SFUND RECORDS CTR

2125112

RECORD OF DECISION AMENDMENT

for the

SOLA OPTICAL USA, INC. SUPERFUND SITE

PETALUMA, CALIFORNIA

U.S. Environmental Protection Agency

Region IX

San Francisco, California

March 2007
ACRONYMS

ARARs Applicable or Relevant and Appropriate Requirements

I CERCLA Comprehensive Environmental Response, Compensation and Liability

Act

DTSC California Department of Toxic Substances Control '

EPA ; United States Environmental Protection Agency

GAC Granular Activated Carbon

ICs Institutional Controls

MCLs Maximum Contaminant Levels

MNA Monitored Natural Attenuation

__ _ _ _ !

NCP National Oil and Hazardous Substances Pollution Contingency Plan

NPDES j National Pollution Discharge Elimination System

ppb Parts Per Billion

PRMD Sonoma County Permit and Resource Management Department

RCRA Resource Conservation and Recovery Act

Regional Board '; San Francisco Bay Regional Water Quality Control Board

_____ _ i _ „ __,„- ___

ROD " ~~" Record of Decisionlor Sola Optical USA, Inc. SuperfundTsTte (1991)

ROD Amendment Record of Decision Amendment

Sola site or Site Sola Optical USA, Inc. Superfund Site

TI j Technical Impracticability

VOC i Volatile Organic Compound
[THIS PAGE INTENTIONALLY LEFT BLANK]
PART 1: THE DECLARATION

I. Site Name and Location

Sola Optical USA, Inc. Superfund Site

Petaluma, Sonoma County, California

EPA ID. No. CAD981171523

II. Statement of Basis and Purpose

This decision document presents the amended remedial action for the Sola Optical USA,

Inc. Superfund Site (Sola site or Site) in Petaluma, Sonoma County, California. The

United States Environmental Protection Agency (EPA) has chosen this action in

accordance with Section 117 of the Comprehensive Environmental Response,

Compensation and Liability Act (CERCLA), as amended, 42 U.S.C. § 9617, and the

National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR §

300.435(c)(2)(ii). This decision is based on EPA's Administrative Record file.

The lead agency for the remedial effort at this Site is the EPA and the state support

agency is the San Francisco Bay Regional Water Quality Control Board (Regional

Board). The Regional Board has informed EPA that it considers the Site to be a low risk

and does not plan to have any further involvement with overseeing remediation.

III. Assessment of Site

The response action selected in the 1991 Record of Decision (ROD), as modified by this

Record of Decision Amendment (ROD Amendment), is necessary to protect public health

or welfare or the environment from actual or threatened releases of hazardous substances,

pollutants, and/or contaminants from this Site which may present an imminent and

substantial endangerment to public health or welfare.

IV. Description of Selected Remedy

This ROD Amendment modifies the previously selected remedy for the Sola site. A

remedial action was selected for the Sola site in 1991. The original remedial action was

groundwater extraction and treatment. The amended remedial action is Monitored

Natural Attenuation (MNA) and institutional controls, with monitoring of both. The goal

for MNA is aquifer restoration. The institutional control will take two forms: a

restrictive covenant and County well permitting restrictions. The restrictive covenant

will prevent inappropriate uses of the groundwater that could result in unsafe exposures

to humans. Sonoma County's well permitting authority will also function as an

institutional control and contribute to the overall protection of human health and the

environment at the Sola site.

Sola operated the groundwater extraction and treatment system for approximately ten

years, after which it ceased active operations and monitored the aquifer's response. The

response demonstrated that natural attenuation was reducing contaminant concentrations
at rates sufficient to achieve the cleanup standards within a reasonable timeframe. Sola

dismantled the groundwater extraction and treatment system in 2002.

V. Statutory Determinations

The amended remedy satisfies the requirements of CERCLA Section 121 and the NCP.

Specifically, the remedy is protective of human health and the environment, complies

with all Federal and State requirements that are applicable or relevant and appropriate, is

cost-effective, and utilizes permanent solutions to the maximum extent possible.

The amended remedy does not include active treatment as a principal element and

therefore does not satisfy the statutory preference for treatment as a principal element of

the remedy. However, MNA will achieve the groundwater cleanup levels in a reasonable

timeframe (less than 10 years) and in a cost-effective manner and follows several years of

extraction and treatment.

If the cleanup takes more than five years from the previous five-year review (completed

in 2005) to achieve cleanup standards, a subsequent five-year review will be conducted to

ensure that the amended remedy is, or will be, protective of human health and the

environment.

VI. Authorizing Signature

A*-*A$h \ iXU^vvo MfriTCh 36,

iDate

Site Cleanup Branch
PART 2: THE DECISION SUMMARY

I. Introduction to the Site and Statement of Purpose

The Sola Optical USA, Inc. Superfund Site is in Petaluma, California, at 1500 Cader

Lane, just west of the intersection of Lakeville Highway and Interstate 101. From 1978

through 2001, Sola manufactured eyeglass lenses at the Site. When operations first

began, Sola stored various manufacturing-related solvents in underground storage tanks

at the Site. After discovering contamination in the groundwater near those tanks, Sola

removed the tanks and has been responsible for cleaning up the remaining volatile

organic compound (VOC) contamination ever since. The Sola site was listed on the

National Priorities List of Superfund sites in February 1990.

The groundwater aquifer at the Site is the source of drinking water for the City of

Petaluma. One of the City's groundwater extraction wells was located near the Sola site,

but it was not impacted by the Site contamination. However, the well was shut down to

avoid interference with the groundwater clean-up.

In 1991, EPA decided that Sola's groundwater treatment system should be expanded.

Sola complied and operated the expanded system for another six years. Eventually,

however, the system became decreasingly effective, and Sola stopped operating it in

1997. Since then, the levels of contamination in the groundwater have continued to

decline, and contamination above the MCL remains in only one monitoring well. EPA is

now adopting a different approach to address the clean-up of that small area.

EPA selected a remedy in a ROD dated September 27, 1991. The original ROD and this

ROD Amendment were selected in accordance with Section 117 of CERCLA, 42 U.S.C.

§ 117, and 40 C.F.R. § 300.435(c)(2)(ii) of the NCP. EPA is the lead agency responsible

for directing the CERCLA remediation process; the Regional Board is the support

agency. The Regional Board has indicated to EPA that it considers the Site a low risk

and does not intend to provide additional input on Site work.

