and maintenance problems for several environmental standardsviolations.

1978 Crystal Chemical submitted an application to the State of Texas for on-site deep wellinjection permit to dispose of wastewaters being stored in four evaporation ponds —Permit denied.

September 1981 Crystal Chemical filed for bankruptcy and abandoned site.

September 1981through February 1983

EPA initiated a number of Emergency Removal Actions to stabilize site 1) disposed of pond wastewater 2) top 12 inches of pond soil treated with lime and placed back in ponds 3) installed temporary cap 4) sold arsenic trioxide that was stored on site 5) disassembled, decontaminated, and sold buildings and process equipment

September 1983 Crystal Chemical was added to the National Priorities List.

1983 EPA took measures to further control surface water runoff and site access byconstructing drains, and fencing and placing additional fill on site.

1983 TDWR, through a cooperative agreement with EPA, initiated a site characterizationstudy.

1984 "Final Report Site Investigation Crystal Chemical Company, Houston, Texas" waspublished citing arsenic as the primary contaminant of concern.

June 1984 TDWR completed an Initial Feasibility Study.

December 1984 EPA and TDWR completed an Addendum Feasibility Study modifying the selectedremedy as a response to public concerns on cost.

October 1986 Passage of the SARA, which called for feasibility study to focus on use of treatmenttechnologies for the site.

May 1987 EPA entered into an Administrative Order of Consent with Southern Pacific (PRP) toconduct the Supplemental Feasibility Study (SFS).

1988 EPA took additional measures to further control surface water runoff and site access byconstructing additional drains, and fencing and placing fill on site.

January 1988 Southern Pacific suspended work on SFS site.

February 1989 New federal regulations allowing off-site treatability studies were promulgated.

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TABLE 1 (Continued) CHRONOLOGY OF SITE EVENTS

CRYSTAL CHEMICAL COMPANY— HOUSTON, TEXAS Date Event

July 1989 Nine water supply wells near the site were sampled, which aided the delineation of thegroundwater contamination.

September1989

Event Southern Pacific requested an extension to complete the SFS — EPAdenied the request.

June 1990 Regulation published identifying in situ vitrification as the best demonstrated availabletreatment technology for arsenic as a RCRA characteristic waste as well as a RCRAlisted waste.

May 1990 EPA completed the SFS.

June 1990 Proposed plan for the site was released for public comment.

September 1990 The ROD for the site was issued by EPA Region 6.

February 1992 An Amended Proposed Plan was released for public comment due to the unavailabilityof the ROD'S selected soil treatment technology — in situ vitrification.

March 1992 EPA entered into an Administrative Order of Consent with Southern Pacific forgroundwater remedy at the site.

June 1992 The amended ROD for the site was issued by EPA Region 6.

September 1992 EPA issued a unilateral Administrative Order to Southern Pacific addressing theRD/RA for the site.

November 1994 Southern Pacific implemented the Remedial Action Operation and Maintenance Plan toensure the long-term integrity of the multi-layer cap.

January 1995 EPA approves Soil Remedial Action Documentation Report summarizing theconstruction of the soil remedy design.

September 1995 Construction of portion of slurry wall within boundary of site, and under WestparkDrive. Completion of monofill.

February 1996 Assessment of the TI of groundwater remediation for the site was completed. Physicalcontainment of contaminated ground water was the recommended alternative.

November 1996 Construction of GWTP completed.

March 1997 Explanation of Significant Differences of the Record of Decision for the groundwaterremedy was issued

May 1998 Major modifications to GWTP completed.

August 1998Revised July1999

Revised Work Plan for Additional Groundwater Investigation was issued.

January 1999 GWTP went online with COH.

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TABLE 1 (Continued) CHRONOLOGY OF SITE EVENTS

CRYSTAL CHEMICAL COMPANY— HOUSTON, TEXASDate Event

July -December1999

A review of historical information and confirmation sampling was conducted on the12.5-acre tract (north of the site) to identify potential environmental issues prior toapproving a proposed property transfer. Ownership of this property was required tocomplete the slurry wall construction.

April 2000 Event EPA initiates the first Five-Year Review. UPRR purchased 12.5-acre tract northof Westpark Drive from Levy estate.

August 2000 Additional monitoring of the 15-foot and 35-foot zones occurred as defined in the WorkPlan for Additional Ground Water Investigation.

September 2002 EPA issued first Five-Year Review Report.

June 2002 Eastern and northern portions of slurry wall complete.

October 2002 PRS construction complete with exception of recovery piping under Westpark Drive.

November 2002 Groundwater samples collected from Shearton Tract.

August 2003 Final section of PRS installed beneath Westpark Drive. Groundwater remedyconstruction complete.

September 2003 Site investigation activities conducted at properties to the west of Shearton Tract.

December 2003 Revised Groundwater Monitoring Plan was issued. Groundwater monitoring resumed in4th Quarter 2003.

December 2004 UPR purchased western 3.8 acres of the Shearton Tract located south of the site.

March 7, 2005 Installation of phytohydraulic control pilot test completed.

June 2005 EPA initiates the second Five-Year Review.Notes:

Crystal Chemical Crystal Chemical Company EPA U.S. Environmental Protection AgencyISV In situ vitrification POTW Publicly owned treatment worksPRP Potentially responsible partyRA Remedial actionRCRA Resource Conservation and Recovery Act RD/RA Remedial Design/Remedial ActionRI/FS Remedial Investigation/Feasibility StudyROD Record of DecisionSARA Superfund Amendments and Reauthorization Action of 1986SFS Supplemental Feasibility StudySouthern Pacific Southern Pacific Transportation Company TDWR Texas Department of Water ResourcesTI Technical ImpracticabilityTWC Texas Water CommissionUPR Union Pacific Railroad Company

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3.2 LAND AND RESOURCE USE

Crystal Chemical produced arsenical, phenolic, and amine-based herbicides on the site from 1968 to1981. Crystal Chemical leased the 6.8-acre tract from the owner Southern Pacific TransportationCompany (Southern Pacific), now Union Pacific Railroad, from 1968 until 1979 when CrystalChemical purchased the property. In 1981, Crystal Chemical ceased operations, filed for bankruptcy,and abandoned the site. With the exception of investigation and remedial activities, the site has beeninactive since September 1981.

The area surrounding the Crystal Chemical site is primarily used for commercial, light industry, andresidential purposes. A site layout map is available as Figure 2.

3.3 HISTORY OF CONTAMINATION

The production of arsenical, phenolic, and amine-based herbicides at the Crystal Chemical site from1968 to 1981 affected soils and ground water on the site and adjacent properties. The contaminationcovered approximately 24.4 acres, which included 6.8 acres on-site and 17.6 acres off-site. Thefollowing paragraphs summarize the assessment and remedial history at the site.

Operation and maintenance problems at the Crystal Chemical facility during the late 1970s resultedin several violations of State of Texas environmental standards. Although the site is not locatedwithin a flood prone area as defined by Federal Emergency Management Agency (FEMA) FloodInsurance Rate Maps (FIRM), the site lies within the limits of the 100-year flood plain of theadjacent HCFCD drainage ditch. In 1976, the site was subject to repeated flooding, which carriedarsenic contaminated wastewaters off-site. In 1978, Crystal Chemical applied to the State of Texasfor an on-site deep well injection permit to dispose of the process wastewaters. The permit wasdenied by the State of Texas.

In September 1981, Crystal Chemical filed for bankruptcy and abandoned the site. EPA initiated anEmergency Removal Action to stabilize the site. Approximately 99,000 gallons of arsenic trioxidewere sold with the building and process equipment. Approximately 600,000 gallons of wastewaterfrom the evaporation ponds were disposed of off-site. The top 12 inches of pond soils were treatedwith lime and deposited back into the ponds. In 1983, the Crystal Chemical property was added tothe National Priorities List (NPL).

EPA is the lead agency for the site, and through a cooperative agreement with the State regulatorybody, the Texas Commission on Environmental Quality (TCEQ), formerly the Texas NaturalResource Conservation Commission (TNRCC), has been involved in all site activities. In 1982 and1983, EPA identified 13 potential responsible parties (PRP) for the site. All PRPs declined toparticipate in the Remedial Investigation/Feasibility Study (RI/FS) for the site. Therefore, EPA andTCEQ conducted an RI/FS to define the types and extent of contamination at the site.

In January 1984, EPA issued the RI/FS report, which indicated that arsenic and phenol weredetected in surface and subsurface soil and ground water. The RI/FS report delineated arseniccontamination across the site to an average depth of 5 to 6 feet below ground surface (bgs).Concentrations of 5,000 milligrams per kilogram (mg/kg) were found to have penetrated from 3 to 7

LEGEND

UNION PAanC RAILROAD

CROUNDWATER TREATMENT PLANT

EXISTING SLURRY WALL

SUBSURFACE LEVEE(APPROXIMATE LOCATION)

PRESSURE RELIEF SYSTEM

CHAN LINK FENCE15-FOOT SAND 20NE WELLCONTAINMENT SYSTEM WELL(35-FOOT SAND ZONE)35-FOOT SAND ZONE TELLRECOVERY YELL LOCATION100-FOOT SAND ZONE WELL

CRYSTAL CHEMICAL NPL SITEHOUSTON, TEXAS

FIGURE 2SITE PLAN

SOURCE: CLIENT SUPPLIED FIGURE 423094B02E03RO. DATED MARCH 1. 2004. &EPA

10 feet bgs in areas throughout the site. Off-site soil borings reported arsenic concentrations of 50mg/kg as deep as 9 feet bgs. Contamination of ground water and subsurface soils was determined tohave been caused by percolation of storm water and surface water. The volume of off-site soilscontaminated with arsenic greater than 30 mg/kg was reported to be 55,000 cubic yards (yd3). Thevolume of on-site soils contaminated with arsenic greater than 300 mg/kg was estimated to be16,500 yd3. An estimated 101,000 yd3 of on-site soils were reported to be contaminated with arsenicgreater than 30 mg/kg.

During the RI/FS, 21 monitoring wells were installed. Based upon soil borings taken during the wellinstallation, three water-bearing zones (15 feet, 35 feet, and 100 feet bgs) were identified. Based onthe information gathered during the RI/FS, an estimated 3 million gallons of water was contaminatedwith arsenic. The highest concentrations of contaminants were found in the 35-foot to 50-footwater-bearing sand layer.

Based on the data collected during the RI, it was determined that if no action was taken to addressthe soil and groundwater contamination, hazardous substances could be released from the CrystalChemical site and endanger public health, welfare, or the environment.

The Record of Decision (ROD) for soil and ground water at the Crystal Chemical site was issued inSeptember 1990. Due to unavailability of the in situ vitrification technology, the soil remedy wasrevised in a ROD Amendment issued in June 1992. In 1996, the selected groundwater remedy wasdetermined to be technically impracticable for portions of the affected area, and an Explanation ofSignificant Differences of the Record of Decisions was issued in March 1997.

Southern Pacific (now UPRR), was identified as the PRP. Crystal Chemical filed for bankruptcy inSeptember 1981. UPRR had previously owned the property and responded to EPA's request toparticipate in the remedial design/remedial action (RD/RA). In March 1992, an administrative order(U.S. EPA Docket No. 6-11-92) was signed by the EPA and Southern Pacific for the groundwaterremedial design. In September 1992, EPA issued a Unilateral Administrative Order (U.S. EPADocket No. VI-15-92) to Southern Pacific for the soil RD/RA and the groundwater remedy RA.

The soil remedy involved the excavation of approximately 55,000 yd3 of off-site soils with arsenicconcentrations exceeding 30 mg/kg and placement of excavated soils into a capped monofill on theCrystal Chemical site. The soil remedy was completed in September 1995. The groundwater remedyinvolved the construction of a groundwater treatment plant (GWTP) and installation of agroundwater containment system consisting of a slurry wall and pressure relief system (PRS). TheGWTP was completed in November 1996 with major modifications completed in May 1998. Thegroundwater containment system was completed in several phases from 1995 to 2003.

4.0 REMEDIAL ACTION

This section discusses the selected remedy, remedy implementation, operation and maintenance(O&M) activities, and O&M costs.

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4.1 SELECTED REMEDY

Soil The selected soil remedy in the September 27, 1990 ROD called for the excavation of off-site soilscontaminated with arsenic, treatment of soils using an innovative treatment technology (in situvitrification), and capping of the entire site after the soil treatment had been completed. Due to theunavailability of the technology, EPA selected a new soil remedy consisting of soil consolidationand capping in the ROD amendment issued on September 16, 1992. The soil consolidation andcapping remedy was completed in September 1995.

The ROD Amendment described the remedy as follows:

1) Resample off-site areas previously identified as contaminated with arsenic in order toidentify all off-site soils with arsenic concentrations exceeding 30 mg/kg.

2) Excavate approximately 55,000 yd3 of off-site soils with arsenic concentrations exceeding 30mg/kg. Backfill off-site excavated areas to previously existing grades.

3) Place excavated soils into a monofill on the Crystal Chemical site.

4) Install multi-layer low permeability cap over entire Crystal Chemical site after excavatedoff-site soils have been placed on-site.

Groundwater The selected groundwater remedy in the September 27, 1990 ROD called for the extraction andtreatment of arsenic-contaminated ground water. The remediation goal specified in the 1990 RODfor the affected ground water zones is 0.050 mg/L, the MCL for arsenic. The 1990 ROD alsoincluded several contingency measures that could be implemented if an extraction and treatmentsystem would not produce the groundwater remediation goal.

During the course of the design for the groundwater remedy, EPA and TNRCC determined thatrestoration of the ground water is technically impracticable for portions of the Crystal Chemical Site.Therefore, EPA determined that the applicable or relevant and appropriate requirement (ARAR) forgroundwater restoration to the MCL of 0.050 mg/L for arsenic should be waived and a slurry wallshould be constructed around the portions of the site where ground water cannot be restored.Extraction and treatment of arsenic-contaminated ground water remained the selected remedy for theremainder of the site, as specified in the 1990 ROD. The decision to waive the groundwater ARARand construct the slurry wall is documented in the Crystal Chemical Site Superfund Explanation ofSignificant Differences of the Record of Decisions (March 1997).

4.2 REMEDY IMPLEMENTATION

UPRR (formerly Southern Pacific) has performed the remediation activities for the Crystal Chemicalsite. EPA provided oversight during the RD and RA, and continues in this function during the O&Mphase. Remedial activities have been completed in phases.

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4.2.1 Soil Remedy

The soil remedial activities for the Crystal Chemical site were initiated in August 1992. Theremediation consisted of excavating approximately 55,000 yd3 of soil located off-site with arsenicconcentrations greater than 30 mg/kg. The excavated soils were consolidated into a monofill at theCrystal Chemical site. The monofill was covered with an engineered cap consisting of ageocomposite clay liner (GCL) covered by 18 inches of buffer soil and 6 inches of seeded topsoil.The GCL consists of a 20-millimeter high-density polyethylene (HDPE) flexible membrane linerwith a bentonite backing. The monofill is located over the entire 6.8-acre Crystal Chemical site andextends onto a portion of the adjacent eastern property owned by UPRR.

After excavation areas were completed, the excavations were backfilled with clean fill from off-sitesources. A security fence with locking gate was installed to prevent access to the site. The soilremedy was completed in September 1995.

4.2.2 Groundwater Remedy

The groundwater remedy for the Crystal Chemical consists of a groundwater recovery and treatmentsystem and a groundwater containment system. The following paragraphs summarize thegroundwater recovery and treatment system and the groundwater containment system operated at theCrystal Chemical site.

