4 I 35 T e c h n o l o g y P a r k w a y , S h e b o y g a n , W i s c o n s i n 5 3 0 8 3

August 21, 2001

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Mr. Garret Bendy, PE Harding ESE, A MACTEC Company 46850 Magellan Drive, Suite 190 Novi, Michigan 48377 169480

Re: Correction Sheets for Technical Memoranda Site-Wide Data Gap Investigation Former Rockwell International Site Allegan, Michigan

Dear Mr. Bendy,

A typographical error was identified in the four final Technical Memoranda issued for the Site-Wide Data Gap Investigation. In the first line of text for each memorandum, the report is referred to as "draft." The word should have been deleted. Revised first pages for each memorandum are attached. These correction sheets should be inserted into the final documents to correct the error.

Earth Tech appreciates the opportunity to support Harding ESE and the Michigan Department of Environmental Quality (MDEQ) at the Former Rockwell Intemational Manufacturing Building Site. If you have questions please contact Andrew Lonergan at (734)779-2812.

T e l e p h o n e

9 2 0 . 4 5 S . 8 7 1 1

F a c s i m i l e

9 2 0 . 4 5 8 . 0 5 3 7

l̂omfu) Andrew J. Lonergan, P.G. Project Manager

/Sf-

cc: B. Harding, Harding ESE S. Townsend, Earth Tech E. Strang, Earth Tech R. Stenson, Earth Tech K. Nolan, Earth Tech 42133 Project File

L:\WORK\421S3\admin\correspn\correction pages.doc

A R T H

A t q c a INTERNATIONAL LTD. COMPANY

TECHNICAL MEMORANDUM No. 1

Date: July 13, 2001

To: Garret Bondy, Harding ESE, A MACTEC Company

From: Drew Lonergan, Project Manager Kris Nolan, Field Technical Lead Rob Stenson, Report Technical Lead

Subject: Site-Wide Hydrogeologic Investigation Former Rockwell International Site Allegan, Michigan

INTRODUCTION

This memorandum summarizes the field procedures and hydrogeologic interpretation associated with the Site-Wide Hydrogeologic Investigation conducted by the Michigan Department of Environmental Quality (MDEQ), Environmental Response Division, on a portion of the Former Rockwell Intemational Manufacturing Site, Allegan, Michigan. The U.S. Environmental Protection Agency (EPA) project area encompasses the entire Former Rockwell Intemational Site. The entire Former Rockwell Intemational Site consists of a portion of the City of Allegan Wastewater Treatment Plant, the main manufacturing facility that was tax-reverted to the City of Allegan, and Allegan Metal Finishing. MDEQ conducted investigation activities on the EPA project area where property ownership was tax-reverted to the City of Allegan, Michigan, and in the residential area south of North Street. Evaluation of previous investigation activities on the site indicated several potential data gaps with respect to the extent of soil and groundwater contamination. The Site-Wide Hydrogeologic Investigation was performed in support of the Data Gap Investigation within the boundaries presented on Figure 1-2.

The investigation summarized in this technical memorandum was performed by Earth Tech, Inc. (Earth Tech), as a Professional Services Contractor under contract to, and review of, Harding ESE, A Mactec Company. Harding ESE is the MDEQ's Project Management Contractor for work at the site.

Technical Memorandum No. 1 is part of a four-technical memorandum set which summarize work completed by the MDEQ at the site during 2000 and 2001 to address identified data gaps associated with previous investigations. The three additional technical memoranda include: Technical Memorandum No. 2, Southem Outfall Investigation is an Addendum to the PCB Sampling Event at the North Street Residence Site; which evaluates the nature and extent of soil and groundwater impacts south of the former manufacturing site; Technical Memorandum No. 3, Northem Lagoons Investigation, which evaluates the nature and extent of soil and groundwater impacts in the lagoon areas north of the former manufacturing site; and Technical Memorandum No. 4, Former Manufacturing Building Investigation, which evaluates the nature and extent of soil and groundwater impacts in the vicinity of the fonner manufacturing building. In addition to these four technical memoranda, an executive summary document was prepared to summarize investigative findings on a site-wide scale.