Eventually, it became clear that the original remedy, a groundwater extraction and

treatment system, would not achieve the cleanup standard of 5 parts per billion (ppb) for

1,1-DCA. Sola's system initially reduced contaminant concentrations, but by the mid1990s those reductions reached an asymptote where concentrations were essentially

staying at the same, elevated levels, despite continued operation of the system. Some

parts of the contaminated aquifer had achieved the cleanup standard by this time, but

others had not. At that point, Sola stopped operating the remedial system and instead

focused on monitoring the aquifer and its contaminant characteristics. Subsequent

analysis of the monitoring data established the reliability and effectiveness of natural

attenuation processes in remediating the small portion of groundwater that was still

slightly contaminated above the clean-up standard.

In addition to revising the groundwater remediation approach, this ROD Amendment

documents EPA's selection of a restrictive covenant as a necessary and appropriate

institutional control at the Site. The five-year review conducted in 2005 identified that no

institutional control was in place (or had been selected in the original ROD) to prevent

inappropriate uses of the groundwater and subsequent exposure to humans during the
clean-up period. EPA concluded that it would need to select institutional controls in a

decision document and to ensure their implementation, in order to guarantee

protectiveness until the clean-up goals are attained.

The decisions documented in this ROD Amendment are based on the Administrative

Record file and will become part of the Administrative Record file in accordance with 40

C.F.R. § 300.825(a)(2) of the NCP.

A copy of the Administrative Record is available for review at the following locations:

Petaluma Public Library

100 Fairgrounds Drive EPA Superfund Records Center

Petaluma CA 94952 95 Hawthorne St., 4th Fl.

(707) 763-9801 San Francisco, CA 94105

Hours: (415)536-2000.

10a-9p Tues & Wed Hours: 8a-5p Mon - Fri

10a-6p Mon, Thu, Fri, Sat
II. Site History, Contamination, and Original Selected Remedy

Site History and Contamination

Sola established a manufacturing facility at 1500 Cader Lane, Petaluma, California, just

west of the intersection of Lakeville Highway and Interstate 101. They manufactured

eyeglass lenses at the Site from 1978 to 2001. The facility had one manufacturing

building and an adjoining administration office building. When Sola began operations, it

had six 1,000-gallon underground storage tanks behind the north corner of the

manufacturing building. The tanks were used to store solvents such as 1,1,1-

trichloroethane (1,1,1-TCA), acetone andmethanol.

In 1982, Sola found low concentrations of VOC contamination in the groundwater

beneath its property near the six storage tanks. The groundwater aquifer was and still is

the City of Petaluma's drinking water source. Although one of the City's groundwater

extraction wells was near the Sola Site, it was not impacted by the contamination.

In 1983, the Regional Board directed Sola to investigate the groundwater contamination

at the Site. Sola identified the following chemicals in the groundwater: 1,1-

dichloroethane (1,1-DCA), 1,1-dichloroethene (1,1-DCE), methylene chloride, and

1,1,1-TCA. These chemicals appeared to have originated from the gravel surrounding

the tank and adjacent soils. In 1985, Sola removed the six storage tanks as well as the

surrounding gravel and several feet of soil from the sides and bottom of the excavation.

Further investigation by Sola revealed the extent of the groundwater contamination. In

1987, the Regional Board ordered Sola to construct and operate a groundwater extraction

and treatment system. The treated groundwater was discharged into Adobe Creek, just

northwest of the Site, under a permit from the Regional Board. The extraction and

treatment system began operating in 1988. Sola also arranged to have the City of

Petaluma shut down the nearby municipal water supply well, to avoid interference with

the groundwater clean-up efforts and prevent potential use of Site-impacted groundwater.

Pumping the municipal well could have gradually drawn the contaminated groundwater

cross-gradient towards it, spreading the contamination.

In 1989, EPA became the lead regulatory agency for remedial activities at the Site. On

February 21, 1990, EPA added the Site to the National Priorities List of Superfund sites.

Soon thereafter, EPA issued an administrative order directing Sola to conduct further

environmental sampling and to prepare a remedial investigation report and a feasibility

study of clean-up options, both of which Sola completed in 1991. That year, EPA also

prepared an assessment of risks posed by the Site (described below).

Human Health Risks

In 1991, EPA prepared a risk assessment to evaluate the human health and environmental

risks posed by contamination at the Site. A risk assessment begins by identifying the

chemical contaminants of concern. The assessment then evaluates pathways through

which the chemicals can travel to reach human or ecological receptors. The human health

evaluation then estimates the duration of possible chemical exposure to humans. (The

ecological assessment is further described in the subsequent section entitled "Ecological

Risk Evaluation"). All of this information is used to calculate a human health risk. This

risk is presented in two parts: the carcinogenic effects (cancer-causing effects), and the
non-carcinogenic effects (all other health effects). The carcinogenic effect is expressed in

terms of an additional chance of contracting cancer, above the normal rate, as a result of

the chemical exposure. The non-carcinogenic effect is shown as a hazard quotient; values

greater than 1 indicate that an effect on human health will occur (such as impacts to

central nervous system or specific organs), and less than 1 indicates that no effect will

occur.

The 1991 risk assessment identified 12 volatile organic compounds (VOCs) as chemicals

of concern: acetone, butanone, 1,1-dichloroethane, 1,2-dichloroethane, 1,1-

dichloroethene, freon 113, 4-methyl-2-pentanone, tetrachloroethene, toluene, 1,1,1-

trichloroethane, 1,1,2-trichloroethane, and trichloroethene. VOCs are extremely volatile,

meaning they vaporize easily and thus constantly move from one medium to another, for

example from soil to water or air. The risk assessment established that the main exposure

pathway for humans was through their homes. This potential exposure was based on a

hypothetical future residential use. However, the Site was and still is used for light

industrial/commercial purposes. Residential uses are not planned for the Site. The

existing groundwater plume does not extend below any residences, and no drinking water

wells operate near the plume. The Site and the surrounding properties receive water from

the City of Petaluma's municipal water supply, which is not impacted by the Site. If

residents were to use the contaminated groundwater for drinking or washing they could

ingest the contaminants or absorb them through their skin. Water from a faucet or

showerhead could release contaminants that residents could inhale. The chemicals could

also move into indoor air from the groundwater and soil beneath homes via "vapor

intrusion."

The risk assessment calculated that a person living in a house directly above the

contamination who was exposed to the vapor intrusion all of his/her life would have an

excess cancer risk of 9 in 1,000,000 (9xlO~6). The national average rate of cancer from all

causes is 1 in 4. The calculated "excess" cancer risk means that if a million people were

exposed to this amount of contamination for their lifetimes, there might be nine

additional cases of cancer. The assessment concluded that there would not be any noncarcinogenic health effects.