Groundwater Recovery and Treatment System The ground-water recovery and treatment system consists of a recovery well (designated RW-1)located south of the monofill on the 3.8-acre tract, a GWTP located east of the monofill on theUPRR owned 5-acre tract, and associated piping connecting RW-1 to the GWTP. Ground water ispumped from the 35-foot zone at RW-1 and is piped to and treated at the GWTP. Construction of theGWTP was completed in October 1996. Pilot testing and startup operations were then initiated. InMay 1997, the COH shut down the GWTP due to an exceedance of the discharge permit for arsenic.The discharge permit requires arsenic concentrations of less than 3 mg/L for grab samples and lessthan 2 mg/L for composite samples. In response to the discharge exceedance, a pump-around loopsystem was installed in 1998. The pump-around loop system allows for the storage of treated groundwater while waiting for laboratory analytical results. Subsequent to the installation of thepump-around loop system, additional pilot testing and startup operations were conducted. TheGWTP was issued a revised COH discharge permit and went back online in January 1999.

The GWTP includes an influent storage tank, multiple treatment tanks, a pump-around loop system,effluent storage tanks, and discharge system. Arsenic concentrations in affected ground waterpumped into the GWTP are decreased by chemical processes including oxidation and iron arsenateprecipitation. The GWTP decreases arsenic concentrations in the affected ground water to less than3 mg/L and discharges the effluent via a batch mode to the COH wastewater system. The groundwater discharged into the COH wastewater system is subsequently treated at a COH publicly ownedtreatment works (POTW).

In 2001, several modifications were made to the GWTP to improve the operational efficiency,including replacement of worn piping, pumps, valves, and other equipment as well as the installationof a process logic control (PLC) system.

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Groundwater Containment System The groundwater containment system is composed of a natural subsurface levee, the slurry wall, andthe PRS. The natural subsurface levee consists of a low-permeability clay that serves as a naturalbarrier to groundwater migration along the northwestern boundary of the plume on the 12.5-acretract formerly owned by the Levy Estate. The slurry wall was installed along the eastern boundary ofthe plume on the 12.5-acre tract, under Westpark Drive, and along the western, southern, and easternedges of the monofill. Figure 2 shows the locations of the slurry wall and natural subsurface levee.The depth of the slurry wall ranges from approximately 39 feet along the eastern segments to 52 feetalong the western edge of the monofill.

The PRS was installed inside the groundwater containment barrier to reduce the buildup of hydraulichead. The PRS consists of six pairs of performance monitoring wells screened in the 35-foot zone,electric submersible pumps, and double-walled recovery piping. Each well pair consists of a 4-inchmonitor well capable of containing an electric submersible pump located inside the watercontainment barrier (interior well) and a 2-inch monitor well located outside of the watercontainment barrier (exterior well). Five of the PRS well pairs are located on the 12.5-acre tract, andone pair is located on the GWTP property. Figure 2 shows the locations of the PRS wells.Groundwater elevations at each pair of the PRS wells are monitored to assess the hydraulic head atthe groundwater containment barrier. Groundwater is pumped from the interior wells as necessary toregulate the hydraulic head inside the water containment barrier. Ground water recovered from thePRS wells are pumped to the GWTP for treatment and discharge. The PRS has been in automaticmode since August 2003.

In February 2005, UPRR began a phytohydraulic control pilot test at the Crystal Chemical site. Theobjective of implementing a phytohydraulic control system is to reduce the amount of waterprocessed at the water treatment plant by reducing the local water table within the site's watercontainment system. Approximately 120 hybrid eucalyptus trees (Eucalyptus camaldulenis) wereplanted in two test areas (60 in each test area). The test areas include a 100-foot by 40-foot areainside the northeast corner of the slurry wall on the 12.5-acre tract and a 200-foot by 20-foot areasouth and west of the recovery well RW-1 on the 3.8-acre tract. In May 2005, six piezometer wellswere installed to monitor the effectiveness of the pilot test. Three piezometers wells were installed ineach test area; one upgradient, one midgradient, and one downgradient of the test areas.

4.3 OPERATION AND MAINTENANCE

Monofill After the construction phase of the soil remedy was completed in September 1995, the maintenanceof the monofill was initiated in accordance with the Remedial Action O&M Plan dated November30, 1994. The O&M Plan requires that the soil remedy be monitored for 30 years, or such time asdetermined by the EPA. After completion of the monofill in September 1995, UPRR conductedmonthly inspections of the monofill until July 2002, at which time UPR reduced the frequency ofinspections to once every quarter. In 2003, UPR reduced the frequency of the inspections tosemi-annually, the minimum frequency required in the O&M Plan.

O&M activities for the monofill include the following activities:

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1. Inspect the monofill cap and side slopes for physical deformities and vegetative cover; 2. Inspect the monofill cap and side slopes for ant mounds or evidence of burrowing rodents; 3. Inspect the perimeter security fence, gates, locks, and property signs; 4. Inspect the perimeter drainage ditches and outfall inlet drains for sediment/debris

accumulation; 5. Inspect the property roads for potholes and structural weakness.

Maintenance of the monofill generally consists of mowing once every 2 months during the growthseason, application of herbicide and insecticide, minor erosion repair of the side slopes, andmaintenance of the perimeter fence. Contractors for UPRR conduct these maintenance activitiesduring the regularly scheduled site inspections. Annual inspection reports, the semi-annualinspection reports; semi-annual and annual groundwater monitoring laboratory reports; and GWTPinfluent and effluent sample data, are submitted to EPA and TCEQ. Dates and noted majorobservations from the O&M annual inspection reports are as follows for the period of September2000 to May 2005:

• April 2004. Erosion Under Fence: A small amount of erosion at the bottom of the fencealong the north, east, and south perimeters was reported in the monofill inspection reportssince the beginning of the five year reporting period through March 2004. A gap in the fence(1.5-feet high by 3-feet wide) on the north-east comer off Westpark Drive was reported in theSeptember 2003 semi-annual inspection report. Fill material and/or topsoil were placed in theeroded areas in April 2004.

• September 2004. Erosion Under Fence; A small amount of erosion at the bottom of thefence on the north and south sides of the monofill was reported in the September 2004semi-annual inspection report. The opening was not passable and the inspection report statedthat the erosion would be re-evaluated during the next inspection.

Groundwater Recovery and Treatment System

The groundwater recovery and treatment system operates continuously. O&M activities for therecovery well and GWTP included the following activities:

1. Inspect treatment plant operations using a daily inspection checklist;

2. Perform routine maintenance tasks;

3. Collect and ship influent and effluent samples;

4. Dispose of filter cake material from GWTP off-site by BFI;

Maintenance of the groundwater recovery and treatment system generally consists of replacingpiping, pumps, and valves as necessary to maintain recovery. Contractors for UPRR conduct thesemaintenance activities on an as needed basis at the Crystal Chemical site. Annual inspection reports;the semi-annual inspection reports; semi-annual and annual groundwater monitoring laboratoryreports; and GWTP influent and effluent sample data, are submitted to EPA and TCEQ. Several

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major modifications were made to the GWTP during the 5-year reporting period to enhanceefficiency and effectiveness. Dates and noted major O&M observations and activities are as followsfor the period of September 2000 to May 2005:

• Late 2001 - Process Logic Control: Installed a process logic control (PLC) system to allowmore remote and automated operations.

• 2002 - System Upgrades: Installed lighting improvements. Completed evaluation of a newflocculent and sulfuric acid delivery system and initiated its implementation. Adjustedprocess logic control (PLC) system to correct pumping rates for the chemical feed meteringpumps and added the control of the pump-around loop and discharge pump to the system.

• Late 2002- Alternative GW Treatment Technologies: Began evaluating alternativegroundwater treatment technologies including an ion exchange system that could replace thecurrent co-precipitation system or be used as post-treatment for further removal of arsenic.

• 2003- System Upgrades: Upgraded the polymer delivery system to operate more efficiently.Upgraded the acid feed system to maintain the system pH requirements at a more constantlevel.

• January 13-26,2004. RW-1: RW-1 was inoperative for approximately two weeks due tomalfunctions in the GWTP system's electrical connections. The GWTP system wascontinually overloaded as a result of an electrical wire being sent to ground. Electrical repairswere conducted and the GWTP system was brought back on line.

• February 10, 2004. Effluent: Grab sample collected from discharge effluent water had areported arsenic concentration of 3.2 mg/L, which exceeded the maximum 3.0 mg/L allowedby the COH permit. Prior to discharge of the effluent water, a sample was collected and fieldscreened using an arsenic test kit. The detected concentration was between 1.0 and 2.0 mg/L.The potential exceedance of the discharge permit was reported to the City of Houston onMarch 2, 2004.

• November 8 - December 6, 2004. RW-1: Groundwater recovery from RW-1 was suspendedfor approximately one month due to problems with GWTP system instrumentation includingpH meters, cabling, and recalibration. The instrumentation problems resulted in irregulartreatment of recovered influent, which caused a backlog of untreated water at the GTWPstorage and process tanks.

• January 4-6, 2005. Groundwater treatment operations were temporarily shut down due to aninoperative transfer pump downstream of Tank-05. The pump was repaired and the systemrestarted on Jan. 6, 2005.

• January - February, 2005. Flow meter for PRS well MW-SW3 indicated low flow eventhough the pump continued to operate on a regular cycle. Repairs were made to the recoverypiping and wiring and the pump was placed back on service on Feb. 17, 2005.

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Slurry Wall with Pressure Relief System

The slurry wall and pressure relief system were installed in several phases. After the finalconstruction phase of the slurry wall and PRS was completed in August 2003, the maintenance ofthe slurry wall and PRS was initiated in accordance with the Remedial Action O&M Plan datedMarch 2004. The O&M Plan requires that the slurry wall/PRS system be inspected quarterly for thefirst year after completion of construction and semiannually thereafter. UPRR conducted quarterlyinspections of the slurry wall/PRS system from December 2003 to December 2004. At this time,UPRR has elected to continue conducting inspections on a quarterly basis.

Upon completion of construction of the groundwater containment system in August 2002, waterlevel measurements were collected monthly from the six pairs of PRS wells until September 2003.Evaluation of the groundwater elevation data revealed stable conditions, and thus the frequency ofmeasurement collection was reduced. Since December 2003, water level measurements have beencollected on the same frequency as the regularly scheduled O&M activities.

O&M activities for the slurry wall and pressure relief system included the following activities:

1. Inspect the slurry wall cap for settling;

2. Inspect the PRS pipe for leaks;

3. Inspect the operation of the pumps;

4. Inspect the condition of well vaults and sumps;

5. Conduct periodic pumping of recovered ground water from MW-SW3 and MW-SW5 prior tocompletion of PRS in August 2003;

6. Measure the groundwater elevation at interior and exterior wells on a quarterly basis.

Maintenance of the slurry wall/PRS generally consists of mowing the surface cover during thegrowth season; minor settlement repair of the slurry wall cap; maintenance of the PRS piping, wellvaults, and sumps; and maintenance of the perimeter fence. Contractors for UPRR conduct thesemaintenance activities during regularly scheduled site inspections of the Crystal Chemical site.Annual inspection reports, semi-annual inspection reports; semi-annual and annual groundwatermonitoring laboratory reports; and GWTP influent and effluent sample data, are submitted to EPAand TCEQ. Dates and noted major modifications to the slurry wall/PRS and observations from theO&M inspection reports are as follows for the period of June 2002 (when first section of slurry wallwere completed) to May 2005:

• November 2002. PRS Replacement Well Installation: MW-SW8A was installed asreplacement well to MW-SW8.

• December 20-27, 2002. Elevated Potentiometric Gradient Between MW-SW5 andMW-SW6: Approximately 800 gallons of ground water were recovered from MW-SW5

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using a submersible pump in response to an increased difference in groundwater elevationsbetween wells MW-SW5 and MW-SW6 that was measured on November 22, 2002 andconfirmed on December 19, 2002. The recovered ground water was pumped into a holdingtank and transported to the GWTP for processing and discharge.

• December 4,2003. Ants: Fire ant mounds observed. Settlement: Settlement was observedaround MW-SW-5 and MW-SW-7. Inspection report states fill material is required in area.

• January 28, 2004. Cleanout/Leak Detection Vaults: Water was observed in the sixcleanout/leak detection vaults. Accumulated water believed to be infiltrated rainwater due torecent rainfall events.

• March, 2004. Cleanout/Leak Detection Vaults: Approximately 5,000 gallons of water wasobserved in the six cleanout/leak detection vaults. Samples of the water were collected andsubmitted for laboratory analysis of arsenic. Analytical results were non-detect for arsenic.Subsequently, the water was pumped from the vaults to the ground surface in May 2004. Theaccumulated water was believed to be infiltrated rainwater from an improperly sealed 2-inchdiameter hole at the bottom of the vault. The hole and associated sump cleanout grate weresealed with crack filler and non-shrinking grout in July 2004. Settlement: Settlement wasobserved. Gravel was placed to restore the cap to the required grade.

• April and May, 2004. PRS well MW-SW-5: Holes were observed in the recovery piping atthe top of the pump at PRS well SW-SW-5. The pump and flow meter were cleaned and therecovery piping was replaced. Low recovery was observed during this time period.

• November and December, 2004. PRS well MW-SW-3: Low recovery was observed atMW-SW-3. Repairs and modifications were made.

• December 1,2004. Cleanout/Leak Detection Vaults: Water was observed in the sixcleanout/leak detection vaults. The accumulated water was believed to be a result of higherthan normal rainfall in November 2004. Evaluation of vault manhole seals, weekly waterlevel observation, and testing and removal was conducted.

• February 18, 2005. Cleanout/Leak Detection Vaults: Cleanout/Leak Detection Vaults 2 and5 were repaired to prevent infiltration of rainwater.

• May 23 and 24, 2005. Cleanout/Leak Detection Vaults: Cleanout/Leak Detection Vaults 1,3, 4, and 6 were repaired to prevent infiltration of rainwater. The high-pressure switch inVault 4 was found to be corroded and non-functional. The switch was removed and cappedoff.

Groundwater Monitoring/Investigation

Groundwater monitoring is conducted at the Crystal Chemical site to assess whether or not thearsenic affected ground water is contained by the containment system and groundwater recoverysystem. Groundwater monitoring is conducted on a regular basis as specified in the Groundwater

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Monitoring Plan dated July 23, 2003 and amended December 12, 2003. Ground water from the threeshallowest water-bearing zones, the 15-foot sand zone, the 35-foot sand zone, and the 100-foot sandzone, are monitored. The monitor well network consists of 2 wells in the 15-foot sand zone, 15 wellsin the 35-foot sand zone, and 3 wells in the 100-foot sand zone.

Groundwater elevation measurements were collected from the 6 pairs of PRS wells on a monthlybasis for 13 months after the completion of the containment system in August 2002. From December2003 to June 2005, groundwater elevation measurements and field samples were collected from the15-foot and 35-foot sand zone wells on a quarterly basis. For the 35-foot zone, groundwater samplesare only collected from

monitor wells located exterior to the groundwater containment system and from MW-33. Monitorwells located interior to the groundwater containment system are gauged only. Groundwaterelevation measurement and field samples have been collected from the 100-foot zone an on annualbasis since September 1999. Table 2 below summarizes the groundwater monitoring plan at theCrystal Chemical site.

Monitor well installation and plugging and abandonment activities are as follows for the period ofSeptember 2000 to June 2005:

• December 2004. P&A of Inactive Monitor Wells: Six inactive monitor wells (wells T4CR,T6R, T12, T13, and two unnamed wells adjacent to MW-17A) were plugged and abandoned.

• April 2005. P&A of MW-29 and MW-32. Installation of MW-32A. Monitor wells MW-29and MW-32 were plugged and abandoned. Replacement well MW-32A was installed outsideslurry wall in the southeast corner of the 12.5-acre tract.

• May 4 and 5, 2005. Piezometers PZ-1 through PZ-6 were installed. Three piezometersinstalled at each of the phytohydraulic control pilot test areas (12.5-acre tract north of siteand 3.8-acre tract south of site).

