3 0 M

PB95-964412

EPA/ROD/R08-95/106 May 1995

EPA Superfun d Record of Decision;

Midvale Slag (O.U. 1), Midvale, UT 4/28/1995
26472

DECLARATION OF RECORD OF DECISION ADMINISTRATIVE RECORD SITE NAME AND LOCATION

Midvale Slag, Operable Unit No. 1, Midvale, Utah i ILE PLAN

STATEMENT OF BASIS AND PURPOSE

This decision document presents the selected remedial action for Midvale Slag, Operable Unit No. 1 (OU1) in Midvale, Utah. The remedial action was chosen in accordance with the

requirements of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) as amended by Superfund Amendments and Reauthorization Act of 1986 (SARA),

and, to the extent possible, the National Oil and Hazardous Substances Contingency Plan (NCP). This decision is based on the administrative record for this site.

The Utah Department of Environmental Quality has jointly worked with the United States Environmental Protection Agency to select a remedy for OU1.

ASSESSMENT OF THE SITE

Actual or threatened releases of hazardous substances from OU1, if not addressed by

implementing the response actions selected in this Record of Decision, may present an imminent

and substantial endangerment to public, health, welfare, or the environment.

DESCRIPTION OF THE REMEDY

The response actions described in this Record of Decision address all known occurrences of

hazardous substances at OU1 that have been identified as contaminants and that present a cancer

risk, non-cancer hazard index or environmental risk in excess of established guidelines. These

occurrences constitute the principal threats at OU1.

The major components of the selected remedy include the following:

• Excavating the upper 18 inches of native soils at 14 residential yards in the Winchester

Estates residential development. The 18-inch depth is considered to be a minimum with

confirmatory sampling used to identify areas requiring additional excavation. Clean fill

would be imported to restore the original grade, and each yard will be restored as closely

as possible to its original condition. The wastes, being non-hazardous, would be

disposed of in Resource Conservation and Recovery Act (RCRA) Subtitle D landfill or

stored at the Midvale Slag OU2 Site pending rewsdy I§te5&m fcf OU2,„

i '': • Placing a 2-foot-thick monolayer soils cover on Parcel WESE (current undeveloped

southeast portion of Winchester Estates; zoned residential).

utahdeq\rod\text.apr
L

^ • Implementing deed restrictions or other institutional controls on Parcel WESE precluding

. most future excavation that would breach the monolayer soil cover. Any native soils

! from permitted excavation must be properly controlled on-site or disposed of in a RCRA

"~ Subtitle D Landfill.

^ • Implementing deed restrictions or other institutional controls on Parcels LR-east, LRwest, LF and LG which would prohibit future residential land use without additional

property remediation to residential soil cleanup levels.

• Ground water monitoring at the hydraulically downgradient site boundary (west and

north) for minimum of 5 years.

; DECLARATION

L The selected remedy is protective of human health and the environment, complies with Federal

and State requirements that are legally applicable or relevant and appropriate to the remedial L. action, and is cost-effective. This remedy utilizes permanent solutions and alternative treatment

technologies to the extent practicable for this site. However, because treatment of the principal

threats of the site was found not to be practicable, this remedy does not satisfy the statutory

_ preference for waste treatment as a principal element of the remedy. OU1 wastes are comprised

of metal-bearing particles (slag and other wastes) finely disseminated throughout a large volume I of soil. The large volume of soils coupled with the absence of a technology capable of

— practically removing the metal contaminants from the matrix precludes waste treatment as an

option.

- Implementing this remedy will result in hazardous substances remaining on OU1, therefore a

review will be conducted within 5 years after commencement of remedial action to ensure that

, the remedy continues to provide adequate protection of human health and the environment. The u

 5 year review will be conducted as required under Section 121 (c) of CERCLA and 40 CFR. §

300.430 (f)(4)(ii) of the NCP.

_ ...._ _.._ _ Director, Hazardous WasWManag^ent Division USEPA Region Vm ^ S

a Executive Director Date Utah Department of Environmental Quality L

utahdeq\rod\textapr
TABLE OF CONTENTS

Section Title Page No.

I SITE NAME, LOCATION, AND DESCRIPTION .................... 1

n SITE HISTORY AND ENFORCEMENT ACTIVITIES ................. 

History of Site Activities History of Federal and State Site Investigations History of CERCLA Enforcement Activities

m HIGHLIGHTS OF COMMUNITY PARTICIPATION ........

IV SCOPE AND ROLE OF RESPONSE ACTION ..................... 5

SUMMARY OF SITE CHARACTERISTICS ......

Geology and Geography Hydrogeology Known and Suspected Sources of Contamination Distribution of Contamination/Affected Media Volume of Contaminated Material Potential Routes for Human Exposure

VI SUMMARY OF SITE RISKS ................................ 8 Exposure Point Concentrations

Exposure Assessment Toxicity Assessment Risk Characterization Uncertainties Environmental Risks

VH REMEDIAL ACTION OBJECTIVES ........................... 13

VIE DESCRIPTION OF ALTERNATIVES .......................... 14 Alternative No. 1 Alternative No. 2 Alternative No. 3 Alternative No. 4 Alternative No. 5 Alternative No. 6

K SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES ....... 18 Criterion 1: Protection of Human Health and the Environment Criterion 2: Compliance with ARARs Criterion 3: Long-Term Effectiveness Criterion 4: Use of Treatment to Reduce Toxicity, Mobility, and Volume Criterion 5: Short-Term Effectiveness

Wahdeq\rod\tcxt.apr Page i
Table of Contents (Continued)

Section Title Page No.

Criterion 6: Implementability Criterion?: Cost Criterion 8: State Acceptance Criterion 9: Community Acceptance

X SELECTED REMEDY ................................... 22

XI STATUTORY DETERMINATION ............................ 

Protection of Human Health and the Environment Compliance with ARARs Cost-Effectiveness Utilization of Permanent Solutions and Alternative Treatment Technologies Preference for Treatment as a Principal Element

XH RESPONSIVENESS SUMMARY ............................. 

Overview Background on Community Involvement Comments Received During the Public Comment Period

XIH REFERENCES ........................................ 55

APPENDIX

A APPLICABLE, RELEVANT OR APPROPRIATE REQUIREMENTS Al Groundwater ARARs A2 Action-Specific ARARs A3 Location-Specific ARARs

TABLES

1 Exposure Point Concentrations

2 Summary of Human Exposure Parameters

3 Total Site Risk Estimates

4 Soil Clean-up Levels

5 Reduction in Soil Contaminant Concentrations Under the Selected Remedy

6 Total Site Risk Reduction Under Selected Remedy

utahdcq\rod\tcxt.*pr , Page ii
Table of Contents (Continued)

FIGURES

1 Midvale Slag Superfund Site Index Map

2 Midvale Slag Site OU1 Parcels

3 Infrared False Color Aerial Photograph

4 Conceptual Model of Exposure Pathways at OU1

5 Winchester Estates RME Cancer Risk From Arsenic

6 Winchester Estates Chronic Hazard Index From Arsenic

7 Winchester Estates Probability of Blood Lead Exceeding 10 ug/dl

8 Point of Compliance for Ground water ARARs

utahdeq\rod\tea.»pr Page iti
L

L

L

*

LDECISION SUMMARY

M ID VALE SLAG OUI SITE MTOVALE, UTAH
L SITE NAME, LOCATION, AND DESCRIPTION

The Midvale Slag Superfund Site encompasses approximately 530 acres. The site is located 12 miles south of Salt Lake City, Utah, and is almost completely within the city limits of Midvale (Figure 1). Operable Unit No. 1 (OU1) encompasses approximately 330 acres (Figure 2) and

is bounded by the following: an east/west line drawn north of the slag piles at approximately

7250 South Street marks the southern border; the Jordan River marks the western border; 6400 South Street marks the northern border; and 700 West Street marks the eastern border. OU1

also includes the Winchester Estates area, the abandoned Midvale Wastewater Treatment Plant (WWTP), and the lagoons area. Because of the unique characteristics of each portion of OU1

and to facilitate the organization of the remedial investigation (PI), OU1 was subdivided into the

following parcels:

• LR - The area occupied by the right-of-way for the proposed Jordan River Boulevard; the southern one-third of OU1.

• LF - The west-central portion of OU1 (site of a small landfill). • LG - The area occupied by the abandoned WWTP lagoons; the east-central

portion of OU1.

• WE - The area occupied by the Winchester Estates; the northern one-third of OU1; bounded on the north by 6400 South and on the west by the Jordan River.

The Winchester Estates Parcel was further subdivided into the following subparcels:

• WENW Residential - The northwestern portion of OU1 that includes the current Winchester Estates residential development; bordered on the north by 6400 South Street and on the west by the Jordan River.