The risk assessment also calculated that a person who used the contaminated groundwater

for residential water supply all of his/her life would have an additional 1 in 10,000

(IxlO"4) risk of contracting cancer. The risk assessment concluded that there would not be

any non-carcinogenic health effects.

Subsequent Risk Evaluation

Additional risk evaluations were conducted in 2005 as part of the five-year review. EPA

performed a screening level evaluation of the potential for remaining levels of

contaminants to cause negative health effects either by entering commercial buildings via

vapor intrusion or through human ingestion of home-grown produce.

To evaluate the potential risk of vapor intrusion, EPA compared the current groundwater

contaminant concentrations to its published "Target Groundwater Concentrations" and

1

 "Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and

Soils," EPA OSWER, November 2002, Doc No. EPA530-D-02-004.
the Regional Board's published "Groundwater Screening Levels for Evaluation of

Potential Vapor Intrusion Concerns."2 All current contaminant concentrations in the

groundwater were found to be well below both the vapor intrusion target and screening

levels. On this basis, EPA determined that vapor intrusion does not pose a human health

risk at this Site.

To evaluate the potential effects on gardens and homegrown fruits and vegetables, EPA

examined other existing studies on the subject. Research demonstrates that volatile

chemicals do not build up in the plant tissues even if contaminated groundwater beneath a

garden manages to reach the plants and the chemicals are absorbed by the plants. When

volatile chemicals move into plant leaves, they are released through the tiny openings in

the plant leaves where gas exchange occurs and therefore do not accumulate. Studies

have also shown that volatile chemicals taken up through plant roots tend to concentrate

in the cells near the surface of the roots. For root vegetables such as beets, carrots and

potatoes, these cells are typically lost during washing and peeling of the produce. Plants

are also able to break down or degrade volatile chemicals. Thus, any such chemicals

taken up by the plants may be present temporarily in the roots and stems of the plant but

are much less likely to be present in the leaves or other above-ground parts of the plant.

In summary, existing studies indicated that uptake and accumulation of volatile chemicals

in plants, and subsequent exposure from human consumption, would be minimal.

Ecological Risk

As part of the 1991 risk assessment, EPA also prepared an ecological risk assessment to

evaluate possible impacts to the environment. The ecological assessment focused on

possible impacts on nearby Adobe Creek. This creek is the closest surface water body to

the Site. At the time of the assessment, a local environmental group had launched a

project to reintroduce anadromous steelhead trout to the creek.

EPA examined data from groundwater monitoring wells between the Sola facility and

Adobe Creek. Based on this data, EPA determined that no contaminants were moving

towards or had reached the creek. The assessment did determine that if the groundwater

extraction system were not operating, contaminated groundwater from the Sola facility

could flow in the direction of Adobe Creek. However, the contaminant concentrations in

the groundwater beneath the Sola facility were below federal surface water quality

criteria for the protection of aquatic life at the time the treatment system was shut off.

Today, the Site environmental setting is not much different than it was in 1991. The one

area in the aquifer that has not yet attained the groundwater clean-up standard is located

on a parcel adjacent to the original facility property. This parcel is currently an open field

in the process of being developed for light industrial/commercial use. Approximately

one-third of that property has been recently graded. The field has not otherwise changed

since the time of the original risk assessment. No new ecological receptors were found at

the Site.

"Screening For Environmental Concerns at Sites With Contaminated Soil and Groundwater, " Regional

Board, February 2005.
Original Selected Remedy

Based on the remedial investigation report, feasibility study, and risk assessment, EPA

issued the original ROD on September 27, 1991. The ROD determined that an expanded

groundwater extraction and treatment system was the most appropriate method for

remediating contamination at the Site. The ROD specified the following:

This remedy addresses groundwater at the site and consists of:

• groundwater monitoring to assure capture of contaminated groundwater and to

demonstrate restoration of groundwater to cleanup standards throughout the

aquifer,

• operation of existing extraction wells (8),

• construction and operation of two (2) additional shallow extraction wells,

• conversion of monitoring wells lf-13 and If-17 to deep extraction wells,

• construction and operation of additional piping for the new and converted wells,

• on-site treatment and discharge off-site or discharge to the City ofPetaluma

sewage treatment system.

The intent of this remedy is to restore groundwater to its beneficial use, which for this

site is drinking water. Based on information obtained during the remedial investigation

and on a careful analysis of all remedial alternatives, EPA and the State of California

believe that the selected remedy will achieve this objective.

The selected remedy includes groundwater extraction for an estimated period of 15 to 20

years. This groundwater extraction system will operate until the cleanup standards are

achieved and continuously maintained throughout the aquifer. The cleanup standards are

state or federally promulgated drinking water standards. Until these standards are

achieved and continuously maintained, EPA will periodically re-evaluate the remedy

every five years with the first evaluation in October 1993. At these evaluations, if

available EPA methodology is more accurate, the risks of' soil/groundwater gases

migrating through the soil into potential residences on the site will be re-evaluated.

It may become apparent, during implementation or operation of the groundwater

extraction system, that contaminant levels have ceased to decline and are remaining

constant at levels higher than the cleanup standards. Based on the performance data,

operation of the extraction system will be adjusted as warranted if so determined during

the periodic EPA evaluations. For example, it may be appropriate to discontinue

operation of extraction wells in areas where cleanup goals have been attained, alternate

pumping at -wells to eliminate stagnation points, and pulse pump to allow aquifer

equilibration and encourage adsorbed contaminants to partition into groundwater for

extraction.
III. Basis for the Document

This section describes the information regarding two issues that prompted and now

support the fundamental remedy change described in this ROD Amendment: (1)

groundwater clean-up, and (2) institutional controls.

Groundwater Clean-up

Sola began operating the groundwater extraction and treatment system in 1987, as

required by the Regional Board. Sola expanded the system in 1992 pursuant to EPA's

ROD, and continued operations. The system was expected to restore the shallow

groundwater to clean-up standards within 15-20 years. Initially, concentrations of the

VOC contamination at the Site decreased significantly. By 1997, however, the rate of

contaminant reduction slowed to almost zero. Groundwater monitoring data at four wells

showed that concentrations of two contaminants, 1,1-DCE and 1,1,-DCA, appeared to

have stabilized and reached an asymptote at levels above the clean-up standards.