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TABLE 2 GROUNDWATER MONITORING PLAN

Well ID Water LevelMeasurements

Total Arsenic (EPAMethod 3020A/7060A)

Frequency

15-Foot Sand Zone

MW-19 X Quarterly

MW-21 X X Quarterly

35-Foot Sand Zone

MW-17A X Quarterly

MW-30 X Quarterly

MW-33 X X Quarterly

MW-SW1 X Quarterly

MW-SW2 X X Quarterly

MW-SW3 X Quarterly


MW-SW5 X Quarterly


MW-SW7 X Quarterly


MW-SW9 X Quarterly


MW-SW11 X Quarterly


100-Foot Sand Zone

MW-28A X X Annual

MW-31 X X Annual

MW-32 X X Annual

4.4 OPERATION AND MAINTENANCE COST

UPRR provided approximate associated costs for the Crystal Chemical site. The costs include thefollowing:

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• Maintain the monofill and surrounding fencing • Operate and maintain the groundwater recovery and treatment system, slurry wall and PRS,

and surrounding fencing • Conduct sampling and analysis of GWTP influent and effluent • Collect groundwater elevation measurements • Conduct sampling and analysis of ground water • Additional labor costs (outside normal operating conditions)

Table 3 provides the approximate costs for the years stated. The reported costs were provided byGeoffrey Reeder of UPRR.

TABLE 3 ANNUAL OPERATION AND MAINTENANCE COSTS

Period Total cost rounded to nearest $1,000

From To Reported Costs

2000 2001 $250,00

2001 2002 $250,00

2002 2003 $250,00

2003 2004 $110,00

5.0 FIVE-YEAR REVIEW PROGRESS

This is the second five-year review for the Crystal Chemical site. The first five-year report wasconducted in September 2000. The site appears to have been properly maintained during the periodbetween reports. The next five-year report will be conducted by September 2010.

6.0 FIVE-YEAR REVIEW PROCESS

This section presents the process and findings of the second five-year review. Specifically, thissection presents the findings of surveys, a site inspection, an ARAR review, and a data review.

6.1 ADMINISTRATIVE COMPONENTS

The Crystal Chemical site Five-year Review team was lead by Mr. Chris Villareal of EPA, RemedialProject Manager for the Crystal Chemical site. Mr. Eric Johnstone and Ms. Courtney Nichols,representatives from Tetra Tech, assisted in the review process.

In June 2005, the review team established the review schedule, which included the followingcomponents:

• Community Involvement • Site Inspection

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• Local Interviews • ARAR Review • Data Review • Five-Year Review Report Development and Review

6.2 COMMUNITY INVOLVEMENT

Activities to involve the community in the five-year review were initiated with a public noticepublished in the local daily newspaper, the Houston Chronicle. This notice informed the public thata five-year review was to be conducted and that the results of the review would be made available tothe public at the information repository, the Judson Robertson-Westchase Library. A copy of thepublic notice and the Affidavit of Publication is available in Appendix C.

6.3 SITE INSPECTION

A site inspection was conducted on July 29, 2005, to assess the condition of the site and themeasures employed to protect human health and the environment from the contaminants still presentat the site. Attendees included (1) Chris Villarreal of EPA; (2) Geoffrey Reeder of UPRR; (3)Michael Wisniowiecki of the Conestoga-Rovers & Associates (CRA); (4) Adolfo Cepeda of HatchMott MacDonald (HMM); and (5) Eric Johnstone and Courtney Nichols of Tetra Tech. The site visitreport, which includes a site inspection checklist (Exhibit A), photographic log of the inspection(Exhibit B), and site survey forms (Exhibit C) is provided in Appendix B.

No evidence of contamination was visible at the site. The vegetation at the site appeared to besimilar to that in typical surrounding areas.

Monofill The monofill was in good condition with no evidence of ants or burrowing animals. Minor erosionwas observed on the side slopes of the monofill. Ruts were also observed in the grass surface coverthat appeared to be a result of the lawn maintenance vehicles that mowed the grass the prior week tothe site visit.

Slurry Wall/Pressure Relief System The cover over the slurry wall was in good condition. No erosion or settling was observed over theslurry wall legs. No ant hills or burrowing animal activity was observed on the slurry wall legs onthe 12.5-acre tract and 6.5-acre tract. Fire ant hills were observed on the Westpark median betweenthe 12.5-acre and 6.5-acre tract, which is maintained by the City of Houston. The leakdetection/clean out vaults were in good condition. Rainwater infiltration had previously beenobserved in the vaults during 2004 and early 2005. The outer seals at all six vaults were repaired inFebruary and May 2005. No rainwater infiltration has been observed since the repairs were made.Approximately 6 inches of water were observed in Vault 1 during the site visit. According to AdolfoCepeda, of HMM, the water is remnant of the rainwater accumulated in the vault prior to the repairs.Mr. Cepeda stated that not all water was removed from the vaults during the repairs.

Site access appeared to be sufficiently restricted because no vandalism was observed. However,minor damage to the gate and fencing near the entrance to the 12.5-acre tract was observed. In

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addition, minor erosion was observed under the fence at the southeast corner of the 12.5-acre tract.A gap approximately 1.5-feet by 1-foot in size was observed between the bottom of the fence andthe top of the ground surface in this area.

Groundwater Recovery and Groundwater Treatment Plant The recovery well (RW-1), and the GWTP were observed in good condition and operating asdesigned. The only reported or observed concern with the GWTP was a corroded sludge decant pipefrom the clarifier in the GWTP. The paved access road to the GWTP was also in good condition.

6.4 LOCAL INTERVIEWS

In accordance with the community involvement requirements of the five-year review process, keyindividuals to be surveyed were identified by EPA. Completed survey forms for the followingpeople are included in Appendix B, Exhibit B:

• Clyde Smith, COH, Department of Public Works and Engineering • Geoffrey Reeder, UPR • Harry A. Shearer, Shearton Development, L. L. C. • Michael Wisniowiecki, Conestoga-Rovers & Associates

A list of continuing or unresolved issues discovered during the interview process are as follows:

• Mr. Geoffrey B. Reeder, of UPR, stated that UPR previously asked EPA for guidance onwhether it is possible to remove the on-site monofill and dispose of the contaminated soilsoff-site. According to Mr. Reeder, EPA has not responded as of August 2005.

• Mr. Michael Wisniowiecki, of Conestoga-Rover & Associates, recommended that thelong-term approach to the affected soil containment in the monofill and the groundwatertreatment and containment be re-evaluated.

6.5 ARAR REVIEW

The amended ROD identified the following ARARs for the Crystal Chemical site soil remedialaction:

• Resource Conservation and Recovery Act (RCRA) landfill requirements in 40 CFR 264.111Subpart G, which specify a cap with permeability less than or equal to the permeability ofany bottom liner of natural sub-soils present at the site.

• RCRA requirements in 40 CFR 264.228 Subpart K, which provides closure requirements forsurface impoundments.

• RCRA landfill closure requirements in 40 CFR 264.310 Subpart N.

• RCRA post-closure and monitoring requirements in 40 CFR 264.117(a) (1), which requires a30-year post-closure period and another period determined by the Regional Administrator.

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• Ambient air quality standards in 40 CFR 50 to protect the quality of air duringimplementation of the soil remedy.

• Clean Water Act (CWA) regulations in 33 CFR 303 that require on-site surface water to meetthe water quality criteria for arsenic of 0.0175 micrograms/liter (ug/L).

• RCRA requirements in 40 CFR 264.18 that address the location of a hazardous wastetransportation, storage, or disposal facility in a 100-year flood plain.

• Flood plain protection requirements in 40 CFR 6, Appendix A.

One of the requirements of a five-year review is to determine if there are any new requirements thatmay pertain to the site. Tetra Tech identified one change to a federal requirement that needs to beconsidered.

New Arsenic MCL. The MCL for arsenic has been changed from 0.050 mg/L to 0.010 mg/L. Thenew MCL is effective January 23, 2006. The arsenic concentrations in well RW-1 (which is locatedin the area of ground water subject to the arsenic MCL) ranged between 30.2 mg/L and 43.8 mg/L,well above both the old and new arsenic MCL. For the portion of the ground water at the CrystalChemical site that is subject to the TI waiver of the 0.050 mg/L arsenic MCL, the TI waiver will stillapply. The TI waiver was granted to avoid pumping and treating in fine-grained sediments for animpracticable amount of time (that is, 200 to 650 years). For portions of the groundwatercontamination that are not subject to this waiver, the new arsenic MCL may need to be evaluated.

ARARs pertaining to remedial action activities at the Crystal Chemical site are divided intochemical-, location-, and action-specific categories and are discussed below.

6.5.1 Chemical-Specific ARARs

Chemical-specific ARARs are usually health-or risk-based numerical values or methodologies that,when applied to site-specific conditions, result in the establishment of numerical values. Thesevalues establish the acceptable amount or concentration of a chemical that may remain in or bedischarged to the ambient environment. If more than one chemical-specific ARAR exists for acontaminant of concern (COC), the most stringent level will be identified as an ARAR for theremedial action. As noted above, there was a change in the chemical-specific ARAR for groundwater.

For groundwater remediation, the chemical-specific ARAR cited in the original ROD was the MCLstandard for arsenic, which at the time was 0.050 mg/L. Based on the "Assessment of the TechnicalImpracticability of Ground-Water Remediation" (February 1996), EPA issued an Explanation ofSignificant Differences in March 1997, which granted an ARAR waiver for the 0.050 mg/L arseniccleanup level based on technical impracticability for parts of the site. The waiver applies to portionsof the groundwater contamination in the splay deposits or off-channel deposits. The ground water inthe splay deposits is contained within a system comprised of a slurry wall, a natural subsurfacelevee, and a PRS. The eastern and northern portions of the slurry wall and most of the PRS wereinstalled in 2002. The final section of the PRS was completed in August 2003.

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The other portion of the contaminated ground water within the subsurface stream channel is notsubject to the ARAR waiver and therefore, must be remediated to 0.050 mg/L using the extractionand treatment remedy selected in the 1990 ROD. Ground water within the subsurface stream channelcurrently exceeds both the old and new arsenic MCL as indicated by the measured arsenicconcentrations from recovery well RW-1. The measured arsenic concentrations from RW-1 havehistorically ranged from 20 to 80 mg/L since the GWTP began operations, and were reportedbetween 30.2 and 43.9 mg/L during 2004. If EPA adopts the new arsenic MCL of 0.010 for theCrystal Chemical site groundwater remedial action, a longer duration for the extraction andtreatment of contaminated ground water in the subsurface stream channel can be expected.

6.5.2 Location-Specific ARARs

Location-specific ARARs are restrictions placed on the concentration of hazardous substances or theconduct of activities solely because they are in special locations. No changes in location-specificrequirements were identified for the Crystal Chemical site.

6.5.3 Action-Specific ARARs

Action-specific ARARs are usually technology- or activity-based requirements or limitations onactions taken with respect to hazardous wastes or requirements to conduct certain actions to addressparticular site circumstances. These requirements are triggered by the particular remedial activitiesthat are selected to accomplish a remedy. No changes in location-specific requirements wereidentified for the Crystal Chemical site.

6.6 DATA REVIEW

Information of the site activities, monitor well data, groundwater recovery and treatment data, andwater elevation data were summarized in the following reports:

• "Annual Remedial Action Report for Soil and Ground Water Remedies, Crystal ChemicalNPL Site" (ERM, 2000).

• "Annual Remedial Action Report for Soil and Ground Water Remedies, Crystal ChemicalNPL Site" (ERM, 2001).

• "2001 Annual Ground Water Sampling Report, Crystal Chemical Site, Houston, Texas"(ERM, 2001).

• "2002 - 3rd Quarter and 2002 Annual Monitoring Report for Soil and Ground WaterRemedial Actions, Crystal Chemical Site, Houston, Texas" (ERM, 2002).

• "2002 Annual Remedial Action Report for Soil and Ground Water Remedies, CrystalChemical NPL Site" (ERM, 2003).

• "2003 Annual Remedial Action Report for Soil and Ground Water Remedies: CrystalChemical NPL Site" (ERM, 2004).

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• Letter report on "Summary of Additional Ground Water Investigation Activities, EPADocket No. CERCLA VI-15-92 - Crystal Chemical Site, Alief (Houston), Texas."

• "2004 Annual Remedial Action Report, Crystal Chemical NPL Site" (Conestoga-Rovers &Associates, 2005).

• "Monthly Progress Report for the Remedial Action for January 2005, EPA Docket No.CERCLA VI-15-92 - Crystal Chemical Site, Houston, Texas," (UPR, February 2005).

• "Monthly Progress Report for the Remedial Action for February 2005, EPA Docket No.CERCLA VI-15-92 - Crystal Chemical Site, Houston, Texas, (UPR, March 2005).

• "Monthly Progress Report for the Remedial Action for March 2005, EPA Docket No.CERCLA VI-15-92 - Crystal Chemical Site, Houston, Texas," (UPR, April 2005).

• "Monthly Progress Report for the Remedial Action for April 2005, EPA Docket No.CERCLA VI-15-92 - Crystal Chemical Site, Houston, Texas," (UPR, May 2005).

• "Monthly Progress Report for the Remedial Action for May 2005, EPA Docket No.CERCLA VI-15-92 - Crystal Chemical Site, Houston, Texas," (UPR, June 2005).

6.6.1 GWTP

Review of annual remedial action reports and monthly progress reports indicate approximately2,054,503 gallons of groundwater was recovered from the GWTP, monitor wells, and PRS fromJanuary 1, 2000 to May 31, 2005. The total quantity of groundwater recovered annually hasfluctuated during the 5-year review reporting period. Major shutdowns, repairs, and modifications tothe GWTP and PRS wells that have impacted groundwater recovery from RW-1 and the PRS wellsare discussed in Section 4.3. Approximately 2,286,848 gallons of ground water were treated at theGWTP and discharged to the COH POTW under a permit issued by the COH. The total amount ofground water recovered annually from 2000 to 2004 and from January 2005 to May 2005 issummarized in Table 4. The total volume of discharged treated water exceeds the amount recoveredbecause purge water from groundwater sampling and leak detection vaults and water used forhydrotesting new tanks and floor washdown were also treated and discharged.

TABLE 4 GROUND WATER RECOVERY AND DISCHARGE SUMMARY

January 2000 through May 2005

Time Period Recovered Ground Water(gallons)

Discharged Treated Water(gallons)

1/1/00 through 1/31/00 1/1/01 through 12/31/01 1/01/02 through 12/31/02 1/01/03 through 12/31/03 1/01/04 through 12/31/04 1/01/05 through 5/31/05

488,955 83,252 608,594 412,365 263,648 197,689

422,624 107,645 646,756 478,511 425,132 206,180

Total - 1/1/00 through 5/31/05 2,054,503 2,286,848

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Analytical data for arsenic in influent samples collected from recovery well RW-1 have ranged from20 to 80 mg/L since the GWTP began operations in October 1996. There have been no exceedancesof the discharge permit during the reporting period or at any time since the effluent storage tankswere installed in 1998. Table 5 below provides a summary of the minimum, maximum, and averageinfluent arsenic concentrations from July 2000 through May 2005.

TABLE 5 GWTP INFLUENT ANALYTICAL DATA SUMMARY

January 2000 through May 2005 Time Period Minimum Influent

Arsenic Concentration(mg/L)

Maximum InfluentArsenic Concentration

(mg/L)

Average InfluentArsenic

Concentration (mg/L)

7/1/00 through 12/31/01 1/01/02 through 12/31/02 1/01/03 through 12/31/03 1/01/04 through 12/31/04 1/01/05 through 5/31/05

NAa 21.4 28.6 30.2 28.4

NAa 56

40.9 43.8 33.1

39.1a 44.78 35.8

36.15 30.56

Notes:

NA Not available a Analytical data for the period of May 2000 to December 2001 were not provided for review.

The average influent arsenic concentration was obtained from the 2003 Annual RemedialAction Report for Soil and Ground Water Remedies (Environmental Resource Management,2004).

6.6.2 Groundwater Monitoring

Groundwater monitoring is conducted in the three shallowest water-bearing zones: the 15-foot sandzone, the 35-foot sand zone, and the 100-foot sand zone. The following sections summarize thegroundwater elevation measurements and arsenic concentrations reported in each zone during thefive-year review period.

