CONSENT DECREE BETWEEN DTSC AND WESTSIDE DELIVERY, LLC

STEPHEN V. WILSON, District Judge.

I. INTRODUCTION

1. On October 5, 2015, Plaintiff, the State of California Department of Toxic Substances Control ("DTSC"), filed the complaint ("Complaint") in this matter pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act, 42 U.S.C. §§ 9601-9675 ("CERCLA") and the California Hazardous Substances Account Act ("HSAA"), California Health and Safety Code § 25300 et seq. against Westside Delivery, LLC ("Westside"). In the Complaint, DTSC seeks 1) to recover under CERCLA section 107(a), 42 U.S.C. § 9607(a), costs it incurred responding to releases and/or threatened releases of hazardous substances at or from the former Davis Chemical Company located at 1550 North Bonnie Beach Place, Los Angeles, California, identified by Los Angeles County Assessor's Parcel Number 5224-026-005 (the "Site"); 2) declaratory relief under CERCLA section 113(g)(2), 42 U.S.C. § 9613(g)(2) that Westside is jointly and severally liable for any future response costs to be incurred by DTSC to address releases and/or threatened releases of hazardous substances at or from the Site; and 3) injunctive relief pursuant to Health and Safety Code section 25358.5 compelling Westside to conduct any necessary future response actions at the Site.

2. In the Complaint, DTSC alleges, in relevant part, the following:

3. DTSC took response actions necessary to remove and remedy the hazardous substances released and/or threatened to be released at and from the Site. DTSC's response actions included, but were not limited to, the following activities: additional investigations of contamination at the Site; implementation of the RAP; enforcement/cost recovery activities; public participation; and compliance with the California Environmental Quality Act. DTSC's response actions were not inconsistent with the National Contingency Plan, 40 C.F.R. Part 300.

4. As of April 2016, DTSC's unreimbursed Response Costs related to the Site were approximately $2.1 million.

5. Since April 2016, DTSC has incurred significant additional enforcement costs that are response costs.

6. DTSC and Westside (collectively, the "Parties") agree, and this Court, by entering this Consent Decree, finds, that this Consent Decree has been negotiated by the Parties in good faith, settlement of this matter will avoid expensive, prolonged and complicated litigation between the Parties, and this Consent Decree is fair, reasonable, in the public interest and consistent with the purpose of CERCLA.

THEREFORE, the Court, with the consent of the Parties to this Consent Decree, hereby ORDERS, ADJUDGES, AND DECREES, as follows:

II. JURISDICTION

7. The Court has subject matter jurisdiction over the matters alleged in this action pursuant to 28 U.S.C. § 1331, 28 U.S.C. § 1367(a), and CERCLA section 113(b), 42 U.S.C. § 9613(b). It also has personal jurisdiction over each of the Parties. Venue is appropriate in this district pursuant to 28 U.S.C. § 1391(b) and CERCLA section 113(b), 42 U.S.C. § 9613(b). Solely for the purposes of this Consent Decree and the underlying Complaint, Westside waives all objections and defenses that it may have to the jurisdiction of the Court or to venue in this district. Westside shall not challenge the terms of this Consent Decree or this Court's jurisdiction to enter and enforce this Consent Decree.

8. The Court shall retain jurisdiction over this matter for the purpose of interpreting and enforcing the terms of this Consent Decree if necessary.

III. SETTLEMENT OF DISPUTED CLAIMS

9. Subject to the reservations of rights in Section VII, this Consent Decree resolves all of DTSC's claims against Westside in the above-captioned action. DTSC agrees to resolve Westside's liability in this action in exchange for consideration from Westside, including payment by Westside to reimburse a portion of DTSC's Response Costs incurred at or in connection with releases and/or threatened releases of hazardous substances at and/or from the Site.

10. Nothing in this Consent Decree shall be construed as an admission by Westside of any issue of law or fact or of any violation of law. Except as otherwise provided by this Consent Decree, this Consent Decree shall not prejudice, waive or impair any right, remedy or defense that Westside may have in any other or further legal proceeding.

11. Westside consents to, and shall not challenge entry of, this Consent Decree or this Court's jurisdiction to enter and enforce this Consent Decree.

12. Upon approval and entry of this Consent Decree by the Court, this Consent Decree shall constitute a final judgment between and among the Parties.

IV. DEFINITIONS

13. Unless otherwise expressly provided herein, terms used in this Consent Decree that are defined in CERCLA or in regulations promulgated under CERCLA shall have the meaning assigned to them therein. Whenever terms listed below are used in this Consent Decree, the definitions below shall apply.

14. "Day" shall mean shall mean a calendar day. In computing any period of time under this Consent Decree, where the last day would fall on a Saturday, Sunday, or federal or State holiday, the period shall run until the close of business of the next Day.

15. "DTSC" shall mean the State of California Department of Toxic Substances Control and its predecessors and successors. DTSC is a public agency of the State of California organized and existing under and pursuant to California Health and Safety Code §§ 58000-18. Under California law, DTSC is the state agency responsible for determining whether there has been a release and/or threatened release of hazardous substances into the environment, and for determining the actions to be taken in response thereto.

16. "Effective Date" shall mean the date the Court enters an Order approving this Consent Decree.

17. "Fair Market Value" shall mean the highest price on the date of valuation that would be agreed to by a seller, being willing to sell but under no particular or urgent necessity for so doing, nor obliged to sell, and a buyer, being ready, willing, and able to buy but under no particular necessity for so doing, each dealing with the other with full knowledge of all the uses and purposes for which the property is reasonably adaptable and available.

18. "Parties" shall mean DTSC and Westside.

19. "Qualifying Sale" shall mean a sale of the Site within three (3) years of the Effective Date, unless Westside has made Substantial and Valuable Improvements to the Site. A Qualifying Sale shall not include the sale of the Site at a tax auction.

20. "Response Costs" shall mean all costs of "removal," "remedial action," or "response" (as those terms are defined by section 101 of CERCLA, 42 U.S.C. § 9601), related to the release and/or threatened release of hazardous substances at, beneath, and/or from the Site, including in the soils and groundwater.

21. "Sale Closing Date" shall mean for a Qualifying Sale the date escrow closes for the sale of the Site.

22. "Sale Proceeds" shall mean for a Qualifying Sale the gross sale price for the site, less brokerage commissions, closing costs, and marketing expenses. In calculating the Sale Proceeds, other payments from escrow, including any lien payments or property tax payments, shall not be deducted from the gross sale price.

23. "Site" shall mean the property located at 1550 North Bonnie Beach Place, Los Angeles, California, in the County of Los Angeles, California, identified by Los Angeles County Assessor's Parcel Number 5224-026-005 and the areal extent of contamination at and emanating from that property, including contamination in the soil or groundwater.

24. "Substantial and Valuable Improvements" shall include the actual construction of significant structural improvements, such as a new building or buildings, or other physical improvements that places the property into productive use (including, for example, grading and paving the whole property to be a parking lot), but does not include permit approvals or grants of entitlement for construction of significant structural improvements, such as a new building or buildings and does not include minor physical improvements such as fencing.

V. WESTSIDE'S OBLIGATIONS

25. Westside or its designee shall pay DTSC $175,000 within thirty (30) Days of the Effective Date.

26. For the period of three (3) years from the Effective Date, Westside will give DTSC written and email notice of any sale agreement Westside enters for the Site or of any notice Westside receives that the Site will be offered at a tax auction. Westside will give such notice within five (5) days of either entering the agreement or receiving notice of the tax sale.

27. In the event of a Qualifying Sale, Westside shall comply with the following:

28. In the event that the Site is sold in a tax auction, any proceeds from that sale are conveyed to Westside pursuant to the Revenue and Taxation Code, and the amount conveyed to Westside exceeds the sum of 1) $175,000 (Westside's payment to DTSC); 2) $80,000 (Westside's purchase price); and 3) Westside's legal fees as documented pursuant to Paragraph 27.b, then Westside shall pay half of the amount exceeding that sum to DTSC. That payment shall be due within thirty (30) Days of the date that Westside receives the payment.

29. The payment(s) specified in Paragraph 25 and (if any) Paragraph 27 shall be made by certified or cashier's check(s) made payable to Cashier, California Department of Toxic Substances Control, and shall bear on its face both the docket number of this proceeding and the phrase "Site Code 300432." On request, DTSC will provide instructions for payment by electronic funds transfer.

The payment shall be sent to:

A copy of the check shall be mailed to:

30. No later than thirty (30) Days after the Effective Date, Westside shall record the land-use covenant for the Site that appears as Exhibit A to this Consent Decree. Nothing herein shall prevent Westside from recording the land-use covenant prior to thirty (30) Days after the Effective Date."

31. No later than thirty (30) Days after the Effective Date, Westside shall dismiss with prejudice its appeal in State of Cal. DTSC v. Westside Delivery, LLC, et al., 9th Circuit Case No. 18-55868, CDCA Case No. 2:17-cv-00785-R-RAO (9th Cir., filed 06/28/18). This requirement shall be moot if the appeal is no longer pending.

32. This Consent Decree is conditioned upon full execution of Westside's obligations in Paragraphs 25 through 31. If these conditions are not met, then this Consent Decree, including the covenant not to sue in Section VI, shall be voidable at the discretion of DTSC, and DTSC may proceed to litigate the Complaint against Westside.

33. Within thirty (30) Days after Westside makes the payment required by Paragraph 25, DTSC shall terminate the lien it imposed on the Site.

VI. COVENANT NOT TO SUE BY DTSC

34. Except as expressly provided in Section VII (DTSC's Reservation of Rights) of this Consent Decree, DTSC covenants not to sue Westside pursuant to CERCLA, the California Hazardous Substances Account Act, Cal. Health & Safety Code sections 25300-25395.3 to: (a) recover DTSC's Response Costs related to the Site, including Response Costs associated with groundwater remediation relating to any hazardous substances released at the Site; or (b) require Westside to conduct response actions, including removal or remedial actions, related to the release and/or threatened release of hazardous substances at or from the Site, including the soil and groundwater. As stated in Paragraph 32, this Covenant Not to Sue is conditioned upon the complete and satisfactory performance by Westside of all its obligations under this Consent Decree.