Continued monitoring reflected no further reductions in contaminant concentrations.

Some parts of the contaminated aquifer had achieved the clean-up standard of 5 ppb (for

1,1-DCA) by this time, but some parts had not. The extraction and treatment system was

no longer effectively removing these lower concentrations of contaminants from the

groundwater.

In 1997, Sola requested approval from EPA to shut off the extraction and treatment

system and issue a technical impracticability (TI) waiver, arguing that the clean-up goals

for these two contaminants could not be achieved using extraction and treatment. EPA

requested instead that Sola examine MNA as a potential remedy for the Site. Sola ceased

operating the groundwater extraction and treatment system and monitored the aquifer's

response.3

The concentrations of the two remaining contaminants slowly declined. In 2001, Sola

analyzed the data gathered since system shut-down in 1997 and presented its evaluation

of MNA, following EPA guidance.4 Sola concluded that extraction and treatment alone

would not be capable of achieving the clean-up standard for the remaining aquifer

contaminant. Sola's evaluation concluded that MNA would likely be an effective remedy

for attaining the clean-up standard. The extraction and treatment system was

decommissioned in 2002.5

Since 2002, monitoring has shown that concentrations of the two contaminants have

continued to decline. Concentrations of 1,1-DCE dropped below the clean-up standard of

6 ppb in all wells in 2004 and has consistently remained below the standard since.6

Concentrations of 1,1-DCA declined as well. The contaminant is now detectable at only

one single on-site well, W-27, where its level has dropped to 12 ppb (as of December

2006), slightly above the clean-up standard of 5 ppb. All other on-site wells show 1,1-

3

 Letter to Claire McCarthy, Sola Optical, from Holly Hadlock, EPA, January 10, 1997.

4

 "Evaluation of Monitored Natural Attenuation as a Remedy to Meet Remedial Action Objectives, Sola

Optical USA, Inc., Site, Petaluma California," LFR Levine Fricke, April 4, 2001.

5

 Letter to Roman Starno, Sola Optical USA, Inc., from Holly Hadlock, EPA, November 5, 2001.

6

 "Second Five-Year Review Report for the Sola Optical USA Inc. Superfund Site," EPA, September 2005.
DCA concentrations below the clean-up standard. The higher level of contamination in

W-27 is likely due to the well's location: W-27 is directly downgradient from the

location of the original contaminant release, and the last of the contaminants have slowly

been released from the soils and flowed down to W-27.

As a result of the findings of the groundwater monitoring and evaluation, EPA is

amending the ROD to select MNA as the remedy for accomplishing the groundwater

clean-up standards.

Institutional Controls

The second issue addressed by this ROD Amendment is the need for institutional

controls. Institutional controls (ICs) are non-engineering, legal measures that help

prevent or limit the potential for exposure to hazardous substances by restricting land or

water use. One common institutional control is a restrictive covenant which is an

agreement, recorded with the county recorder's office, whereby a land owner agrees to

restrict the use of his or her property.

EPA first identified the need for institutional controls in its 1991 health risk assessment.7

The assessment recommended that institutional controls be implemented at the Site to

prevent any use of the contaminated groundwater for drinking water supplies before

drinking water standards are achieved. The remedy selected in the 1991 ROD, however,

did not include institutional controls.

The second Site five-year review, conducted in 2005, again raised the need for

institutional controls at the Site. The review found that no controls were in place (or had

been selected in the original ROD) that would prevent inappropriate uses of the

groundwater, creating a risk of unsafe exposures to humans during the clean-up period.

Therefore, the five-year review recommended that institutional controls be selected in a

decision document and implemented to guarantee protectiveness during the interim cleanup period until the clean-up standards are attained.

In response to this recommendation, EPA has identified an appropriate institutional

control mechanism, a restrictive covenant, to be included in this ROD Amendment and

discussed in more detail below.

7

 "Public Health Risk Assessment, Sola Optical USA, Inc. Site, " CH2M Hill, April 1991.

8

 "Second Five-Year Review Report for the Sola Optical USA Inc. Superfund Site, " EPA, September 2005.

10
IV. Description of Current Alternatives

Original Selected Remedy

The 1991 ROD selected a treatment remedy to restore contaminated groundwater to its

beneficial use (drinking water). The original remedy did not include any containment

components or institutional controls.

The selected remedy required groundwater extraction and treatment system until the

clean-up standards were achieved and continuously maintained throughout the affected

portions of the aquifer. Depending on the particular contaminant, the standards were set

at either the state or federally promulgated drinking water standards (5 ppb for 1,1-DCA).

The ROD estimated that the remedy would need to operate for 15 to 20 years to attain the

clean-up standards.

The major Applicable or Relevant and Appropriate Requirements (ARARs) associated

with the original remedy consisted of federal and State of California laws and regulations

establishing drinking water standards and requirements for solid and hazardous waste

handling and disposal, hazardous waste control laws, as well as municipal or county

hazardous material ordinances. These requirements are described below.

EPA determined that both the federal and State of California drinking water standards,

whichever was most stringent for each chemical of concern, were ARARs for the Site

groundwater. See the following table for details.

1990 Maximum Drinking Water Cleanup

Concentration (ppb) Standards (ppb) Standards

chemical Shallow Deep State Federal (PPb)

1,1-DCE

1,1-DCA

1,1,1-TCA

Freon 113

1,400

280

220

9

22

1

10

2

6

5

200

1,200

7

--

200

--

6

5

200

1,200

The groundwater extraction and treatment system used granular activated carbon (GAC)

adsorption for VOC removal. GAC use triggers requirements for the regeneration or

disposal of the spent GAC. If the spent GAC were a "listed" or "characteristic" waste, it

would be regulated as a hazardous waste under the federal Resource Conservation and

Recovery Act (RCRA) and California's hazardous waste control laws.9 On-site storage

of contaminated GAC may also trigger substantive requirements under state laws10 and

municipal or county hazardous material ordinances, including construction and

monitoring requirements for storage facilities.

New Remedy

The new remedy utilizes the following:

• Monitored Natural Attenuation to achieve groundwater clean-up standards;

9

 California Health & Safety Code §§25100, etseq.; California Code of Regulations, tit 22, §§67520-

67525.

10

 California Code of Regulations, tit 22 §§67180-67194 and §§67240-67248.

11
• Institutional Controls to protect against inappropriate use of the contaminated

groundwater until the clean-up standards are achieved; and

• Monitoring of both of the remedy components until clean-up standards are

achieved and sustained.

