February 2011

Sola Optical 

Superfund Site

United States Environmental Protection Agency, Region 975 Hawthorne Street (SFD-6-3)San Francisco, CA 94105Attn: Alejandro Díaz (Sola 2/11)Official BusinessPenalty for Private Use, $300Address Service Requested

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U.S. EPA

Permit No. G-35

EPA Reviews Cleanup of Site

The United States Environmental Protection Agency (EPA) has 

completed its third five-year review for the Sola Optical USA, Inc. 

Superfund Site (Site) in Petaluma, California. The purpose of the 

five-year review process is to evaluate whether a Superfund cleanup 

remedy is still protective of human health and the environment. 

Information Repositories 

Two information repositories hold the third five-year review 

report, as well as other relevant documents, for Sola Optical 

USA, Inc: 

U . S . E N V I R O N M E N T A L P R O T E C T I O N A G E N C Y 

Sola Optical Superfund Site location

Petaluma Public Library 

100 Fairgrounds Drive 

Petaluma CA 94952 

(707) 763-9801 

Mon, Thurs, Fri, Sat: 

 10:00 a.m. to 6:00 p.m. 

Tues, Wed: 

 10:00 a.m. to 9:00 p.m. 

Superfund Records Center 

95 Hawthorne St., 

Room 403 

Mail Stop SFD-7C 

San Francisco, CA 94105 

(415) 536-2000 

Mon-Fri: 

 8:00 a.m. to 5:00 p.m. 

Find it on the Web... You can obtain the 

Five-Year Review Report, as well as other site 

information, from EPA’s Web site at: 

http://www.epa.gov/region09/solaoptical

Dante Rodríguez 

EPA Project Manager 

75 Hawthorne Street 

(SFD-7-1) 

San Francisco, CA 94105 

(415) 972-3166 

rodriguez.dante@epa.gov 

Alejandro Díaz 

EPA Community 

Involvement Coordinator 

75 Hawthorne Street 

(SFD-6-3) 

San Francisco, CA 94105 

(415) 972-3242 or 

Toll free (800) 231-3075 

diaz.alejandro@epa.gov Sola Optical USA, Inc. 

Superfund Site Lakeville Hwy.

McDowell Blvd.

Lakeville Hwy.

South Ely Rd.

Frates Rd.

Casa Grande Rd.

ROUTE 101 Petaluma River Caulfield Lane Kenilworth Dr.

Shollenberger

 Park

Kenilworth 

ParkWashington

Washington 

Square

Cader Ln.

Cader Lane

Lakevi

l

l

e

H

i

g

h

w

ay

Shallow Monitoring Well 0 FEET 200

Plume

Building

Parking 

Lot

Undeveloped Field

0 FEET 2,000

For More Information 

If you have questions about the Sola Optical Superfund Site 

or would like to be added to the mailing list, please contact: 

SDMS DOCID# 1138656
Summary of 

Five-Year Review Findings Cleanup Remedy Selected in 1991 ROD Site Background

What is Monitored 

Natural Attenuation? 

MNA is the process by which contaminated groundwater is 

cleaned-up by natural forces. Natural forces include various physical, chemical and biological processes that act without human 

intervention to reduce contaminants in groundwater. At the Site, 

contaminant levels are closely monitored to make sure attenuation is actually occurring.

This five-year review was completed in September 2010. The 

first and second five-year reviews for this Site were completed 

in September 2000 and September 2005, respectively; and the 

next five-year review will be performed in 2015, if necessary. 

The cleanup for this site is still underway. When it is completed, all contaminant levels will meet the cleanup standard, 

and use of the property and underlying groundwater will 

not be restricted or limited. In this five-year review, EPA has 

determined that the remedy, as specified in the 1991 Record of 

Decision (ROD) and the 2007 ROD Amendment, is currently 

protective of human health and the environment. Groundwater 

contamination has been reduced below the cleanup standard in 

all but a very limited area around one well, and no one is currently being exposed. However, the five-year review identified 

follow-up actions that will be taken, including: 

1. Properly implementing permitting restrictions under the 

County of Sonoma – Permit and Resource Management 

Department Permits Plus system.

2. Determining whether a restrictive covenant is needed to 

prevent groundwater use.

The Sola Site will continue to have Five-Year Reviews in the 

future until the residual contamination in the groundwater at 

the Site achieves the clean-up standard. 

The remedy for the Site, as specified in the 1991 ROD, called for: 

t Converting two deep monitoring wells to extraction wells, to 

prevent the movement of contaminants into the deeper portion of 

the aquifer; 

t Constructing two additional shallow extraction wells, to reduce 

the clean-up time; 

t Using the existing carbon filter system to treat any water discharged off-site to Adobe Creek; 

t Monitoring the groundwater to confirm capture of the contaminant plume and to measure progress towards achieving the 

cleanup standard of 5 micrograms per liter. 

In March 2007, EPA issued an amendment to the ROD and added 

Monitored Natural Attenuation (MNA) to the remedy:

t MNA to achieve groundwater clean up standards, 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 for groundwater restoration.

Sola Optical USA, Inc. manufactured optical lenses on a 

35-acre site from 1978 through 2001. Six 1,000 gallon underground storage tanks, located behind the north corner of the 

manufacturing building, were used for storing solvents. In 

1982, the California Department of Health Services found 

acetone in an on-site well. Subsequently, Sola reported that 

soil adjacent to the six underground solvent storage tanks were 

contaminated with volatile organic compounds (VOCs), as was 

the shallow groundwater beneath the facility. In 1986, the State 

found low levels of solvents in the Petaluma #5 City Well. The 

well was shut down until the groundwater cleanup could be 

completed. Groundwater extraction and treatment occurred at 

the Site from 1988 to 1997. By 1997, the groundwater extraction system was no longer reducing contamination concentrations, so it was shut down and groundwater was monitored to 

see if concentrations increased again. The concentrations did 

not increase, so in 2001, the groundwater treatment system was 

dismantled and MNA was used as the Site remedy. 

The Sola manufacturing facility closed in October 2001, and 

the property was sold in 2002. The other part of the Site, an 

eleven acre property adjacent to the manufacturing facility, 

was sold to RNM Properties in 2000 for commercial development. Sola Optical, Inc., no longer owns any part of the Site. 

The former manufacturing facility is currently occupied by 

at least two different tenants, who use the main building and 

loading docks. 

EPA