VII. DTSC'S RESERVATION OF RIGHTS

35. Claims Regarding Other Matters. DTSC reserves, and this Consent Decree is without prejudice to, all rights against Westside with respect to all matters not expressly included within DTSC's Covenant Not to Sue (Section VI).

36. Reservation of Claims. DTSC reserves, and this Consent Decree is without prejudice to, all rights against Westside with respect to the following matters:

37. Government Authority. Except as expressly provided in the Consent

Decree, nothing in the Consent Decree is intended nor shall it be construed to preclude DTSC from exercising its authority under any law, statute or regulation. Furthermore, nothing in the Consent Decree is intended, nor shall it be construed, to preclude any other state agency, department, board or entity or any federal entity from exercising its authority under any law, statute or regulation.

38. Claims Against Other Persons. DTSC reserves, and this Consent Decree is without prejudice to, all rights, claims, and causes of action DTSC may have against any person other than Westside. Nothing in this Consent Decree is intended to be nor shall it be construed as a release, covenant not to sue, or compromise of any claim or cause of action, which DTSC may have against any person or other entity that is not Westside.

39. Unknown Conditions/New Information. Notwithstanding any other provision in the Consent Decree, DTSC reserves, and this Consent Decree is without prejudice to, the right to institute proceedings in this action or in a new action, and/or to issue an administrative order seeking to compel Westside to perform response activities at the Site and/or to pay DTSC for additional Response Costs, if:

VIII. COVENANT NOT TO SUE BY WESTSIDE

40. Westside covenants not to sue, and agrees not to assert any claims or causes of action against DTSC or any DTSC contractors or employees that arise out of the transaction or occurrence that is the subject matter of the Complaint, or for any injuries, losses, costs, or damages caused or incurred as a result of the performance of the requirements of this Consent Decree or the DTSC's response actions at the Site.

41. This Section VIII (Covenant Not to Sue by Westside) does not pertain to any matters other than those specifically addressed in this Consent Decree, applies only to DTSC and does not extend to any other department, agency, board or body of the State of California. Westside reserves, and this Consent Decree is without prejudice to, all rights against DTSC with respect to all other matters not expressly included within the scope of this Consent Decree.

42. In any legal proceedings that DTSC may initiate against Westside for non-compliance with this Consent Decree, and subject to this Consent Decree, Westside may raise any and all defenses that Westside deems to be relevant to the issue of whether or not they have complied with the terms of this Consent Decree.

IX. EFFECT OF SETTLEMENT AND CONTRIBUTION PROTECTION

43. With regard to claims for contribution against Westside for "Matters Addressed" in this Consent Decree, the Parties agree, and the Court finds as follows:

44. "Matters Addressed". The "Matters Addressed" in this Consent Decree are all response actions taken or to be taken and all Response Costs incurred or to be incurred at or in connection with the Site by DTSC.

45. The protection provided for in this Section IX is conditioned upon compliance by Westside with its obligations under Paragraphs 25 through 31 of this Consent Decree.

46. Nothing in this Consent Decree limits or impairs the right of DTSC to pursue any person other than Westside for unrecovered Response Costs incurred by DTSC.

47. The Court shall retain jurisdiction over this matter for the purpose of interpreting and enforcing the terms of this Consent Decree if necessary.

X. NOTIFICATION

48. Notification to or communication among the Parties as required or provided for in this Consent Decree shall be addressed as follows:

XI. GENERAL PROVISIONS

49. Parties Bound. This Consent Decree shall apply to, be binding upon, and inure to the benefit of the Parties and their representatives, successors, heirs, legatees, and assigns.

50. No Rights in Other Parties. Except as provided in Paragraph 49 regarding parties bound, nothing in this Consent Decree shall be construed to create any rights in, or grant any cause of action to, any person not a Party to this Consent Decree or a Related Person.

51. No Waiver of Enforcement. The failure of DTSC to enforce any provision of this Consent Decree shall in no way be deemed a waiver of such provision or in any way affect the validity of this Consent Decree. The failure of DTSC to enforce any such provision shall not preclude it from later enforcing the same or any other provision of this Consent Decree.

52. Attorneys' Fees. Except as expressly provided in this Consent Decree, the Parties will not seek to recover attorneys' fees and/or litigation costs against each other.

53. Final Agreement. This Consent Decree constitutes the final, complete and exclusive agreement and understanding between the Parties with respect to the settlement embodied in this Consent Decree.

54. Modifications. This Consent Decree may be modified only upon written approval of the Parties and with the consent of the Court.

55. Signatories. Each signatory to this Consent Decree certifies that he or she is fully authorized by the Party he or she represents to enter into the terms and conditions of this Consent Decree, to execute it on behalf of the Party represented, and to legally bind that Party to all the terms and conditions of this Consent Decree.

56. Counterparts. This Consent Decree may be executed in two or more counterparts, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument.

57. Agent. Westside has appointed and authorized the agents identified in Paragraph 48 to this Consent Decree to receive notices with respect to all matters arising under or relating to this Consent Decree.

XII. ENTRY OF THE CONSENT DECREE

58. This Consent Decree shall be lodged with the Court for a period of not less than thirty (30) Days. The Consent Decree also is subject to a public comment period of not less than thirty (30) Days. DTSC may modify or withdraw its consent to this Consent Decree if comments received during the public comment period disclose facts or considerations that indicate that this Consent Decree is inappropriate, improper or inadequate. Westside consents to the entry of this Consent Decree without further notice.

59. If, for any reason, the Court declines to approve this Consent Decree in the form presented, this Consent Decree is voidable at the sole discretion of any Party and the terms of the Consent Decree may not be used as evidence in any litigation between the Parties.

60. Upon entry of this Consent Decree by the Court, this Consent Decree shall constitute the final judgment between DTSC and Westside.

The Court finds that there is no just reason for delay and therefore enters this judgment as a final judgment under Fed. R. Civ. P. 54 and 58.

IT IS SO ORDERED, ADJUDGED, AND DECREED.

Exhibit A

LAND USE COVENANT AND AGREEMENT

ENVIRONMENTAL RESTRICTIONS

County of Los Angeles, Assessor Parcel Number(s): 5224-026-005 Davis Chemical Site Department Site Code: 300432

This Land Use Covenant and Agreement ("Covenant") is made by and between Westside Delivery, LLC, (the "Covenantor"), the current owner of property located at 1550 North Bonnie Beach Place, in the County of Los Angeles, State of California (the "Property"), and the Department of Toxic Substances Control (the "Department"). Pursuant to Civil Code section 1471, the Department has determined that this Covenant is reasonably necessary to protect present or future human health or safety or the environment as a result of the presence on the land of hazardous materials as defined in Health and Safety Code section 25260. The Covenantor and the Department hereby agree that, pursuant to Civil Code section 1471 and Health and Safety Code, sections 25227 and 25355.5, the use of the Property shall be restricted as set forth in this Covenant and that the Covenant shall conform with the requirements of California Code of Regulations, title 22, section 67391.1.

ARTICLE I

STATEMENT OF FACTS

1.1. Property Location. The Property that is subject to this Covenant, totaling approximately 1/3 acres is more particularly described in the attached Exhibit A, "Legal Description", and depicted in Exhibit B. The Property is located in an area that consists of light industrial facilities with exception of a residence located on an adjacent property uphill and to the south southeast of the site. The Property is also identified as County of Los Angeles, Assessor Parcel Number(s) 5224-026-005.

1.2. Remediation of Property. This Property has been investigated and/or remediated under the Department's oversight. The Department approved a Remedial Action Plan, in accordance with Health and Safety Code, division 20, chapter 6.8. The remedial activities conducted at the Property include excavation of soil impacted by volatile organic compounds (VOCs) and installation of a soil vapor extraction (SVE) system. Hazardous substances, including PCE at concentrations up to 43 ppm, TCE at concentrations up to 35 ppm, and cis-1,2-DCE at concentrations up to 2.0 ppm, remain at the Property above levels acceptable for unrestricted land use.

1.3. Human Health Risk Assessment. In connection with the Remedial Action Plan, a Screening Human Health Risk Assessment and Presumptive Feasibility Study Report (HHRA) was prepared to assess the human health risk following completion of the remediation pursuant to the Remedial Action Plan. A copy of the HHRA is attached hereto as Exhibit C. The HHRA assumed that the remediated Property would be regraded for commercial and/or industrial development based on the needs of the Property owner. (HHRA pg. 47.) The HHRA concluded that the preferred remedial alternative under the Remedial Action Plan would eliminate or reduce to acceptable levels the identified risks from the soils, and would provide a long-term, permanent solution to allow the Property to be developed for future commercial or industrial use. (HHRA pg. 51.)

1.4. Basis for Environmental Restrictions. As a result of the presence of hazardous substances, which are also hazardous materials as defined in Health and Safety Code section 25260, at the Property, the Department has concluded that it is reasonably necessary to restrict the use of the Property in order to protect present or future human health or safety or the environment, and that this Covenant is required as part of the Department-approved remedy for the Property. The Department has also concluded that the Property, as remediated and when used in compliance with the Environmental Restrictions of this Covenant, does not present an unacceptable risk to present and future human health or safety or the environment.

ARTICLE II

DEFINITIONS

2.1. Department. "Department" means the California Department of Toxic Substances Control and includes its successor agencies, if any.

2.2. Environmental Restrictions. "Environmental Restrictions" means all protective provisions, covenants, restrictions, requirements, prohibitions, and terms and conditions as set forth in this Covenant.

2.3. Improvements. "Improvements" includes, but is not limited to buildings, structures, roads, driveways, improved parking areas, wells, pipelines, or other utilities.

2.4. Lease. "Lease" means lease, rental agreement, or any other document that creates a right to use or occupy any portion of the Property.

2.5. Occupant. "Occupant" or "Occupants" means Owner and any person or entity entitled by ownership, leasehold, or other legal relationship to the right to occupy any portion of the Property.