• WESE - The undeveloped southeast portion of Winchester Estates; bordered on

the east by South Main Street.

H. SITE HISTORY AND ENFORCEMENT ACTIVITIES

History of Site Activities

Little information is available describing historical activities on OU1 prior to the 1940s. Before

that time, it is generally believed that the land was used as pasture with no industrial activities. A 1952 aerial photograph of the southern two-thirds of OU1 showed no evidence of

commercial/industrial use or disturbed ground with the exception of a small landfill (less than

1 acre) and an associated unpaved road. Disposal of domestic trash and household goods

occurred on the southwest corner of the LF Parcel from approximately the 1940s until a landfill

was established by the county in the 1960s. The South Valley Water Reclamation District

operated the Midvale WWTP on the Midvale OU1 Site (LR Parcel) from 1959 until 1986. The

plant originally consisted of a trickling filter system. An aerated lagoon system consisting of

three lagoons was added in 1976 and operated until the closure of the WWTP in 1986. The

lagoons were closed according to an approved Closure Plan and material excavated as part of

the Interstate Highway 215 construction project was subsequently deposited on the former lagoon

location.

utahd«i\rod\text.apr Page 1
The land to the south of the Midvale Slag OU1 Site was the site of historical smelting activities

beginning in 1871 and ending in 1958. It is the smelting activities that are presumed to account

for the contaminants detected at OU1. The former smelter site is being addressed under CERCLA as Operable Unit 2 of the Midvale Slag Site.

History of Federal and State She Investigations

The U.S. Environmental Protection Agency (USEPA) conducted a Preliminary Assessment (PA)

and Site Inspection (SI) of the Midvale Slag Site in 1984. The PA report described the presence

of air- and water-quenched slags and recognized that smelting residues of sulfide ores may

contain significant quantities of arsenic. The PA report recommended further action on the site

and that the action be given a high priority. The SI report gave the site a Hazard Ranking of

77.08 and declared that a significant and immediate hazard appears to exist at the site. The SI

report recommended that the site be included in the next update of the National Priority List as

a proposed site for remedial action under CERCLA.

In August 1985, Ecology and Environment (EE), a Technical Assistance Team contractor,

conducted an investigation of surface water and sediment in the Jordan River. This investigation

concluded that no significant contamination of surface water could be detected. Jordan River

sediment was found to contain elevated levels of arsenic, cadmium, chromium, cobalt, lead, manganese, mercury and zinc as compared with local background sampling stations upstream

of the Midvale site. The EE report also concluded that further definition of surface waters may

be necessary.

USEPA and Utah Department of Environmental Quality (UDEQ) subsequently funded

investigative and remedial activities from 1992 to the present including a Site Characterization, Baseline Human Health Risk Assessment (BRA), Feasibility Study (FS), and Ecological

Evaluation. The results of this work indicate that elevated levels of arsenic, cadmium and lead

in surface soils pose an unacceptable risk to some residents in the developed area (Winchester Estates). The BRA concluded that, if the undeveloped portions of OU1 should be developed,

exposure to surface soils could result in unacceptable health risks depending on the type of land

use. Details of the BRA are summarized in Section VI, Summary of Site Risks.

History of CERCLA Enforcement Activities

Under CERCLA a search is conducted to identify those parties responsible for the contamination

at the site in order to secure monetary compensation for the costs incurred to investigate and

clean up the site.

The Potentially Responsible Party (PRP) Search for the Midvale Slag Site was conducted for Region Vm of the USEPA by Camp, Dresser & McKee, Inc., under REM n Contract, Work Assignment No. 323-8671. The final PRP Search was submitted to USEPA on November 14,

1986.

utahdeq\rod\lexLipr Page 1
On April 27, 1988, USEPA Region Vm sent General Notice Letters to the following PRPs:

1) UV Industries, c/o Paid Kolton

2) Century Tenninals/Blackhawk Slag, c/o Roberta McConnell

3) Sharon Steel Corporation, c/o Alan Bell

4) Valley Materials, c/o Robert Stringer

5) Littleson, Inc., c/o U.S. Corp Co.

6) Butterfield Joint Ventures, c/o Gerald Butterfield

On March 23, 1989, Notice Not To Notice Letters were sent to the above list of PRPs as a follow-up to the General Notice Letters. These letters explained to the PRPs that USEPA would

not invoke special notice procedures and offered the opportunity to voluntarily perform the RI/FS . On May 16, 1989, the firm of Parsons, Behle & Latimer informed USEPA that the "Valley Materials Group" included: Century Tenninals/Blackhawk Slag, Valley Materials Corp., and Littleson, Inc. The firm represented Littleson, Inc., d.b.a Valley Materials Corp. and Century Terminals, Inc. d.b.a. Blackhawk Slag.

In response to a CERCLA Section 104(e) request, Robert L. Soehnlen, President of Littleson, Inc. informed USEPA that Valley Materials Corporation ("Valley Materials") was merged into Littleson, Inc. on or about December 1986. Littleson, Inc. was the surviving corporation.

On September 27, 1990, USEPA's Regional Counsel notified Littleson's attorney (Thomas N. Crowther) that USEPA intended to conduct an RI/FS at the Midvale Slag Site. Littleson was

given the opportunity to participate through the possible negotiations of an Administrative Order

on Consent. In a phone conversation, USEPA was informed by Littleson's attorney that Littleson was not interested in any negotiations.

Littleson, Inc. was issued a letter of "Notice of Decision Not To Use Special Notice Procedures

(for) Remedial Design/Remedial Action (RD/RA) on September 27, 1993. This letter was a

solicitation of interest to participate in RD/RA activities at the Site. USEPA indicated in the

letter that a lack of response by Littleson would be construed as a refusal to "...negotiate a resolution of liabilities in connection with the response....", and the letter further considered a

lack of response from Littleson as declining "...any involvement in performing the response

activities." Littleson, Inc. did not respond to this Notice Letter.

The Superfund Liability at the Midvale Slag Site for UV Industries, UV Liquidating Trust and Sharon Steel was settled in a Consent Decree dated November 13, 1990.

The Superfund liability at the Midvale Slag Site for Littleson, Inc. (or Valley Material Group)

has not been settled at this date.

HIGHLIGHTS OF COMMUNITY PARTICIPATION

UDEQ and USEPA community relations staf f conducted interviews with residents in the

impacted area to determine their concerns. As part of these interviews, each interviewee was

utahdeq\rod\text.apr Page 3
asked what would be the most effective way to keep the public involved. These suggestions

were incorporated into a Community Relations Plan, developed by URS (an USEPA contractor)

and adopted in 1991. All public documents relating to OU1 were made available at the Ruth Vine Library in Midvale. Municipalities such as the cities of Midvale and West Jordan as well as the Utah Department of Transportation were particularly interested in how Superfund activities would impact the

proposed extension of the Jordan River Boulevard through the OU1. Regular meetings were

held between these interested parties beginning in 1990. Officials from the cities were briefed

periodically, and UDEQ responded to requests for information from potential businesses seeking

to locate in the area.

In preparation for a soil sampling program conducted in 1991 at Winchester Estates residential

yards, a pre-sampling meeting was held with the owner of the trailer park. When the sample

analyses were completed, an availability session was held at which residents could pick up their

sample results and talk to representatives of USEPA and UDEQ about the results. Fact sheets

were mailed to interested parties, and a public informational meeting on the status of the site was

held on 2 May 1991.

Additional sampling of residential yards in late 1993 was preceded by meetings between UDEQ

and the trailer park manager who subsequently notified the residents of the planned field

activities. The results of the second round of sampling were mailed to individual residents.

A Proposed Plan, outlining USEPA's and UDEQ's preferred remedy and the public participation

process, was mailed on 7 July 1994. An advertisement was placed in the Salt Lake Tribune

providing notice on the availability of the Proposed Plan, the time and location of the public

meetings and the duration of the public comment period (11 July through 10 August). A public meeting was held on 27 July 1994 at the Midvale City Hall in the city council

chambers. Approximately 35 members of the community were present with questions focusing

on the compatibility of the preferred remedy with future development plans for OU1. Prior to

the public meeting the Citizens For A Safe Future For Midvale (Citizens Group) requested a 30-

day extension of the public comment period so that an independent contractor could review the FS Report for technical accuracy. The contractor would be hired by the Citizens Group using

funds provided by a USEPA Technical Assistance Grant. The extension was granted and an

advertizement was placed in the Salt Lake Tribune providing notice that the close of the public

comment period was extended to 10 September 1994.

A second extension was requested by the Citizens Group on 9 September 1994, and was denied

by USEPA on 12 September 1994. The basis for the denial was the fact that the documents to

be reviewed by the Citizens Group had been available to the public for several months prior to

the issuance of the Proposed Plan. At the close of the public comment period, written comments had been received from the Citizens Group; Mr. David Ovard of the Salt Lake County Water Conservancy District; Mr. Bruce Nieveen, Environmental Engineer for Midvale City; and Mr. Volney Wallace, a private

citizen. Responses to these comments are included in this Record of Decision (ROD)

(Section XII).

