SFUND RECORDS CTR

2114981

LEVINE-FRICK

OLFR

E

October 22, 2002 001-01954-02-001

Ms. Holly Hadlock

United States Environmental Protection Agency

75 Hawthorne Street

San Francisco, California 94105

Subject: Work Plan to Implement Monitored Natural Attenuation as a Remedial Measure at

the Former Sola Optical U.S.A. Facility, 1500 Cader Lane, Petaluma, California

Dear Ms. Hadlock:

LFR Levine-Fricke (LFR) has prepared this work plan at the request of the United States

Environmental Protection Agency (EPA) on behalf of American Optical, Sola, for the

implementation of Monitored Natural Attenuation (MNA) as a remedy for volatile organic

compounds (VOCs) in groundwater at the former Sola Optical U.S.A. facility located at 1500

Cader Lane in Petaluma, California ("the Site").

This work plan presents a groundwater monitoring program for assessing natural attenuation of the

VOCs 1,1-dichloroethene (1,1-DCE) and 1,1-dichloroethane (1,1-DCA) in groundwater at the Site.

The program includes selected wells to be sampled, frequency of and rationale for sampling, wells

to be destroyed and rationale for destruction, confirmation sampling, and exit strategy for the

program.

Proposed Groundwater Monitoring Program

LFR proposes the following groundwater monitoring program for the Site: semiannual sampling of

monitoring wells W-27, E-3, and E-5 and annual sampling of monitoring wells W-22, W-25, LF-2,

and E-7 (Figure 1). Wells W-27, E-3, and E-5 were selected for semiannual monitoring because

they are located within the plume and represent groundwater with the highest concentrations of

VOCs at the Site.

Wells W-22, W-25, LF-2, and E-7 are located downgradient from the plume and were selected for

annual monitoring for use as sentry wells. Concentrations of VOCs in these wells have been below

maximum contaminant levels (MCLs) for at least the last five years (i.e., since 1997 or before).

Groundwater monitoring will consist of purging each well of from three to five well casing volumes

using either a Teflon bailer (a new disposable bailer will be used for each well) or a centrifugal

pump. Well sampling equipment will be cleaned with high-pressure hot water (steam-cleaned)

before sampling of each well. Wells will be purged until field parameters of pH, temperature, and

specific conductance have stabilized to within 10 percent of the previous reading.

1900 Powell Street, 12th Floor, Emeryville, California 94608-1827 • (510) 652-4500 • fax (510) 652-2246 • www.lfr.com

Offices Worldwide
f»ILFR

Groundwater samples will then be collected from the well using a disposable Teflon bailer and

decanted from the bailer into laboratory-supplied containers preserved with hydrochloric acid. Each

sample container will then be sealed with a chain-of-custody seal, labeled and stored in a chilled ice

chest for transportation to Curtis & Tompkins, Ltd., Analytical Laboratories ("C&T"), a statecertified laboratory located in Berkeley, California, under strict chain-of-custody protocol. Samples

will be analyzed for VOCs using EPA Method 8260B (using an 8010 list).

To provide quality assurance and quality control (QA/QC) data, one field blank (equipment rinsate

blank) and one duplicate sample will be collected per sampling event.

Groundwater Monitoring Well Destruction

LFR proposes to destroy the following groundwater monitoring wells: W-14, LF-25, LF-26, E-6,

E-10, and E-l 1 (Figure 1). Concentrations of VOCs in these wells have been below MCLs for 2 to

11 years. Wells W-14 and E-10 are located within 15 feet of well E-l, which is being retained as a

contingency well. Only one well is needed to quantify groundwater in that area, and well E-l can

double as both a monitoring and a contingency well if needed. Well E-l 1 is located within 10 feet

of well LF-2 and is not needed to characterize the plume. Wells LF-25 and LF-26 were initially

used as downgradient sentry wells at the southern boundary of the property. Given the extent and

current VOC concentrations in groundwater at the Site, the downgradient extent of VOC-affected

groundwater can be monitored using wells W-22 and LF-2. Well E-6 is located within 25 feet of

well W-25 and is not needed as a monitoring well or contingency well because VOC concentrations

in this well have been at or below MCLs for at least 7 years.

Each of the wells proposed for destruction will be sampled once prior to destruction to verify that

concentrations of VOCs are still below MCLs.

Contingency Wells

Wells E-l, E-2, and E-4 are to be retained as contingency wells.

Confirmation Sampling

Groundwater monitoring will continue at the Site on a semiannual basis until sample analytical

results indicate that VOC concentrations in groundwater have been at or below MCLs in all wells

for a period of 2 years. At that time LFR will submit a request to stop monitoring and prepare a

letter to the EPA requesting case closure for the Site. This letter will include a request for

destruction of all monitoring wells on the current monitoring program and all remaining

contingency wells.

wp-sola-mna-oct02-01954: vch
1SILFR

Please call me with any questions or comments at (510) 652-4500.

Sincerely,

Larry L/puyade

Senior Project Hydrogedlogist

Enclosure: Figure 1

wp-sola-mna-oct02-01954: vch
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C A D E R LANE

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4—GROUNDWATER

TREATMENT SYSTEM

INDUSTRIALWASTEWATER

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EXPLANATION

Shallow (up to approx. 30 feet) monitoring well

Intermediate (up to approx. 60 feet) monitoring well

Former extraction well

Fence line

Wells retained as part of proposed monitoring program (7)

Contingency wells (3)

Well Proposed for destruction (6)

Outline of shallow groundwater with concentrations

of 1,1-DCE that exceeded the maximum contaminant

level of 6 micrograms per liter (9/99 & 3/00 data)

1,1-DCE 1,1-Dichloroethene

60 120 FEET

Proposed Groundwater Monitoring Program

Sola Optical U.S.A., Petaluma, California

@LF

LEVINE'FRICK

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Figure 1