2.6. Owner. "Owner" or "Owners" means the Covenantor, and any successor in interest including any heir and assignee, who at any time holds title to all or any portion of the Property.

ARTICLE III

GENERAL PROVISIONS

3.1. Runs with the Land. This Covenant sets forth Environmental Restrictions that apply to and encumber the Property and every portion thereof no matter how it is improved, held, used, occupied, leased, sold, hypothecated, encumbered, or conveyed. This Covenant: (a) runs with the land pursuant to Civil Code section 1471 and Health and Safety Code section 25355.5; (b) inures to the benefit of and passes with each and every portion of the Property; (c) is for the benefit of, and is enforceable by the Department; and (d) is imposed upon the entire Property unless expressly stated as applicable only to a specific portion thereof.

3.2. Binding upon Owners/Occupants. This Covenant: (a) binds all Owners of the Property, their heirs, successors, and assignees; and (b) the agents, employees, and lessees of the Owners and the Owners' heirs, successors, and assignees. Pursuant to Civil Code section 1471, all successive Owners of the Property are expressly bound hereby for the benefit of the Department; this Covenant, however, is binding on all Owners and Occupants, and their respective successors and assignees, only during their respective periods of ownership or occupancy except that such Owners or Occupants shall continue to be liable for any violations of, or non-compliance with, the Environmental Restrictions of this Covenant or any acts or omissions during their ownership or occupancy.

3.3. Incorporation into Deeds and Leases. This Covenant shall be incorporated by reference in each and every deed and Lease for any portion of the Property entered into after the date of recordation of this Covenant.

3.4. Conveyance of Property. The Owner and new Owner shall provide Notice to the Department not later than 30 calendar days after any conveyance or receipt of any ownership interest in the Property (excluding Leases, and mortgages, liens, and other non-possessory encumbrances). The Notice shall include the name and mailing address of the new Owner of the Property and shall reference the site name and site code as listed on page one of this Covenant. The notice shall also include the Assessor's Parcel Number(s) noted on page one. If the new Owner's property has been assigned a different Assessor Parcel Number, each such Assessor Parcel Number that covers the Property must be provided. The Department shall not, by reason of this Covenant, have authority to approve, disapprove, or otherwise affect proposed conveyance, except as otherwise provided by law or by administrative order.

3.5. Costs of Administering the Covenant to Be Paid by Owner. The Department has already incurred and will in the future incur costs associated with this Covenant. Therefore, the Covenantor hereby covenants for the Covenantor and for all subsequent Owners that, pursuant to California Code of Regulations, title 22, section 67391.1(h), the Owner agrees to pay the Department's costs in administering, implementing and enforcing this Covenant incurred after the date of recordation of this Covenant.

ARTICLE IV

RESTRICTIONS AND REQUIREMENTS

4.1. Restricted Uses. Health and Safety Code, section 25227 provides that a person shall not engage in any of the following on land that is subject to a recorded land use restriction pursuant to Health and Safety Code, section 25355.5, unless the person obtains a specific approval in writing from the Department for the land use on the land in question:

4.2. Permitted Uses. Consistent with Health and Safety Code, section 25227, and as documented in the HHRA, the Department does not consider the use of the Property for commercial or industrial use a new use. The development and use of the Property for future commercial and/or industrial uses remains subject to the soil management requirements and prohibited activities listed herein. Should site conditions be altered beyond those conditions in the approved HHRA, an updated HHRA may be required by the Department.

4.3. Soil Management. Soil management activities at the Property are subject to the following requirements in addition to any other applicable Environmental Restrictions:

4.4. Prohibited Activities. The following activities shall not be conducted at the Property:

4.5. Access for Department. The Department shall have reasonable right of entry and access to the Property for inspection, investigation, remediation, monitoring, and other activities as deemed necessary by the Department in order to protect human health or safety or the environment.

4.6. Annual Inspection and Reporting Requirements. The Owner shall conduct an annual inspection of the Property verifying compliance with this Covenant and shall submit an annual inspection report to the Department for its approval by January 30 of each year. The annual inspection report should include the dates, times, and names of those who conducted the inspection and reviewed the annual inspection report. It also should describe how the observations that were the basis for the statements and conclusions in the annual inspection report were performed (e.g., drive by, fly over, walk in, etc.). If any violation is noted, the annual inspection report must detail the steps taken to correct the violation and return to compliance. If the Owner identifies any violations of this Covenant during the annual inspection or at any other time, the Owner must within 10 calendar days of identifying the violation: (a) determine the identity of the party in violation; (b) send a letter advising the party of the violation of the Covenant; and (c) demand that the violation cease immediately. Additionally, a copy of any correspondence related to the violation of this Covenant shall be sent to the Department within 10 calendar days of its original transmission.

4.7. Five-Year Review. As set forth in Sections 1.2 and 1.4, the Property was remediated under the Department's oversight, and this Covenant is required as part of the Department-approved remedy for the Property. The Department has also concluded that the Property, as remediated and when used in compliance with the Environmental Restrictions of this Covenant, does not present an unacceptable risk to present and future human health or safety or the environment. In addition to the annual reviews noted above, after a period of five (5) years from date of recordation of this Covenant and every five (5) years thereafter, Owner shall submit a Five-Year Review report documenting continued compliance with the Environmental Restrictions of this Covenant. The report shall describe the results of all inspections and any sampling analyses, tests and other data generated or received by Owner. As a result of any review work performed, DTSC may require Owner to perform additional review work or modify the review work previously performed by Owner.

ARTICLE V

ENFORCEMENT

5.1. Enforcement. Failure of the Owner or Occupant to comply with this Covenant shall be grounds for the Department to require modification or removal of any Improvements constructed or placed upon any portion of the Property in violation of this Covenant. Violation of this Covenant shall be grounds for the Department to pursue administrative, civil, or criminal actions, as provided by law.

ARTICLE VI

VARIANCE, REMOVAL AND TERM

6.1. Variance from Environmental Restrictions. Any person may apply to the Department for a written variance from any of the Environmental Restrictions imposed by this Covenant. Such application shall be made in accordance with Health and Safety Code section 25223.

6.2. Removal of Environmental Restrictions. Any person may apply to the Department to remove any of the Environmental Restrictions imposed by this Covenant or terminate the Covenant in its entirety. Such application shall be made in accordance with Health and Safety Code section 25224.

6.3. Term. Unless ended in accordance with paragraph 6.2, by law, or by the Department in the exercise of its discretion, this Covenant shall continue in effect in perpetuity.

ARTICLE VII

MISCELLANEOUS

7.1. No Dedication Intended. Nothing set forth in this Covenant shall be construed to be a gift or dedication, or offer of a gift or dedication, of the Property, or any portion thereof, to the general public or anyone else for any purpose whatsoever.

7.2. Recordation. The Covenantor shall record this Covenant, with all referenced Exhibits, in the County of Los Angeles within 10 calendar days of the Covenantor's receipt of a fully executed original.

7.3. Notices. Whenever any person gives or serves any Notice ("Notice" as used herein includes any demand or other communication with respect to this Covenant), each such Notice shall be in writing and shall be deemed effective: (a) when delivered, if personally delivered to the person being served or to an officer of a corporate party being served; or (b) five calendar days after deposit in the mail, if mailed by United States mail, postage paid, certified, return receipt requested:

Any party may change its address or the individual to whose attention a Notice is to be sent by giving advance written Notice in compliance with this paragraph.

7.4. Partial Invalidity. If this Covenant or any of its terms are determined by a court of competent jurisdiction to be invalid for any reason, the surviving portions of this Covenant shall remain in full force and effect as if such portion found invalid had not been included herein.

7.5. Statutory References. All statutory or regulatory references include successor provisions.

7.6. Incorporation of Exhibits. All exhibits and attachments to this Covenant are incorporated herein by reference.

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IN WITNESS WHEREOF, the Covenantor and the Department hereby execute this Covenant.

Covenantor: Westside Delivery LLC

Department of Toxic Substances Control:

ACKNOWLEDGMENT

A notary public or other officer completing this certificate verifies only the identity of the individual who signed the document to which this certificate is attached, and not the truthfulness, accuracy, or validity of that document.

Notary Public, personally appeared ________________________________________, who proved to me on the basis of satisfactory evidence to be the person(s) whose name(s) is/are subscribed to the within instrument and acknowledged to me that he/she/they executed the same in his/her/their authorized capacity(ies), and that by his/her/their signature(s) on the instrument the person(s), or the entity upon behalf of which the person(s) acted, executed the instrument.

I certify under PENALTY OF PERJURY under the laws of the State of California that the foregoing paragraph is true and correct.

WITNESS my hand and official seal.

ACKNOWLEDGMENT

A notary public or other officer completing this certificate verifies only the identity of the individual who signed the document to which this certificate is attached, and not the truthfulness, accuracy, or validity of that document.

Notary Public, personally appeared ________________________________________, who proved to me on the basis of satisfactory evidence to be the person(s) whose name(s) is/are subscribed to the within instrument and acknowledged to me that he/she/they executed the same in his/her/their authorized capacity(ies), and that by his/her/their signature(s) on the instrument the person(s), or the entity upon behalf of which the person(s) acted, executed the instrument.

I certify under PENALTY OF PERJURY under the laws of the State of California that the foregoing paragraph is true and correct.

WITNESS my hand and official seal.