Btahdeq\rod\tcxt.»pr Page 4
I V. SCOPE AND ROLE OF RESPONSE ACTION

The Midvale Slag Site has been divided into two OUs. This was done to permit the expeditious

completion of an RI/FS and remedial action on OUI to accommodate the proposed Jordan River Boulevard (TRB) construction. The proposed JRB alignment traverses OUI from west to east.

While OUI is mostly vacant land, OU2 is the site of a former smelting operation and in many

places is covered with piles of waste material associated with smelting such as slag, calcine, and

tailings. It is inferred from the OUI RI and other data that contaminants detected on OUI were

transported from OU2 by wind, surface water, and man.

The response actions presented in this ROD will address contaminants that have been transported

onto OUI from the "source areas" on OU2. A separate Engineering Evaluation/Cost Analysis (EE/CA) for OU2 is under way, and response actions to address the source area(s) will be

implemented, if appropriate.

V. SUMMARY OF SITE CHARACTERISTICS

Geology and Geography

The OUI area is located in the Salt Lake Valley, a north-south oriented topographic feature

bounded to the west by the Oquirrh mountains and on the east by the Wasatch Range. Thrusting, faulting, folding, and igneous intrusions are responsible for the presence and form

of these mountain ranges. These ranges are the source of the Quaternary alluvial sediments that

overlie much of the valley floor.

OUI lies on the Jordan River floodplain and slopes gently to the west, towards the river. Floodplain soils consist of silty clay loams, silty clays, sands, and gravels. Sand and gravelly

fill materials from an 1-215 highway construction project were spread over the southeastern

portion of OUI, primarily Parcel LG and the eastern portion of Parcel LR. The thickness of

fill materials was determined by borehole data to range from zero at the western margin of the

fill to 19 feet along the eastern edge of Parcels LR east and LG (URS, 1992). Figure 3 is an

infrared false-color photograph of OUI taken shortly after placement of the fill . The fill material consistently grades to a silty and sandy clay at the native soil interface. The

top 30 feet of the native zone typically is an organic, sticky clay, silty in places and becoming

sandier downward. The clay is underlain by fine- to medium-grained sand, which coarsens

downward and often grades into gravelly sands or sandy gravels. The occurrence of slag layers

within the native soil zone was noted during drilling in the spring of 1992. These occurrences

appeared to correlate with the presence of relatively high metals content based on chemical

analyses. The slag layers were noted throughout OUI but were most apparent on the LG and LR parcels.

ufehdcq\rod\tcxt.apr page 5
Hvdrogeology

The shallow water-bearing zone is unconfined and is composed of clay, silt, and sand beds with

common gravel beds that are often clayey and sandy. Typically, the water table is encountered

between 5 and 20 feet below the ground surface.

Generally, ground water flow in the Upper Sand and Gravel Aquifer is northwesterly, but varies

seasonally from southwesterly to northerly beneath portions of the site. The groundwater

velocity is estimated to range between 0.22 and 1.87 feet/day.

Known and Suspected Sources of Contamination

There are no known discrete waste sources at OUI. The only suspected waste features within

the OU boundaries are a small landfill and an abandoned WWTP (and associated lagoons). Site

characterization data suggest that both of the features have not contributed to elevated levels of

the contaminants of concern (arsenic, cadmium and lead) detected in site soils.

It is inferred from available data that the metal (and metalloid) contaminants detected on OUI

are derived from discrete waste sources identified on OU2. The transport mechanisms

postulated to account for contaminants at OUI include the following:

• Wind transport of slag dust onto OUI from slag piles on OU2.

• Surface water transport of slag dust and possibly larger particles onto OUI from

slag piles on OU2.

• Fallout of smelter fume onto OUI from smelter chimneys on OU2 and/or the

south chimney on OUI of the Sharon Steel site.

• Deliberate placement of slag and possibly other smelter waste onto OUI to fill

wetlands or other low areas and to sand roads in the Winchester Estates

development during snow or ice events.

Distribution of Contamination/Affected Media

Discrete surface and subsurface native soil samples, and discrete ground water, sediment, and

surface water samples were collected during the RI. Analytical parameters included metals,

volatile and semi-volatile organic compounds (VOC and SVOCs, respectively), and

pesticides/polychlorinated biphenyls (PCBs). Metals were detected in all media sampled; VOCs

were detected in ground water and some subsurface soils; SVOCs were detected in all media

sampled; and pesticides/PCBs were detected in soils, surface water, and sediment.

All chemical detections were screened during the RI/FS to determine which of the detections

were actual site contaminants. The data were further screened in the BRA to determine which

of the contaminants contributed significantly to cancer and non-cancer risk. Screening methods

included exclusion based on frequency of detection, exclusion based on potential laboratory or

utahdeq\rod\tcxt.apr Page 6
field contamination, exclusion based on background comparisons, exclusion based on

beneficiality (minerals considered essential or beneficial to good health), and the results of the

risk quantification (only those chemicals posing significant human health risks were considered

to be contaminants of concern [COCs]). Based on these criteria, and on experience at similar

smelting sites, UDEQ/USEPA designated arsenic, cadmium, and lead as the COCs at OU1.

In addition to screening chemical detections for those chemicals posing significant health risks,

the BRA identified which environmental media contain concentrations of COCs high enough to

pose a significant threat to the public. Based on this analysis, UDEQ/USEPA identified surface

and subsurface soils as the only media of concern.

The distribution of the COCs in soils at OU1 demonstrates few discernable patterns. Typically, COC concentrations decrease with depth although a few pockets exhibiting high COC

concentrations have been noted at depths up to 6 feet below the native soils surface. The

horizontal distribution of COCs shows no clear concentration gradients, with some of the highest

concentrations found in the Winchester Estates development at the far northern end of OU1. Typically the highest COC concentrations were found in association with visible slag.

Arsenic concentrations in soils range up to the low 1,000's of milligrams per kilogram (mg/kg),

but more typically range from the 10's to 100's of mg/kg. Cadmium occurs as high as 97 mg/kg, but more typically ranges from 0.5 to 10 mg/kg. Locally, lead concentrations in the

1,000's mg/kg were detected with typical concentrations in the 10's and 100's of mg/kg. In

general, when one COC occurs at a high concentration, the other COCs are proportionally

elevated as well. Results of toxicity characteristic leaching procedure testing of the most highly

contaminated soils on OU1 reveal that they are not toxicity characteristic hazardous wastes.

The potential exists for mobilization of contamination from soils to ground water. However, OU1 wastes have been present on the site for many years and in some locations groundwater is

in direct contact with visible slag without appreciable affect s on groundwater. COC

concentrations in OU1 ground water are below Federal Maximum Contamination Limits

(MCLs). See Section IX for a more thorough discussion of ground water applicable or relevant

and appropriate requirements (ARARs). Arsenic displays both carcinogenic and non-carcinogenic effect s (skin lesions, neurotoxicity,

liver and kidney effects). When ingested, cadmium displays only non-carcinogenic effect s (kidney damage). Although thought to be a weak carcinogen, the main basis for concern with

lead is non-carcinogenic effect s (neurotoxicity and reproductive effects). Lead effect s are of

concern primarily for children since they are more susceptible to the effect s of lead and also tend

to have higher exposure.

Volume of Contaminated \tatcrial

The lack of distinct waste piles on OU1 coupled with the presumed mechanisms for deposition

of the COC make waste volume estimation difficult . COC deposition by surface water and wind

transport of slag from OU2, and smelter fume fallout would be expected to result in a variable

distribution of contaminants, the details of which may not be resolved by the sample spacing

(approximately 100-feet) employed during the RI. As a result, determining the distribution of

«tahdcq\rod\textapr Page 7
waste "pockets" would involve an intensive sampling and analysis program. Such a sampling

effort was considered impractical based on costs and the time requirements given the size of OU1.

Therefore, for any given parcel where the exposure point concentration (EPQ calculated as the

upper 95th confidence limit of the arithmetic mean (assuming a lognormal distribution) exceeds

clean-up levels, the entire parcel is considered contaminated. The assumed depth of

contamination is based on the presumed maximum depth of likely human exposure and is

uniform across the entire parcel. For the LF, LG, LR, and WESE parcels, that depth is 10 feet

below the native soil surface. For the WENW Parcel (current residential area), the depth is 1.5

feet.

Soil clean-up levels have been set based on standard exposure scenarios using a population

appropriate for the current land zoning. For Parcels LR-east, LR-west, LG and LF, the EPCs

do not exceed these levels. Therefore, no material requiring remediation exists on these parcels. Soil clean-up levels and EPCs are discussed in detail in Sections VI and Vn.