E A R T H S I T E C H

A fqCO MBIMIIONAL LTD. COU»m

L:\WORK\42l33\admin\lechmeml\#l Draft 6-19 Sile Wide HydrogeoNF.W.doc Page I

TECHNICAL MEMORANDUM NO. 2 - ADDENDUM SOUTHERN OUTFALL INVESTIGATION

Date: August 10, 2001

To: Matt Williams, MDEQ ERD, Kalamazoo District Office Gartet Bondy, Harding ESE, A MACTEC Company

From: Drew Lonergan, Project Manager Kris Nolan, Field Technical Lead Rob Stenson, Report Technical Lead

Subject: PCB Sampling Event at the North Street Residence Site Investigation Fonner Rockwell International Site Allegan, Michigan

INTRODUCTION

This memorandum summarizes the field procedures and hydrogeologic interpretation associated with the Site-Wide Hydrogeologic Investigation conducted by the Michigan Department of Environmental Quality (MDEQ), Environmental Response Division, on a portion of the Former Rockwell Intemational Manufacturing Site, Allegan, Michigan. The U.S. Environmental Protection Agency (EPA) project area encompasses the entire Former Rockwell Intemational Site. The entire Former Rockwell Intemational Site consists of a portion of the City of Allegan Wastewater Treatment Plant, the main manufacturing facility that was tax-reverted to the City of Allegan, and Allegan Metal Finishing. MDEQ conducted investigation activities on the EPA project area where property ownership was tax-reverted to the City of Allegan, Michigan, and in the residential area south of North Street. Evaluation of previous investigation activities on the site indicated several potential data gaps with respect to the extent of soil and groundwater contamination. The Site-Wide Hydrogeologic Investigation was performed in support of the Data Gap Investigation within the boundaries presented on Figure 2-1.

The investigation summarized in this technical memorandum was performed by Earth Tech, Inc. (Earth Tech) as a Professional Services Contractor under contract to, and review of, Harding ESE, A Mactec Company. Harding ESE is the MDEQ's Project Management Contractor for work at the site.

Technical Memorandum No. 2 Addendum, Southem Outfall Investigation, is part of a four-technical memorandum set which summarize work completed by the MDEQ at the site during 2000 and 2001 to address identified data gaps associated with previous investigations. The three additional technical memoranda include: Technical Memorandum No. 1, Site Wide Hydrogeologic Investigation, which evaluates the hydrogeologic setting of the former manufacturing site; Technical Memorandum No. 3, Northem Lagoons Investigation, which evaluates the nature and extent of soil and groundwater impacts in the lagoon areas north of the former manufacturing site; and Technical Memorandum No. 4, Former Manufacturing Building Investigation, which evaluates the nature and extent of soil and groundwater impacts in the vicinity of the former manufacmring building. In addition to these four technical

E A R T H ^ 3 1 T E C H

A t i ; C O KTEHNATlONAt ITD. C D M « N Y

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TECHNICAL MEMORANDUM No. 3

Date: August 10, 2001

To: Matt Williams, MDEQ ERD, Kalamazoo District Office Gan-et Bondy, Harding ESE, A MACTEC Company

From: Drew Lonergan, Project Manager Kris Nolan, Field Technical Lead Rob Stenson, Report Technical Lead

Subject: Northern Lagoons Investigation Former Rockwell International Site Allegan, Michigan

INTRODUCTION

This memorandum summarizes the field procedures and hydrogeologic interpretation associated with the Site-Wide Hydrogeologic Investigation conducted by the Michigan Department of Environmental Quality (MDEQ), Environmental Response Division, on a portion of the Former Rockwell Intemational Manufacturing Site, Allegan, Michigan. The U.S. Environmental Protection Agency (EPA) project area encompasses the entire Former Rockwell Intemational Site. The entire Fonner Rockwell Intemational Site consists of a portion of the City of Allegan Wastewater Treatment Plant, the main manufacturing facility that was tax-reverted to the City of Allegan, and Allegan Metal Finishing. MDEQ conducted investigation activities only on the EPA project area where property ownership was tax-reverted to the City of Allegan, Michigan, and in the residential area south of North Street. Evaluation of previous investigation activities on the site indicated several potential data gaps with respect to the extent of soil and groundwater contamination. The Site-Wide Hydrogeologic Investigation was performed in support of the Data Gap Investigation within the boundaries presented on Figure 3-1.

