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Pacific Southwest, Region 9: Superfund

Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations

Motorola, Inc. (52nd Street Plant)

EPA #: AZD009004177

State: Arizona(AZ)

County: Maricopa

City: Phoenix

Congressional District: 01

Other Names: Motorola 52nd Street; Motorola, Inc. Discrete Semiconductor

Bulletin Board

On 10/13/17, this website will no longer be updated. Site information will be migrated to the new web page at: http://www.epa.gov/superfund/motorola52ndst .
EPA appreciates your patience through this transition. If you have questions, please contact EPA staff listed below.


Description and History

NPL Listing History

NPL Status: Final

Proposed Date: 10/15/84

Final Date: 10/04/89

Deleted Date:

The Motorola, Inc. (52nd Street Plant) Superfund Site (Site) is a large area of contaminated groundwater extending from the former Motorola facility and other sources. The responsible parties have operated various soil gas and interim groundwater treatment systems since the early 90’s that have reduced contamination. In addition, vapor intrusion mitigation has been installed at 16 homes. EPA and Arizona Department of Environmental Quality (ADEQ) are working to develop final cleanup actions over the next few years.

The Site is located in Phoenix, Arizona, generally between 52nd Street on the east, Palm Lane on the north, 7th Avenue on the west, and Buckeye Road on the south. Because of the size of the site, it has been divided into three areas called Operable Units (OUs) in order to better manage the cleanup efforts (click here to see Site Map).

ADEQ is the lead agency for activities in OU1 and OU2 with the exception of the vapor intrusion/indoor air investigation in OU1 and OU2. EPA is the lead agency for OU 3.

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Contaminants and Risks

Contaminated Media
  • Groundwater
  • Air
  • Soil and Sludges

EPA and ADEQ identify Contaminants of Concern (COCs) during the RI/FS process that help drive cleanup decisions at a site. At the Motorola 52nd Site, past studies have identified Volatile Organic Compounds (VOCs) as the COCs that are currently driving cleanup. Under the classification of VOC, Trichloroethene (TCE) and Tetrachloroethene (PCE) are the two specific contaminants of concern. EPA and ADEQ are currently gathering information across all OUs and may be adding COCs.

Various measures have been put into place to reduce groundwater migration and contamination, and to prevent soil exposure. EPA has also been studying the possibility for soil vapor from contaminated groundwater to migrate into buildings and impact indoor air. In OU1, Freescale Semiconductor, Inc. (Freescale, an independent company spun off from Motorola in 2004), has sampled 115 residences, 4 schools and 7 commercial buildings with EPA oversight. Freescale also installed sub-slab depressurization systems at 15 homes and apartment units and successfully reduced TCE concentrations to below 2ug/m3 in those homes/buildings.

In the Phoenix area, drinking water is provided primarily though surface water (95%) and limited groundwater (5%) from areas located outside of the the Motorola 52nd Street Superfund Site.

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Who is Involved

This site is being addressed through Federal, State, and potentially responsible parties' actions.

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Investigation and Cleanup Activities

In the past, chemicals were spilled/leaked at the former Motorola plant at 52nd Street and McDowell Road, the Honeywell facility at 34th Street and Air Lane, and potentially at other facilities in the area. These chemicals seeped downward through the ground and mixed with the groundwater and formed a wide spread groundwater plume toward the west. Freescale and Honeywell (the Companies) have been working to investigate and cleanup the contamination. ADEQ and EPA closely monitor all work performed by the Companies at this site.

The Site was proposed for the National Priorities List (NPL) in October 1984 and placed on the final NPL in November 1989 to investigate the presence of soil and groundwater contamination by chlorinated solvents (more information on Site contaminants can be found below).

Initial Actions

1st Interim Remedy 1988
In 1988, prior to final listing, ADEQ and USEPA approved a groundwater recovery and treatment system as an interim remedy known as OU1. In 1989, ADEQ and Motorola entered into a consent order requiring Motorola to design and implement groundwater and soil remedies. The full-scale treatment system was constructed in 1992 and designed to restrict contaminant migration at the Crosscut Canal along 46th Street, and to reduce the levels of contamination at the Motorola facility. Since 1992, Motorola/Freescale has been operating and maintaining the system under ADEQ oversight.