For Parcel WESE, the EPCs exceed the clean-up levels, and the entire parcel is considered

contaminated to a depth of 10 feet. For Parcel WENW clean-up levels are exceeded on 14

residential yards. The combined volume of contaminated material for these two parcels is

approximately 185,000 cubic yards (cy).

Potential Routes For Human Exposure

Much of the site is currently undeveloped or fenced and the only exposed population is the

hypothetical trespasser. However, Parcel WENW is currently occupied by single family

dwellings. These individuals are exposed to site wastes in the form of contaminated surface soil

and house dust on a daily basis.

Hypothetical future residents/workers would be exposed to COC-containing surface soils on Parcel WESE, and portions of Parcels LF and LR-west. Although COC-containing native soils

are present on Parcels LG and LR-east, both of these parcels are entirely covered with fill

material imported during the construction of an 1-215 interchange. Therefore, the only possible

exposure would involve excavating through the fill and into the native soils during building

construction associated with future land development. The excavated native soils would have

to be spread on the land surface and remain at the surface for a long-term exposure to occur.

V I. SUMMARY OF SITE RISKS

Exposure Point Concentrations

As discussed in Section V, arsenic, cadmium and lead were determined to be the COCs, and

surface and subsurface soils were considered to be media of concern for the purpose of

developing remedial alternatives. However, because the COCs occur in ground water (below Federal MCLs), the contribution to cancer and non-cancer risk made by ground water was

incorporated into the risk estimation.

utahdeq\rod\text.«pr Page 8
Exposure point concentrations of COCs in soil were calculated using chemical data for native

soils sampled between 0 and 1 foot below the native soils surface. It is assumed that the vast

majority of a current or hypothetical future exposure would involve shallow soils. EPCs were

calculated and evaluated for each parcel and are summarized on Table 1.

Exposure Assessment

The BRA (Life Systems, Inc. [LSI], 1992) evaluated a number of plausible exposure pathways

for current and future residents and future workers. Based on the results of the risk assessment,

the exposure pathways of primary concern are those shown in Figure 4.

Under current site conditions, the population most likely to be exposed is the residents in Winchester Estates. Exposure routes of main concern are ingestion of soil and dust. Ingestion

of vegetables is of lesser concern. Ingestion of ground water was not evaluated because the

homes are supplied with municipal water. In the future, currently vacant areas of OU1 might

be developed for commercial use, especially if the proposed JRB is completed. Therefore,

potential exposures for hypothetical future workers were also assessed.

As with the residents, the exposure pathway of greatest concern for future workers is direct

ingestion of contaminated soils and dust. This includes exposure to native soils that are

currently on the surface, and to buried native soils that might be brought to the surface by

excavation. In addition, future workers might be exposed to ground water drawn from wells

installed at the site, and exposures of this population via ingestion of ground water were also

evaluated.

Other exposure pathways were considered in the BRA. However, it was determined that direct

ingestion of soils (including house dust) and ground water are the only significant pathways. Subsequent to the BRA, a second risk characterization was performed to support the selection

of remedial goals and the development of remedial alternatives. This effort was performed by Roy F. Weston, Inc. (WESTON®), under contract to UDEQ and was presented in the Final FS Report (WESTON, 1994). Differences between the original and revised risk calculations include

the use of additional surface soils chemical data collected at the Winchester Estates development,

use of a lower bioavailability factor (0.8) for arsenic in soils and house dust, as well as other

more minor changes detailed in the FS Report. In addition, the revised risk characterization

quantified the risk posed only by the COCs and only for the direct ingestion of soils, house dust,

garden vegetables, and ground water.

Table 2 summarizes the amounts of soil (including house dust), and ground water assumed to

be ingested by a child or adult per unit of body weight. These intake factors coupled with the

EPCs and toxicity factors for each COC form the basis for the risk calculation.

Toxicity Assessment

Toxic effect s of exposure to COCs can be separated into cancer causing effect s and non-cancer

effects. Cancer slope factors have been developed by USEPA's Carcinogen Assessment Group

for estimating excess lifetime cancer risks associated with exposure to potentially carcinogenic

utihdeq\rod\texUtpr
chemicals. Slope factors, which are expressed in units of (mg/kg-day)*1

 are multiplied by the

estimated intake of a potential carcinogen, in mg/kg-day, to provide an upper-bound estimate

of the excess lifetime cancer risk associated with exposure at that intake level. The term "upperbound" reflects the conservative estimate of the risks calculated from the slope factor. Use of

this approach makes underestimation of the actual cancer risk highly unlikely. Slope factors are

derived from the results of bioassays to which animal-to-human extrapolation and uncertainty

factors have been applied. Slope factors have been developed for different routes for human

exposure (inhalation, ingestion, etc.). However, because direct ingestion of OU1 COCs is

considered the only significant exposure pathway, only the oral slope factor is used. Of the OU1 COCs, only arsenic has cancer causing effect s by the oral pathway. The oral slope factor for

arsenic is 1.8E+00 (mg/kg-day)-1.

Reference doses (RfDs) have been developed by USEPA for evaluating the potential for adverse

non-cancer health effect s from exposure to chemicals exhibiting non-carcinogenic effects . RfDs, which are expressed in units of mg/kg-day, are estimates of daily exposure levels for humans,

including sensitive individuals, which are without significant risk of non-cancer effects. Estimated intakes of chemicals from environmental media (e.g., the amount of a chemical

ingested from contaminated drinking water) can be compared to the RfD. RfDs are derived

from human epidemiological studies or animal studies to which uncertainty factors have been

applied (e.g., to account for the use of animal data to predict effect s on humans). These

uncertainty factors help ensure that the RfDs will not underestimate the potential for adverse

non-carcinogenic effect s to occur. The oral RfD for arsenic and cadmium are 3.0E-4 mg/kg-day

and l.OE-3 mg/kg-day, respectively.

Lead is a special case since there are no USEPA-approved RfD values for lead. The method

for calculating the non-cancer risks due to lead is detailed below.

Risk Characterization

Excess lifetime cancer risks are determined by multiplying the intake level with the slope factor. These risks are probabilities that are generally expressed in scientific notation (e.g., 1 x 10"1

 or IE-1). An excess lifetime cancer risk of IE-6 indicates that, as a plausible upper bound, an

individual has a one in one million chance of developing cancer as a result of site-related

exposure to a carcinogen over a 70-year lifetime under the specific exposure conditions at the

site.

Table 3 shows the estimated total excess cancer risks for hypothetical future populations on each

of the undeveloped parcels based on the current land zoning. Figure 5 shows the estimated total

excess cancer risk for the existing population (residential) at the Winchester Estates development

on a residential yard-by-yard basis.

For Parcels LR-east, LR-west, LF and LG, potential cancer risks to hypothetical future workers

are within the USEPA's range of acceptable risks (IE-4 to IE-6). However, for hypothetical

future residents on Parcel WESE, the potential cancer risk exceeds the acceptable range. For

current residents on the Winchester Estates development (Parcel WENW), the potential cancer

risks exceed the acceptable range on 11 of the residential yards. All of the cancer risk

probabilities presented on Table 3 and Figure 5 are due to arsenic.

utihdcq\rod\l£Xt.apr Page 10
Potential concern for non-carcinogenic effect s of a single contaminant in a single medium is

expressed as the hazard quotient (HQ)(or the ratio of the estimated intake derived from the

contaminant concentration in a given medium to the contaminants RfD). By adding the HQ's

for all contaminants within a medium or across all media to which a given population may

reasonably be exposed, the Hazard Index (HI) can be generated. The HI provides a useful

reference point for gauging the potential significance of multiple contaminant exposures within

a single medium or across media.

The chemical-specific HI values for the populations (current and hypothetical future based on

current land zoning) exposed at the site are summarized in Table 3. The Hi's for arsenic and

cadmium were not summed because their effect s are judged not to be additive.

COC concentrations equivalent to an HI equal to or greater than one may cause non-cancer

effects . As shown on the table, for Parcels LR-east, LR-west, LF and LG, the HI for

hypothetical future workers is less than one, indicating non-cancer risks are not of concern. However, for hypothetical future residents on Parcel WESE, the HI exceeds one. For current

residents on the Winchester Estates development (Parcel WENW), the HI exceeds 1 on 10

residential yards. Figure 6 illustrates the distribution of HI values on a yard-by-yard basis.

The non-cancer effect s of lead were evaluated using a mathematical model developed by USEPA called the Uptake/Biokinetic (UBK) Model. The model predicts the probability of a child having

a blood-lead concentration over 10 micrograms per deciliter (pg/dl) given the following inputs:

• Lead concentration in a given medium or media.