15-Foot Zone A summary of the groundwater elevation and arsenic analytical data for groundwater samplescollected from the 15-foot sand zone during the five-year review period are presented in Appendix Dand Appendix E, respectively. All arsenic concentrations for groundwater samples collected fromthe 15-foot zone were reported below the Remedial Action Objective (RAO) of 0.050 mg/L or werereported as non-detect with reporting limits below the RAO. Furthermore, all reported arsenicconcentrations were below the new MCL of 0.010 mg/L with the exception of one sample collectedfrom well MW-19 in September 2004. Arsenic concentrations reported in MW-19 for the threesubsequent quarterly sampling events were below the new MCL.

In September 2003, direct-push groundwater samples were collected from the 15-foot zone to thewest of the site along Westpark Drive. All arsenic concentrations were reported below the RAO of0.050 mg/L or were reported as non-detect with reporting limits below the RAO. Furthermore, all

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reported arsenic concentrations were below the new MCL of 0.010 mg/L with the exception of onesample collected from boring DP-114. The arsenic concentrations for the direct-push groundwatersamples are summarized in Appendix E.

35-Foot Zone A summary of groundwater elevation and arsenic analytical data for groundwater samples collectedfrom the 35-foot sand zone PRS wells and monitor wells during the five-year reporting period ispresented in Appendix D and E, respectively. The reported arsenic concentrations for groundwatersamples collected from the performance monitoring wells exterior to the groundwater containmentsystem were all below the RAO of 0.050 mg/L indicating that the groundwater containment systemis operating effectively. Reported arsenic concentrations for groundwater samples collected fromwell MW-31, located south of the monofill near RW-1, range from 0.834 mg/L to 1.74 mg/L.

In November 2002 and September 2003, direct-push and temporary monitor well groundwatersamples were collected from the 35-foot zone to the south of the site on the UPRR 3.8-acre tract andto the west of the 3.8-acre tract along the HCFC ditch. The groundwater investigation was conductedto access the extent of arsenic impact at the southwestern corner of the 3.8-acre tract and todetermine if arsenic-affected ground water had migrated across the HCFCD ditch to the westernedge. Analytical results revealed that arsenic concentrations exceeding the 0.050 mg/L RAO werelimited to the western portion of the 3.8-acre tract. Arsenic concentrations were reported asnon-detect or below 0.050 mg/L for groundwater samples collected from the western edge of theHCFCD ditch.

100-Foot Zone A summary of groundwater elevation and arsenic analytical data for groundwater samples collectedfrom the 100-foot sand zone during the five-year reporting period is presented in Appendix D andAppendix E, respectively. The reported arsenic concentrations from the 100-foot monitoring wellswere all below the RAO of 0.050 mg/L with the exception of two elevated arsenic concentrationsdetected at MW-32 in December 2004 and January 2005. Analytical data from the 4th quarter 2004groundwater monitoring event revealed an arsenic concentration 0.327 mg/L at MW-32. Thereported concentration was the first exceedance of the remedial goal at MW-32 or any other well inthe 100-foot zone. To confirm the presence of arsenic concentrations above the RAO in the 100 footzone, MW-32 was re-sampled in January 2005. Analytical results for the confirmation samplerevealed an elevated arsenic concentration of 0.427 mg/L. Cross-contamination between the 35-footzone and 100-foot zone was the suspected source of the elevated arsenic concentrations reported atMW-32. To eliminate this possible pathway, MW-32 was plugged and abandoned in April 2005. Areplacement well, MW-32A, was installed in the southeast corner of the 12.8-acre tract outside ofthe slurry wall containment system and screened in the same depth interval as MW-32. Theanalytical result for arsenic in ground water collected at MW-32A in May 2005, was below the RAOindicating that cross-contamination between the 35-foot zone and 100-foot is not occurring.

PiezometersIn May 2005, three piezometers were installed at each of the pytohydraulic control pilot test areaslocated on the 12.5-acre and 3.8-acre tracts owned by UPRR. At each test area, one piezometer wasinstalled upgradient, midgradient, and downgradient of each phytohydraulic control zone.Groundwater elevation data for the six piezometers is summarized in Appendix D.

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7.0 TECHNICAL ASSESSMENT

The conclusions presented in this section support the determination that the selected remedy for theCrystal Chemical site is currently protective of human health and the environment. EPA Guidanceindicates that to assess the protectiveness of a remedy, three questions shall be answered.

Question A: Is the remedy functioning as intended by the decision documents?

• RA performance - Based on review of documents, ARARs, and the site inspection, theselected remedy for on- and off-site soil and ground water has been completed in accordancewith the 1990 ROD, 1992 amended ROD, and 1997 Explanation of Significant Differencesfor the ROD. Cleanup goals and performance standards were achieved as documented by theannual inspection reports.

• Cost of system and O&M - O&M cost information for the calendar years 2000 through2003, was approximately $250,000, annually. O&M cost information for the calendar year2004 was approximately $110,000.

• Opportunities for optimization - In addition to conducting maintenance activitiesassociated with the issues identified during the site inspection, UPRR should continue topursue alternative groundwater treatment technologies and/or water table reductiontechnologies to reduce the treatment costs. In an effort to increase the potential for siteredevelopment, UPRR will be evaluating alternatives to the current affected soil containmentremedy.

• Early indicators of potential issues - There is no indication of remedy failure. The monofill and slurry wall/PRS are inspected on a regular basis and O&M activities are performedon the monofill and slurry wall/PRS as required. The GWTP operates on a continuous basisand maintenance activities are conducted as required.

• Implementation of institutional controls - Institutional controls (i.e., deed recordation) arecurrently being pursued by UPRR through the City of Houston. Human contact withcontaminated ground water will not occur if restrictions are implemented.

Question B: Are the assumptions used at the time of remedy selection still valid?

• Changes in standards and to be considered - There have been no changes that bear on theprotectiveness of the selected remedy.

• Changes in exposure pathways - There have been no changes that bear on theprotectiveness of the selected remedy.

• Changes in toxicity and other contaminant characteristics - The MCL for arsenic hasbeen changed from 0.050 mg/L to 0.010 mg/L. The new MCL is effective January 23, 2006.For portions of the groundwater contamination that are outside the groundwater containmentsystem, the new arsenic MCL may need to be considered.

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• Changes in risk assessment methodologies - There have been no changes that bear on theprotectiveness of the selected remedy.

• Expected progress toward meeting RAOs - The remedial action objectives (RAO) relatingto contaminated soil have been met. Institutional controls that are required to meet theremedial objective associated with the prevention of exposure to contaminated ground waterare being pursued. Monitoring is needed to establish that the groundwater RAO is being met.If EPA adopts the new arsenic MCL of 0.010 mg/L for the Crystal Chemical site groundwater remedial action, a longer duration for the extraction and treatment of contaminatedground water can be expected.

Question C: Has any other information come to light that could call into question theprotectiveness of the remedy?

• No other information has been identified that calls the protectiveness of the selected remedyinto question.

Technical Summary

According to documents and data reviewed, the site inspection, and the interviews, the remedyappears to be functioning as intended by the 1990 ROD, 1992 amended ROD, and 1997 Explanationof Significant Differences for the ROD. There have been no changes in the physical conditions ofthe site that would affect the protectiveness of the remedy. The ARARs cited in the RODs have beenmet. There is no other information other than the change in the arsenic MCL that calls into questionthe protectiveness of the remedy.

8.0 ISSUES

This section describes issues associated with the Crystal Chemical site identified during thefive-year review.

1. Minor erosion on monofill - Areas with minor erosion were noted on the northern andwestern side slopes of the monofill.

2. Rutting of monofill surface cover - Ruts in the grass surface cover were observed in a fewareas on the northeast corner of the monofill. The ruts appeared to be caused by the lawnmaintenance vehicles that mowed the grass cover the week before the site visit.

3. Minor fence and gate maintenance - Minor fence and gate damage was observed at theentrance gate to the 12.5-acre northern tract of land.

4. Minor erosion at northern property - Minor erosion was observed under the fence at thesoutheast corner of the 12.5-acre northern tract. A gap approximately 1.5-feet by 1-foot inarea was observed below the fence in this area.

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5. Rainwater ponding within vaults - The quarterly inspection reports for late 2004 and early2005, note that rainwater appeared to be ponding and infiltrating into the cleanout/leakdetection vaults of the PRS system. Repairs were made to the seals at all six vaults inFebruary and May 2005. During the site visit, approximately 6 inches of standing water wasobserved in Vault #1. According to Adolfo Cepeda of Hatch Mott MacDonald (HMM), norainwater infiltration has been observed since the repairs in February and May 2005. Mr.Cepeda stated that not all the infiltrated water was removed from the vaults during the repairactivities and that the standing water was remnant of the ground water that infiltrated prior tothe repairs.

6. Leaf debris on drainage outlet - Leaf debris was noted over the drainage outlet on thewestern side of the monofill.

7. Corroded pipe in GWTP - The sludge decant pipe from the clarifier within the GWTP iscorroded.

8. Deed recordation - According to the November 1994 "Remedial Action Operation andMaintenance Plan" UPR is required to record a notation on the deed or any instrumentnormally examined during a title search, which will allow any potential buyer to be madeaware of site conditions. Deed recordation documents for the site and off-site properties havebeen prepared using a recent boundary survey of the extent of the affect ground water.According to Michael Wisniowiecki of CRA, the documents have been reviewed andapproved by all off-site property owners with the exception of the COH. The COH iscurrently reviewing the deed recordation documents and the deed recordation will becompleted upon approval by the COH.

Table 6 is a summary table of issues identified and if they currently affect the remedy protectivenessis provided below.

TABLE 6 IDENTIFIED ISSUES

Issue Currently Affects Remedy Protectiveness(Yes/No)

Minor erosion on monofill No

Rutting of monofill surface cover No

Minor fence and gate maintenance No

Minor erosion at northern property No

Rainwater ponding within vaults No

Leaf debris on drainage outlet No

Corroded pipe in GWTP No

Deed recordation No29

These issues could affect the protectiveness for remedy if not addressed.

9.0 RECOMMENDATIONS AND FOLLOW-UP ACTIONS

Table 7 summarizes recommendations and follow-up actions for the Crystal Chemical site. UPRR isresponsible for conducting follow-up actions, and EPA will provide oversight.

10.0 PROTECTIVENESS STATEMENT

Based on the information available during the second five-year review, the selected remedy for theCrystal Chemical site appears to be performing as intended. The RA for soil and ground water are protective of human health and the environment. Since both soil and groundwater are protective, theremedy for the site is protective of human health and the environment.

11.0 NEXT REVIEW

The Crystal Chemical site requires ongoing five-year reviews. The next review will be conductedwithin the next 5 years, but no later than September 2010.

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TABLE 7 RECOMMENDATIONS AND FOLLOW-UP ACTIONS

CRYSTAL CHEMICAL SITE Issue Recommendations and Follow-up Actions Party

ResponsibleOversight

AgencyMilestone Date Follow-up Actions Affect

Long-Term RemedyProtectiveness (Yes/No)

Minor erosion on monofill Continue to monitor the areas of the monofill experiencing minorerosion, and reseed when appropriate to prevent impact upon themonofill

UPR EPA Within 1 year ofsubmittal of this report

Yes

Rutting of monofill surfacecover

Instruct lawn maintenance crew to be careful during lawnmaintenance activities to prevent rutting of monofill grass surfacecover.

UPR EPA Prior to next lawnmaintenance event

Yes

Minor fence and gatedamage

Repair damage to fencing and gate at southern entrance to12.5-acre northern tract.


Yes

Minor erosion on 12.5-acretract

Place fill material under the southeast corner of the fence at the12.5-acre northern property where an approximately 1.5-feet by1-foot gap exists under the fencing


Yes

Rainwater ponding withinvaults

Continue to inspect cleanout/leak detection vaults to accesswhether or not rainwater infiltration is occurring, and conductadditional repairs if needed to prevent groundwater infiltration.Vacuum and/or evaporate all standing water in vaults.


Yes

Leaf debris on drainageoutlet

Leaf debris over drainage outlets should be removed duringroutine mowing activities.

UPR EPA During next lawnmaintenance event

Yes

Corroded pipe in GWTPprocess line

Replace corroded sludge decant pipe from the clarifier inthe GWTP.


Yes

Deed recordation Continue to communicate with COH during their review ofthe deed recordation documents. Complete deed recordationupon approval of all parties.


Yes

Notes: COH City of HoustonEPA U.S. Environmental Protection AgencyGWTP Groundwater treatment plantUPRR Union Pacific Railroad Company

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APPENDIX A

DOCUMENTS REVIEWED

(Four Pages)

DOCUMENTS REVIEWED

U.S. Environmental Protection Agency (EPA). 1988. CERCLA Compliance with Other LawsManual. August.

EPA. 1990. CERCLA Record of Decision for Crystal Chemical Company Site, Houston, Texas,September.

EPA Region 6 Administrative Order, Docket No. VI-15-92, addressing the RemedialDesign/Remedial Action for Crystal Chemical Company Superfund Site, September 3, 1990.

EPA Region 6 Administrative Order, Docket No. VI-11-92, on Consent for the Remedial Design ofGround Water Contamination at Crystal Chemical Company Site, March 31, 1992.

Amended CERCLA Record of Decision for Crystal Chemical Company Site, Houston, Texas, June16, 1992.

"Remedial Action Operation and Maintenance Plan," prepared for Southern Pacific TransportationCompany, San Francisco, California, by Industrial Compliance, Overland Park, Kansas,November 30, 1994.

EPA Superfund Explanation of Significant Difference for Record of Decision: Crystal ChemicalCompany Superfund Site, Houston, Texas, March 17, 1997.

"Operation and Maintenance Manual for the Ground Water Recovery and Treatment System, CrystalChemical Site, Houston, Texas," prepared for Union Pacific Railroad Company, by ERM,Houston, Texas, November 16, 1998 and revised January 31, 2000.

Letter dated April 6, 2000, to Chris Villarreal, EPA Region 6, Dallas, Texas, from Marsha Lutz,ERM, Houston, Texas, on Ground Water Elevation Data for the Crystal Chemical Site.

Letter report, dated April 20, 2000, to Mr. David Young, Union Pacific Railroad Company, Houston,Texas, from Robert Coffman, ERM, Houston, Texas on Soil and Ground Water Sampling forLevy Estate Property Transfer Investigation; Crystal Chemical NPL Site, Houston, Texas.

"Annual Remedial Action Report for Soil and Ground Water Remedies, Crystal Chemical Site,Houston, Texas," prepared for Union Pacific Railroad Company, by ERM, Houston, Texas,August 29, 2000.

"First Five-Year Review Report for the Crystal Chemical Company Site, Houston, Harris County,Texas," by EPA, Dallas, Texas, September 2000.

"2000 Annual Ground Water Sampling Report, Crystal Chemical Site, Houston, Texas," preparedfor Union Pacific Railroad Company, by ERM, Houston, Texas, October 23, 2000.

"Additional Ground Water Investigation, Crystal Chemical Company NPL Site, Houston, Texas,"prepared for Union Pacific Railroad Company, by ERM, Houston, Texas, February 26, 2001.

A-l

"Annual Remedial Action Report for Soil and Ground Water Remedies, Crystal Chemical Site,Houston, Texas," prepared for Union Pacific Railroad Company, by ERM, Houston, Texas,March 27, 2001.

"Site Investigation Report, 3802 Rogerdale Road, Houston, Texas" prepared for SheartonDevelopment Company, LLC, by Landmark Environmental LLC, October 2001.

"Construction Quality Assurance Plan, Crystal Chemical NPL Site, Houston, Texas" prepared forUnion Pacific Railroad Company, by ERM, Houston, Texas, October 24, 2001.

"2001 Annual Ground Water Sampling Report, Crystal Chemical Site, Houston, Texas," preparedfor Union Pacific Railroad Company, by ERM, Houston, Texas, December 14, 2001.