EXHIBIT A

LEGAL DESCRIPTION

The legal description of the property is as follows:

TRACT # 6479 LOTS 9 AND LOT 10 BLK G

APN: 5224-026-005

EXHIBIT B

SITE

Exhibit C

SCREENING HUMAN HEALTH RISK ASSESSMENT AND PRESUMPTIVE FEASIBILITY STUDY REPORT DAVIS CHEMICAL SITE 1550 NORTH BONNIE BEACH PLACE LOS ANGELES, CALIFORNIA

Presented to

Department of Toxic Substances Control Cypress, California

Prepared for

Heller Ehrman White & McAuliffe, LLP San Francisco, California

Prepared by

ENVIRON International Corporation Irvine, California

February 15, 2005

Prepared by

ENVIRON International Corporation

707 Wilshire Boulevard, Suite 4950 Los Angeles, California 90017 Tel: 213.943.6300 Fax: 213.943.6301

and

2010 Main Street, Suite 900 Irvine, California 92614 Tel: 949.261.5151 Fax: 949.261.6202

CONTENTS

TABLES

FIGURES

APPENDICES

LIST OF ACRONYMS AND ABBREVIATIONS

EXECUTIVE SUMMARY

On behalf of the Respondents to the Consent Order issued by the California Environmental Protection Agency (Cal/EPA) Department of Toxic Substances Control (DISC) on December 17, 2002 for the Davis Chemical Company site, located at 1550 North Bonnie Beach Place, Los Angeles, California (Site), Heller, Ehrman, White & McAuliffe, LLP retained ENVIRON International Corporation (ENVIRON) to perform a screening Human Health Risk Assessment (HHRA) and presumptive feasibility study (FS) for the Site. A remedial investigation (RI) report for the Site was previously prepared by ENVIRON and submitted to DISC on November 21, 2003.

The RI report for the Site found that volatile organic compounds (VOCs) are the main chemicals of potential concern (COPCs) at the Site based on their ubiquity and elevated concentrations. The predominant COPCs at the Site include tetrachlorethene (PCE), trichloroethene (ICE), and, to a lesser extent, their breakdown products.

ENVIRON conducted a screening HHRA to evaluate the reasonable potentially complete pathways and potentially exposed human receptors to COPCs at the Site. The results of the screening HHRA show that the estimated cancer risk from VOCs is 4 x 10-3 for indoor commercial workers and 7 x 10-5 for outdoor commercial workers The major chemical contributors to the risk estimates are PCE, ICE, 1,1,2,2-tetrachloroethane, vinyl chloride, 1,1,2-trichloroethane, 1,2-dichloroethane, and benzene. Furthermore, the estimated noncancer hazard index (HI) for VOCs is 38 for indoor commercial workers and 0.4 for outdoor commercial workers. The major chemical contributors to the HIs are PCE and 1,2,4-trimethylbenzene The results of the screening HHRA also show that the estimated cancer risks for semivolatile VOCs (SVOCs), pesticides, polynuclear aromatic hydrocarbons (PAHs), and metals are less than 1 x 10-6 and the noncancer HIs are less than 1 for both the indoor and outdoor commercial workers. As part of the screening HHRA, risk-based target concentrations (RBICs) were developed for all COPCs at the Site

ENVIRON performed an evaluation and screening process in compliance with the National Contingency Plan (NCP), Title 40 of the Code of Federal Regulations (CFR), Part 300 (40 CFR 300). Because the soil at the Site is affected by VOCs, ENVIRON selected the presumptive remedy approach, in accordance with the United States Environmental Protection Agency (USEPA) guidance for conducting a presumptive FS under Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) (USEPA, 1993b), and in general accordance with the USEPA guidance for conducting an FS under CERCLA (USEPA, 1988a). The presumptive FS was conducted to evaluate remedial alternatives responsive to the Site's Remedial Action Objectives, which include (1) reduction of human health risks; (2) reduction of risks to the environment; and (3) compliance with Applicable or Relevant and Appropriate Requirements (ARARs). The need for soil remediation at the Site was assessed based on potential risks to human health and the environment.

In accordance with USEPA guidance, four technologies and/or process options were selected for possible implementation at the Site These technologies and process options were combined into alternatives for treatment of soil at the Site. A preliminary screening of the alternatives was performed based on effectiveness, implementability, and cost., Based on this screening, the following three alternatives were retained for further consideration using the NCP criteria: 1) Alternative 1: "No Action," retained as required by the USEPA (1993a); 2) Alternative 4a: In situ soil vapor extraction (SVE) combined with "hot spot" excavation and off-site disposal/recycling; and 3) Alternative 4b: In situ SVE combined with "hot spot" excavation and ex situ SVE. Of these three, Alternative 4b was considered as the most suitable remedial alternative for the Site.

Alternative 4b consists of a combination of in situ SVE and excavation and on-site ex situ SVE treatment, Soil in the portions of the Site affected by concentrations of VOCs exceeding RBTCs will be excavated, stockpiled on-site, and treated using a network of ex situ SVE pipes. The residual contaminated soils will be treated with an in situ SVE system. The extracted vapors from both the in situ and ex situ wells and pipes will be passed through a series of two granular activated carbon (GAC) vessels for removal of VOCs from the vapor phase The vacuum pump for the in situ SVE system will be used to impart the necessary vacuum in the ex situ SVE system. It is anticipated that six to twelve months of remediation will be necessary to reduce soil concentrations to acceptable levels This estimate is based on ENVIRON's previous experience with similar systems installed at similar sites. Upon completion of the remediation, ENVIRON will discuss with DTSC whether the treated stockpiled soil will be either spread on site, if approved and certified as "clean" by DISC, or taken off-site for disposal as non-hazardous waste

The total estimated cost for Alternative 4b is approximately $340,000, which includes approximately $230,000 for capital costs, $50,000 for annual operation and maintenance (O&M) charges, and $60,000 for post-remediation costs. This alternative, when implemented, will eliminate or reduce to acceptable levels the identified risks from the soil at the Site. Also, the alternative will provide for future redevelopment of the land for commercial/industrial use.

1.0 INTRODUCTION

1.1 Background

On behalf of the Respondents to the Consent Order issued by the California Environmental Protection Agency (Cal/EPA) Department of Toxic Substances Control (DTSC) on December 17, 2002 for the Davis Chemical Company site (Site; Figure 1), Heller, Elliman, White & McAuliffe, LLP retained ENVIRON International Corporation (ENVIRON) to perform a supplemental remedial investigation (RI) at the Site. The results from the RI were presented in a separate report (ENVIRON, 2003) and are summarized below.

Based on ENVIRON's review of DISC files and the Consent Order for the Site, as well as an interview with Ms. Diana Davis, a trustee of the Davis Family Trust, during a Site visit on February 19, 2003, ENVIRON concluded that either the Davis Chemical Company or the Davis Family Trust has owned the Site from approximately 1949 until the present. From 1949 until approximately November 1990, Davis Chemical operated as a recycle' of spent solvents and transporter of waste solvents from various small manufacturing operations. The record also indicates that Betterbilt Chemicals (Betterbilt) operated at the Site from August 1, 1990 until October 2.3, 1990. Betterbilt's operations included fuel-blending activities and recovering acetone from waste polyester resins. Betterbilt also acted as a hazardous waste transporter

In 1996, Smith-Emery conducted a soil investigation that consisted of advancing five borings to assess potential environmental impacts from the former acetone/lacquer-thinner recycling operations at the Site The results of the investigation were documented in the report entitled "Report of Environmental Sampling, 1550 North Bonnie Beach Place, Los Angeles, California," dated November 12, 1996 Soil samples were analyzed for total petroleum hydrocarbons (TPH) as lacquer thinner, which was not found above the reporting limits (RLs) of 0.1 milligram per kilogram (mg/kg) in any of the soil samples analyzed by the laboratory. Based on the findings from its subsurface investigation, Smith-Emery recommended obtaining Site closure from DISC

ENVIRON conducted a supplemental RI for the Davis Site. The first phase of the supplemental RI included a soil gas survey on June 28, 2003, followed by the advancement of ten soil borings across the Site between July 1 and 3, 2003. The second phase of the supplemental RI, which involved the advancement of six additional soil borings and the installation of three piezometers, took place between October 2 and 3, 2003

From Tune through October 2003, ENVIRON collected soil gas samples at 6 locations and analyzed them for volatile organic compounds (VOCs), advanced 16 soil borings and sampled them to a maximum depth of 51 feet below ground surface (bgs), analyzed 69 soil samples for VOCs, and analyzed selected soil samples for polynuclear aromatic hydrocarbons (PAHs), semi-volatile organic compounds (SVOCs), organochlorine pesticides, polychlorinated biphenyls (PCBs), and metals

Soil types observed by ENVIRON in the upper 50 feet of the subsurface under the Site included silty clays (from ground surface to a depth of approximately 7 feet bgs), underlain by a zone of silts and sandy silts with thinly interbedded sands (from a depth of approximately 7 feet bgs to a depth of approximately 30 feet bgs). These silts and sandy silts are underlain by a sequence of clays and silty clays with subordinate silts and minor sandy silts. The clays under the Site, where contiguous, act to attenuate the downward migration of chemicals. Further, the Site is located in a non-water-bearing highland area although shallow ground water has been observed at a depth of approximately 26 to 27 feet bgs in the three on-Site piezometers (ENVIRON, 2005).

Although present at discernible concentrations, PAHs, SVOCs, pesticides, and PCBs appear to be of no or minor importance at the Site. Similarly detected metals concentrations are typical of state background concentrations. VOCs are the main chemicals of potential concern (COPCs) at the Site based on their ubiquity and elevated concentrations. The most predominant COPCs at the Site are tetrachlotethene (PCE), trichloroethene (ICE), and, to a lesser extent, their breakdown products

Elevated concentrations of acetone were reported for soil samples from the boring that was advanced near the former acetone/thinner aboveground feed tank location (i.e., Boring SB3; see Figure 2). In this boring, the elevated acetone concentrations were confined to the upper 15 feet of the soil. The highest reported concentration of acetone, 279,000 micrograms pie kilogram (μ/kg), was more than an order of magnitude lower than the preliminary remediation goal (PRG) of 6,000,0001.μ/kg for acetone in soil for the industrial site scenario.