• Human child intake of the medium.

• Absorption fraction of lead from the medium.

• Biokinetic slope factor relating blood lead to absorbed dose.

If a child has a 5% or less chance of exceeding a blood lead concentration of 10 pg/dl , the

concentration of lead in the environmental medium is considered to be acceptable. The model

results for hypothetical future residents on Parcel WESE are summarized on Table 3. For Parcel WESE, the model results indicate a 3% probability of exceeding a 10 jig/dl blood-lead

concentration, which is considered acceptable. Because the UBK model applies only to children,

the model was not run for workers in Parcels LR, LG, and LF. For Parcel WENW (current

residential development), the model was run for each individual residential yard, and the results

are illustrated on Figure 7. For this parcel, 13 residential yards exceed the USEPA threshold

criterion of 5%.

Uncertainties

There are a number of steps in the risk assessment process where uncertainty exists. In general, USEPA employs conservative assumptions when uncertainties and data gaps exist. For example, USEPA intentionally seeks to calculate doses to humans that on average are higher than most

people would actually receive, but are still within a reasonable range. Likewise, in order to

preserve a margin of safety, USEPA employs estimates of chemical toxicity that are

intentionally conservative; that is, they are more likely too high than too low. An example of

this is the cancer slope factor in which the "upper-bound" reflects the conservative estimate of

utahdeq\rod\text.ipr Page 11
the risks calculated from the cancer slope factor. Use of this approach ensures that risk

estimates and clean-up goals are conservative.

Environmental Risks

In order to determine and evaluate the threat or potential threat to the environment posed by

contamination at the Midvale Slag Site, OU1, an Environmental Evaluation was prepared by Life Systems as a part of the BRA process (NCP, 40CFR300.420 [d] [4]).

The scope of the evaluation was limited to considering the potential exposures and impacts to

selected ecologic resources from site-related contamination. This summary addresses only OU1

(the northern part of the Site). However, it may be recognized that potential ecologic receptors

in both the terrestrial and aquatic environment are mobile and may cross operable unit

boundaries as well as move on- and off-site without any real restrictions.

The data used in this evaluation are limited to soil, surface water, and sediment data collected

within the boundary of the OU, and the surface water and sediment data from the Jordan River.

Contaminants of potential ecologic concern are chemicals present on the OU that could pose a

risk of adverse impacts to exposed ecologic receptors. Contaminants of concern were selected

for the ecologic evaluation using the same guidelines applied in the Human Health Evaluation.

As determined at many other mining/smelter waste sites, risk is nearly always dominated by

arsenic, cadmium, and/or lead. Additionally, copper, zinc, and aluminum are commonly of

concern for aquatic receptors on such sites. At the Midvale Slag Site, the potential toxic effect s

appear to be dominated by arsenic and lead found in the site soils.

The potential for adverse effect s from exposure to COCs at OU1 was evaluated using the

following combination of approaches:

1) Comparison of measured soil concentrations to concentrations of metals in soils

known to be toxic to plants and soil invertebrates (e.g., worms, snails, slugs,

insects, mites, etc.).

2) Comparison of measured sediment concentrations to concentrations of chemicals

associated with adverse biological effect s at other sites.

3) Comparison of measured surface water concentrations to Federal Ambient Water Quality Criteria and the Utah Water Quality Standards.

4) Identification of site-related chemicals with the potential for food-chain transfer.

5) Identification of site-related chemicals that are toxic to mammals and birds

potentially exposed to site soils and sediments.

Using the above approaches, the ecologic evaluation determined that the potential for adverse

effect s to plants and animal communities do exist at the Midvale Slag Site. The USEPA is not

utahdcq\rod\tcxt.apr Page 12
aware of any critical habitats affected by site contamination, nor of any endangered species or

habitats of endangered species affected by site contamination.

Furthermore, the finding of potential adverse ecologic effect s at the Midvale Slag Site is

tempered by a significant number of uncertainties including: 1) a nonstatistical comparison

between site sample concentrations and background concentrations; 2) unknown length of

exposure of site receptors to contaminants in soils, surface water, and sediments; 3) unknown

biological uptake resulting from exposure to chemical concentrations in environmental medial

(bioavailability); 4) use of calculated toxicity reference values (TRY) for determining soil

toxicity levels; and 5) use of surrogate species for development of acceptable soil

concentrations.

Although USEPA recognizes the potential for adverse ecologic effect s as discussed in the Environmental Evaluation of the BRA, the intended future use of this Operable Unit as a commercial/industrial development site coupled with the cost and technical impracticability of

a pristine clean up precludes the need to take any action to address these potential effects.

V IL REMEDIAL ACTION OBJECTIVES

Remedial action objectives were developed by USEPA and UDEQ based on an evaluation of the BRA. The objectives incorporate joint decisions on risk management issues and were used to

guide development of remedial alternatives and clean-up levels.

As discussed in Section V, USEPA/UDEQ selected arsenic, cadmium and lead as the COCs at OU1. In addition, soil was determined to be the only medium of concern.

Clean-up levels are media-specific concentrations of COCs which represent human health risk

equivalent to a pre-specified cancer risk, HI or distribution of blood-lead levels. Clean-up levels

are presented in Table 4 and are calculated using the same exposure algorithms used to calculate

health risks incorporating the expected media-specific ingestion rates, exposure duration, and

body weight for the exposed population. Using these variables, the carcinogenic and noncarcinogenic toxicity of a given COC (slope factor or RfD, respectively) and a target risk level,

one can solve for the clean-up level. For current and hypothetical future residents, clean-up

levels for arsenic, cadmium and lead are 73 rag/kg, 49 mg/kg and 650 mg/kg, respectively. For

hypothetical future workers, clean-up levels for arsenic and cadmium are 960 mg/kg and 2,980

mg/kg, respectively. Because lead is of primary concern for children, a clean-up level was not

calculated for worker exposure.

Clean-up levels can also be ARARs, however, ARARs do not exist for soils, so clean-up levels

are the health-based concentration thresholds calculated by the method described above.

Clean-up levels developed for OU1 are chemical-specific concentrations in soils that when

achieved will result in a cancer risk of IE-4 or less and a HI of less than 1. These clean-up

levels take into consideration the total site risk due to ingestion of ground water (excluding Parcel WENW where residents are served by municipal water), ingestion of soil, ingestion of

house dust, and ingestion of garden vegetables.

utabdeq\rod\texLtpr f*gc 13
Vin. DESCRIPTION OF ALTERNATIVES

A focused FS (WESTON, 1994) was conducted to develop and evaluate remedial alternatives

for a limited number of COCs in one environmental medium (arsenic, cadmium and lead in soils

only). Remedial alternatives were assembled from applicable remedial technology process

options and were evaluated based on the nine criteria specified in the NCP. Also taken into account in looking at remedial alternatives is the fact that only Parcels WESE

and WENW are currently zoned for residential use and that Parcels LR-east, LR-west, LF and LG are currently zoned for commercial/industrial use. Remedial alternatives were evaluated that

would permit continued land use under the current zoning plan; however, for evaluation

purposes, alternatives were evaluated that would permit flexibility for land use, such as

residential use on those parcels currently zoned commercial/industrial and commercial/industrial

use on Parcel WESE.

Summaries of the alternatives retained for final consideration to address the overall site risks are

listed below. More detailed descriptions can be found within the FS report. In addition to the

remedial alternatives, the NCP requires that a no-action and limited-action alternative be

considered at every site. The no-action alternative serves primarily as a point of comparison for

other alternatives. Most remedial technologies and process options were eliminated in the preliminary screening

process because there currently is no practical way to remove low levels of metallic

contaminants (in a slag matrix) from large volumes of soils. Therefore, the remedial alternatives

were assembled from two primary remedial technologies: capping and excavation. Institutional

controls are also incorporated into several of the remedial alternatives to maintain the

protectiveness of the remedy.

Alternative No. 1

Alternative 1 is the no-action alternative, required by the NCP, and provides a baseline for

comparison with other alternatives. A ground water monitoring program would be conducted

under the no-action alternative.

The 5-year present-worth cost is $48,000 including contingencies. The estimated operation and

maintenance (O&M) costs incurred under this alternative would be associated with sampling and

analyses of ground water in existing wells. It may be necessary to install additional wells at

additional cost.

Alternative No. 2

Alternative 2 is a limited-action alternative which would include institutional controls, such as

deed restrictions, and working with local zoning agencies to change the land zoning for the

undeveloped area (Parcel WESE) from residential to commercial/industrial. In addition, this

alternative would entail the excavation and off-site disposal of the upper 18 inches of native soils

at 14 residential yards in the current development (Parcel WENW). The 18-inch depth is

utahdcq\nxi\tcxtapr Page 14
considered to be a minimum, with confirmatory sampling used to identify areas requiring

additional excavation.