"Operations and Maintenance Plan for Ground Water Remedial Design Addendum- Revised SlurryWall, Crystal Chemical NPL Site, Alief (Houston), Texas," prepared for Union PacificRailroad Company, by ERM, Houston, Texas, January 25, 2002.

Letter dated March 13, 2002, to Chris Villarreal, EPA Region 6, Dallas, Texas, from Marsha Lutz,ERM, Houston, Texas, on Change of Physical Address for the Crystal Chemical Site,Houston, Texas, EPA Docket No. CERCLA VI-15-92.

"Operations and Maintenance Plan for Ground Water Remedial Design Addendum-Revised SlurryWall with Pressure Relief System, Crystal Chemical NPL Site, Alief (Houston), Texas,"prepared for Union Pacific Railroad Company, by ERM, Houston, Texas, September 5, 2002.

Letter Report dated October 21, 2002, to Chris Villarreal, EPA Region 6, Dallas, Texas, fromMarsha Lutz, ERM, Houston, Texas, on Ground Water Monitoring Results for Slurry WallPerformance Monitoring Wells, Crystal Chemical Site, Houston, Texas, EPA Docket No.CERCLA VI-15-92.

"2002 - 3rd Quarter and 2002 Annual Monitoring Report for Soil and Ground Water RemedialActions, Crystal Chemical Site, Houston, Texas," prepared for Union Pacific RailroadCompany, by ERM, Houston, Texas, December 13, 2002.

"2002 Annual Remedial Action Report for Soil and Ground Water Remedies, Crystal Chemical NPLSite, Alief (Houston), Texas," prepared for Union Pacific Railroad Company, by ERM,Houston, Texas, February 27, 2003.

"Fourth Quarter 2002 Ground Water Monitoring Report, Crystal Chemical NPL Site, Alief(Houston), Texas," prepared for Union Pacific Railroad Company, by ERM, Houston, Texas,February 27, 2003.

Letter June 27, 2003, to City Secretary, Director of Public Works & Engineering, and Director ofFinance and Administration, City of Houston, Texas from M.C. Walton, Union PacificRailroad, Spring, Texas, on Letter of Acceptance of City Council June 25, 2003 Agenda ItemNo. 31 - Ordinance Issuing a Permit to Union Pacific Railroad Company for construction,using, occupying, operating, maintaining, and repairing a ground water recovery pipe withina 12-inch casing pipe across the 10900 block of Westpark, a public street right-of-way of theCity of Houston, Texas.

A-2

Letter dated July 23, 2003, to Chris Villarreal, EPA Region 6, Dallas, Texas, from Geoffrey Reeder,Union Pacific Railroad, Spring, Texas, on Ground Water Monitoring Plan for the CrystalChemical Site, Houston, Texas, EPA Docket No. CERCLA VI-15-92.

"Preliminary Close Out Report, Crystal Chemical Company Site, Houston, Texas," by EPA Region6, Dallas, Texas, October 2003.

Letter dated December 12, 2003, to Chris Villarreal, EPA Region 6, Dallas, Texas, from GeoffreyReeder, Union Pacific Railroad, Spring, Texas, on Response to EPA's August 11, 2003 andTCEQ's August 11 and 12, 2003 Comments on the Ground Water Monitoring Plan for theCrystal Chemical Site, Houston, Texas, EPA Docket No. CERCLA VI-15-92.

"2003 Annual Remedial Action Report for Soil and Ground Water Remedies, Crystal Chemical NPLSite, Alief (Houston), Texas," prepared for Union Pacific Railroad Company, by ERM,Houston, Texas, March 2004.

"Operations and Maintenance Plan for Ground Water Remedial Design Addendum-Revised SlurryWall with Pressure Relief System, Crystal Chemical NPL Site, Alief (Houston), Texas,"prepared for Union Pacific Railroad Company, by ERM, Houston, Texas, March 2004.

"Quality Assurance Project Plan, Crystal Chemical NPL Site," prepared for Union Pacific RailroadCompany, by ERM, Houston, Texas, March 2004.

Letter dated March 29, 2004, to Chris Villarreal, EPA Region 6, Dallas, Texas, from GeoffreyReeder, Union Pacific Railroad, Spring, Texas, on Response to EPA's March 9, 2004Comments on the Construction Documentation and Remedial Action Report for GroundWater Remedy, Crystal Chemical Site, Houston, Texas, EPA Docket No. CERCLAVI-15-92.

Letter report, dated April 30, 2004, to Mr. Chris Villarreal, EPA, Dallas, Texas, from Geoffrey B.Reeder, Union Pacific Railroad, Spring, Texas on Summary of Additional Ground WaterInvestigation Activities; Crystal Chemical Site, Alief (Houston), Texas.

Letter dated June 28, 2004, to Robert Wucher, Jr., TCEQ Superfund Engineering Section, Austin,Texas, from Micheal Wishiowiecki, Conestoga-Rovers & Associates, Houston, Texas, onResponse to Slurry Wall Hydraulic Gradient Inquiry, Crystal Chemical Site, Houston, Texas,EPA Docket No. CERCLA VI-15-92.

"2004 Annual Remedial Action Report, Crystal Chemical NPL Site, CERCLA VI-15-92, 10965Westpark Drive, Houston, Texas," prepared for Union Pacific Railroad Company, byConestoga-Rover & Associates, Houston, Texas, January 2005.

Letter dated February 3, 2005, to Mr. Chris Villarreal, EPA, Dallas, Texas, from Geoffrey B.Reeder, Union Pacific Railroad, Spring, Texas on Monthly Progress Report for the RemedialAction for January 2005, EPA Docket No. CERCLA VI-15-92 - Crystal Chemical Site,Houston, Texas.

Letter dated March 8, 2005, to Mr. Chris Villarreal, EPA, Dallas, Texas, from Geoffrey B. Reeder,Union Pacific Railroad, Spring, Texas on Monthly Progress Report for the Remedial Actionfor February 2005, EPA Docket No. CERCLA VI-15-92 - Crystal Chemical Site, Houston,Texas.

A-3

Letter dated April 6, 2005, to Mr. Chris Villarreal, EPA, Dallas, Texas, from Geoffrey B. Reeder,Union Pacific Railroad, Spring, Texas on Monthly Progress Report for the Remedial Actionfor March 2005, EPA Docket No. CERCLA VI-15-92 - Crystal Chemical Site, Houston,Texas.

Letter dated May 3, 2005, to Mr. Chris Villarreal, EPA, Dallas, Texas, from Geoffrey B. Reeder,Union Pacific Railroad, Spring, Texas on Monthly Progress Report for the Remedial Actionfor April 2005, EPA Docket No. CERCLA VI-15-92 - Crystal Chemical Site, Houston,Texas.

"Crystal Chemical Company, Texas, EPA ID#TXD990707010, Site ID: 0603555" fact sheet,prepared by EPA Region 6, May 5, 2005.

Letter dated June 3, 2005, to Mr. Chris Villarreal, EPA, Dallas, Texas, from Geoffrey B. Reeder,Union Pacific Railroad, Spring, Texas on Monthly Progress Report for the Remedial Actionfor May 2005, EPA Docket No. CERCLA VI-15-92 - Crystal Chemical Site, Houston,Texas.

A-4

APPENDIX B

SITE VISIT REPORT

(Seven Pages)

SITE VISIT REPORT FOR SECOND FIVE-YEAR REVIEW FOR CRYSTAL CHEMICAL COMPANY SUPERFUND SITE

HOUSTON, HARRIS COUNTY, TEXAS

Prepared for

United States Environmental Protection Agency Region 6

Dallas, Texas

Contract No. : 68-W6-0037 Work Assignment No. : 123-FRFE-0617 Date Prepared : August 15, 2005Prepared by : Courtney Nichols, Tetra Tech EM Inc. Telephone No. : (832) 251-5181 EPA Remedial Project Manager : Mr. Chris Villareal Telephone No. : (214) 665-8315

CONTENTS

Section Page

ACRONYMS AND ABBREVIATIONS B-3

1.0 INTRODUCTION B-4

2.0 BACKGROUND B-4

3.0 SITE VISIT ACTIVITIES B-5

4.0 FINDINGS B-6

REFERENCES B-7

Exhibit

A PHOTOGRAPHS

B SITE VISIT CHECKLIST

B-2

ACRONYMS AND ABBREVIATIONS

ARAR Applicable or relevant and appropriate requirement

Crystal Chemical Crystal Chemical Company

EPA U.S. Environmental Protection Agency Region 6

MCL Maximum contaminant level

mg/L milligrams per liter

NPL National Priorities List

PRP Potentially responsible party

RA Remedial action

RAC Response Action Contract

RAO Remedial action objective

rod Record of Decision

Tetra Tech Tetra Tech EM Inc.

Southern Pacific Southern Pacific Railroad

TCEQ Texas Commission on Environmental Quality

TNRCC Texas Natural Resource Conservation Commission

UPR Union Pacific Railroad

B-3

1.0 INTRODUCTION

Tetra Tech EM Inc. (Tetra Tech) received Work Assignment No. 123-FRFE-0617 fromU.S.Environmental Protection Agency Region 6 (EPA) under Response Action Contract (RAC) No.68-W6-037. Under this work assignment, Tetra Tech was directed to conduct the second five-yearreview of the remedial action (RA) implemented at the Crystal Chemical Company (CrystalChemical) Superfund site in Houston, Texas.

Tetra Tech visited the site on July 29, 2005, to assess whether all components of the selected remedyare operating in accordance with criteria established in the September 1990 Record of Decision(ROD), September 1992 ROD amendment, and March 1997 Explanation of Significant Differences.This report provides background information on the site, summarizes site visit activities, andpresents Tetra Tech's findings. References cited are listed at the end of this text. Exhibit A containsphotographs taken during the site visit, and Exhibit B contains the five-year review site visitchecklist completed by Tetra Tech. Exhibit C contains surveys that document interviews that wereconducted during the site inspection and throughout the five-year review process.

2.0 BACKGROUND

The Crystal Chemical Company site is located at 10985 Westpark Drive in southwest Houston,Harris County, Texas. The site consists of approximately 6.8 acres of land. The site is bound on thewest by the Harris County Flood Control District (HCFCD) ditch number D124-00-00, on the northby Westpark Drive and a 12.5-acre tract of land owned by the Union Pacific Railroad (UPR), on theeast by a five-acre tract owned by UPR, and on the south by a 3.8-acre tract of land owned by UPRand vacant land owned by Shearton Development. The area surrounding the Crystal ChemicalCompany site is primarily used for commercial, light industry, and residential purposes.

The site was the operating location of the Crystal Chemical Company from 1968 to 1981. CrystalChemical Company leased the 6.8-acre tract from the owner Southern Pacific TransportationCompany (Southern Pacific), now Union Pacific Railroad (UPR), from 1968 until 1979 whenCrystal Chemical Company purchased the property. In 1981, Crystal Chemical Company ceasedoperations, filed for bankruptcy, and abandoned the site. UPR was later identified as a potentiallyresponsible party (PRP).

The Crystal Chemical was placed on the National Priorities List (NPL) in 1983. EPA signed theROD that addressed soil and ground water contamination on September 27, 1990. Due to theunavailability of the technology for the selected soil remedy, EPA issued a ROD Amendment onSeptember 16, 1992. During the course of implementation of the selected ground water remedy, theEPA determined the restoration of the ground water is technically impracticable for portions of thesite. As a result, the EPA issued an Explanation of Significant Differences on March 19, 1997. Theremedial action objectives (RAO), selected remedy, and implementation status for soil andgroundwater at the Crystal Chemical site are discussed in the following paragraphs.

Soil Contamination The selected soil remedy in the September 27, 1990 ROD called for the excavation of off-site soilscontaminated with arsenic, treatment of soils using an innovative treatment technology (in situvitrification), and capping of the entire site after the soil treatment had been completed. Due to theunavailability of the technology, EPA selected a new soil remedy consisting of soil consolidationand capping in the ROD amendment issued on September 16, 1992. The soil consolidation andcapping remedy was completed in September 1995.

B-4

The ROD amendment described the on-site and off-site soil remedy as follows:

1) Resample off-site areas previously identified as contaminated with arsenic in order toidentify all off-site soils with arsenic concentrations exceeding 30 mg/kg.

2) Excavation of approximately 55,000 yd3 of off-site soils with arsenic concentrationsexceeding 30 mg/kg. Backfill off-site excavated areas to previously existing grades.

3) Placement of excavated soils into a monofill on the Crystal Chemical site.

4) Install multi-layer low permeability cap over entire Crystal Chemical site afterexcavated off-site soils have been placed on-site.

EPA determined that this soil remedy is protective of human health and the environment, attainsfederal and state requirements that are applicable or relevant and appropriate, is cost-effectivecompared to equally environmentally protective alternatives, and utilizes permanent solutions andalternative treatment technologies to the maximum extent practicable.

Ground Water Contamination

The selected ground water remedy in the September 27, 1990 ROD called for the extraction andtreatment of arsenic contaminated ground water. The remediation goal specified in the 1990 RODfor the affected ground water zones is 0.050 milligrams/liter (mg/L), the maximum contaminantlevel (MCL) for arsenic. The 1990 ROD also included several contingency measures that could beimplemented if an extraction and treatment system would not produce the ground water remediationgoal.

During the course of the design for the ground water remedy, EPA and the Texas Natural ResourceConservation Commission (TNRCC) (now Texas Commission on Environmental Quality [TCEQ])determined that restoration of the ground water is technically impracticable for portions of theCrystal Chemical Company Site. Therefore, EPA determined that the applicable or relevant andappropriate requirement (ARAR) for ground water restoration to the MCL of 0.050 mg/L for arsenicshould be waived and a slurry wall should be constructed around the portions of the site whereground water cannot be restored. The extraction and treatment of arsenic contaminated ground waterremained the selected remedy for the remainder of the site as specified in the 1990 ROD. Thedecision to waive the ground water ARAR and construct the slurry wall is documented in the CrystalChemical Company site Superfund Explanation of Significant Differences of the Record ofDecisions (EPA, 1997).

EPA determined that this ground water remedy is protective of human health and the environment,attains federal and state requirements that are applicable or relevant and appropriate, is cost-effectivecompared to equally environmentally protective alternatives, and utilizes permanent solutions andalternative treatment technologies to the maximum extent practicable.

3.0 SITE VISIT ACTIVITIES

A site visit was conducted on July 29, 2005, to assess the condition of the site and the protectivemeasures employed to protect human health and the environment from the contaminants still presentat the site.

B-5

The following key individuals identified by EPA participated in the site visit:

• Chris Villareal, EPA • Micheal Wisniowiecki, Conestoga-Rovers & Associates • Adolfo Cepeda, Hatch Mott MacDonald • Geoffrey Reeder, UPR • Eric Johnstone, Tetra Tech • Courtney Nichols, Tetra Tech

The site visit included evaluation of the monofill, slurry wall/pressure relief system, and groundwater treatment plant, including the surface cover, equipment, monitoring wells, leak detection/cleanout vaults, recovery wells, postings, phytohydraulic control test areas, and site fencing. Photographstaken during the site visit are presented in Exhibit A, the completed five-year review site visitchecklist is presented in Exhibit B, and survey forms are presented in Exhibit C. The site visitfindings are summarized below.

The weather during the site visit was overcast with scattered thunderstorms. No evidence ofcontamination was visible at the site. The site's general appearance is good, with healthy vegetationcovering the site. The grass at the site had been mowed as part of regular site maintenance activitiesthe week prior to the site visit.

4.0 FINDINGS

No evidence of contamination was visible at the site. The vegetation at the site appeared to besimilar to that in typical surrounding areas.

Monofill The monofill was in good condition with no evidence of ants or burrowing animals. Minor erosionwas observed on the side slopes of the monofill. Ruts were also observed in the grass surface coverthat appeared to be a result of the lawn maintenance vehicles that mowed the grass the prior week tothe site visit.