The term "Monitored Natural Attenuation," as used by EPA in Directive Number 9200.4-

17P, refers to the reliance on natural attenuation processes (within the context of a

carefully controlled and monitored site cleanup approach) to achieve site-specific

objectives within a time frame that is reasonable compared to that offered by other more

active methods. The natural attenuation processes that are at work in such a remediation

approach include a variety of physical, chemical, or biological processes that, under

favorable conditions, act without human intervention to reduce the mass, toxicity,

mobility, volume, or concentration of contaminants in soil or groundwater.11 The

following natural attenuation mechanisms may be active at the Site: dilution, dispersion,

diffusion, volatilization, sorption, biodegradation, and abiotic degradation. All of these

processes result in a decrease in the dissolved-phase concentration of the contaminant.

However, only biodegradation and abiotic destruction result in destruction of the

contaminant.

MNA will be utilized until the clean-up standards are achieved and continuously

maintained throughout the aquifer. The standards are the state or federally promulgated

drinking water standard, whichever is more stringent, in this case the state standard. This

remedy will achieve the clean-up standard within an estimated one to three years. The

MNA must be monitored, pursuant to an EPA-approved monitoring plan, and the data

and analysis reported to EPA.

The second component of the remedy is the implementation of institutional controls. As

noted above, ICs are non-engineering, legal measures that limit the potential for exposure

to hazardous substances by restricting land or water use. These controls can consist of

governmental controls, proprietary controls, enforcement tools, or informational controls.

Governmental controls are usually implemented and enforced by a state or local

government and are used to restrict property or resource use; examples include zoning,

well drilling or water usage restrictions, licensing, and permitting. Proprietary controls

are legal instruments placed in the chain of title to real property that convey a property

interest for purposes of imposing restrictions on land or water use. A common

proprietary control in California is a restrictive covenant which is an agreement, recorded

with the county recorder's office, whereby a land owner agrees to restrict the use of his or

her property. The State of California has promulgated a specific statute authorizing and

establishing requirements for such covenants (discussed further in ARARs discussion

below).

Enforcement tools for 1C components include enforceable orders and consent decrees,

which EPA can use to compel a party to limit certain site activities and to ensure the

performance of affirmative obligations. Informational controls provide potential users of

11

 "Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and Underground

Storage Tank Sites," Office of Solid Waste and Emergency Response, Directive Number 9200.4-17P, U.S.

Environmental Protection Agency, April 1999.

12
land or water information about the presence of hazardous substances and often warn

against taking specific actions, but these controls (including State registries, deed notices,

and advisories) are not enforceable.

The primary institutional control for this Site will be a restrictive covenant. A restrictive

covenant, also known as a deed restriction, is a type of proprietary control that is signed

by the property owner and, typically, the State of California, and that includes EPA as a

third-party beneficiary with rights to enforce. The restrictive covenant at the Sola site

will restrict the use of groundwater contaminated above the clean-up level. The objective

of the restriction is to prevent uses of the groundwater that could result in unacceptable

exposure of humans or the environment to contaminants. The restrictive covenant must

remain in place until the groundwater clean-up standard is met and maintained for at least

two years throughout the Site.

The local well permitting process provides an additional layer of institutional control that

will help prevent human exposure to contaminated groundwater at the Sola site. The

Sonoma County Permit and Resource Management Department (PRMD) is responsible

for issuing all well installation permits in the county. PRMD has a system called Permit

Plus that is used to maintain information about properties. At EPA's request, PRMD

placed a note in the Permit Plus system regarding the Site parcel that lies directly above

the contaminated groundwater. The note states that the parcel is part of a Superfund site

and that well permits should not be issued before consulting with PRMD and U.S. EPA.

According to PRMD, if anyone requests a permit for the Sola site parcel, PRMD will see

that notation.

The institutional controls must also be monitored, pursuant to an EPA-approved

monitoring plan, and the results reported to EPA.

The primary ARARs associated with the new remedy consist of federal12 and State of

California1 drinking water standards and the state regulations regarding environmental

restrictive covenants.14 The federal and State of California drinking water standards were

described in the "Original Selected Remedy" section above. Their application to the new

remedy is the same as for the original remedy. The state regulations regarding

environmental restrictions are California Civil Code Section 1471 (a) and Title 22 of the

California Code of Regulations, Section 67391. l(a)(l), (a)(2), and (d). Section 1471

specifies how environmental covenants are to be recorded and made applicable to

successors. The substantive provision of Section 1471 - subpart (a) - is an ARAR for

this ROD Amendment because compliance with this section is necessary for the

restrictions to run with the land. The substantive provisions of Section 67391.1 - (a)(l),

(a)(2), and (d) - are also ARARs for this ROD Amendment. These regulations include

requirements for imposing covenant restrictions and for properly recording the covenant.

12

 Safe Drinking Water Act (SDWA), Section 1412,42 USC §300g-l; National Primary Drinking Water

Regulations, 40 CFR Part 141.

13

 California Safe Drinking Wai

Domestic Water Quality Monitoring Regulations, California Code of Regulations, tit. 22, div. 4, ch. 15.

14

 California Ci

(a)(2), and (d).

13

 California Safe Drinking Water Act, California Health & Safety Code §§116270-116751; California

)

14

 California Civil Code section §1471(a); and California Code of Regulations, tit 22, §67391.1 (a)(l),

13
Remedial Action Objectives

The ROD Amendment will not affect the Remedial Action Objectives stated in the

original ROD. Those objectives are to restore groundwater to its beneficial use, which is

drinking water. For the remaining contaminant of concern, 1,1-DCA, the cleanup

standard is the state promulgated drinking water standard of 5 ppb.

Expected Outcomes

The expected outcome of this ROD Amendment is the same as the expected outcome of

the 1991 ROD: the contaminated groundwater will be restored to its beneficial use as

municipal supply. This ROD Amendment contemplates no changes to land use or

cleanup levels.

14
V. Evaluation of Alternatives

The purpose of this evaluation is to compare the three remedial action alternatives

identified using the "nine criteria" established in the National Contingency Plan, 40 CFR

§ 300.430(e)(9). The resulting strengths and weaknesses of the alternatives are then

weighed to identify the alternative providing the best balance among the nine criteria.

The criteria are:

(1) overall protection of human health and the environment;

(2) compliance with applicable or relevant and appropriate requirements (ARARs);

(3) reduction of toxicity, mobility, or volume through treatment;

(4) long-term effectiveness and permanence;

(5) short-term effectiveness;

(6) implementability;

(7) cost;

(8) state acceptance; and

(9) community acceptance.