2nd Interim Remedy 1994

In 1994, ADEQ and USEPA selected a second interim remedy near 20th and Washington Streets designed to contain and treat the groundwater contamination in the OU2 area. ADEQ signed a Consent Decree with Motorola for the remedial design of OU2 in 1996. The design was completed and approved in December 1999. USEPA signed the Explanation of Significant Differences to the OU2 Record of Decision (ROD) in September 1999 to describe the changes in water treatment technology and end-use of the treated water. USEPA issued a Unilateral Admistrative Order to Freescale and Honeywell in November 1998 for the construction of the OU2 treatment system and operation and maintenance of the system for two years.

This Order was amended in December 2003 to provide for long-term operation and maintenance of the system by the Companies. The OU2 treatment system construction began in March 2000 and was completed in October 2001.

The OU2 treatment system became fully operational in December 2001. The Companies are responsible for the operation of this system under ADEQ and EPA oversight. Also in OU2, Honeywell, has been conducting an investigation of soil and groundwater contamination at its facility. ADEQ and Honeywell entered into an administrative order on consent (AOC) in September 1999 to conduct a remedial investigation (RI) at the 34th St. Facility. The AOC required Honeywell to investigate its potential source areas and to define the full extent of its contamination at and emanating from the 34th St. Facility. Honeywell completed this RI in 2008 and completed a baseline Human Health Risk Assessment in 2012.

Site Studies

2012 Human Health Risk Assessment – OU2

As part of the human health risk assessment, a workplan for an indoor air vapor intrusion investigation at the Honeywell 34th street facility began in 2011. Honeywell discovered a jet fuel plume at their facility that was mingling with the larger VOC plume. They installed a Biologically- enhanced Soil Vapor Extraction (BSVE) system to address the jet fuel plume in 2009 managed by the ADEQ Leaking Underground Storage Tank (LUST) Action under a corrective action plan. As of the first quarter of 2012 the BSVE system has removed in excess of 4,000,000 pounds of petroleum hydrocarbons and recently, removal rates have averaged over 5000 pounds per day indicating that the BSVE system is performing very well.

Cleanup Ongoing

Third Operable Unit

In 1997, USEPA and ADEQ established a third OU study area to address groundwater contamination downgradient of OU2. USEPA entered into an AOC with Honeywell and Arizona Public Service Company to perform the remedial investigation/feasibility study (RI/FS) for the OU3 Study Area in late 2009. The Remedial Investigation began in 2010.

Status: Source Investigations and Soil Gas Sampling near Soil Vapor Monitoring Well – 1 (SVMW-1) started in 2014. This investigation will help complete the groundwater investigation and, ultimately, the RI/FS with a target completion of summer 2017.

Recent and Upcoming Activities in OU 1 and OU2

The OU1 and OU2 treatment plants have been effective in containing the plume and reducing concentrations of contaminants in most areas. However, the 2011 Five Year Review of the remedies concluded that there were several issues that needed to be addressed in order to get to a final remedy.

One major issue is addressing an ongoing source of contamination—dense non-aqueous phase liquid (DNAPL) that has seeped into fissures in bedrock—and the other is to complete the evaluation of the vapor intrusion pathway in OU1 and OU2.

In 2009, a Bedrock Pilot Study was initiated in order to evaluate the effectiveness of extracting DNAPL from bedrock using wells. The data from this study indicates removal of DNAPL is assisting the groundwater cleanup, and a conclusion as to how to proceed will be reviewed as more data is received.

In 2011, EPA entered into an agreement with Freescale to investigate the soil gas to indoor air pathway in OU1. Soil gas samples were taken first and analyzed for TCE and PCE. Because concentrations of TCE were above health-based screening levels, from 2011 to 2014 EPA followed up with subslab and indoor air sampling of homes, apartment buildings, and commercial buildings in the suspected area. Under EPA oversight, Freescale sampled 115 residences, 4 schools and 7 commercial buildings. Sixteen (16) mitigation systems were installed and are routinely monitored. Although 4 locations refused mitigation, all remaining homes now have levels below current health-based screening levels.

An investigation into whether vapor intrusion is occurring in OU2 is scheduled for 2016, following similar protocol as what was used in OU1.


OU1 – To assist in the bedrock study and help further identify groundwater and soil vapor conditions, additional groundwater and soil vapor monitoring wells were installed in late August 2013 through Fall 2013. Ongoing monitoring of the homes and apartment units equipped with indoor air mitigation systems will continue through 2016 when the frequency of monitoring will be evaluated based on the data gathered.