Slurry Wall/Pressure Relief System The cover over the slurry wall was in good condition. No erosion or settling was observed over theslurry wall legs. No ant hills or burrowing animal activity was observed on the slurry wall legs onthe 12.5-acre tract and 6.5-acre tract. Fire ant hills were observed on the Westpark median betweenthe 12.5-acre and 6.5-acre tract, which is maintained by the City of Houston. The leakdetection/clean out vaults were in good condition. Rainwater infiltration had previously beenobserved in the vaults during 2004 and early 2005. The outer seals at all six vaults were repaired inFebruary and May 2005. No rainwater infiltration has been observed since the repairs were made.Approximately 6 inches of water was observed in Vault 1 during the site visit. According to AdolfoCepeda, of Hatch Mott MacDonald, the water is remnant of the rainwater accumulated in the vaultprior to the repairs. Mr. Cepeda stated that not all water was removed from the vaults during therepairs.

Site access appeared to be sufficiently restricted because no vandalism was observed. However,minor damage to the gate and fencing near the entrance to the 12.5-acre tract was observed. Inaddition, minor erosion was observed under the fence at the southeast corner of the 12.5-acre tract.A gap approximately 1.5-feet by 1-foot in size was observed between the bottom of the fence andthe top of the ground surface in this area.

B-6

Groundwater Recovery and Ground Water Treatment Plant The recovery well, RW-1, and ground water treatment plant were observed in good condition andoperating well. The only reported or observed concern with the GWTP was a corroded pipe leadingfrom the sludge out clarifier in the GWTP process line. The paved access road to the ground watertreatment plant was in good condition as well.

REFERENCES

Conestoga-Rover & Associates. 2005. "2004 Annual Remedial Action Report, Crystal ChemicalNPL Site, CERCLA VI-15-92, 10965 Westpark Drive, Houston, Texas," prepared for UnionPacific Railroad Company, January.

U.S. Environmental Protection Agency (EPA). 1990. CERCLA Record of Decision for CrystalChemical Company Site, Houston, Texas, September.

EPA. 1992. Amended CERCLA Record of Decision for Crystal Chemical Company Site, Houston,Texas, June 16.

EPA. 1997. EPA Superfund Explanation of Significant Difference for Record of Decision: CrystalChemical Company Superfund Site, Houston, Texas, March 17.

B-7

APPENDIX C

PUBLIC NOTICE

(Two Pages)

j 19992607 TETRATECHEMINC. Jul202005 Pagel

AFFIDAVIT OF PUBLICATION

STATE OF TEXAS:

COUNTY OF HARRIS:

Before me, the undersigned authority, a Notary Public in and for the Stateof Texas, on the day personally appeared: VICKI EUBANKS, who after being dulysworn, says that she is the SUPERVISOR-ACCOUNTS RECEIVABLE at the HOUSTONCHRONICLE, a daily newspaper published in Harris County, Texas, and that thepublication, of which the annexed herein, or attached to, is a true and correctcopy, was published to-wit:

TETRA TECH EM INC.RAN A LEGAL NOTICESIZE BEING: 1 X 64 L

producthe

19992607 82256915

dateJul 20 2005

class1240.0

pageG_wedalll2

VICKI EUBANKSSUPERVISOR - ACCOUNTS RECEIVABLE

Sworn and subscribed to before me, this the 20th Day of July A.D, 2005

Notary Publ(ig in and for the State of Texas

[19992607 TETRATECHEMINC. Jul202005 ' * Page 2

CRYSTAL CHEMICALCOMPANY SUPERHWDSITEPUBLIC NOTICEU& EPA Beoion 6 ISecond Rve-VbWof Site RemedyThe U.S. EnvironmentalProtection Agency (EPA)Region 6 Is conducting asecond Five-Year Reviewof the remedy for theCrystal Chemical Com-pany Superfund Site(site). The site Is locatedat 3932 Rogerdale Road Insouth-western Houston,Harris County, Texas. Thepurpose of the Five-YearReview Is to evaluate Iftrie site remedy Is protec-tive of human hearth andthe environment The se-lected site remedy In-cluded consolidating andcapping arsenic contami-nated soils on-slte to pre-vent direct contact andrainwater Infiltration, andthe containment and on-slte treatment of con-taminated ground water.The Five-Year Review Isscheduled to be com-pleted by September2005. Once completed,the results of the Five-Year Review will be madeavailable to the public atthe following location:lixtoon Robertson -

322> WilcraM Street,Houston, Texas 77M2For more Informationabout the site, contact:Mr.Chrbvniarreal-Ramedlal Project

U.S. Envirc..Protection Agency, Re-Dion s, (Mall Code 6SF-LI44S Ross Avenue, Suite,1200, Dallas, Texas

(214) 665-6756 or you maycall EPA's toll free numberIn Dallas at (800) 533-3508Information about theSite also Is available onthe internet atwwjr.jpa.aov/r.BlonG/

APPENDIX D

SUMMARY OF GROUNDWATER ELEVATION RESULTS

(Six Pages)

SUMMARY OF 2000-2005 GROUNDWATER ELEVATION DATA15-Foot, 35-Foot, and 100-Foot Zones andPhytohydraulic Control Pilot Test Piezometers

Monitor Well Date

Depth to GroundWater (Feet

BTOC)Ground Water

Elevation (Feet MSL)15-Foot Zone Monitor Wells

MW-19

MW-21

12/12/033/9/20046/9/20049/7/2004

1 1/30/20043/9/055/23/0512/10/033/9/2004

6/1 1/20049/8/200412/3/20043/10/055/24/05

13.369.5510.9413.1911.069.5113.5017.3516.3616.4017.0616.7116.6018.47

65.1068.9167.5265.2767.4068.9564.9659.1160.1060.0659.4059.7559.8657.99

35-Foot Zone Monitor WellsMW-8

MW-17AMW-20MW-23

MW-30

MW-33

5/23/055/23/055/23/055/23/05

12/10/20033/9/20046/9/20049/4/2004

11/30/20045/23/05

12/10/20033/9/20046/9/20049/4/2004

11/30/20045/23/05

19.0418.0219.5819.7112.9820.7322.0321.9520.7222.7123.2822.2022.5722.4622.2123.96

59.1460.1357.2859.5157.9359.1857.8857.9659.1957.2057.0558.1357.7657.8758.1256.37

100-Foot Zone Monitor Wells

MW-28A

9/18/009/25/01

9/25/01 Dup9/19/0212/12/033/9/046/9/049/7/04

1 1/30/0412/2/04

101.58102.23102.23101.73101.96101.76101.57101.58102.29

Not Measured

-22.05-22.70-22.70-22.20-22.43-22.23-22.04-22.05-22.76

Not Measured

D-l

Monitor Well Date


BTOC)Groundwater

Elevation (Feet MSL)100 Foot Zone Monitor Wells Continued

MW-31A

MW-32

MW-32A

9/18/009/25/019/19/0212/12/033/9/046/9/049/7/04

11/30/049/18/009/25/019/19/0212/12/033/9/046/9/049/7/04

1 1/30/045/23/05

101.80102.42102.00102.59102.16101.97101.83102.59102.62103.12102.57102.97102.82102.67102.6

103.1798.92

-21.44-22.06-21.64-22.23-21.80-21.61-21.47-22.23-22.18-22.68-22.13-22.53-22.38-22.23-22.16-22.73-22.10

Phytohydraulic Control Pilot Test PiezometersPZ-1PZ-2PZ-3PZ-4PZ-5PZ-6PZ-1

5/23/055/23/055/23/055/23/055/23/045/23/055/23/05

22.5522.3922.8418.8519.3619.8922.55

55.9455.4455.2457.9057.1556.3455.94

Notes:

BTOC Below top of casingDup DuplicateMSL mean sea level

D-2

Summary of 2000-2005 Groundwater Elevation Data35 - Foot Zone PRS Wells

Date

8/7/028/21/029/17/0210/21/0211/22/0212/30/02

1/28/032/25/034/30/035/29/036/24/037/29/038/27/039/25/0310/30/0311/24/03

12/10/033/9/20046/9/20049/7/2004

11/30/20041/5/20053/9/05

8/7/028/21/029/17/0210/21/0211/22/0212/30/02

1/28/032/25/034/30/035/29/036/24/037/29/038/27/039/25/0310/30/0311/24/033/9/20046/9/20049/4/2004


BTOC)

GroundwaterElevation (Feet

MSL)MW-SW1 - Interior Well17.06

16.4615.7614.8413.9113.8713.6913.5614.5

15.1515.515.315.5

15.0514.814.4214.59

12.513.0514.19

10.66 a

13.6513.58

59.30

59.9060.6061.5262.4562.4962.6762.8061.8661.2160.8661.0660.8661.3161.5661.9461.77

63.8663.3162.17

65.70 a

62.7162.78

MW-SW3 - Interior Well23.4122.9021.3020.1919.7419.6719.9619.7820.521.3

21.1520.6520.820.821.120.7724.0220.3420.29

53.5654.0755.6756.7857.2357.3057.0157.1956.4755.6755.8256.3256.1756.1755.8756.2052.9556.6356.68


BTOC)


MSL)

Difference inElevation

(Feet)MW-SW2 - Exterior Well

14.9914.3214.4114.1913.1813.4913.7013.2913.7514.4514.714.614.815.414.1

13.6513.93

12.0512.3113.5012.8713.5412.30

60.70

61.3761.2861.5062.5162.2061.9962.4061.9461.2460.9961.0960.8960.2961.5962.0461.7663.6463.3862.1962.8261.8563.39

MW-SW4 - Exterior Well20.0319.4019.5519.5519.2419.1119.3319.1

19.8820.821.619.8520.219.719.8

20.4318.6819.7219.82

56.4057.0356.8856.8857.1957.3257.1057.3356.5555.6354.8356.5856.2356.7356.6356.0057.7556.7156.61

-1.40

-1.47-0.680.02-0.060.290.680.40-0.08-0.03-0.13-0.03-0.031.02

-0.03-0.10.010.22-0.07-0.022.88 a

0.86-1.12

-2.84-2.96-1.21-0.100.04-0.02-0.09-0.14-0.080.040.99-0.26-0.06-0.56-0.760.20-4.80-0.080.07

D-3

Date

11/30/20043/9/05

8/7/028/21/029/17/0210/21/021 1/22/0212/19/0212/20/0212/21/0212/26/0212/27/0212/30/02

1/6/031/9/031/14/031/24/03

1/28/032/25/034/30/035/29/036/4/03

6/24/037/29/038/27/039/25/0310/30/0311/24/0312/10/033/9/20046/9/20049/4/2004

11/30/20043/9/05

8/7/028/21/029/17/0210/21/021 1/22/0212/30/022/25/034/30/035/29/036/24/03


BTOC)


MSL)MW-SW3 - Interior Weil20.6020.91

56.3756.06

MW-SW5 - Interior Well23.6623.2222.0521.4921.0520.6321.20

Not measured21.3222.6020.8321.2521.2021.3021.5221.2521.0421.8022.5022.7022.4522.0022.1021.8021.7521.1225.9520.4225.4521.6325.8425.41

54.0054.4455.6156.1756.6157.0356.46

Not measured56.3455.0656.8356.4156.4656.3656.1456.4156.6255.8655.1654.9655.2155.6655.5655.8655.9156.54

51.71"57.2452.2156.0351.8152.25

MW-SW7 - Interior Well24.1523.6822.0821.2820.6920.6120.6421.4522.122.05

53.7454.2155.8156.6157.2057.2857.2556.4455.7955.84


BtOC)


MSL)MW-SW4 - Exterior Well19.6619.79

56.7756.64

MW-SW6 - Exterior Well22.7922.4122.4822.3922.1322.1022.2022.3422.1522.3621.9522.3322.1222.0122.5022.2422.0222.8223.5523.6523.4022.9023.1522.4022.5022.1322.8821.0821.9022.4122.2621.43

54.7955.1755.1055.1955.4555.4855.3855.2455.4355.2255.6355.2555.4655.5755.0855.3455.5654.7654.0353.9354.1854.6854.4355.1855.0855.4554.7056.5055.6855.1755.3256.15

MW-SW8A - Exterior WellNot installedNot installedNot installedNot installed

20.9020.8220.8221.6422.3522.25

Not installedNot installedNot installedNot installed

56.8956.9756.9756.1555.4455.54


(Feet)

-0.40-0.58

-0.79-0.730.510.981.161.551.08NA0.91-0.161.201.161.000.791.061.071.061.101.131.031.030.981.130.680.831.09

-2.990.74-3.470.86-3.50-3.90

NANANANA0.310.310.280.290.350.30

D-4

Date

7/29/039/25/0310/30/0311/24/0312/10/033/9/20046/9/20049/4/2004

11/30/20043/9/05

8/7/028/21/029/17/0210/21/021 1/22/0212/30/02

1/28/032/25/034/30/035/29/036/24/037/29/038/27/039/25/0310/30/0311/24/0312/10/033/9/20046/9/20049/4/2004

11/30/20043/9/05

8/7/028/21/029/17/0210/21/0211/22/0212/30/021/28/032/25/034/30/035/29/036/24/037/29/03


BTOC)

Ground WaterElevation (Feet

MSL)MW-SW7 - Interior Well21.6521.121.2

20.8221.4619.9020.5321.0820.6520.37

56.2456.7956.6957.0756.4357.9957.3656.8157.2457.52

MW-SW9 - Interior Well19.1518.6718.9018.9518.3518.3218.6518.2919.1219.719.719.319.518.718.818.3918.9717.4217.9518.6518.3118.11

57.8458.3258.0958.0458.6458.6758.3458.7057.8757.2957.2957.6957.4958.2958.1958.6058.0259.5759.0458.3458.6858.88

MW-SW11 - Interior Well17.2016.7216.5615.7315.0116.1015.2714.9615.8216.2016.3015.90

58.8359.3159.4760.3061.0259.9360.7661.0760.2159.8359.7360.13


BTOC)

Ground WaterElevation (Feet

MSL)MW-SW8A - Exterior Well

21.821.3

21.3520.9921.6320.0620.6421.2821.00

—

55.9956.4956.4456.8056.1657.7357.1556.5156.79

—MW-SW10 - Exterior Well

19.1318.7018.9018.9918.4018.3418.5618.3519.1219.719.7

19.2519.518.7

18.7518.4519.0117.5018.0118.7018.3919.02

57.8858.3158.1158.0258.6158.6758.4558.6657.8957.3157.3157.7657.5158.3158.2658.5658.0059.5159.0058.3158.6257.99

MW-SW12 - Exterior Well16.1015.6915.9415.9115.2215.3015.4815.1516.0916.4516.3016.15

60.1460.5560.3060.3361.0260.9460.7661.0960.1559.7959.9460.09


(Feet)

0.250.300.250.270.270.260.210.300.45

—

-0.040.01-0.020.020.030.00-0.110.04-0.02-0.02-0.02-0.07-0.02-0.02-0.070.040.020.060.040.030.060.89

-1.31-1.24-0.83-0.030.00-1.010.00-0.020.060.04-0.210.04

D-5

Date

8/27/039/25/0310/30/0311/24/0312/10/033/9/20046/9/20049/4/2004

11/30/20041/5/20053/9/05


BTOC)


MSL)MW-SW11 - Interior Well

16.0015.3515.3514.9515.2714.1014.4815.25

11.96"15.4514.02

60.0360.6860.6861.0860.6661.9361.5560.78

64.07 a

60.5862.01


BTOC)


MSL)MW-SW12 - Exterior Well

16.2015.6015.6015.2015.6414.3614.6815.2515.0115.7215.05

60.0460.6460.6461.0460.6061.8861.5660.9961.2360.5261.19


(Feet)

-0.010.040.040.040.060.05-0.01-0.212.84a

0.060.82

Notes:

BTOCDupMSL

Anomalous data, well pressure unequilibratedElevation is not representative of historical values.Below top of casingDuplicatemean sea level

D-6

APPENDIX E

SUMMARY OF GROUNDWATER ANALYTICAL RESULTS

(Four Pages)

Summary of 2000-2005 Groundwater Analytical Data15 - Foot Zone

Monitor Well

MW-21

Date12/12/033/9/20046/11/20049/8/200412/3/20043/10/055/24/05

Total ArsenicConcentration

(mg/L)0.0070 B0.00686 B0.0072 B0.0102

O.0034O.00340.0028 B

Notes:

Bmg/L

Estimated. Detected value is below reporting limit,milligrams per liter

Summary of 2003 Additional Groundwater Investigation Analytical Data15 - Foot Zone Direct-Push Groundwater Samples

Well IDDP-112DP-113DP-114DP-115DP-116

Date Sampled9/26/039/26/039/26/039/26/039/26/03

Total Arsenic(mg/L)

0.00593 B0.0165

0.00768 B0.0031 1U0.00429 B

Notes:

Bmg/LU

Estimated. Detected value is below reporting limit.millgrams per literNon-detect.