RA#1: No Action

RA#1 is the "No Action" alternative, required by the NCP. This evaluation establishes a

baseline against which to compare the other alternatives. The No Action alternative

consists of no further action to clean up contaminated groundwater at this Site. The

existing contamination would remain in the groundwater at its current concentrations,

until it naturally degrades over time. Currently, one chemical of concern, 1,1-

dichloroethene (1,1-DCA) exists in the groundwater at concentrations exceeding its 5 ppb

clean-up goal. No groundwater monitoring or institutional controls would be

implemented.

RA#2: Extraction and Treatment, Institutional Controls

RA#2 consists of groundwater extraction, treatment, and off-site disposal of treated

effluent, and institutional controls. This alternative resembles the remedial action

selected in the 1991 ROD, with the addition of institutional controls. The 1991 ROD

selected groundwater extraction, on-site treatment with GAC adsorption, and off-site

discharge to nearby Adobe Creek under a National Pollution Discharge Elimination

System (NPDES) permit. The extraction system previously consisted of eleven

extraction wells in the shallow aquifer, and two extraction wells in the deep aquifer. Sola

dismantled the system in 1998, so this alternative would involve rebuilding the treatment

unit and associated conveyance system. The system could possibly utilize the existing

monitoring wells for extraction.

RA#2 would include institutional controls, in the form of a restrictive covenant with the

property owner, to restrict use of the contaminated groundwater that could result in

unacceptable exposure of humans or the environment to the contamination.

15
RA#2 would take an estimated 18 months to design and construct, and would take an

estimated 1 to 3 years to attain the clean-up goal. The present worth cost would be

approximately $572,000.

RA#3: Monitored Natural Attenuation, Institutional Controls

RA#3 is the new proposed alternative that consists of MNA and institutional controls.

MNA relies on natural attenuation processes to achieve clean-up standards. With MNA,

Sola and EPA would closely monitor the groundwater for key parameters to track how

the contamination is changing over time. This alternative would rely on existing

groundwater monitoring wells, so it would take no additional time to construct. It is

estimated that this alternative will achieve the clean-up standards within 1 to 3 years.

The institutional controls for this alternative would be the same as RA#1. The first

control consists of a restrictive covenant with the property owner to restrict groundwater

uses that could result in unacceptable exposure to humans or the environment. The

second control consists of the County's well permitting controls. The present worth cost

of this alternative is approximately $149,000.

CRITERIA 1: Overall Protection of Human Health and the Environment

Overall protection of human health and the environment addresses whether a remedy

provides adequate protection and describes how risks posed through each pathway are

eliminated, reduced or controlled through treatment, engineering controls, or institutional

controls.

The no-action alternative (RA#1) would not provide adequate protection of human

health. (As documented in the 1991 ROD, EPA determined that the Site contamination

did not pose a risk to the natural environment). It is expected that RA#1 would achieve

the clean-up standard over time because natural attenuation processes will be occurring

without any human intervention. However, we would not know when the clean-up goal

was achieved because we would not be monitoring the groundwater. The no-action

alternative will not protect human health during the interim period between now and

when the clean-up standard is reached. No enforceable institutional control currently

prevents use of the water that would expose humans to unsafe contaminant

concentrations. The local county health department is responsible for approving well

permit applications, and its files do indicate the existence of on-site contamination. The

department has informed EPA that it would not issue any well permits on the property

without consultation, but no written agreement or other instrument requires county

compliance. If the county permits a well to be drilled into the contamination, or if an

existing well were to be used for a residential water supply, such activity might result in

human exposure in excess of acceptable risk levels. Therefore, this alternative does not

provide adequate protection of human health.

Remedial alternatives #2 and #3 are both protective of human health. RA#2 includes

groundwater extraction and treatment with institutional controls, and RA#3 includes

monitored natural attenuation with institutional controls. Both alternatives require

recordation of a restrictive covenant, which is an institutional control that EPA is able to

enforce, that prohibits use of the contaminated groundwater until the clean-up standard is

achieved. RA#2 employs groundwater extraction and treatment to achieve the clean-up

standard. RA#3 employs natural attenuation mechanisms and close monitoring of the

16
groundwater during this clean-up timeframe. Thus, both alternatives will protect human

health currently and in the future.

CRITERIA 2: Compliance with ARARs

"Compliance with ARARs" addresses whether an alternative meets applicable or relevant

and appropriate requirements (ARARs), legal standards, limitations, or criteria. ARARs

must be promulgated under federal or state law to address a contaminant, remedial action,

location or other circumstance present at a site. To be selected as ARARs, state

promulgated laws must be more stringent than federal ARARs and have been identified

to EPA by the state in a timely manner and applied consistently by state agencies.

The chemical-specific ARARs for the Sola site are federal15 and State of California16

drinking water standards, according to the 1991 ROD. EPA deemed both to be "relevant

and appropriate" to Site conditions. The appropriate remedial standard for the remaining

contaminated groundwater is the State MCL for 1,1-DCA.

For RA#1, the no-action alternative, it is expected that natural attenuation will be

occurring; however, for the groundwater to be utilized as a drinking water source, the

California Safe Drinking Water Act requires monitoring, which is not being conducted in

this alternative. Therefore, RA#1 does not fully comply with this ARAR.

RA#2 and RA#3 do comply with this ARAR since both will attain the clean-up standard

specified by law and both would meet the ARAR monitoring requirements.

RA#2, the extraction and treatment remedy, would implicate action-specific ARARs and

other "to be considered" standards pertinent to the use of GAC adsorption in a treatment

system. The remedy would need to meet these additional requirements if the spent GAC

is a listed or characteristic waste. These requirements include the Solid Waste Disposal

Act17 and California's hazardous waste control laws18 associated with regeneration or •

disposal of the spent GAC. RA#2 can meet these requirements.

CRITERIA 3: Long-Term Effectiveness and Permanence

"Long-term effectiveness and permanence" refers to the ability of a remedy to reliably

protect of human health and the environment over time. This criterion includes the

consideration of residual risk and the adequacy and reliability of controls.

All three alternatives would achieve permanent long-term protection, as they would attain

the clean-up standard in the groundwater. As discussed earlier, even RA#1, the no-action

alternative, would attain the clean-up standard through natural attenuation mechanisms.