OU2 – In summer 2013, ADEQ will negotiate and sign a Statement of Work (SOW) and Administrative Order on Consent. This action will allow investigations on the RI to begin, as well as additional investigations on the potential for Vapor Intrusion.

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Cleanup Results to Date

The interim actions undertaken by Motorola, Honeywell and AZ Public Service have made the site safer while additional cleanup activities are being planned.

The 2016 Five-Year Review Report completed on September 27, 2016 concluded that -

  • The OU1 interim remedy is currently protective of human health and the environment, because groundwater is confirmed to be contained laterally and there is currently no exposure to contaminated groundwater in the OU.
  • A protectiveness determination at the OU2 interim remedy cannot be made until further information is obtained for potential vapor intrusion. EPA is currently conducting a vapor intrusion investigation, including soil vapor sampling and indoor air sampling at and near areas of concern.

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Potentially Responsible Parties

Potentially responsible parties (PRPs) refers to companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site.

Potentially Responsible Parties
The Motorola 52nd Street facility was originally constructed in 1956 and was in operation until the third quarter of 1999. Freescale has agreed to implement the requirements of the OU1 ADEQ consent decree (CD), the EPA Administrative Order of Consent for investigating and remediating the vapor intrusion pathway in OU1, and the OU2 EPA Unilateral Administrative Order (UAO).

The Honeywell 34th Street facility was constructed in 1951 and continues to operate today. Historically, the Honeywell facility has operated under the names of AiResearch Manufacturing Company of Arizona, Garrett Turbine Engine Company, and AlliedSignal Aerospace Company. Located on approximately 188 acres and consisting of more than 130 buildings, Honeywell and its predecessors have conducted jet engine design, assembly, testing, and repair at the site.

In 1992 and 2003, USEPA conducted Potentially Responsible Party (PRP) searches which identified numerous PRPs for the Site. As of January 2012, USEPA and ADEQ have entered into enforcement agreements with:

  • Freescale
  • Honeywell
  • Arizona Public Service
  • the Salt River Project
  • Phoenix Newpapers
  • Baker Metals
  • Adobe Air/Arvin Meritor/Cooper Industries
  • Walker Power
  • Kachina Joray, ITT
  • Canon

Other potential sources are under investigation to determine whether they contributed to the groundwater contamination and are responsible for investigation and cleanup.

