Free Memorandum - District Court of Arizona - Arizona

ATTACHMENT B

Case 2:03-cv-02226-ROS

Document 75-3

Filed 06/21/2006

Page 1 of 6

u.s. Environmental Protection Agency

Responsiveness Summary for Comments on Parial Consent Decree
Crane Co. et al v. United States, DJ. Ref. 90-11-2-248/1
Published in the Federal Register on April

26, 2006

Mar Aycock

Remedial Proj ect Manager Environmental Protection Agency, Region IX Superfund Division

Case 2:03-cv-02226-ROS

Document 75-3

Filed 06/21/2006

Page 2 of 6

Comments from the City of Goodyear and the City of Avondale

on Partial Consent Decree, Crane Co. et al v. United States published in the Federal Register on April 26, 2006 Phoenix-Goodyear Airport (North) Superfund Site
The United States received two comment letters regarding the Proposed Partial Consent Decree, Crane Co. et at v. United States, D.J. Ref. 90-11-2-248/1. The first comment letter, dated May 22,2006, contained comments £Yom Mayor James M. Cavanaugh on behalf ofthe City of Goodyear, Arzona. The second comment letter was on behalf of the City of Avondale, Arzona, from Marie Lopez-Rogers, Mayor, dated
May 23,2006. Both comment letters are generally supportive of the entr of

the Parial

Consent Decree. Because the letters came £Yom cities where the Phoenix-Goodyear Airport (North) Superfund Site (Site) is located, both letters raised concerns about groundwater contamination and potential impacts on current and future municipal wells. Because the issues raised are nearly identical, they are addressed together in this
responsiveness sumar. Where both cities have commented on the same subject matter,

the more comprehensive comment is quoted.
City of Goodyear, page 2, paragraph 4: City of Avondale, page 2, paragraph 3: "EP A's WHP A model is a relatively simple analytical model, with limited capabilities in

comparson to others curently being used."
EP A Response:

The groundwater flow model for the PGA-North Site is still under development. The CD requires that the Site-specific groundwater flow model include delineation of 5-year capture zones for individual wells consistent with EPA's 1991 WHPA modeL. EPA's 1991 WHPA model is generic, however, and thus is being used only as guidance to
develop the Site-specific modeL.

The Site-specific model takes into consideration all ofthe regional wells and their pumping data based on current information. The Site-specific model also incorporates new information on the hydrology of the area based on drilling data collected at the Site over the last 14 years. Once completed, the Site-specific model is expected to be used to predict the regional flow of groundwater and contaminants in the plume. This will assist in identification of at-risk wells, in enabling cities and other water purveyors to locate future drinking water wells away £Yom areas influencing the plume, and in appropriately
locating extraction wells for clean up. Specifically, by incorporating the Site-specific

information, the new model will be able to evaluate all wells within the Site area, such as the wells in the vicinity of the COG-18 well field identified as a concern in the City of
Goodyear's letter.

The flow of groundwater and the contaminated plume are affected by local pumping rates, so as new wells are located and as existing wells increase their pumping rates to accommodate the Cities' increasing needs, the model is expected to be useful in
predicting the potential capacity and life of any given existing or proposed well. EP A

Case 2:03-cv-02226-ROS

Document 75-3

Filed 06/21/2006

Page 3 of 6

EP A Response to City Comments

Page 3 of5
works closely with the Arzona Deparent of

Environmental Quality (ADEQ) and the Arzona Deparment of Water Resources (ADWR) where the Agencies are involved in approval of new well locations so that all of the factors affecting well production and plume influence are considered. While the Site-specific model is being developed, ADWR's regional flow model, which has been used for several years for this purpose, is
being used.

City of Goodyear, page 3, paragraph 1: "(T)he Goodyear water supply is in a very vulnerable state and will continue to be so unless plume management strategies (installation of extraction wells) and contingency
plans are implemented, as necessary, on an expedited basis. EP A must ensure that, as the

Parial Consent Decree requires, Settling Defendants are prepared to 'implement measures to ensure provision of uninterrpted water supply' on a timely basis. Because of the limitations of the model, the rapid growth in the area and the possibility that irrgation wells may be converted to potable water use, the City also suggests that wells currently used for Settling Defendants' at-risk analysis also include an evaluation of
irrgation only."

City of Avondale, page 2, paragraph 4: "Because of the limitations of the model and the rapid growth of the area, Avondale

requests that Settling Defendants at-risk analysis specifically include an evaluation of potential impacts on all of Avondale's water supply wells."
EP A Response:
EP A is aware of the vulnerabilities associated with the water supplies in both the City

of

Goodyear and the City of Avondale. Because of this, EP A has included representatives £Yom both Cities at preliminar meetings to discuss the Site and implications that the the Cities' water supplies. On an ongoing remedy would have on the management of basis, EP A has solicited and included comments £Yom both Cities and their associates for the plume's impact on area water work plans developed by Crane Co. for evaluation of supplies. In addition, the Cities of Goodyear and Avondale have been included in the quarterly Regulatory Agency meetings, held in Phoenix, in which major decisions have
been made regarding characterization of the Site and plans for protection of

both Cities'
the Cities'

water supplies. Technical specialists representing both Cities associated with the
development of the groundwater model and hydrophysical investigations of

wells have been included in all major meetings regarding the Site, and an effort has been made to ensure that comments provided by the Cities regarding Crane Co. deliverables have been adequately addressed.