15

 Safe Drinking Water Act (SOWA), Section 1412, 42 USC §300g-l: National Primary Drinking Water

Regulations 40 CFR Part 141.

16

 California Safe Drinking Water Act, California Health & Safety Code §§116270-116751; California

Domestic Water Quality Monitoring Regulations, California Code of Regulations, tit. 22, div. 4, ch. 15.

17 As amended by the Resource Conservation and Recovery Act, 42 USC §§6901, et seq.

18

 California Code of Regulations, tit. 22, §§67520-67525.

17
CRITERIA 4: Reduction of Toxicity, Mobility, or Volume through Treatment

t

"Reduction of toxicity, mobility, or volume through treatment" refers to the degree to

which a remedy uses treatment to clean-up the contaminated media. This contrasts with

remedies that reduce risk through removing an exposure pathway, such as containment.

Only RA#2 involves treatment. RA#2's groundwater extraction and treatment system

would physically remove contaminated groundwater and treat it with a carbon adsorption

filter to reduce the volume of contaminated media. In contrast, RA#1 and RA#3 both

rely on natural attenuation mechanisms to reduce contaminants via intrinsic processes in

the groundwater. As described above, Sola operated an extraction and treatment system

for a decade. Based on data gathered both at the time and subsequent to the system's

shut-down, Sola has demonstrated that active treatment of the groundwater was not

effectively reducing the remaining contamination and that natural attenuation was more

effective.

CRITERIA 5: Short-Term Effectiveness

"Short-term effectiveness" refers to the degree to which an alternative avoids adverse

impacts to human health and the environment posed during construction and

implementation. This covers the period of time until the clean-up standards are achieved.

RA#1, the no-action alternative, poses a short-term risk of exposure to contaminated

groundwater because this remedy does not include an institutional control to restrict

groundwater use. There currently are no water supply wells within the contaminant

plume, so no one is being exposed to the contaminated groundwater. In addition, the

county health department that issues well permits is aware of the contamination and has

indicated it would not allow wells therein. However, we have no binding agreement or

other instrument that would dictate how the County is to implement well installation

restrictions, and of course there remains the possibility that a landowner could install a

well without seeking a permit from the county. Therefore, this remedy is considered

somewhat problematic with respect to short-term effectiveness.

RA#2 and RA#3 would not pose short-term risks to human health because both remedies

include institutional controls that are enforceable by EPA. The institutional controls

would take the form of restrictive covenants with the property owner, restricting use of

the contaminated groundwater until cleanup is achieved.

CRITERIA 6: Implementability

"Implementability" refers to the technical and administrative feasibility of implementing

a remedy, including the availability of materials and services needed.

All three of the alternatives are implementable. RA#1 and RA#3 do not involve any

further physical construction. The only physical activity that RA#3 involves is

monitoring groundwater conditions, which is a standard and uncomplicated procedure.

RA#2 requires physical construction of a pump, piping, and carbon treatment system;

such construction involves well known methods and commonly available materials.

RA#2 and RA#3 would involve administrative procedures to implement the restrictive

covenant. The administrative procedure typically consists of EPA working with a State

environmental agency (either the Regional Board or the Department of Toxic Substances

Control (DTSC)) and the land owner to obtain agreement on a restrictive covenant. The

18
covenant would restrict use of the contaminated groundwater, and would require annual

oversight payments to the State agency by the responsible party. This activity is

implementable, but it requires agreement by the State agency, the responsible party, and

the land owner. The owner may not agree to the covenant. Therefore EPA considers

RA#2 and RA#3 implementable but potentially problematic.

CRITERIA?: Cost

This criterion examines the projected costs for each remedial alternative, including

estimated capital and annual operation and maintenance costs, and the present worth.

RA#1, no action, would not involve any cost, as no action (including monitoring) is

taken.

RA#2 would include administrative costs associated with negotiating and recording the

restrictive covenant. The estimated up-front cost for negotiating and recording the

restrictive covenant is $42,500. In addition, implementing RA#2 would require capital

costs for design and construction of a new extraction and treatment system. The

estimated capital cost for the new extraction and treatment system is approximately

$156,000. The estimated annual cost for monitoring and maintaining the restrictive

covenant is $3,400 per year for a 5 year period. The estimated cost for operating,

maintaining, and monitoring the extraction and treatment system is approximately

$100,000 per year for the 3 years that clean-up is projected to take, then an additional 2

years of continued compliance monitoring at a cost of $8,000 per year (total 5 years).

Upon obtaining assurance that the clean-up standard has been met and maintained, the

restrictive covenant can be terminated and the extraction and treatment system can be

removed. The estimated cost for the restrictive covenant termination process is $4,000.

The estimate cost for the extraction and treatment system demolition and demobilization

is $90,000, which would be incurred at year 5. The present value cost for RA#2 overall,

incorporating the up-front and capital costs, operation, monitoring and maintenance costs,

and demolition and demobilization costs, is $572,000.

RA#3 would require no additional capital costs for physical construction, but would incur

the same up-front costs for implementing the restrictive covenant as RA#2. RA#3 would

incur ongoing annual costs for monitoring natural attenuation, as well as monitoring and

maintaining the restrictive covenant. The estimated annual cost for monitoring natural

attenuation is $18,000 per year for the 3 years it is estimated the clean-up will take,

followed by 2 years of continued but decreased compliance monitoring at a cost of

$8,000 per year. The estimated annual costs for monitoring and maintaining the

restrictive covenant is the same as for RA#2, and the estimated timeframe for which these

costs would be incurred is the same as well. Upon obtaining assurance that the clean-up

standard has been met and maintained, the restrictive covenant can be terminated and the

monitoring wells abandoned or demolished. The estimated cost for the restrictive

covenant termination process is $4,000. The estimated cost for the abandonment or

demolition of the monitoring wells is $34,500 which would be incurred at year 5. The

present value cost for RA#3 overall, incorporating the up-front costs, monitoring costs,

maintenance costs, and demolition costs, is $149,000.

19
CRITERIA 8: State Acceptance

State acceptance indicates whether the State in which the Site resides agrees with the

preferred alternative, based on its review of the RI, FS, and Proposed Plan.

The Regional Board began overseeing cleanup at the Site in 1983, prior to EPA

involvement, and subsequently performed the support agency role after EPA took the

lead in 1989. The Regional Board, however, has not been involved at the Site over the

past decade. While preparing the Proposed Plan, EPA contacted the Regional Board to

solicit renewed involvement and input into the decision-making process. The Regional

Board informed EPA that it considers the Site to be a low risk and therefore not in need

of further Regional Board involvement. EPA also contacted DTSC regarding the Site,

and DTSC deferred to the Regional Board.