Clean fill would be imported to restore the yards to original grade. Since the soils are not

considered RCRA hazardous waste, they would be transported to a nearby permitted solid waste

(RCRA Subtitle D) landfill or stored on OU2 of the site pending remedy selection for OU2.

The selection of 14 residential yards for remedial action is based on the number of individual

yards that contain surface soil with COC concentrations constituting an unacceptable cancer or

non-cancer risk (Refer to Section VI). Deed restrictions or other institutional controls

prohibiting future residential land use without additional property remediation to residential soil

clean-up levels on Parcels LR-east, LR-west, LF and LG would be part of this alternative

The timeframe to implement Alternative 2 is less than 1 year. The 5-year present-worth cost

of this alternative is $1,252,000 including contingencies. Long-term (5-year) costs are

associated with ground water monitoring. The costs associated with remediation of selected

residential yards were extracted from contractor bids for similar work at the Sharon Steel OU2 Site.

Alternative No. 3

Alternative 3 consists of placing a compacted permeable soil cover (non-RCRA Cap) over

exposed native soils in the undeveloped residential area (Parcel WESE), and excavating the

upper 18 inches of native soils at 14 residential yards in the current residential development

(Parcel WENW). Deed restrictions or other institutional controls would be utilized to prohibit

residential land use on the remaining parcels of the OU unless additional property remediation

to residential soil clean-up levels occurs.

Residential yards would be remediated by excavation of the upper 18-inches of native soils. The 18-inch depth is considered to be a minimum, with confirmatory sampling used to identify

areas requiring additional excavation. Clean fill would be imported to restore the original grade,

and each yard would be restored as closely as possible to its original condition. The wastes,

being non-hazardous, would be transported to the nearest solid waste (RCRA Subtitle D) landfill. Alternatively, the soils may be stored on the Midvale Slag OU2 site pending remedy selection

for OU2.

Emplacement of a compacted permeable cover on the undeveloped residential area would be

accomplished using material taken from the 1-215 fill placed on the rest of the site. This

remedial action would be coupled with erosion controls (grading and revegetation), institutional

controls, and ground water monitoring. The placement of a soil cover over native materials

would create a barrier between the wastes and potential human receptors interrupting the route

for dermal exposure, ingestion, and inhalation of contaminated soils. The final compacted

surface would be covered with topsoil and revegetated with native plants to minimize erosion

by wind and surface water.

The compacted permeable soil cover would have a minimum thickness of 2 feet (including

topsoil). This minimum thickness of soil cover is necessary to ensure public health protection

utahdcq\rod\tcxt.apr Page 15
based on preventing earth moving equipment tires from penetrating the cover in the event of

future land development.

To minimize activities that would breach the protective soils cover, this remedial action would

be coupled with the following deed restrictions or other institutional controls for Parcel WESE:

• Excavations would be permitted on a case-by-case basis to be reviewed and

approved. Native soils that are brought to the surface would be segregated from

clean cover soils and placed back in the excavation and covered with clean

overburden. Excess native soils would be disposed of at a solid waste (RCRA Subtitle D) landfill .

On the undeveloped commercial zoned areas of OU1 (Parcels LR-west and east, LG and LF)

future land use would be commercial/industrial unless additional property remediation to

residential soil clean-up levels occurs. Under this alternative, a ground water monitoring

program would be implemented across OU1.

The timeframe to implement Alternative 3 is less than 1 year. The 30-year present-worth cost

for Alternative 3 is $2,597,000.

Alternative No. 4

Alternative 4 consists of placing a compacted permeable soil cover (Non-RCRA Cap) over

exposed native soils on the undeveloped residential area (Parcel WESE) and undeveloped

commercial area without fill (Parcels LR-west and LF), and excavating surface soils to a depth

of 18 inches at 14 residential yards (Parcel WENW). The 18-inch depth is considered to be a

minimum with confirmatory sampling used to identify areas requiring additional excavation. The

placement of a soil cover would permit residential development of OU1 with restrictions on the

depth of future excavations. Deed restrictions or other institutional controls would be

implemented on Parcels WESE, LR-west, and LF to prevent future development activities from

breaching the soil cover (with the limited exceptions described under Alternative 3).

A portion of the clean fill placed on Parcels LG and LR-east in 1987 would be used to cover

areas of exposed native soils on adjacent parcels. The compacted permeable soil cover would

have a minimum thickness of 2 feet. This minimum thickness of soil cover is necessary to

ensure public health protection based on preventing earth moving equipment tires from

penetrating the cover in the event of future land development activities.

In order to minimize erosion of the soil cover and to minimize the need to adjust the grade

during any future development, the existing land surface would be modified during the remedial

design/remedial action (RD/RA) phase. The RD would consist of a site Master Plan, which

would ensure that the RA is implemented such that future land uses would not compromise the

remedy.

The Master Plan would establish the general development plan for OU1. As part of this

planning process, specific areas of OU1 would be designated for development into

commercial/industrial, office, or open space facilities. The Master Plan would further designate

ntahdeq\rod\texL«pr Page 16
utility corridors, including water/sewer, electrical, telephone, and storm water drainage, and

would establish the general grading plan for the development of OU1. The RA would consist of construction of the basic components of the Master Plan. The site

would be graded to conform with the drainage and erosion aspects of the Master Plan, while

adhering to the minimum soil cover requirements. The utility corridors would be constructed

using conduit banks, where appropriate, or designated for future overhead or underground

development. The site Master Plan would provide limits and restrictions on the future

excavations.

The final compacted surface would be covered with topsoil and revegetated with native plants

to minimize erosion by wind and surface water. It is anticipated that maintenance of the

compacted cover would be required until the land is developed. Once the land is developed, the

property owner can be expected to maintain either a hard top (asphalt, concrete, or a structure)

or landscaped surface. Under this alternative a ground water monitoring program would be

implemented.

The timeframe to implement Alternative 4 is less than 1 year. The 30-year present-worth cost

for Alternative 4 is $4,543,000.

Alternative No. S

Alternative 5 is identical to Alternative 4 except that the undeveloped residential area (Parcel WESE) would undergo excavation and off-site disposal of native soils rather than waste

containment.

Prior to excavation, existing vegetation would be removed, and the native soils excavated to a depth of 10 feet. Removal of the upper 10 feet of soils on the undeveloped residential area is

based on the expectation that under unlimited future use, excavations for home/building

foundations, utilities, and land grading would not exceed this depth. The wastes, not being

classified as a RCRA hazardous waste would be transported to a RCRA Subtitle D landfill. Alternatively, the soils may be stored on the Midvale Slag OU2 Site pending remedy selection

for OU2. The excavation would be filled with imported clean fill . In order to minimize erosion and to

minimize the need to adjust the grade during any future development, the existing land surface

would be worked to establish a uniform grade. The final graded surface would be compacted,

covered with topsoil, and revegetated with native plants to minimize erosion by wind and surface

water. Because wastes would remain on-site on Parcels LR, LF and LG, a ground water

monitoring program would be implemented.

The timeframe to implement Alternative 5 is 2 years. The 30-year present-worth cost for Alternative 5 is $43,936,000.

uUhdcq\rod\tcxt.apr Page 17
Alternative No. 6

Alternative 6 includes excavation to a depth of 18 inches and off-site disposal of native surface

soils in 14 residential yards (Parcel WENW). The 18-inch depth is considered to be a minimum

with confirmatory sampling used to identify areas requiring additional excavation. Native soils

would also be excavated to a depth of 10 feet and disposed of off-site for the remaining areas

ofOUl .

Implementation of Alternative 6 on the undeveloped residential area (Parcel WESE) and

undeveloped commercial areas (Parcels LR-west and east, LF and LG) would involve first

excavating those areas with native soils exposed at the surface. Then, existing clean fill on Parcels LR-east and LG and imported fill would be used to fill the excavation(s). The newly

exposed native soils on the eastern portion of OU1 would then be excavated to 10 feet. This

second excavation would be filled using imported fill . The timeframe to implement alternative 6 is 8 years. The capital cost for Alternative 6 would

be $204,816,000. It is important to note that the remediation costs for Alternative 6 represent

approximately $1,000,000 per acre.

I X. SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

The comparative analysis provides the basis for explaining how the selected remedy satisfies the

statutory requirements as to the effectiveness and implementability of the alternative. The

remedial alternatives presented in Section Vm were analyzed in detail in the FS using the nine

evaluation criteria specified in the NCP. The nine criteria are: 1) overall protection of human

health and the environment; 2) compliance with ARARs; 3) long-term effectiveness; 4) reduction

in toxicity, mobility, or volume through treatment; 5) short-term effectiveness; 6)

implementability; 7) cost; 8) state acceptance; and 9) community acceptance. The resulting

comparisons of each alternative by the nine criteria are discussed below.