The highest concentrations of PCE at 221,000 μg/kg and TCE at 15,200 μg/kg were reported for soil samples collected from two soil borings advanced at the eastern corner of the Site near the area where fluid was observed to be flowing onto the Site from the neighboring uphill property located to the south-southeast. These concentrations are significantly higher than the PRGs of 3,400 μg/kg and 110 μg/kg for PCE and ICE in soil for the industrial site scenario, respectively. ENVIRON believes that the industrial activities conducted at the uphill property may have caused, or at the least contributed to, the reported elevated concentrations of PCE and ICE at this area of the Site. Based on the RI findings, ENVIRON conducted a screening human health risk assessment (HHRA), as described in Section 2.0 The HHRA identified 1,2,4-trimethylbenzene as the second largest contributor to noncancer hazard index (HI), the primary contributor being PCE Direct contact with liquid 1,2,4-trimethylbenzene is irritating to the skin and breathing the vapor is irritating to the respiratory tract causing pneumonitis. Breathing high concentrations of the chemical vapor causes headache, fatigue, and drowsiness. Production of 1,2,4-trimethylbenzene occurs during petroleum refining as a major component of the C9 aromatic hydrocarbon fraction (or simply the C9 fraction). It typically constitutes around 40 percent of the C9 fraction with other trimethyl-benzenes and ethyltoluenes making up the remainder of this fraction. The primary use of the C9 fraction, approximately 99% of its production volume, is as a gasoline additive., Volatilization is the major route of removal of 1,2,4-trimethylbenzene from soil; although, biodegradation may also occur (USEPA, 1994). Given the automobile repair activities conducted on the neighboring uphill property, there is a potential that the source of 1,2,4-trimethylbenzene at the Site is the neighboring uphill property.

The feasibility study (FS) conducted by ENVIRON, using the results of the RI and HHRA, was a presumptive FS. A presumptive FS, as discussed in sections 1.2 through 1.4, is intended to accelerate the FS process at a site.

1.2 Introduction to the Presumptive Remedy Approach

The presumptive remedy approach prescribes the most appropriate remedial alternatives for specific categories of sites contaminated with specific types of chemicals (United States Environmental Protection Agency (USEPA), 1993b). The USEPA (1996a) defines presumptive remedies as:

The USEPA (1993a) has conducted a detailed review of technologies for most of the presumptive remedies site categories and has determined that certain technologies are routinely omitted from consideration on the basis of their effectiveness, implementability, and cost or have not been selected under the nine criteria analysis identified in National Contingency Plan (NCP) Section 300.430 (e) (9). See Section 4.6 On the other hand, certain technologies have been routinely utilized to remediate specific categories of sites contaminated with specific types of chemicals. Based on these efforts, the USEPA has issued presumptive remedies for the following five types of sites:

The idea behind the presumptive remedy approach is that it should accelerate most phases of an RI/FS investigation by focusing the efforts on technologies that, in the past, have proven to be effective for a given contamination scenario If a site qualifies under the presumptive remedy approach, then the FS study will be limited in its considerations to the no action alternative and the presumptive remedy technologies (USEPA, 1993a)

1.3 Determination to Use the Presumptive Remedy Approach

The USEPA has described a presumptive remedy process for soils contaminated with VOCs, which includes steps used to identify sites and contamination scenarios that may be amenable to the presumptive remedy approach (USEPA, 1993b) The first step in this process is to determine whether VOCs are the major contaminant class present at the site. Also, if VOCs are present at levels of concern based on a HHRA, then a presumptive remedy approach may be applicable to the site. The majority of contaminants found at the Site are VOCs (see Section 3.0 for details). Furthermore, as discussed in the HHRA (Section 2.0), VOCs account for greater than 95 percent of the health and environmental risks at the Site.

The next step in the process requires the identification of non-VOCs contaminants that may potentially affect remedial strategies chosen to target VOCs in soils. ENVIRON has determined that, in addition to VOCs, other chemicals do exist at the Site. As previously indicated, these chemicals include SVOCs, PAHs, pesticides, metals, and petroleum hydrocarbons. While present at discernable concentrations, most compounds in these classes of chemicals are at relatively low concentrations (considerably below established PRGs) and do not pose a significant health or environmental threat. Moreover, they should not interfere with the remedial strategies prescribed for the removal of VOCs from soils.

The rest of the screening for the presumptive remedial process is concerned with selecting the appropriate presumptive remedy for the given site and ensuring that stakeholders are aware of the prescribed approach.

Given these observations and the site-specific chemical and geological data at the Site, ENVIRON believes that a presumptive remedial approach is appropriate for the Site.,

1.4 Presumptive Feasibility Study Objectives and Approach

The objectives of this presumptive FS were to evaluate presumptive remedial technologies for addressing the affected media at the Site and process options for the implementation of those technologies. The affected media at the Site are soils. ENVIRON performed an evaluation and screening process in compliance with the NCP Title 40 of the Code of Federal Regulations (CFR), Part 300 (40 CFR 300). The guidance prepared by the USEPA for performing a presumptive FS under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA; USEPA, 1993b) were followed in addition to guidance for performing an FS under CERCLA (USEPA, 1988a), The ground water was encountered at the Site and was considered not to require immediate investigation and is not addressed in this presumptive FS.

The approach used in this presumptive FS consisted of several steps. First, presumptive remedial action objectives and Applicable or Relevant and Appropriate Requirements (ARARs) were defined for the Site. Then, affected media at the Site and their approximate extents were defined. This was followed by considering various technologies and their associated process options for addressing the wastes at the Site under the presumptive remedial approach. Next, the process options were screened based on their effectiveness, implementability, and relative cost. A detailed evaluation of these remedial alternatives was performed using the nine criteria required by the NCP. Finally, based on a comparative analysis of the remedial alternatives, a preferred alternative was recommended for the Site.

1.5 Report Organization

The remainder of this report is divided into the following sections:

2.0 SCREENING HUMAN HEALTH RISK ASSESSMENT

2.1 Introduction

2.1.1 Overview

This section presents the screening human health risk assessment (screening HHRA) conducted for the Site. This screening HHRA evaluates reasonable potentially complete pathways and potentially exposed human receptors at the Site. The results of the screening HHRA will be used to identify areas of concern at the Site and to support remedial decisions recommended in the presumptive FS This risk assessment is based on continued commercial use of the Site. If the land use should change, this risk assessment may need to be reevaluated.

The methodology used in this assessment is consistent with the following Cal/EPA and USEPA risk assessment guidance:

2.1.2 Organization

This risk assessment section is divided into nine subsections as follows:

2.2 Selection of Chemicals of Potential Concern

The purpose of this subsection is to identify those chemicals that will be quantitatively evaluated in this screening HHRA. This selection of chemicals was developed based upon the analytical results from the RI Report (ENVIRON, 2003).

As discussed in the RI, eight VOCs were detected in soil gas samples collected on-site. The following chemicals were detected in on-site soils: ten metals, seven pesticides, two SVOCs, three PAHs and 37 VOCs. The total number of chemicals detected on-site in soil gas and/or soil is 59 (summarized in Table 2.1)

For the purposes of this screening HHRA, all detected chemicals are considered COPCs and are further evaluated,

2.3 Identification of Populations, Exposure Pathways, and Conceptual Site Model

Once the potentially exposed populations are identified, the complete exposure pathways by which individuals may contact chemicals present in the soil and soil gas at a site are determined An exposure pathway is defined as "the course a chemical or pollutant takes from the source to the organism exposed" (USEPA, 1988b) An exposure route is "the way a chemical or pollutant enters an organism after contact" (USEPA, 1988b), A complete exposure pathway requires the following four key elements:

An exposure pathway is not complete unless all four elements are present

A conceptual site model (CSM) for potential exposure pathways is used to show the relationship between a chemical source, exposure pathway, and potential receptor at a site. The CSM identifies all potential or suspected chemical sources, potentially impacted media, and potential receptors It also identifies the potential human exposure routes for contacting impacted media. These source-pathway-receptor relationships provide the basis for the quantitative exposure assessment. In fact, only those complete source-pathway-receptor relationships are included in the quantitative risk evaluation.

The CSM for the Site is shown in Figure 3 Section 2.3.1 discusses the potentially exposed populations and Section 2.3.2 discusses the potentially complete exposure pathways

2.3.1 Potentially Exposed Populations

2.3.2 Relevant Exposure Pathways

2.4 Exposure Assessment

The purpose of this subsection is to develop an upper-bound estimate of the theoretical intake for each of the potentially exposed human populations via each of the exposure routes identified in the CSM. Estimates of human intake are a function of exposure parameters such as duration, frequency, and contact rates. This section provides the equations and assumptions used to develop the intake factors used in the calculation of risks.

2.4.1 Estimation of Intake

Where:

Tables 2.2 through 2.5 present the route-specific equations used in this screening HHRA. The equations for exposure via inhalation of vapors is presented in Table 2.2, inhalation of windblown soil particulates in Table 2.3, incidental ingestion of soil in Table 2.4, and dermal contact with soil in Table 2.5 Exposure assumptions used to estimate intake for the potential populations of concern are summarized in Table 2.6 and discussed below.

2.4.2 Exposure Assumptions

2.4.2.1 Human Physiological Assumptions

2.4.2.2 Population-Specific Assumptions

2.4.2.3 Route-Specific Assumptions

2.4.3 Quantification of Exposure

2.5 Estimates of Chemical Migration by Volatilization

This subsection describes the approach used to estimate intermedia transfer factors needed to evaluate the risk from inhalation pathways. Chemicals detected in soil can potentially migrate in a vapor phase through the unsaturated zone to indoor or ambient air. This migration is quantified for the purposes of risk assessment through an intermedia transfer factor. This transfer factor is defined so that when it is multiplied by the source concentration of a chemical in soil gas or soil, the product is the resulting steady-state concentration that is predicted in indoor or ambient air

Intermedia transfer factors for the exposure scenarios will be estimated using the screening-level model of vapor migration described by Johnson and Ettinger (1991). Specifically, Version 3.0 of the spreadsheet developed by the USEPA (2003) for soil-to-indoor air was used. Also, though the spreadsheet is designed for evaluating soil as a source, it also provides intermediate results that allow evaluation of a soil gas.