CRITERIA 9: Community Acceptance

Community acceptance indicates the public support of a given alternative.

EPA mailed the Proposed Plan to the residential and business addresses within a half mile

radius of the Site, soliciting input from the community through the public comment

process. The mailing, which included both English and Spanish versions, went out on

Tuesday, January 16, 2007. It announced the public comment period would run from

January 20 to February 20, 2007, and it announced that EPA would hold a public meeting

on January 24, 2007. EPA mailed out an additional announcement to the same parties on

January 24, 2007, extending the public comment period to March 6, 2007.

EPA held a public meeting on January 24, 2007, from 6:30 p.m. to 8:30 p.m., at the

Petaluma Public Library at 100 Fairgrounds Drive, Petaluma. The purpose of the public

meeting was to present the proposed clean-up plan amendment to the public, and to

solicit public comment. Only one person attended the meeting.

No member of the public submitted comments on the proposed plan or otherwise

expressed opposition to the proposed remedy amendment. It is therefore assumed that

the remedy has community acceptance.

Summary of Comparison

After evaluating the clean-up options, EPA is selecting MNA with institutional controls

(RA#3) as the remedy that provides the best balance of the criteria. The three alternatives

rate evenly on a number of criteria. The criteria where differences between the

alternative exist are as follows: RA#1 (No Action) does not satisfy the threshold criteria

of Overall Protection of Human Health and Environment because it does not provide

adequate controls to prevent potential exposure to contaminated groundwater. It also

does not meet the requirements of all the ARARs because it does not include monitoring

and reporting. RA#1 also presents potential short-term risk because it does not have the

type of institutional control that provides the most protection (restrictive covenant)

against potential exposure during the remainder of the clean-up. RA#2 (Extraction and

Treatment, ICs) and RA#3 (MNA, ICs) have some potential implementability

uncertainties because for the restrictive covenant, consent of the responsible party and the

property owner are required. EPA has not yet contacted the property owner, and

therefore does not know whether the owner will consent to implementing a restrictive

covenant. RA#2 (Extraction and Treatment, ICs) will be much more expensive (present

20
worth $572,000) than RA#3 (MNA, ICs - present worth $149,000). RA#1 (No Action)

has no cost associated with it.

In summary, RA#1 (No Action) cannot be selected because it does not meet the two

threshold criteria, Overall Protection of Human Health and Environment, and Meeting

ARARs. A comparison of RA#2 (Extraction and Treatment, ICs) and RA#3 (MNA, ICs)

shows that the only difference is cost; RA#2 will cost significantly more than other

alternatives, without providing any offsetting advantages. Therefore, RA#3 is the best

choice.

21
VI. Support Agency Comments

As mentioned in Section V above, the Regional Board began overseeing cleanup at the

Site in 1983, prior to EPA involvement, and performed the support agency role after EPA

took the lead in 1989. The Regional Board, however, has not been involved at the Site

over the past decade. While preparing the Proposed Plan, EPA contacted the Regional

Board to solicit renewed involvement and input into the decision-making process. The

Regional Board informed EPA that it considers the Site to be a low risk and therefore not

in need of further Regional Board involvement. EPA also contacted DTSC regarding the

Site, and DTSC deferred to the Regional Board.

VII. Statutory Determinations

EPA expects RA#3 (MNA, ICs) to satisfy the following statutory requirements of

CERCLA, Section 121(b): (1) be protective of human health and the environment; (2)

comply with ARARs (or justify a waiver); (3) be cost-effective; (4) utilize permanent

solutions and alternative treatment technologies or resource recovery technologies to the

maximum extent practicable; and (5) satisfy the preference for treatment as a principal

element to the maximum extent practicable. Once the clean-up standard for 1,1-DCA has

been reached, EPA believes that no contamination above clean-up levels will remain onsite, and any use restrictions may be lifted.

VIII. Public Participation Compliance

The public participation requirements set out in the NCP, 40 C.F.R. §300.435(c)(2)(ii),

for amending a ROD have been or will be met. The NCP requires that EPA do the

following: (1) issue a notice of availability for the Proposed Plan in a major local

newspaper of general circulation, (2) make the Proposed Plan and supporting information

available for public comment, (3) provide at least 30 days for submission of public

comments on the Proposed Plan and extending that period upon request, (4) provide the

opportunity for a public meeting at or near the facility, (5) keep a transcript of the

comments received at the public meeting, (6) including in the ROD Amendment a

response to each significant comment, (7) publish a notice of the availability of the ROD

Amendment in a major local newspaper of general circulation, and (8) make the ROD

Amendment and supporting information available to the public in the administrative

record and at the information repository prior to the commencement of the remedial

action.

EPA mailed the Proposed Plan to the residential and business addresses within a half mile

radius of the Site, soliciting input from the community through the public comment

process. The mailing, including both English and Spanish versions, went out on

Tuesday, January 16, 2007. It announced that the public comment period would run from

January 20 to February 20, 2007, and that EPA would host a public meeting on January

24, 2007. EPA mailed out an additional announcement to the same parties on January 24,

2007, extending the public comment period to March 6, 2007.

22
On January 10, 2007, EPA sent an electronic copy of the administrative record, including

the Proposed Plan, to the Petaluma Public Library. The administrative record contains

the documentation supporting the Proposed Plan and ROD Amendment.

EPA placed a notice of availability of the Proposed Plan in a newspaper called the

Petaluma Argus Courier on January 31, 2007. This newspaper is a major local

newspaper of general circulation in Petaluma.

EPA held a public meeting on January 24, 2007, from 6:30 p.m. to 8:30 p.m., at the

Petaluma Public Library at 100 Fairgrounds Drive, Petaluma. The purpose of the public

meeting was to present the proposed clean-up plan amendment to the public, and solicit

public comment. Only one person attended the meeting. EPA had the meeting recorded

and produced a written transcript of the meeting.

Upon issuance of the ROD Amendment, EPA will make it available to the public by

placing a copy in the Petaluma Public Library. EPA will then publish a notice of the

availability of the ROD Amendment in the Petaluma Argus Courier.

23
PART 3: THE RESPONSIVENESS SUMMARY

No member of the public submitted comments on the proposed plan.

24
FIGURE 1: Location and Extent of Contamination

Sola Optical USA, Inc. Superfund Site, Petaluma, CA

December 2006

25