Criterion 1: Protection of Human Health and the Environment

This criterion addresses whether or not a remedy provides adequate protection and how risks

posed through each pathway are eliminated, reduced, or controlled through treatment,

engineering controls, or institutional controls.

All of the final alternatives considered except alternative one, are protective of human health and

the environment. However, the amount of protection increases incrementally with each

alternative through Alternative 6. Only Alternative 1 does not provide overall protection of

human health and the environment. Alternatives 2 through 6 rely on a combination of waste

removal waste containment, and institutional controls for protection of human health and the

environment.

For logistical and engineering reasons detailed in the FS Report (UDEQ, 1994), excavation and

disposal of site wastes from the current residential area in Winchester Estates is considered the

only possible remedial action. Alternative 2 couples this action with institutional controls on

utahdeq\rod\textapr P«ge 18
other parcels to limit the human exposure. Alternatives 3 and 4 combine excavation and disposal

at residential yards with capping of the remaining areas at OU1. The creation of a physical

barrier between the wastes and the receptor population coupled with institutional controls ensures

the protectiveness of the remedy. Alternatives 3 and 4 provide a reduction in the site risk level

over that achieved under Alternatives 1 and 2.

Alternatives 5 and 6 are analogous to Alternatives 3 and 4 except that excavation and off-site

disposal of site wastes are substituted for capping. However, Alternatives 5 and 6 do not result

in any further reduction in site risk when compared with Alternatives 3 and 4. Remaining soil

concentrations of COCs at the surface would be equal to or below background concentrations. Implementation of Alternatives 5 and 6 will, however, further reduce the possibility of future

ground water impacts on this OU and eliminate the need for institutional controls and

accompanying enforcement on the treated parcels.

Criterion 2; Compliance with ARARs

Compliance with ARARs addresses whether a remedy will meet all Federal and State

environmental laws and/or provide a basis for a waiver from any of these laws. The ARARs

are divided into chemical-specific, action-specific, and location-specific groups.

There are no chemical quality standards for soils promulgated through Federal or State

regulations. Therefore, compliance with ARARs is not applicable for contaminated soils at OU1. ARARs do exist for ground water, they include Federal and State drinking water

standards such as Maximum Contamination Limit Goals (MCLGs), or MCLs when MCLGs are

zero. Ground water ARARs are summarized on a table presented as Appendix Al.

USEPA and UDEQ are working together to determine how and under what circumstances the Utah Ground Water Quality Protection Rule, R317-6, Utah Admin. Code, is applicable or

relevant and appropriate. Those determinations have not yet been made. However, since USEPA and UDEQ have agreed, that even if the Ground Water Quality Protection Rule is an ARAR in this situation, an alternate concentration limit shall apply and the ARAR will be met

as set forth below, a final determination on the status of UDEQ's Ground Water Quality Protection Rule will not be made for the purposes of this ROD. Utah's Ground Water Protection Standard (Rule) for lead is 15 micrograms per liter G*g/£) R317-6-2.1, Utah Admin. Code. A sample from one of the 25 ground water monitoring stations on OU1 (Well No. LF08) was found to exceed this standard by 8 pg/l . In response to this occurrence, the USEPA

and UDEQ have agreed to the application of an Alternate Concentration Limit (ACL) for OU1

that will bring OU1 into compliance with the Rule. An ACL is permitted under the Rule

providing that it meets certain requirements, including requirements that the ACL is protective

of human health and the environment, and is justified by site-specific circumstances.

The decision to apply an ACL for Well No. LF-08 in this case is based on the following:

(1) The magnitude of the exceedance.

(2) The very limited spatial distribution of exceedances indicates that Well No. LF-08

is not representative of the ground water quality under the entire site.

ntahdeq\rod\text.apr Page 19
(3) The relatively high cost of implementing a remedy to address this small suspect

area, and the small benefit of doing so.

Given the application of the ACL for Well No. LF-08 in this manner, OU1 is considered at this

time to be in compliance with the Rule, and all proposed remedies are also in compliance.

Action-specific ARARs are detailed in Appendix A2. Alternatives 2 through 6 would comply

with all action-specific ARARS.

Location-specific ARARs are detailed in Appendix A3. Alternatives 2 through 6 would comply

with location-specific ARARs.

Criterion 3: Long-Term Effectiveness

This evaluation criteria involves consideration of the risks that remain after the site has been

remediated. Items of concern are the presence of any receptors near the site, magnitude of the

remaining risk from untreated waste or treatment residuals, adequacy of controls that are used

to manage treatment residuals or untreated waste, and reliability of these controls.

Under Alternative 1, the risks posed by OU1 will remain unchanged and therefore, the remedy

is not considered to be effective. Long-term effectiveness increases incrementally from Alternatives 2 through Alternative 6. Although Alternatives 2 through 6 all achieve protection

of human health and the environment, each successive alternative requires fewer restrictions on

future land use. Alternative 3 offers a high level of long-term effectiveness using a combination of engineering

and institutional controls. Excavation and off-site disposal of wastes on Parcel WENW provides

the maximum possible long-term effectiveness by removing the wastes from the site. For Parcel WESE, the placement of a soil cover will interrupt the route for human exposure to

contaminated native soils permitting future residential development although maintenance of the

cover may be required. Cover maintenance may include periodic fillin g of erosional features

coupled with revegetation. By use of institutional controls prohibiting future residential

development, the existing risks posed by the remainder of OU1 are below a level of concern. Therefore, Alternative 3 is an effective remedy for this portion of the site.

Criterion 4; Use of Treatment to Reduce Toxicitv. Mobility, and Volume

Treatment of the wastes is not considered under any of the alternatives. A considerable portion

of the waste appears to be slag distributed throughout a soil matrix. The large volumes of slagcontaining soils, coupled with the nature of slag, precludes the effective use of treatment

technologies. Essentially, there is no practical and cost-effective way to remove the toxic metals

from the slag matrix; therefore, the proposed alternatives will not satisfy the statutory preference

for treatment as a principal element of remediation with a strong bias against off-site landfilling

of untreated wastes.

titahdcq\rod\texLapr Page 20
Criterion S: Short-Term Effectiveness

This criterion involves investigation of the effect s of the alternatives during construction and

implementation. Items of concern are the protection of the community and the workers during

implementation of remedial measures, potential environmental impacts, and the time required

to achieve remedial action goals.

The remedial alternatives are combinations of three components: excavation, capping and

institutional controls. Short-term risks increase with an increasing amount of earth work and

increase further with the off-site transport of excavated soil. These risks take the form of

potential injury or death from earth moving equipment and traffic accidents during transport of

contaminated soils to the disposal/storage site. Other short-term risks would include fugitive

dust and potential impacts to surface water bodies due to site runoff during remediation

activities.

Based on the above analysis, short-term effectiveness decreases (short-term risk increases)

incrementally from Alternative 1 through Alternative 6.

Criterion 6: Implementabilftv

This criterion refers to the technical and administrative feasibility of the remedy, including the

availability of materials and services needed to implement the chosen solution. It also includes

coordination of Federal, State, and local governments to clean up the site.

All of the remedial alternatives are implementable. Equipment, materials and manpower for

earthwork projects are readily available in the Salt Lake City area. In addition, disposal

facilities exist within 100 miles of the site that can accept excavated soils. Treatability studies

performed on OU1 soils indicate that all wastes are not characteristic hazardous waste by toxicity

and may be disposed of in a RCRA Subtitle D landfill. Alternatively, the wastes may be stored

on the Midvale Slag OU2 Site pending remedy selection for OU2.

The use of institutional controls on Parcel WESE would be possible with the agreement of the

property owner and the approval of the cities and counties involved.

Although all of the remedies are implementable, Alternatives 4,5 and 6 will require significantly

more time to implement. In particular, Alternative 6 will require 8 years as compared with Alternative 3, which will require less than 1 year.

Criterion?! Cost

Alternatives 1 through 4 are considered cost-effective. Each of these alternatives provides an

incremental increase in protectiveness with a reasonable incremental increase in cost. Alternatives 5 and 6, however, are not considered cost-effective. The small incremental increase

in protectiveness achieved under Alternatives 5 and 6 as a result of waste removal contrasts

sharply with the 10- to 100-fold increase in cost.

utahdeqVrodMextapr Page 21
Criterion 8; State Acceptance

UDEQ has worked in partnership with USEPA throughout the RI/FS and concurs with the

selected remedy for this site.