The Johnson and Ettinger model and its variants couple the following fate and transport processes:

The first process in the above list, source zone partitioning, determines the vapor concentration of the chemical at the soil source. The last three processes, when considered together, describe the attenuation of the source soil vapor concentration as it migrates to indoor air. In the context of the Johnson and Ettinger model, the combined effect of these three attenuation processes is typically referred to as a, the soil vapor attenuation coefficient Intermedia transfer factors, as used in this risk assessment, include the effect of source zone partitioning as well as the three attenuation processes. Therefore, the transfer factor for soil is simply the product of the appropriate partition coefficient and the vapor attenuation coefficient. Because soil gas data include the partitioning effect, the transfer factor for soil gas is the soil vapor attenuation coefficient (a).

The calculation of transfer factors is based on parameters describing the properties of the COPCs, the vadose zone, the surface barrier, and the air dispersion zone. The physical-chemical properties for the COPCs are shown in Table 2.9 Based on guidance from USEPA (1991a), only COPCs that easily volatilize are included in the evaluation of indoor and ambient air. These include chemicals with a Henry's Law constant of greater than 1 x 10-5 atmosphere-cubic meter per mole (atm-m3/mol) and a molecular weight of less than 200 grams [g]/mole.

Vadose zone soil parameters, including soil bulk density, porosity, and water-filled porosity, which are used to calculate the effective diffusion coefficients used in the model, are shown in Table 2.10 These parameters ate defined based on soil physical property measurements taken from Sample SB7-2.0-2.5 collected at a depth of 2.0 to 2.5 feet bgs. This is the shallowest sample and the only sample in the depth interval between the top of the soil gas detections and the ground surface Though some deeper measurements were also available, the physical properties from shallower soils were considered more representative for the purposes of predicting exposures to soil gas. The sandy soil type is used to calculate vapor permeability for advection across the building foundation because guidance states that coarse-grained soil or disturbed fine-grain soil is often found within the foundation (USEPA, 2002a) This soil type and the shallow soil properties are used in the modeling of all transfer factors for this screening HHRA

With these constant soil parameters, there are two different exposure scenarios to be considered:

In each case, the source of chemical migration is considered to be either soil gas or soil. Soil gas concentration data are considered more representative for the purposes of assessing exposures related to vapor migration. Soil data are not recommended by the USEPA in their recent guidance for evaluating vapor migration when data from soil gas are available (USEPA, 2002a). However, soil gas data are not available for all COPCs or all areas at the Site, so it was necessary to calculate transfer factors from soil contamination

The inputs associated with the above two exposure scenarios are described below.

2.5.1 Migration into Buildings

2.5.2 Migration into Outdoor Air

2.6 Toxicity Assessment

The purpose of the toxicity assessment is to present the weight-of-evidence regarding the potential for a chemical to cause adverse effects in exposed individuals, and to characterize quantitatively, where possible, the relationship between exposure to a chemical and the increased likelihood and/or severity of adverse effects (i.e., the dose-response assessment). Well conducted epidemiological studies that show a positive association between exposure to a chemical and a specific health effect are the most convincing evidence for predicting potential hazards for humans. However, human data that would be adequate to serve as the basis for the dose-response assessment are available for only a few chemicals, In most cases, toxicity assessment for a chemical has to rely on information derived from experiments conducted on non-human mammals, such as the rat, mouse, rabbit, guinea pig, hamster, dog, or monkey.

When the dose-response assessment is based on animal studies, it usually requires two types of extrapolation: high-to-low dose extrapolation and interspecies extrapolation. High-to-low dose extrapolation involves predicting the incidence rate of an adverse effect at low exposure levels based on the results obtained at high exposure levels. Interspecies extrapolation involves predicting the likelihood of an adverse effect in humans based on results obtained from animal studies. In the absence of evidence to the contrary, it is assumed that adverse effects observed in animals also will occur in humans.

Chemicals are usually evaluated for their potential health effects in two categories, carcinogenic and noncarcinogenic. Different methods are used to estimate the potential for carcinogenic and noncarcinogenic health effects to occur. All chemicals produce noncarcinogenic effects at sufficiently high doses but only some chemicals are associated with carcinogenic effects Most regulatory agencies consider carcinogens to pose a risk for cancer at all exposure levels (i.e., a "no-threshold" assumption); that is, any increase in dose is associated with an increase in the probability of developing cancer In contrast, noncarcinogens generally are thought to produce adverse health effects only when some minimum exposure level is reached (i.e., a threshold dose).

Sections 2.6.1 and 2.6.2 describe the methods used for the chronic toxicity assessment of carcinogens and noncarcinogens, respectively. Section 2.6.3 identifies the hierarchy of sources used to select toxicity values for this assessment.

2.6.1 Carcinogenic Effects

Cancer slope factors (CSFs) are used to quantify the response potency of a potential carcinogen. CSFs are typically calculated for carcinogens in Group A, B1, and B2 The USEPA decides to derive CSFs for Group C chemicals on a case-by-case basis.

CSFs may be based on either human epidemiological or animal data and are calculated by applying a mathematical model to extrapolate from responses observed at relatively high exposure doses in the studies to responses expected at lower doses of human exposure to environmental contaminants. A number of mathematical models and procedures have been developed for the extrapolation. In the absence of adequate data to the contrary, the linearized multistage model is employed (USEPA, 1989).

In general, the CSF is a plausible upper-bound estimate of the probability of a response per unit intake of a chemical, e.g., (mg/kg/day)-1, over a lifetime. The CSF is used in risk assessments to estimate an upper-bound lifetime probability of an individual developing cancer as a result of exposure to a particular level of a potential carcinogen. The true value of the risk is unknown, and may be as low as zero.

2.6.2 Noncar cinogenic Effects

2.6.3 Sources of Toxicity Values

2.7 Risk Characterization

Risk characterization is the final step of the risk assessment. It is defined as the combination of the exposure assessment and toxicity assessment to produce an estimate of cancer risk and noncancer hazard, along with a characterization of uncertainties in the estimated risk. This section presents the results of the risk assessment for the Site. In Section 2.7.1, the methods for estimating cancer risks and noncancer hazard indices (HIs) are discussed. Section 2.7.2 presents the estimated cancer risks and chronic noncancer HIs for the future on-site workers. Section 2.7.3 presents the RBTCs for Site soils.

2.7.1 Methodology

Estimating cancer risks and noncancer HIs requires information regarding the level of intake of the chemical and the relationship between intake of the chemical and its toxicity as a function of human exposure to the chemical. The methodology used to derive the cancer risks and noncancer HIs for the selected chemicals is based on guidance provided by USEPA (1989).

The potential risk associated with a chemical in all media can be estimated using equations that describe the relationships among the estimated intake of site-related chemicals, toxicity of the specific chemicals, and overall risk for carcinogenic and noncarcinogenic health effects.

For carcinogenic effects, the relationship is given by the following equation (USEPA, 1989):

Risk = I x CSF

Where:

The relationship for noncarcinogenic effects is given by the following equation (USEPA, 1989):

Where:

The HI is the sum of more than one hazard quotient for multiple substances and/or multiple exposure pathways.

The NCP is commonly cited as the basis for acceptable incremental risk levels. According to the NCP, lifetime incremental cancer risks posed by a site should not exceed one hundred in a million (1 x 10-4) to one in a million (1 x 10-6) For noncancer health hazards, a target HI of one is identified. As a risk management policy, the Cal/EPA generally considers 1 x 10-6 to be a point of departure for purposes of making risk management decisions, with most approved remediations achieving incremental risk levels of ten in one million (1 x 10-5) or lower. The California Safe Drinking Water and Toxic Enforcement Act ("Proposition 65") considers 1 x 10-5 as a no significant risk level.

Individual chemical exposures that yield HIs of greater than one may be of concern for noncancer health effects (USEPA, 1989). Hazard indices for individual chemicals may be segregated based on target organ (e.g., liver, kidney, respiratory system), thus a cumulative HI for all chemicals that is greater than one may still indicate a safe exposure.

2.7.2 Estimated Cancer Risks and Noncancer Hazard Indices

As a first screening step, all cancer risks and noncancer HIs were calculated using the maximum concentration detected in each medium, A summary of these screening cancer risks and noncancer HIs are presented in Tables 2.15 through 2.20 and is discussed below.

Estimated cancer risks are expressed using scientific notation (e.g., 1 x 10-6) and estimated HIs are expressed using decimal notation (e.g., 0.001), unless they are below 0.0001 and then they are expressed using scientific notation. Results presented in the text are expressed using one significant figure. The use of one significant figure for reporting risk results is recommended by USEPA (1989). Results prior to rounding are shown in the tables. Presentation of results prior to rounding is intended to facilitate the checking of calculations by reviewers.

2.7.2.1 Future Indoor Commercial Worker

As shown in Table 2.16, based on the maximum chemical concentrations detected in soil, the estimated excess lifetime cancer risk was 4 x 10-3 and the estimated noncancer hazard index was 38. The contribution to the cancer risk estimate by chemical class is as follows:

As shown in Table 2.16, the estimated cancer risks for detected SVOCs, pesticides, and metals were well below the target cancer risk of 1 x 10-6.

In the screening assessment, VOCs with an estimated risk greater than 1 x 10-6 included:

The contribution to the noncancer hazard index by chemical class is as follows:

2.8 Uncertainties

The process of estimating risk has inherent uncertainties associated with the calculations and assumptions used. The approach used in this assessment has been health protective whenever possible and tends to overestimate exposures. A discussion of the key uncertainties used in the estimation of risk for this assessment is discussed below.

2.9 Summary and Conclusions

The purpose of the screening HHRA was to evaluate the reasonable potentially complete pathways and potentially exposed human receptors at the Site. There are no current on-site workers. Current populations of concern would be on-site trespassers. As the Site is expected to remain commercial/industrial, future on-site populations will include on-site workers and visitors. Future on-site workers are expected to be on-site with greater frequency and duration than trespassers or visitors and, therefore would be the maximum exposed population. Only the future on-site worker is evaluated in this screening HHRA. Any health risks to trespassers or visitors would be lower than those estimated for on-site workers The potential exposure pathways of concern at the Site include direct contact with soil and the migration of vapors from soil into indoor and outdoor air. Potential routes of exposure include inhalation of vapors and/or windblown particulates, incidental ingestion of soil, and dermal contact with soil.