With regard to "the possibility that irrgation wells may be converted to potable water use," EP A is in agreement that wells used for irrgation should be included in subsequent at-risk analyses, particularly if a paricular well is being considered for potable water supply. EP A has requested documentation in the past, such as proposals £Yom the City of locations) and is committed to providing Goodyear (for potable water sources and well technical oversight (in conjunction with the Arzona Department of Environmental Water Resources) to determine the suitability of Quality and the Arzona Deparment of wells and their locations prior to converting a well to a potable water system.

Case 2:03-cv-02226-ROS

Document 75-3

Filed 06/21/2006

Page 4 of 6

EP A Response to City Comments

Page 4 of5

With regard to evaluation of all ofthe City of Avondale's water supply wells, EP A reiterates its concern about all supply wells that are used for domestic water supply in the the City of Avondale's wells are already area should be evaluated. To this end, all of included in the new regional model as their pumping rates directly affect the flow at the PGA-North Site. Additionally, once the model is complete and approved, it will be made
available as a tool to calculate captue zones of any area wells. EP A will request that Avondale's wells continue to be included in futue analyses including model rus and

the placement of Five-Year Capture Zones, as well as evaluations of sentinel and extraction wells that will affect subsequent captue of contaminants in the plume.
evaluations of

City of Goodyear, page 3, paragraph 2: City of Avondale, page 2, paragraph 5: "It does not appear that, in the event that the at-risk well is a Goodyear well, any formal role in remedy selection is provided by the City. Nevertheless, Goodyear believes that the City should be engaged and consulted in the development of any response actions pertaining to its wells, recognizing, among other things, that wellhead treatment mayor may not be accepted as readily by the public as other options."
EP A Response:

EP A will continue, as it has in the past, to include the City of Goodyear and the City of Avondale in decisions regarding the development of any response actions pertaining to use of wellhead the appropriateness of that City's wells. This includes evaluation of treatment as a response action. The process as set forth in detail in the Parial CD consists in par of requiring Crane Co. to submit well investigation workplans which will propose any alternatives being considered to address a well that is impacted, such as well abandonment or wellhead treatment. Any alternative proposed must be reviewed and approved by EP A prior to being implemented. As has been the case in the past, EP A will solicit comments £Yom the subject well owner, whether it is a city or a private water provider, regarding the alternatives being considered prior to approving and finalizing any action. The public acceptability of any alternative wil be considered in this process as well.
City of Goodyear, page 3, paragraph 3: City of Avondale, page 2, paragraph 4:
"Task 4.1 requires Settling Defendants to notify EP A after concluding that certain wells

are at-risk. There is no express requirement that Goodyear be notified in the event that the identified well is a City well, and Goodyear formally requests hereby that it be copied on the relevant notifications made to EP A. The informational needs of a municipal water provider are certainly no less than those ofEP A."

Case 2:03-cv-02226-ROS

Document 75-3

Filed 06/21/2006

Page 5 of 6

EP A Response to City Comments

Page 5 of5
EP A Response:

EP A is in agreement that any well owner should be informed when any well is identified as "at-risk." EP A will make a formal request to Crane Co. to include the well owner, whether it is the City or a private well owner, in any relevant notifications that are made to EP A. EP A will provide a copy ofthe letter requesting this notice to the cities and other stakeholders at the time of its distribution.
City of Goodyear, page 3, paragraph 4: City of Avondale, pages 2-3, paragraph 6: "(T)he City requests that it be notified concurent with EP A, in the event that Settling Defendants become aware of any release or threatened release of a Waste Material that may pose an immediate threat to the public or the environment as set forth on Section VX of the Consent Decree. As the local first responder, the City requires concurrent notice of any such events."
EP A Response:

EP A will request that Crane Co. notify the appropriate City in the event that they become aware of any release or threatened release of a Waste Material that may pose an immediate threat to the public or the environment as set forth in Section XV ofthe
Consent Decree. To facilitate that process, the Cities should provide EP A with the

appropriate emergency contact. EP A will copy the Cities and other stakeholders on the notification request when it is distrbuted.
City of Goodyear, page 3, paragraph 4: City of Avondale, page 3, paragraph 1: "(T)he City formally requests that it continue to be included on the distribution list for all correspondence associated with the reporting requirements outlined in Section X the Consent Decree:" (Reporting Requirements) of
EP A Response:

For several years, representatives ofthe City of Goodyear, and more recently the City of Avondale as well, have been included on the distrbution list for correspondence related
to the Site. EP A will continue, as requested, to include both Cities on such distribution

lists and will make a formal request to Crane Co. to similarly include the Cities on all correspondence associated with the Consent Decree's reporting requirements. In the Consent Decree will be addition, all of the reports required pursuant to Section X of available to the public in the Site file maintained at EP A.

Case 2:03-cv-02226-ROS

Document 75-3

Filed 06/21/2006

Page 6 of 6