The investigation summarized in this technical memorandum was completed by Earth Tech, Inc. (Earth Tech) as a Professional Services Contractor under contract to, and review of, Harding ESE, A Mactec Company. Harding ESE is the MDEQ's Project Management Contractor for work at the site.

Technical Memorandum No. 3 is part of a four-technical memorandum set which summarize work completed by the MDEQ at the site during 2000 and 2001 to address identified data gaps associated with previous investigations. The three additional technical memoranda include: Technical Memorandum No. 1, Site Wide Hydrogeologic Investigation, which evaluates the hydrogeologic setting of the fonner manufacturing site; Technical Memorandum No. 2, PCB Sampling Event at the North Street Residence Site; which evaluates the nature and extent of soil and groundwater impacts south of the former manufacturing site; and Technical Memorandum No. 4 Former Manufacturing Building Investigation, which evaluates the nature and extent of soil and groundwater impacts in the vicinity of the former manufacturing building. In addition to these four technical memoranda, an executive summary document was prepared to summarize investigative findings on a site wide scale.

E A R T H ^ s j T E C H

A t q C a MBWHONAL LTD. COMmKY

L:\WORK\42133\admin\leclimem3\#3 Dral'l Nonhern l,agoons.doc P a g e 1

TECHNICAL MEMORANDUM No. 4

Date: August 10, 2001

To: Matt Williams, MDEQ ERD, Kalamazoo District Office Ganret Bondy, Harding ESE, A MACTEC Company

From: Drew Lonergan, Project Manager Kris Nolan, Field Technical Lead Rob Stenson, Report Technical Lead

Subject: Fonner Manufacturing Building Investigation Former Rockwell International Site Allegan, Michigan

INTRODUCTION

This memorandum summarizes the field procedures and hydrogeologic interpretation associated with the Site-Wide Hydrogeologic Investigation conducted by the Michigan Department of Environmental Quality (MDEQ), Environmental Response Division, on a portion of the Former Rockwell Intemational Manufacturing Site, Allegan, Michigan. The U.S. Environmental Protection Agency (EPA) project area encompasses the entire Former Rockwell Intemational Site. The entire Former Rockwell Intemational Site consists of a portion of the Chy of Allegan Wastewater Treatment Plant, the main manufacturing facility that was tax-reverted to the City of Allegan, and Allegan Metal Finishing. MDEQ conducted investigation activities only on the EPA project area where property ownership was tax-reverted to the City of Allegan, Michigan, and in the residential area south of North Street. Evaluation of previous investigation activities on the site indicated several potential data gaps with respect to the extent of soil and groundwater contamination. The Site-Wide Hydrogeologic Investigation was performed in support of the Data Gap Investigation within the boundaries presented on Figure 4-1.

The investigation summarized in this technical memorandum was completed by Earth Tech, Inc. (Earth Tech), as a Professional Services Contractor under contract to, and review of, Harding ESE, A Mactec Company. Harding ESE is the MDEQ's Project Management Contractor for work at the site.

Technical Memorandum No. 4 is part of a four-technical memorandum set which summarize work completed by the MDEQ at the site during 2000 and 2001 to address identified data gaps associated with previous investigations. The three additional technical memoranda include: Technical Memorandum No. 1, Site-Wide Hydrogeologic Investigation, which evaluates the hydrogeologic setting ofthe former manufacturing site; Technical Memorandum No. 2, PCB Sampling Event at the North Street Residence Site; which evaluates the nature and extent of soil and groundwater impacts of the fonner manufacturing site; and Technical Memorandum No. 3 Northem Lagoons Investigation, which evaluates the nature and extent of soil and groundwater impacts in the lagoon areas north of the former manufacturing site. In addition to these four technical memoranda, an executive summary document was prepared to summarize investigative findings on a site-wide scale.

E A R T H ^ ^ 1 T E C H

A fiyCD ImtHNATKNAl OD. COMPANY

L:\WORK\42133\admin\lechmem4\#4 Draft Building lnvestigati(in2.doc Page 1

13151-00(008)GN-WA013 SEP 25/2001

13151-10(009)GN-WA014 JAN 11/2002