E-l

Summary of 2000-2005 Groundwater Analytical Data35 - Foot Zone PRS and 35-Foot Zone Monitor Wells

Well ID

MW-SW1

MW-SW2

MW-SW3

MW-SW4

MW-SW5

MW-SW6

MW-SW7

MW-SW8A

Date Sampled9/18/02

3/10/05

9/18/0212/30/0212/10/033/9/046/9/04

6/9/04 (DUP)9/8/04

9/8/04 (DUP)

12/2/0412/2/04 (DUP)

3/10/055/24/059/17/023/11/059/18/0212/30/0212/10/033/9/046/9/049/7/0412/1/043/9/05

5/24/059/17/053/11/059/18/0212/30/0212/10/033/9/046/9/049/7/0412/1/043/11/055/23/053/10/0511/21/0212/30/0212/11/03

3/9/046/9/049/7/0412/1/04

Total Arsenic(rag/L)O.020

0.00675 B

O.00100.0038 B0.0069 B0.0108

O.0034O.00340.0059 B0.0036 BO.0034O.0034O.003400.0030 B

<0.020.0171 BO.005

0.0028 BO.0028O.0034<0.0034O.0034O.0034O.00340O.0020O.020

9.050.0069

0.0028 BO.0028<0.0034<0.0034<0.0034<0.0034

0.00394 BO.00200.0728

0.0146 B0.0105

0.0078 B

O.0034<0.00340.0043 BO.0034

DissolvedArsenic (mg/L)

NA

NA

0.0019 BNANANANANANANA

NANANANANANA

0.0053NANANANANANANANANANA

0.0053NANANANANANANANANANANANA

NANANANA

E-2

Well ID

MW-SW8A

MW-SW9

MW-SW10

MW-SW11

MW-SW12

MW-30

MW-33

Date Sampled3/9/055/23/059/17/023/10/059/18/0212/30/02

12/30/02 (DUP)12/11/033/9/046/9/049/8/0412/1/043/9/055/23/059/17/023/10/059/18/02

9/18/02 (DUP)12/30/0212/11/033/9/04

3/9/04 (DUP)6/9/049/8/0412/1/043/10/055/23/0511/21/0211/21/0212/15/033/9/046/9/049/8/0412/1/043/10/055/24/05

Total Arsenic(mg/L)O.00340.0041 B

274O.04170.0208 B0.0094 B0.0085 B0.0033 B0.0068 BO.0034O.0034O.0034O.0034O.0020

16.60.02930.01610.0136O.001

0.0040 B0.0046 B0.0047 BO.00340.0054 B0.0044 BO.00340O.0020

0.6561.74

0.87201.02000.7550.831.56

O.003400.834

DissolvedArsenic (mg/L)

NANANANA

0.01 57 BNANANANANANANANANANANA

0.02220.0176

NANANANANANANANANANANANANANANANANANA

Notes:

B Estimated. Reported value is less than the reporting limit.DUP Duplicate field sample.mg/L milligrams per literNA Not analyzed.

E-3

Summary of 2000-2005 Groundwater Elevation and Analytical Data100 - Foot Zone

Monitor Well

MW-28A

MW-31A

MW-32

MW-32A

Date9/18/00

9/25/019/25/01 Dup

9/19/0212/12/0312/2/049/18/009/25/019/19/02

9/19/02 Dup12/15/0312/3/049/18/00

9/1 8/00 Dup9/25/019/19/0212/12/0312/3/045/23/05

Total ArsenicConcentration

(mg/L)0.0010

O.0013O.0013O.001

0.0033 BO.00340.001O.0013O.001<0.001

<0.00311O.0034

0.0010.001

O.0013O.001<0.0028

0.3270.0052 B

DissolvedArsenic

Concentration(mg/L)0.0010

O.0013<0.0013<0.001

NANA

O.011<0.0013<0.001<0.001

NANA

0.0010.001

O.0013<0.001

NANANA

Notes:

B Estimated. Reported value is less than the reporting limit.DUP Duplicate field sample.mg/L milligrams per literNA Not analyzed.

E-4

EXHIBIT A

PHOTOGRAPHS

(13 Pages)

EXHIBIT B

SITE VISIT CHECKLIST

(Ten Pages)

FIVE-YEAR REVIEW SITE VISIT CHECKLIST

I. SITE INFORMATION

Site Name: Crystal Chemical Company Site

Location and Region: Houston, Texas / Region 6

Agency, office, or company leading the five-year review:Tetra Tech EM, Inc.

Date of Inspection : 7-29-05

EPA ID: TXD990707010

Weather/temperature:

Scattered thunderstorms, overcast, hot andhumid, mid 90s

Remedy Includes: (Check all that apply)E><] Landfill cover/containmentIXI Access controlsI I Institutional controls

[x] Ground water pump and treatmentI I Surface water collection and treatmentI I Other-Leachate collection and treatment

Attachments: Inspection team roster attached Site map attached

II. INTERVIEWS (Check all that apply)

1. O&M Site Manager XName: Michael J. Wisniowiecki, Conestoga-Rovers & Associates

Title: Project Manager Date: 7/29/05

Interviewed: I I by mail IXI at site I I by phone Phone no.Problems, suggestions: None.

I I Report attached

2. O&M Staff

Name: Adolfo Cepeda, Hatch Mott MacDonaldTitle: Operator Date: 7/29/05

Interviewed: I I by mail £<] at site I I by phone Phone no.iiiieivicwcu. i i uy man i/\i ui sue | | uy piiuiic riiuiie iiu.

Problems, suggestions: Sludge out clarifier pipeline in the GWTP is corroded and needs to bereplaced.

| Report attached

3. Local regulatory authorities and response agencies (i.e.; State and Tribal offices, emergencyresponse office, police department, office of public health or environmental health, zoning office,recorder of deeds, or other city and county offices, etc.). Fill in all that apply.

Agency.

ContactName Title Date Phone no.

Problems, suggestions: I I Report attach*

4. Other interviews (optional): EH Report

;d

attached

III. ON-SITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)

1. O&M DocumentsIXI O&M manual (long term monitoring plan)

IXI As-built drawings

IXI Maintenance logs(annual inspection reports)

Remarksi

2. Site-Specific Health and Safety Plan

1 1 Contingency plan/emergency response

Remarks^

IXI Readily available 1X1 Up to date 11X1 Readily available IXI Up to date I I

1X1 Readily available XI Up to date 1 1

1X1 Readily available IXI Up to date 1 1

plan I I Readily available 1 1 Up to date IXI

3. O&M and OSHA Training Records [X] Readily available |E]Uptodate Q

Remarks: At Corporate office of Hatch Mott MacDonald.

4. Permits and Service Agreements

1 1 Air discharge permitIXI Effluent dischargeIE! Waste disposal, POTW1 1 Other permits

Remarks:

5. Gas Generation Records

6. Settlement Monument Records

7. Ground Water Monitoring Records

Remarks: Available from CRA.

8. Leachate Extraction Records

9. Discharge Compliance Records

D AirIE! Water (effluent)

Remarks:.

10. Daily Access/Security Logs

Remarks:

1 1 Readily available 1 1 Up to date 1X1IXI Readily available 1X1 Up to date 1 11X1 Readily available IXI Up to date I I1 I Readily available 1 1 Up to date IXI

f~1 Readily available |~~| Up to date IXI

1 1 Readily available 1 1 Up to date IXI

IXI Readily available 1X1 Up to date 1 1

1 1 Readily available 1 1 Up to date IXI

1 I Readily available I I Up to date XIIXI Readily available XI Up to date 1 1

IE1 Readily available |E1 Up to date D

N/AN/A

N/A

N/A

N/A

N/A

N/AN/AN/AN/A

N/A

N/A

N/A

N/A

N/AN/A

N/A

IV. O&M COSTS

1. O&M Organization

I I State in-house I I Contractor for State

[X] Contractor for PRP D Other

in-house

2. O&M Cost Records

I I Readily available I [ Up to date I I Funding mechanism/agreement in place

I I Original O&M cost estimate I I Breakdown attached

Total annual cost by year for review period, if available

Date

From: Jan 1,2000

From: Jan 1,2001

From: Jan 1,2002

From: Jan 1,2003

From: Jan 1,2004

Date

Dec. 31,2000

Dec. 31,2001

Dec. 31,2002

Dec. 31,2003

Dec. 31,2004

Total Cost

$250,000 estimate

$250,000 estimate

$250,000 estimate

$250,000 estimate

$110,000 estimate

I | Breakdown attached

I I Breakdown attached




Remarks: Estimated O&M costs provided by Geoffrey Reeder of UPR.

3. Unanticipated or Unusually High O&M Costs During Review Period

Decrease in O&M costs coincided with change in PRP contractor.

V. ACCESS AND INSTITUTIONAL CONTROLS Applicable Q N/A

A. Fencing

1. Fencing damaged

Remarks:

Location shown on site map Gates secured N/A

B. Other Access Restrictions

1. Signs and other security measures [X] Location shown on site map I I N/A

Remarks:

C. Institutional Controls

1. Implementation and enforcement

Site conditions imply ICs not properly implemented | | Yes 1X1 No | | N/ASite conditions imply ICs not being fully enforced I I Yes ^ No I I N/A

Type of monitoring (e.g., self-reporting, drive by) Site InspectionsFrequency Quarterly

Responsible party/agency UPR / EPAContact Michael J. Wisniowiecki, Project Manager. 713-734-3090

Name Title Date Phone no.

Reporting is up-to-date 1X1 Yes Q No I I N/AReports are verified by the lead agency IXI Yes Q No I I N/ASpecific requirements in deed or decision documents have been met I I Yes IXI No I I N/AViolations have been reported I I Yes |^ No I I N/A

Other problems or suggestions: I I Report attachedDeed recordation for the properties impacted by the arsenic ground water plume is currently beingpursued. Once the deed recordation is completed, specific requirements in deed or decision documentswill have been met.2. Adequacy I I ICs are adequate 1X1 ICs are inadequate I I N/A

Remarks: Once the deed recordation for on-site and off-site impacted properties is complete, theICs will be adequate.

D. General

1. Vandalism/trespassing I I Location shown on site map IXl No vandalism evidentRemarks: No trespassing or vandalism was present within the fenced compounds. However, atrespasser was observed on the UPR 12.5-acre tract outside the fenced area.

2. Land use changes onsite IXI N/ARemarks:

3. Land use changes offsite [XJ N/ARemarks:

VI. GENERAL SITE CONDITIONS

A. Roads ^Applicable D N/A

Remarks: In good condition, no pot holes or major structural problems observed.

B. Other Site Conditions

Remarks:

VII. LANDFILL COVERS - monofill |EI Applicable D N/A

A. Landfill Surface - (monofill surface)

1. Settlement (Low spots) I I Location shown on site map 1X1 Settlement not evidentAreal extent DepthRemarks:

2. Cracks I I Location shown on site map 1X1 Cracking not evident

Lengths _Remarks:

Widths Depths.

3. Erosion 1X1 Location shown on site map OErosion not evidentAreal extent 15 foot wide patches on west and northern portionsDepth 2 inchesRemarks: Erosion on north side appears to be caused by mowing activities

4. HolesAreal extentRemarks:

I I Holes evident Holes not evidentDepth.

5. Vegetative Cover ^ Grass ^ Cover properly established I |No signs of stressI I Trees/Shrubs (indicate size and locations on a diagram) (None)Remarks: Several ruts were observed in the grass surface cover that appear to be caused by thelandscaping maintenance vehicles that mowed the grass the week prior to the site visit._

6. Alternative Cover (armored rock, concrete, etc.) IXI N/ARemarks:

7. BulgesAreal extent.Remarks:

Location shown on site mapDepth

Bulges not evident

8. Wet Areas/Water DamageI I Wet areasI I PondingI I SeepsI I Soft subgradeRemarks:

1X1 Wet areas/water damage not evidentI I Location shown on site mapI I Location shown on site mapI I Location shown on site mapI I Location shown on site map

I | Areal extentI | Areal extentI I Areal extent.

Areal extent

9. Slope Instability I I Slides I I Location shown on site mapIXI No evidence of slope instability Areal extent

Remarks:

B. Benches D Applicable [X] N/A(Horizontally constructed mounds of earth placed across a steep landfill side slope to interrupt the slope in order to slowdown the velocity of surface runoff and intercept and convey the runoff to a lined channel.)

1. Flows Bypass BenchRemarks:

Location shown on site map N/A or okay

2. Bench BreachedRemarks:

I I Location shown on site map N/A or okay

3. Bench Overtopped I I Location shown on site mapRemarks:

N/A or okay

C. Letdown Channels EH Applicable £3 N/A(Channel lined with erosion control mats, rip rap, grout bags, or gabions that descend down the steep side slope of thecover and will allow the runoff water collected by the benches to move off of the landfill cover without creating erosiongullies.) ^

1. Settlement Location shown on site map No evidence of settlement

2.

3.

4.

5.

Areal extent DepthRemarks:

Material Degradation I I Location shown on site map I I No evidence of degradationMaterial type Areal extentRemarks:

Erosion | | Location shown on site map | | No evidence of erosionAreal extent DepthRemarks:

Undercutting I [ Location shown on site map 1 1 No evidence of undercuttingAreal extent DepthRemarks:

Obstructions Tvoe1 [ No obstructions 1 1 Location shown on site map

Areal extent Size

6.

Remarks:

Excessive Vegetative Growth TypeONO evidence of excessive growth 1 1 Vegetation in channels does not obstruct flow1 1 Location shown on site map Areal extent

D.

1.

2.

3.

4.

5.

E.

1.

Remarks:

Cover Penetrations | | Applicable |X1 N/A

Gas Vents I | Active 1 1 Passive1 I Properly secured/locked 1 1 Functioning 1 1 Routinely sampled1 1 Evidence of leakage at penetration 1 1 Needs O&MRemarks:

Gas Monitoring ProbesI | Properly secured/locked I I Functioning I I Routinely sampled1 I Evidence of leakage at penetration 1 1 Needs O&MRemarks:

Monitoring Wells (within surface area of landfill)I | Evidence of leakage at penetration I I Needs O&MRemarks:

Leachate Extraction WellsI | Properly secured/locked 1 1 Functioning [^Routinely sampledI | Evidence of leakage at penetration 1 1 Needs O&MRemarks:

Settlement Monuments | | Located 1 1 Routinely surveyedRemarks:

Gas Collection and Treatment 1 1 Applicable IXI N/A

Gas Treatment FacilitiesI | Flaring I I Thermal destruction 1 11 I Good condition 1 1 Needs O&MRemarks:

D GoodDN/A

D GoodDN/A

DN/A

DGoodDN/A

DN/A

condition

condition

condition

Collection for reuse

2. Gas Collection Wells, Manifolds, and Piping | | Good condition |_J Needs O&MRemarks:

3. Gas Monitoring Facilities1 1 Good conditionRemarks:

F. Cover Drainage Layer1. Outlet Pipes Inspected

Remarks:2. Outlet Rock Inspected

Remarks:

(e.g., gas monitoring of adjacent homes or buildings)D Needs O&M D N/A

D Applicable |E1 N/A[_] Functioning I" "I N/A

| | Functioning I I N/A

G. Detention/Sedimentation Ponds I I Applicable [X] N/A

1. Siltation Areal extent Size1 1 N/A I I Siltation not evidentRemarks:

2. Erosion Areal1 1 Erosion not evidentRemarks:

3. Outlet WorksRemarks:

4. DamRemarks:

H. Retaining Walls

1. DeformationsHorizontal displacementRotational displacementRemarks:

2. DegradationRemarks:

extent Depth

1 1 Functioning 1 1 N/A

| | Functioning | | N/A

D Applicable [El N/A

1 1 Location shown on site map 1 1 Deformation not evidentVertical displacement

1 I Location shown on site map I I Degradation not evident

I. Perimeter Ditches/Off-Site Discharge |E1 Applicable D N/A

1. SiltationAreal extent

1 1 Location shown on site map IXI Siltation not evidentDeoth

Remarks: Leaf debris was observed around the edges of the drains located on the western side ofthe monofill that discharge to the adiacent HCFCD ditch.