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Documents and Reports

Show details for Administrative RecordsAdministrative Records
Show details for Community InvolvementCommunity Involvement
Hide details for Fact SheetsFact Sheets
11/01/99Construction Of Groundwater Treatment System Planned (English & Spanish)
02/01/00Construction Plans for Motorola (52nd Street) Superfund Site Cleanup (English/Spanish)
02/01/00Planes de construcción para la depuración del sitio Superfund de Motorola en 52nd Street
01/01/01Environmental Bulletin (English & Spanish)
02/01/01Environmental Bulletin( English/Spanish)
09/01/01Comments Requested on Groundwater Study(43k)
10/01/01EPA to Install Monitoring Wells in the Operable Unit Three Study Area
10/01/01EPA to Install Monitoring Wells in the Operable Unit Three Study Area.(English/Spanish)
01/01/02Environmental Bulletin
Bolletín Ambiente (English/Spanish)
09/01/021) This is to update you on the U.S. Environmental Protection Agency’s
groundwater investigation activities in the Operable Unit Three Study Area and to request your input on the next phase of this work. (English/Spanish).
2) Proposed Monitoring Well Locations Map.
03/01/03Environmental Bulletin
Boletín Medio Ambeiental (English/Spanish)
03/01/04Clean Up is Working at Operable Unit 2
02/01/05EPA and ADEQ Identify More Potentially Responsible Parties and Initiate Facility Investigations (English & Spanish)
08/01/05Meeting Notice
12/01/05Meeting Notice
04/01/06Public Comment for 5-Year Review
07/06/06Meeting Notice
05/01/07May 2007 Site Update
11/01/08November 2008 Site Update (in English y en español)
07/09/09Community Event - July 22, 2009.
09/01/09Boron Fact Sheet
09/01/09Community meeting announcement
09/01/09OU3 Administrative Order of Consent Press release
10/21/09Open House - New System to Cleanup Fuel Realeases in Soil Groundwater ( (in English y en español)
11/23/09United States Environmental Protection Agency Signs Agreement with Honeywell International Inc. and Arizona Public Service Company
01/04/10Open house announcement Feb. 11, 2010
04/28/10Motorola 52nd St. Superfund Site Important Announcements
05/26/10Motorola 52nd St. Brief Overview/background
09/09/10CIG Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario
11/26/10Community Meeting - Soil Gas Sampling Work Plan
01/07/11CIG Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
05/19/11Community Meeting - Open House / Reunión Pública y Jornada de puertas abiertas
06/10/11CIG Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
10/25/11Community Informational Group Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
12/02/11Five-Year Review Completed / La Revisión de cada Cinco Años está Completada
01/10/12Community Informational Group Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
01/23/12Community Meeting - Open House / Reunión Pública y Jornada de puertas abiertas
04/03/12Community Informational Group Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
04/23/12Update on Vapor Intrusion to Indoor Air Investigation at the Motorola 52nd Street Superfund Site (English/Spanish/Somali)
06/27/12ADEQ/EPA Notice Upcoming Environmental Work at the Semiray Facility / Aviso de ADEQ/EPAPróximo Trabajo Medioambiental en las Instalaciones Semiray
08/01/12Community Informational Group Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
10/03/12Community Informational Group Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
01/08/13Community Informational Group Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
01/18/13Community Informational Group Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
04/24/13April 24th - Motorola CAG Meeting Invitation - Agenda
01/29/14Winter 2014 Soil Gas Sampling and Investigation Activities - English
01/29/14Winter 2014 Soil Gas Sampling and Investigation Activities - Spanish
03/19/14Community Informational Group Meeting Announcement / Aviso de reunión del Grupo Informativo Comunitario (CIG)
Show details for Legal DocumentsLegal Documents
Show details for MapsMaps
Show details for Records of DecisionRecords of Decision
Show details for Technical DocumentsTechnical Documents

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Community Involvement

Public Meetings: A new Community Information Group was formed in 2010 and meets regularly. The next webinar is scheduled for Wednesday, October 26, 2016, from 6:00pm-8:30pm.

Please contact the Community Involvement Coordinator, Carlin Hafiz, at (213) 244-1814 if you or a local group would like to get more involved or would like to be added to the mailing list.

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Public Information Repositories

The public information repositories for the site are at the following locations:

Arizona Dept. of Environmental Quality,
Remedial Projects Unit
1110 W. Washington St.
Phoenix, AZ 85007-2935
(602) 771-4154

Phoenix Public Library,
Saguaro Branch
2802 North 46th Street
Phoenix, AZ
(602) 262-6801

Phoenix Public Library,
Central Branch
1221 N. Central Avenue
Phoenix, AZ 85004
(602) 262-4636

The most complete collection of documents is the official EPA site file, maintained at the following location:

Superfund Records Center

Mail Stop SFD-7C

95 Hawthorne Street, Room 403

San Francisco, CA 94105

(415) 820-4700

Enter main lobby of 75 Hawthorne street, go to 4th floor of South Wing Annex.

Additional Links

ADEQ's web site for the Motorola 52nd St. site: https://www.azdeq.gov/environ/waste/sps/Motorola_52nd_Street.html

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EPA Site Manager
Rachel Loftin
US EPA Region 9
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Community Involvement Coordinator
Carlin Hafiz
US EPA Region 9
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Public Information Center
(415) 947-8000 or toll-free (866) 372-9378
State Contact
Laura Fischer, OU1 & OU2, Karin Harker, OU3
Wendy Flood, CIC
Laura (602) 771-0200
Karin: (602) 771-0361
Wendy: (602) 771-4410
1110 W. Washington St.
Phoenix, AZ 85007-2935
PRP Contact
Jenn McCall
Tao Wu
(480) 814-4587
(602) 231-2015
Jenn McCall:
Tao Wu:
Honeywell International
111 S. 34th Street
Phoenix, AZ 85034
Community Contact
Our Community Involvement Plan contains a list of community contacts for this site. Please contact EPA or ADEQ for this information, or contact your local neighborhood association, group, or city councilman.
Other Contacts
After Hours (Emergency Response)
(800) 424-8802

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