As a first screening step, all cancer risks and noncancer HIs were calculated using the maximum concentrations detected in each medium. For soil gas, the results of the screening HHRA show that the estimated cancer risks are less than 1 × 10-6 and the noncancer HIs are less than 1 for both the indoor and outdoor commercial worker. For soil, the results of the screening HHRA show that for SVOCs, pesticides, PAHs, and metals the estimated cancer risks are less than 1 × 10-6 and the noncancer HIs are less than 1 for both the indoor and outdoor commercial workers. For VOCs, the estimated cancer risk is 4 × 10-3 for indoor commercial workers and 7 × 10-5 for outdoor commercial workers The major chemical contributors to the risk estimates are 1,1,2,2-tetrachloroethane, tetrachloroethene, vinyl chloride, trichloroethene, 1,1,2-trichloroethane, 1,2-dichloroethane, and benzene Also for VOCs, the estimated noncancer HI is 38 for indoor commercial workers and 0.4 for outdoor commercial workers. The major chemicals contributors to the HIs are tetrachloroethene and 1,2,4-trimethylbenzene.

RBICs were developed for all VOCs detected in soil at the Site. The purpose of developing the RBTCs is to evaluate potential future building construction at the Site. The RBICs can be used to screen the soil gas and soil data collected at the Site to determine if further evaluation is needed (e g., identification of an exposure area), if remediation is needed, or if there should be any future restrictions on the location of buildings at the Site.

3.0 REMEDIAL ACTION OBJECTIVES AND ARARs

3.1 Chemicals of Potential Concern (COPCs)

As presented in Section 2.0, the COPC selection process began with identifying human populations and complete exposure pathways to conduct a quantitative risk assessment. Next, an exposure assessment was conducted to estimate the magnitude of the actual or potential human exposures to chemicals in the soil at the Site. Subsequently, chemical migration by volatilization from the soil into indoor and outdoor spaces was estimated using appropriate fate and transport modeling Toxicity values were identified for the chemicals evaluated, which was used in the risk characterization. The risk characterization combined and analyzed the results of the exposure and toxicity assessments in order to characterize the potential for adverse health effects to occur as a result of exposure to Site-related chemicals. Those chemicals that posed a carcinogenic risk above 10-6 or a HI above I were considered COPCs

3.2 Development of Remedial Action Objectives

The California Hazardous Substances Account Act (HSAA) incorporates the NCP by reference1, including its broad directive to protect public health and the environment, and to comply with ARARs, The primary remedial action objectives (RAOs) for the Site are as follows:

3.3 Preliminary Remediation Action Levels

ENVIRON compared the concentrations of chemicals at the Site to the PRGs to help evaluate the distribution and significance of the detected chemicals. The RI report and the HHRA identified the COPCs that are detected at concentrations exceeding the PRGs. The RI also identified the areas of the Site where such concentrations have been found. As part of the presumptive FS, RBTCs were developed for the Site. RBICs, which are discussed in Section 2.7, are media-specific (i.e., soil) concentrations derived for specific land-use scenarios that are believed to be protective of human health and the environment.

3.4 Description of ARARs

4.0 DETAILED ANALYSIS OF THE PRESUMPTIVE REMEDY ALTERNATIVES

4.1 Introduction

Because the soil at the Site is affected by VOCs, ENVIRON selected the presumptive remedy approach, in accordance with the USEPA (1993b) guidance for conducting a presumptive FS under CERCLA and in general accordance with the USEPA (1988a) guidance for conducting an FS under CERCLA The presumptive FS was conducted to evaluate remedial alternatives responsive to the RAOs identified in Section 3.2. The need for soil remediation at the Site was assessed based on potential risks to human health and the environment.

The presumptive FS was conducted using the following steps First, presumptive response actions that are appropriate for addressing the remediation of the waste and waste-containing materials at the Site were identified according to procedures outlined by the USEPA (USEPA, 1993b; see Section 4.2). Second, for each response action, prescribed presumptive remedial technologies and their associated process options were evaluated (Section 4.3). Third, an additional screening was performed based on relative cost of the process options within each technology (Section 4.4). Fourth, a detailed evaluation of the remedial alternatives was conducted using the nine criteria required by the NCP (Section 4.5) Finally, based on a comparative analysis of the remedial alternatives, a preferred alternative was recommended for the Site (Section 4.6).

4.2 Prescribed Response Actions

Based on the RAOs described in Section 3.2 and on recommendations by the USEPA (1993b), the presumptive response actions that are appropriate for the affected materials at the Site include:

The response actions are discussed in the following sections.

4.3 Prescribed Presumptive Remedial Technologies

The identified remedial technologies for the affected materials at the Site are discussed in the following sections

4.4 Preliminary Screening and Estimated Costs of Alternatives

The remedial technologies and process options presented above were assembled into remedial alternatives for the Site. The remedial alternatives include the following:

ENVIRON performed a preliminary screening of the identified alternatives for the Site, based on effectiveness, implementability, and cost. Effectiveness was evaluated based on the proven reliability of the alternative to achieve the RAOs. Implementability was evaluated based on the availability of the technology and the ease of implementation and permitting Cost was evaluated based on the total cost to implement the remedial alternative. The results of the screening based on effectiveness, implementability, and cost are presented in Table 4.2. This table describes the reasons for retaining or rejecting each process The "no action" response presented in Table 4.2 was retained as a baseline alternative, as required by presumptive remedy approach (USEPA, 1993a). Based on this screening, the alternatives retained for further consideration under the NCP criteria were the following: 1) Alternative 1: "No Action", retained as required by the USEPA (1993a); 2) Alternative 4a: In situ SVE combined with "hot spot" excavation and off-site disposal/recycling; and 3) Alternative 4b: In situ SVE, combined with "hot spot" excavation and ex situ SVE.

4.5 Detailed Evaluation of the Alternatives

The NCP mandates a detailed evaluation of the remedial alternatives, involving assessing each of the remedial alternatives against nine NCP criteria and a comparison of the relative performance of the remedial alternatives against those criteria. The nine NCP evaluation criteria are:

An alternative must meet Criteria 1 and 2, known as "threshold criteria," in order to be recommended Criteria 3 through 7, known as "balancing criteria," are evaluated to determine the best overall solution. After public comment, the DTSC may alter its preference on the basis of the last two "modifying" criteria A discussion of the nine criteria follows:

Detailed evaluation criteria for the nine NCP criteria are summarized in Table 4.1. Applications of these criteria to the three alternatives retained after the preliminary screening are presented in Tables 4.3 through 4.5.

4.6 Comparative Evaluation of the Alternatives

The relative performance of each of the three alternatives retained after the screening process against the nine NCP criteria is given in Table 4.6, based on the information in Tables 4.2 through 4.5 The purpose of the comparative evaluation presented in Table 4.6 was to select a preferred remedial alternative that will be most suitable for the Site, based on the NCP criteria.

Alternative 1 (no action) fails to meet the site RAOs, i.e. reduce human health and environmental risks and comply with ARARs As shown in Table 4.6, the No Action alternative has low scores using the nine NCP criteria.

Alternatives 4a and 4b meet the primary RAOs for the Site, the secondary RAO of providing for the reuse of the Site as anticipated by the Site's current zoning, and most of the NCP criteria. As presented in Table 4.6, Alternative 4a satisfies all NCP criteria satisfactorily except for Criterion 4: reduction of toxicity, mobility, or volume Since the excavated soil from the "hot spot" will be transported off-site for disposal as hazardous waste, the volume and the future toxicity and mobility of the contaminants are not reduced Under Alternative 4b, the excavated soil from the "hot spot" will be treated on-site by ex situ SVE and either spread on site, if approved and certified as "clean" by DISC, or taken off-site for disposal as non-hazardous waste As such, the contaminants will be transferred from the on-site soils to the GAG. Once the GAC from the vessels have been regenerated, the volume and future toxicity and mobility of the contaminants will be reduced. Thus, Alternative 4b, which includes an in situ SVE system combined with "hot spot" excavation and on-site and ex situ SVE is the most suitable remedial strategy for the Site. This alternative meets all primary and secondary RAOs and will effectively and efficiently remediate the soils at the Site

5.0 PREFERRED ALTERNATIVE FOR THE SITE

5.1 Introduction

The presumptive FS process followed by ENVIRON consisted of several steps. It was initially determined that the Site qualifies for a presumptive FS because the soils are impacted by VOCs Therefore, the FS was reduced in scope and considered only the treatment technologies endorsed by the USEPA under the presumptive remedy approach (USEPA, 1993b). Next, a screening HHRA was performed to identify the COPCs and their related RBICs at the Site. Based on this HHRA, presumptive remedial action objectives and ARARs were defined for the Site. Then, affected media at the Site and their approximate extents were defined. This was followed by considering various technologies and their associated process options for addressing the wastes at the Site under the presumptive remedial approach. These processes were assembled into remedial alternatives

The alternatives developed included no action (Alternative 1), excavation and disposal/recycling (Alternative 2), in situ SVE (Alternative 3), and a combination of alternatives 2 and 3 (Alternative 4). Next, this set of alternatives was screened based on their effectiveness, implementability, and relative cost. A detailed evaluation of these remedial alternatives was performed using the nine criteria required by the NCP. Based on the screening and the NCP analysis, Alternative 4b was considered as the most suitable remedial alternative for the Site.

Alternative 4b consists of a combination of in situ SVE and excavation and on-site ex situ SVE treatment. Soil in the portion of the Site affected by elevated concentrations of VOCs (described previously), will be excavated, stockpiled on-site, and treated using a network of ex situ SVE pipes. The remainder of the contaminated soils will be treated with an in situ SVE system. The extracted vapors from both systems will be passed through a series of two granular activated carbon (GAC) vessels for removal of VOCs from the vapor phase. The vacuum pump for the in situ SVE system will be used to impart the necessary vacuum in the ex situ SVE system.