2. Vegetative Growth 1 1 Location shown on site map 1 1 N/A£<] Vegetation does not impede flowAreal extent TvoeRemarks:

3. ErosionAreal extentRemarks:

I | Location shown on site map 1X3 Erosion not evidentDepth

4. Discharge Structure 1X1 Functioning I IN/ARemarks:

VIII. VERTICAL BARRIER WALLS £<3 Applicable Q N/A

1. Settlement I I Location shown on site map 1X1 Settlement not evidentAreal extent DepthRemarks:

2. Performance Monitoring Type of monitoring Ground water monitoring exterior to slurry wallI I Performance not monitored Frequency Quarterly

I I Evidence of breachingHead differential During 5-year review differential ranged from maximum of 1.55 ft to -4.8 ftbetween the interior and exterior pressure relief system monitoring wells.Remarks: Ground water is pumped from wells SW-6 and SW-4 to regulate head differential at slurrywall.

IX. GROUND WATER/SURFACE WATER REMEDIES |EI Applicable D N/A

A. Ground Water Extraction Wells, Pumps, and Pipelines IXI Applicable I I N/A

1. Pumps, Wellhead Plumbing, and Electrical1X1 Good condition I I All required wells located I I Needs O&M I I N/ARemarks:

2. Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances[El Good condition D Needs O&MRemarks: Need to vaccum or evaporate standing water in vaults.

3. Spare Parts and Equipment1X1 Readily available I I Good condition I I Requires upgrade I I Needs to be providedRemarks: Some parts are readily available, most parts are ordered on an as needed basis.

B. Surface Water Collection Structures, Pumps, and Pipelines I I Applicable IXI N/A

1. Collection Structures, Pumps, and ElectricalI I Good condition I I Needs O&MRemarks:

2. Surface Water Collection System Pipelines, Valves, Valve Boxes, and Other AppurtenancesI I Good condition I I Needs O&MRemarks:

3. Spare Parts and EquipmentI | Readily available I I Good condition I I Requires upgrade I I Needs to be providedRemarks:

C. Treatment System IXI Applicable DN/A1. Treatment Train (Check components that apply)

1X1 Metals removal I 1 Oil/water separationI I Air stripping I I Carbon absorbersI I Filters

Bioremediation

I I Additive (e.g., chelation agent, flocculent)D OthersLJ Good condition [X] Needs O&MI I Sampling ports properly marked and functionalI I Sampling/maintenance log displayed and up to dateI I Equipment properly identifiedIXI Quantity of ground water treated annually Ranged from 107, 645 gallons in 2001 to 646,156

gallons in 2002I I Quantity of surface water treated annuallyRemarks: Need to replace sludge out clarifier pipe which is heavily corroded

2. Electrical Enclosures and Panels (Properly rated and functional)D N/A lElGood condition D Needs O&MRemarks:

3. Tanks, Vaults, Storage VesselsI I N/A ^3 Good conditionRemarks:

Proper secondary containment I I Needs O&M

4. Discharge Structure and AppurtenancesI I N/A ^Good conditionRemarks:

Needs O&M

5. Treatment Building(s)I I N/A IXI Good condition (esp. roof and doorways)1X1 Chemicals and equipment properly storedRemarks:

Needs repair

6. Monitoring Wells (Pump and treatment remedy)IXI Properly secured/locked IXI Functioning 1X1 Routinely sampled[XI All required wells located I I Needs O&MRemarks:

conditionDN/A

D. Monitored Natural Attenuation I I Applicable IXI N/A1. Monitoring Wells (Natural attenuation remedy)

I | Properly secured/locked [^Functioning I I Routinely sampledI I All required wells located I I Needs O&M

Remarks:

I I Good conditionDN/A

X. OTHER REMEDIES

If there are remedies applied at the site that are not covered above, attach an inspection sheet describing the physicalnature and condition of any facility associated with the remedy. An example would be soil vapor extraction.

XI. OVERALL OBSERVATIONS

A. Implementation of the Remedy

Describe issues and observations relating to whether the remedy is effective and functioning as designed. Begin with abrief statement of what the remedy is to accomplish (i.e., to contain contaminant plume, minimize infiltration and gasemission, etc.).

The monofill and ground water containment system are designed to contain arsenic affected soil andground water, respectively. The ground water recovery and treatment system is designed to removeand treat arsenic impacted ground water south of the ground water containment system. Based onreview of documents. ARARs, and the site inspection, the remedies are being implementedeffectively and are functioning as designed.

B. Adequacy of O&M

O&M activities at the site are adequate. The monofill and slurry wall/PRS are inspected on a regularbasis and O&M activities are performed on the monofill and slurry wall/PRS as required. TheGWTP operates on a continual basis and maintenance activities are conducted as required.

C. Early Indicators of Potential Remedy Failure

There is no indication of remedy failure. The remedies are being implemented effectively and arefunctioning as designed.

D. Opportunities for Optimization

Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.

In addition to conducting the maintenance activities associated with the issues discussed in the 5-Year Review Report. UPR should continue to pursue alternative ground water treatmenttechnologies and/or water table reduction technologies to reduce the treatment costs.

10

EXHIBIT C

SURVEYS

(Ten Pages)

SUPERFUND SITE SURVEY - FORM A

Site Name: Crystal Chemical Company Site EPA Work Assignment No.: 123FRFE-06ZZ

Subject: 5-Year Review Citizen Survey Date:

Contact Made By:

Name: Chris Villarreal Title; Remedial Project Manager Organization; U.S. EPA

Telephone No.: (214)665-6758E-Mail; VUlaiTeal.chris(Sjgpa.goy

Street Address: 1455 Ross Avenue, Suite 1200City, State, Zip: Dallas, Texas 75202

Name: Eric Johnstone Title: Project Manager Organization: Terra Tech EM Inc.

Telephone No.: (214) 74Q-2001E-Mail:[email protected]

Street Address: 350 N. St. Paul Street, Suite 2600City, State, Zip: Dallas, Texas 75201

Individual Contacted:

Name: Mr. Harry A. Shearer Organization: SheartonDevelopment Company

Telephone No.:E-Mail Address:

Street Address: P.O. Box 24766City, State, Zip: Minneapolis, MN 55424

Survey Questions

1. What is your impression of the project (general sentiment)?

7**- /e*apf <*> ^^ 0/te^T^t&^ZZ^ /t%* /t*j >t£~***

1 sentiment)/ _. > -f}^**~~r* .?*:

2. effect have site operations had on the surrounding community?

3. Are you aware of any comflfunity concerns regarding the site or its operation and!If so, please provide details.

ion?

Page 1 of2


Subject: 5-Year Review Information Survey

EPA Work Assignment No.: 123-FRFE-0677

Date: J/Z'&fl?^

SUPERFUND SITE SURVEY - FORM A (continued)

4.

Survey Questions (Cont)

Are you aware of any events, incidents, or activities at the site such as vandalism, trespassing, oremergency responses from local authorities? If so, please provide details.

5. Do you feel well informed about the site's activities and progress?

6. Do you have any comments, suggestions, or recommendations regarding the site's management oroperation?

Page 2 of 2

SUPERFUND SITE SURVEY - FORM D

Site Name: Crystal Chemical Company Site EPA Work Assignment No.: 123-FRFE-06ZZ

Subject: 5-Year Review Information Survey Date:

Contact Made By:

Name: Chris Villarreal Tide: Remedial Project Manager Organization; U.S. EPA

Telephone No.: (214) 665-6758E-Mail: [email protected]


Name: Eric Johnstone Title: Project Manager Organization: Tetra Tech EM Inc.

Telephone No.: (214) [email protected]

Street Address: 350 N. St. Paul Street, Suite 2600City, State, Zip: Dallas, Texas 75201


Name: Geoffrey B. Reeder, P.G. Title: Manager, EnvironmentalSite Remediation

Organization: Union PacificRailroad


Street Address: 24125 Aldine Westfield RoadCity, State, Zip: Spring, TX 77373

Survey Questions


2. Has your office conducted routine communications or activities (site visits, inspections, reportingactivities, etc.) regarding the site? If so, please provide the purpose and results?

'HAS Sirs:

U Pu/rrH

Page 1 of 2

SUPERFUND SITE SURVEY - FORM D (continued)

Site Name: Crystal Chemical Company Site EPA Work Assignment No.: 123-FRFE-0677

Subject: 5-Year Review Information Survey Date:


3. Have there been any complaints, violations, or other incidents related to the site reported to your office?If so, please provide details.

4. Do you feel well informed about the site's activities and progress?

5. Do you have any comments, suggestions, or recommendations regarding the project?

i-r

Page 2 of2


Subject: 5-Year Review Operation and Maintenance

EPA Work Assignment No.: 123-FRFE-06ZZ

Date: 8/2/05

SUPERFUND SITE SURVEY - FORM C

Contact Made By:

Name: Chris Villarreal

Telephone No.: (214) 665-6758E-Mafl: villarreal.chris(o)epa.gov

Name: Eric Johnstone

Telephone No.: (214) 740-2004E-Mail: eric.iohnstonefSrttenii.com

Title: Remedial Project Manager Organization: U.S. EPA


Title: Project Manager (

Street Address: 350 N. St. Paul StreeCity, State, Zip: Dallas, Texas 75201

)rganization: TetraTechEM Inc.

.Suite 2600


Name: Michael J. Wisniowiecki, P.G.


Tide: P/uprjls*?MW\6>&A.

Organization: Conestoga-Rovers &Associates

Street Address: 13431 Cullen Blvd.City, State, Zip: Houston, TX 77047

Survey Questions


Generally very good in the overall short-term O&M and complianceactivities. Long-term approach to achieving ROD requirementsneeds review.

2. Please describe the on-site operation and maintenance (O&M) presence, including staff, frequency of siteinspections, and (O&M) activities.

CRA has handled compliance and regulatory requirements for UPRR at theCrystal Chemical site since March 2004. This includes ground watermonitoring and reporting, monthly reporting of compliance, O&M, andrelated activities, and regulatory concerns. Hatch, Mott, and MacDonaldperforms all OSM activities for UPRR.

Page 1 of3

Site Name: Crystal Chemical Company She EPA Work Assignment No.: 123-FRFE-0677

Subject: 5-Year Review Operation & Maintenance Survey Date: 8/2/05


Survey Questions (Continued)

3. Please describe any significant changes in (he O&M requirements, maintenance schedules, or samplingroutines since start-up or in the last 5 years. Do they affect the protectiveness or effectiveness of theremedy?

•mere have been no significant changes as described above since CRAbegan work at the site in March 2004. CRA will be beginning semiannualground water sampling in 4th quarter 2005 after obtaining EPA approvalas allowed in EPA's 12/03 letter reply. This change in ground watermonitoring frequency is based on consistent potentiometrix: measurementsand relatively low analytical results for arsenic over the past sevenquarterly monitoring events.

4. Have there been unexpected O&M difficulties or costs at the site since start-up or in the last 5 years?If so, please provide details.

There have been no unexpected O&M difficulties noted since March 2004with two exceptions:1) Leak Detection / Cleanput Vaults - The six vaults were observed to

be full to just below grade on two occasions in 2004, with the water"not detect" for arsenic and seemingly related to relatively largerainfall events. Recovery piping and sump locations on each vaulthave been resealed in 2005 to block subsurface infiltration ofsurface runoff. No further infiltration has been noted to date.

2) Recovery Pumps MW-SW-3 and MW-SW-5 have had intermittent operationalproblems though repairs have been made and operations restored inan expeditious fashion.

Page 2 of 3


Site Name: Crystal Chemical Company Site EPA Work Assignment No.: 123-FRFE-0677

Subject: 5-Year Review Operation & Maintenance Survey Date: 8/2/05

Survey Questions (Continued)

S. Can you provide insight to potential O&M problems?

None foreseen based on our experience and involvement with theOfiM.

6. Do you have any comments, suggestions, or recommendations regarding the project?

We recommend reevaluation of the long-term approach to:1) Ground water control and treatment and2) Affected soil containment in the monofill cap.

Page 3 of3

Tetra Tech EM Inc.One Dallas Centre • 3SO N. St. Paul St. Suite 2600 » D»llM,TX 75201 * (214) 7544765 » FAX (214) 922-9715

July 18,2005

Assistant Operations ManagerPretreatment Program Enforcement GroupIndustrial Wastewater ServiceDepartment of Public Works and EngineerCity of Houston10500 Bellaire BouiisvardHouston, TX 77072 ,

Subject: Questionnaire for Crystal Chemical Site

Dear Ms. McKnight:

The enclosed questionnaire is provided to gain your opinions concerning the Crystal Chemical Superfundsite 3502 Rogerdale Road, Houston, Texas. The U.S. Environmental Protection Agency (EPA) preparedthis questionnaire to gather input from local agencies.

Please complete the questionnaire and return it to me in the encloshave any questions regarding this information, please call me at (21^work assignment manager) at 214-665-6758.

Sincerely,

Eric Johnstone

Enclosure (2)

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LCEPA

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RECEIVED W 212005

> eontttnt raeyctod fliw and h reoydaWe

SUPERFUND SITE SURVEY - FORM BSite Name: Crystal Chemical Company Site EPA Work Assignment No.: 123-FRFE-06ZZ

Subject; 5-Year Review Local Authority Survey Datet

Contact Made By;

Name: Chris Villarreal Title: Remedial Project Manager Organization: U.S. EPA

Telephone No.: (214) 665-6758E-Mail: [email protected]


Name: Eric Johnstone

Telephone No.: (214) 740-2001E-Mail: eric.iohnstonefatttemi.com

Title: Project Manager Organization: Tetra Tech EM Inc.

Street Address: 350 N. St. Paul Street, Suite 2600City, State, Zip: Dallas* Texas 75201

lividullIndividul Contacted:

Title: Aro>laaul QpoiotimisManager-

Organization: Dept. of PublicWorks and Engineering

Telephone No.:E-Mail Address

Street Address: 1 0500 Bellaire Blvd.City, State, Zip: Houston, TX 77072

Survey Qoestions

1. What is your impression of the pro

2. Has your office conducted routine communications or activities (site visits, inspections, reportingactivities, etc.) regarding the site? If so, please provide the purpose and results.

I

iC f 0

3. Have there been any complaints, violations, or other incidents related to the site requiring a response byyouroffice? If so, please pro vide details of the events and the results of the responses.

Wo

Page 1 of 2

She Name: Crystal Chemical Company Site

Subject: 5-Year Review Local Authority Survey

EPA Work Assignment No.: 123-FRFE-0677

Date:

SUPERFUND SITE SURVEY - FORM B (continued)


4. Do you feel wellinfonned about the site's activities and progress?

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5. Have there been any changes in State laws and regulations that may impact the protect! veness of theground water or soil remedies?

T &t*?S

6. Has the site been in compliance with permitting and reporting requirements? / __,

7. Do you have any comments, suggestions, or recommendations regarding the site's management oroperation? I

Ho

Page 2 of 2