Deletion of the Midvale Slag Superfund Site

Responsiveness Summary

March 23, 2015

Introduction

A Notice of Intent to Delete for the Midvale Slag Superfund Site was published in the 

Federal Register on February 5, 2015 (80 FR 6946). The publication of this notice informed the 

public that EPA planned to delete the Site from the National Priorities List and provided a 30-

day public comment period on the proposed deletion. The closing date for comments on the 

Notice of Intent to Delete was March 9, 2015. One written comment was received (this

comment is available in the Information Repositories); therefore EPA has prepared this 

Responsiveness Summary. In addition, all public comments were considered in EPA’s final 

decision to delete the Site from the NPL. 

Responsiveness Summary

The Responsiveness Summary has been prepared to provide response to the comment 

submitted to EPA during the 30-day public comment period regarding the Notice of Intent to 

Delete (79 FR) the Midvale Slag Superfund Site. The original comment is provided below and is 

available at http://www.regulations.gov, Docket ID No. EPA-HQ-SFUND-1991-0006, with the 

support materials under document type “Public Submissions”, and at the information repositories 

at the following addresses:

The Ruth Tyler Branch Library, Midvale, UT 84047; Phone: 801-944-7641 

Or the EPA Web Page, www2.epa.gov/region8/Midvale slag

Or by calling EPA Region 8 at 303.312.7279 and leaving a message.

Comment and Response (comment is italicized)

Comments from Bryan M. Bliek, Freshman at Dartmouth College

I cannot support deletion. According to agency literature, the EPA may delete a final NPL site if 

it determines that no further response is required to protect human health or the environment. 

Has the EPA made enormous progress? Absolutely. But to say no further response is required is 

patently false and egregiously flouts the Superfund Amendments and Reauthorization Act, which 

emphasizes the importance of permanent remedies.

A main EPA objective was Protect Jordan River Water Quality. The cleanup of the Midvale Slag 

Superfund Site has greatly improved the local aquatic environment in the adjacent stretches of 

the Jordan River. However, a permanent remedy is impaired by external influences. In 2002, the 

EPA identified upstream Superfund sites that continue to contaminate the water in the Midvale 

Slag Superfund Site, including Kennecott. At Kennecott North, there is surface and ground water 

contaminated with heavy metals, the migration of which is pointedly described as not under 

control; at Kennecott South there is heavy metal in the surface and ground water, with especially 

high lead and arsenic levels. Combined, this specifically threatens the portion of the Jordan 
River under Midvale Slag Superfund Site jurisdiction. Thus, at this time, further response is 

absolutely required in order to protect human health, the environment, and the water quality of 

the Jordan River, as well as to create a permanent solution.

There is recourse. As long as the Midvale Slag Superfund Site remains on the NPL, it could 

characterize this threat as [a release of] hazardous substances that [is] serious, but not 

immediately life threatening explicit grounds upon which long-term remedial action can be 

implemented. Ideally, the EPA would deem it appropriate to realize this action by absorbing the 

Kennecott operational units (which are not NPL-designated) into the Midvale Slag Superfund 

Site, the justification being the overlapping area of impact (the Jordan River). Then, under 

Midvale Slags NPL powers, it could affect long-term remedial action at the source, a permanent 

solution to heavy metals contamination in the Jordan River.

Even if this scenario is technically and legally impossible, then the fact remains that there is no 

permanent solution for the Midvale Slag Superfund Site and that, indeed, there will have to be 

further action to protect human health and the environment, which should dissuade the EPA 

from pursuing deletion. Upstream contamination would continue ad infinitum, necessitating 

long-term remedial reactions and cleanup beyond the scope of mere operations, management, 

and five-year reviews. In turn, this necessitates the preservation of NPL status since, according 

to the Comprehensive Environmental Response, Compensation, and Liability Act, long-term 

remedial response actions are applicable only to NPL sites.

In summary, to pursue deletion now would declare Mission Accomplished prematurely, when 

there is clearly still a need to permanently protect human health, the environment, and the water 

quality of the Jordan River.” 

Response:

Results from on-going monitoring of groundwater and surface water show that the Jordan River 

water quality is not being impacted by the Site. This information is available in support 

documentation in the local repository and at http://www.regulations.gov, Docket ID No. EPAHQ-SFUND-1991-0006.

The Kennecott North and Kennecott South Sites which are located upstream, are not part of this 

Site. EPA is addressing Kennecott North and South like an NPL site pursuant to a Consent 

Decree settlement with Kennecott. The Consent Decree settlement includes appropriate response 

activities to address contamination in the Jordan River.

Section 300.425(e)(3) of the NCP states that the deletion of a site from the NPL does not 

preclude eligibility for further response actions, should future conditions warrant such actions. 

Therefore, even with deleting Midvale Slag from the NPL, this does not mean that EPA is 

finished. The EPA and the state will continue to implement and enforce the ICs, to perform

operation and maintenance, monitor groundwater and surface water, and perform five-year 

reviews.