The remediated Site will be regraded for commercial and/or industrial redevelopment. The Site grading requirements will be developed based on the needs and requirements of the Site owners and the City of Los Angeles.

5.2 Conceptual Design of the Main Alternative 4b Processes

The main processes that will be included in the implementation of Alternative 4b include the following:

Conceptual designs for these processes are presented in the following sections

5.3 Mitigation Measures

5.4 Conclusion

The presumptive FS concludes that when the preferred remedial alternative for the Site (i.e., Alternative 4b), which includes an in situ SVE system combined with limited excavation and on-site and ex situ SVE, is implemented, it will achieve the remedial objectives for the Site and eliminate or reduce to acceptable levels the identified risks from the soils. It will further provide a long-term, permanent solution for the Site and allow the property to be developed for future commercial or industrial use.

Prior to the full-scale implementation of this remedial measure, an SVE pilot test will be performed to evaluate the effectiveness of an SVE system in addressing the VOCs at the Site, the proper lateral spacing of the SVE wells (e.g., radius of influence), and the potential impact of the presence of the perched ground water to the operation of the SVE system. The SVE pilot test will be described in ENVIRON's RAP for the Site

6.0 LIMITATIONS

This report was prepared exclusively for use by DISC, Respondents to the Consent Order, and Heller, Ehrman, White & McAuliffe, LLP, and may not be relied upon by any other person or entity without ENVIRON's express written permission. The conclusions presented in this report represent ENVIRON's professional judgment based on the information available to us during the course of this assignment and is true and correct to the best of ENVIRON's knowledge as of the date of the assignment ENVIRON made reasonable efforts to verify the written and oral information provided in this report. Nevertheless, this report is accurate and complete only to the extent that information provided to ENVIRON was itself accurate and complete.

7.0 REFERENCES

California Base Closure Environmental Committee (CBCEC), 1994. Treatment Technologies Applications Matrix for Base Closure Activities, Revision 1, Technology Matching Process Action Team, November, 1994.

California Code of Regulations (CCR), Current Edition. Toxics Supplement, Barclays Official California Code of Regulations Title 14 (California Integrated Waste Management Board), Title 22 (Department of Toxic Substances Control), Title 23 (State Water Resources Control Board), Title 26 (Toxics), Title 27 (California Environmental Protection Agency), Barclays Law Publishing, San Francisco, California.

California Environmental Protection Agency (Cal/EPA), 1992. Supplemental Guidance, for Human Health Multimedia Risk Assessments of Hazardous Waste Sites and Permitted Facilities. Department of Toxic Substances Control. Sacramento, CA. July.

____, 1994. Preliminary Endangerment Assessment Guidance Manual (PEA). Department of Toxic Substances Control. January.

____, 2000. Guidance of the Dermal Exposure Pathway. Memorandum to Human and Ecological Risk Division. January 7 (Draft).

____, 2003a. All Chronic Reference Exposure Levels Adopted by the Office of Environmental Health Hazard Assessment. September.

____ 2003b. California Cancer Potency Values Office of Environmental Health Hazard Assessment. September.

Department of Health Services (DHS), 1991. Remedial Technology Matrix for Soils and Sludges, Remedial Technology Unit, Alternative Technology Division, June.

ENVIRON International Corporation (ENVIRON), 2003. Remedial Investigation Report, Davis Chemical Site, 1550 North Bonnie Beach Place, Los Angeles, California. November 21.

____, 2005. Report of Piezometer Monitoring, Former Davis Chemical Site, 1550 North Bonnie Beach Place, Los Angeles, California. January 14

Johnson, P.C. and R.A. Ettinger, 1991. Heuristic Model for Predicting the Intrusion Rate of Contaminant Vapors Into Buildings, Environmental Science and Technology, 25, 1445-1452.

U.S. Environmental Protection Agency (USEPA), 1988a. Guidance for Conducting Remedial Investigations and Feasibility Studies under CERCLA, OSWER Directive 9355.3-01, Interim Final, October.

____, 1988b. Superfund Exposure Assessment Manual. EPA/540/1-88/001. Office of Remedial Response. Washington, D. C.

____ 1989. Risk Assessment Guidance for Superfund. Volume I: Human Health Evaluation Manual (Part A) Interim Final. Office of Emergency and Remedial Response. EPA-540/1-89/002, Washington, D.C. December.

____, 1991a. Risk Assessment Guidance for Superfund. Volume I: Human Health Evaluation Manual (Part B: Development of Risk-Based Preliminary Remediation Goals). Office of Emergency and Remedial Response. Publication 9285.7-01B, December.

____, 1991b. Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual. Supplemental Guidance Standard Default Exposure Factors. Office of Emergency and Remedial Response, March 25.

____, 1993a, Presumptive Remedies. Site Characterization and Technology Selection for CERCLA Sites with Volatile Organic Compounds in Soils, OSWER Directive 9355.0-48FS, September.

____, 1993b. Presumptive Remedies: Site Characterization and Technology Selection, for CERCLA Sites with Volatile Organic Compounds in Soils, OSWER Directive 9355.0-48FS, September.

____, 1994. Chemical Summary for 1,2,4-Trimethylbenzene, prepared by Office of Pollution Prevention and Toxics, August.

____, 1996a. User's Guide to the VOCs in Soils Presumptive Remedy, OSWER Directive 9355.0-63FS, July.

____, 1996b. Soil Screening Guidance: User's Guide. Publication 9355.4-23, July.

____, 1997a. Exposure Factors Handbook EPA/600/P-95/002Fa. August.

____, 1997b. Health Effects Assessment Summary Tables (HEAST). FY 1997 Update Office of Research and Development. EPA 540-R-97-36, July.

____, 2000. User's Guide for the Johnson and Ettinger (1991) Model far Subsurface Vapor Intrusion into Buildings (Revised). Prepared by Environmental Quality Management, Inc. Contract No 68D70002, December.

____, 2001. Risk Assessment Guidance for Superfund Volume I-Human Evaluation Manual (Part E, Supplemental Guidance, for Dermal Risk Assessment). Interim Final EPA/540/R/99/005, September.

____, 2002a OSWER Draft Guidance for Evaluating the Vapor Intrusion to Indoor Ail Pathway from Groundwater and Soils (Subsurface Vapor Intrusion Guidance), December.

____, 2002b. Region 9 PRGs Table 2002 Update. October 1.

____, 2003. User's Guide for Evaluating Subsurface Vapor Intrusion into Buildings. Prepared by Environmental Quality Management, Inc Office of Emergency and Remedial Response June 19.

____, 2004 Integrated Risk Information System (IRIS). Online database maintained by the USEPA http://www.epa.gov/iriswebp/iris/index.html. Cincinnati, OH

TABLES

Table 4.3

Detailed Evaluation of Alternative 1

(No Action)

Davis Chemical

1550 N. Bonnie Beach Place

Los Angeles, California

DESCRIPTION OF ALTERNATIVE: Alternative 1 consists of no further action at the site Hence, no remedial activities will be undertaken, and the site will be left in its current condition. No monitoring will be conducted and no institutional controls will be put in place to control the future use of the site

1. OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT

2. COMPLIANCE WITH ARARS

3. LONG-TERM EFFECTIVENESS AND PERMANENCE

4. REDUCTION OF TOXICITY, MOBILITY, AND VOLUME THROUGH TREATMENT

SHORT-TERM EFFECTIVENESS

5. IMPLEMENTABILITY

6. COST

CONCLUSIONS

The "No Action" alternative would not provide any reduction in risks to on-site workers, trespassers, off-site residents, and hypothetical future on-site residents and would not meet the site RAOs Because the alternative does not meet the threshold criteria of overall protection of human health and the environment, it was dropped from further consideration

Table 4.4

Detailed Evaluation of Alternative 4a

(In Situ SVE Combined with "Hot Spot" Excavation and Off-Site Disposal/Recycling)

Davis Chemical

1550 N. Bonnie Beach Place

Los Angeles, California

DESCRIPTION OF ALTERNATIVE: Alternative 4a consists of installing and operating an in situ soil vapor extraction (SVE) system to remove the soil-bound VOCs, followed by treating the off-gas of the SVE using granular activated carbon (GAC) technology. In addition to this, the most highly contaminated soils (i.e., "hot spots") will be excavated for off-site disposal

1. OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT

2. COMPLIANCE WITH ARARS

3. LONG-TERM EFFECTIVENESS AND PERMANENCE

4. REDUCTION OF TOXICITY, MOBILITY, AND VOLUME THROUGH TREATMENT

5. SHORT-TERM EFFECTIVENESS

6. IMPLEMENT ABILITY

7. COST

CONCLUSIONS

Table 4.5

Detailed Evaluation of Alternative 4b

(In situ SVE Combined with "Hot Spot" Excavation and Ex Situ SVE)

Davis Chemical

1550 N. Bonnie Beach Place

Los Angeles, California

DESCRIPTION OF ALTERNATIVE: Alternative 4b consists of installing and operating an in situ soil vapor extraction (SVE) system to remove the soil-bound VOCs, followed by treating the off-gas of the SVE using granular activated carbon (GAC) technology. In addition to this, the most highly contaminated soils (i.e., "hot spots") will be excavated for ex situ treatment on-site using SVE The off-gas from this treatment system will be directed into the same GAC columns used for the in situ SVE system.

1. OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT

2. COMPLIANCE WITH ARARS

3. LONG-TERM EFFECTIVENESS AND PERMANENCE

4. REDUCTION OF TOXICITY, MOBILITY, AND VOLUME THROUGH TREATMENT

5. SHORT-TERM EFFECTIVENESS

6. IMPLEMENTABILITY

7. COST

CONCLUSIONS

The combined in situ SVE and excavation and on-site and ex situ SVE meets the primary RAOs for the site and meets the secondary RAO of providing for the development of the Davis site as anticipated by the site's current zoning, meets most of the NCP criteria.

FIGURES

APPENDIX A

Cost Breakdown of Removal Action Alternatives