Criterion 9: Community Acceptance

The Proposed Plan was issued on 7 July 1994. A public meeting was held on 27 July 1994 at

the Midvale City Hall in Midvale, Utah. Members of the community attended the meeting and

asked questions and made statements. Little opposition to the proposed remedy was expressed. Some of those that did object questioned the need for any remedial action. Prior to the public

meeting the Citizens For A Safe Future For Midvale (Citizens Group) requested a 30-day

extension of the public comment period so that an independent contractor could review the FS Report for technical accuracy. The extension was granted and an advertisement was placed in

the Salt Lake Tribune providing notice that the close of the public comment period was extended

to 10 September 1994. A second extension was requested by the Citizens Group on 9 September

1994, and was denied by USEPA on 12 September 1994. The basis for the denial was the fact

that the documents to be reviewed by the Citizens Group had been available to the public for

several months prior to the issuance of the Proposed Plan. Written comments and questions

were received prior to the close of the public comment period. Those comments and responses

are presented in this ROD in Section Xn.

X. SELECTED REMEDY

Alternative 3 has been selected as the remedy for OU1. Alternative 3 consists of excavating

surface soils at 14 residential yards (Parcel WENW), placing a compacted permeable soil cover

(Non-RCRA Cap) over exposed native soils in the undeveloped residential area (Parcel WESE),

and implementing deed restrictions or other institutional controls on the remaining parcels of the OU to prohibit residential land use unless additional remediation to residential soil clean up

levels occurs.

Residential yards will be remediated by excavation of the upper 18 inches of native soils. The

18-inch depth is considered to be a minimum with confirmatory sampling used to identify areas

requiring additional excavation. Clean fill would be imported to restore the original grade, and

each yard will be restored as closely as possible to its original condition. The wastes, being

nonhazardous, would be transported to the nearest solid waste (RCRA Subtitle D) landfill. Alternatively, the soils may be stored on the Midvale Slag OU2 Site pending remedy selection

for OU2.

Emplacement of a compacted permeable cover on the undeveloped residential area would be

accomplished using a portion of the existing clean fill on the LG and LR parcels. This remedial

action would be coupled with erosion controls (grading and revegetation), institutional controls,

and ground water monitoring. The final compacted surface will be covered with topsoil and

revegetated with native plants to minimize erosion by wind and surface water.

utahdeq\nxIVtexLipr Page 22
The compacted permeable soil cover would have a minimum thickness of 2 feet. This minimum

thickness of soil cover is necessary to ensure public health protection based on preventing earth

moving equipment tires from penetrating the cover during potential future land development.

To minimize activities that would breach the protective soil cover, this remedial action would

be coupled with the following institutional controls.

• Excavations would be permitted on a case-by-case basis to be reviewed and

approved. Native soils that are brought to the surface would be segregated from

clean cover soils and placed back in the excavation and covered with clean

overburden. Excess native soils would be disposed of at a solid waste (RCRA Subtitle D) landfill. The following institutional controls would be imposed on the undeveloped commercial zoned

areas of OU1 (Parcels LR-west and east, LG and LF):

• Future use of the property will be industrial/commercial unless additional

remediation to residential soil clean up levels occurs.

• If for any reason site soils need to be transported/disposed of off-site (e.g. excess

soils from utility or foundation excavation) they will be disposed of in a RCRA Subtitle D facility.

The above mixture of remedial actions and deed restrictions or other institutional controls will

provide for land use that is consistent with the current zoning of the OU, and will also allow for

a change in land use in the future for some of the parcels from commercial/industrial to

residential should such a change be desired by the land owner(s) and the local city governments.

Implementation of the above-described remedial actions and institutional controls will result in

a post remediation cancer risk and non-cancer HI less than IE-4 and 1, respectively, for the

entire OU. Pre- and post-remediation soil concentrations and risk levels are presented on Tables

5 and 6, respectively.

Ground water in the Upper Sand & Gravel Aquifer would be monitored (semi-annual water level

measurements and water samples) for at least 5 years following completion of remedial action. The point of compliance (with ARARs) for ground water will be the hydraulically downgradient

site boundary (portions of the west and north site boundaries as shown on Figure 8). Existing monitoring wells will be supplemented with one or more additional monitoring wells to be

installed during or immediately after the remedial action. Ground water samples will be

analyzed for total and dissolved arsenic, cadmium, and lead. If at the end of the 5-year

monitoring period ARARs have not been exceeded in any of the samples analyzed, ground water

monitoring will be discontinued.

The estimated cost of this remedy is $2,597,000. The capital cost of each major component of

the remedy along with operation and maintenance costs are summarized below:

utahdeq\rod\text.«pr Page 23
Estimated Costs of the Selected Remedy

Capital Costs

Removal Component Unit Quantity Unit Cost Estimated Cost

1) Excavation/off-site Disposal

Containment Component

1) Prepare site

2) Install cover

Institutional Controls

Residential Yard 14

Acre Acre

1) Administrative Costs LS

Ooeration and Maintenance Costs

$59,000

37

37

N /A

$ 4,676

21,297

N /A

Design Costs (20%)

Contingencies (20%)

$826,000

$173,000

788,000

$ 10.000

$1,797,000

359.000

$2,156,000

431.000

$2,587,000

Annual Cost

1) Cover maintenance and ground water monitoring

TOTAL COSTS

(Present value using 5 % discount)

$ 9,670

$2,597,000

XL STATUTORY DETERMINATION

Protection of Human Health and The Environment

The potential for exposure to soils posing an excess cancer risk or non-cancer HI of IE-4 and 1,

respectively, is eliminated through waste removal by excavation, waste containment or

institutional controls.

Compliance with ARARs

There are no chemical-specific ARARs for soils at OU1, and ground water is in compliance with ARARs. The selected remedy includes the installation of a permeable, single-layer soil cover,

the only objective of which is to prevent direct contact between human receptors and the

contaminated native soils. Accordingly, the intent is inconsistent with that of a RCRA cap and

utahdeq\rod\t£XLapr Page 24
the RCRA requirements are not ARAR. The remedy complies with those location-specific ARARs that were identified as applicable.

Cost-Effectiveness

Although Alternatives 2 through 6 all achieve acceptable levels of protectiveness, Alternative

3 does this without changing the existing land zoning or requiring the excavation and off-site

disposal of large soil volumes. The limited additional protectiveness associated with waste

removal (Alternatives 5 and 6) contrasts sharply with the 10- to 100-fold increase in costs when

compared with Alternative 3.

Utilization of Permanent Solutions and Alternative Treatment Technologies

Treatment of wastes is not considered under any of the alternatives. A considerable portion of

the waste appears to be slag distributed throughout a soil matrix. The large volume of slagcontaining soils, coupled with the nature of the slag, precludes the effective use of treatment

technologies. Essentially, there is no practical and cost-effective way to remove the toxic metals

from the slag; Therefore, permanent solutions would be limited to waste removal, which, as

previously discussed, is not considered to be cost-effective.

Preference for Treatment as a Principal Element

As previously discussed, treatment of wastes is not considered under any of the alternatives,

therefore, the selected remedy will not satisfy the statutory preference for treatment as a

principal element of remediation.

Alternative 3 would result in some incremental reduction in mobility for the treated areas

(excavation/removal and capping). However, transport of site wastes via surface water or air

is not considered to represent a significant exposure pathway (LSI, 1992).

X H. RESPONSIVENESS SUMMARY

Overview

At the time of the public comment period, USEPA and UDEQ had already selected a preferred

alternative for Midvale Slag OU1 in Midvale, Utah. The preferred alternative addresses soil

contamination by either removing the contaminated soil, capping the contaminated soil or

restricting the type of future land use.

Based on the comments received during the public comment period and during public meetings,

the residents of the surrounding communities and local community groups support the preferred

remedy for OU1. Objections to the proposed remedy were limited to concerns about current or

future effect s of OU1 wastes on the deep principal aquifer and in some cases, commentors

questioned the need for any remedial action at all.

utahdeqVrodMexLipr Page 25
These sections follow:

• Background on Community Involvement

• Comments Received During the Public Comment Period

- Part I: Response to Local Community Concerns

- Part II: Response to Specific Legal and Technical Questions

Background on Community Involvement

UDEQ and USEPA community relations staf f conducted interviews with residents in the

impacted area to determine their concerns. As part of these interviews, each interviewee was

asked what would be the most effective way to keep the public involved. These suggestions

were incorporated into a Community Relations Plan, developed by URS (an USEPA contractor)

and adopted in 1991. All public documents relating to OU1 were made available at the Ruth Vine Library in Midvale. Municipalities such as the cities of Midvale and West Jordan as well as the Utah Department of Transportation were particularly interested in how Superfund activities would impact the

proposed extension of the Jordan River Boulevard through the OU1. Regular meetings were

held between these interested parties beginning in 1990. Officials from the cities were briefed

periodically, and UDEQ responded to requests for information from potential businesses seeking

to locate in the area.

In preparation for a soil sampling program conducted in 1991 at Winchester Estates residential

yards, a pre-sampling meeting was held with the owner of the trailer park. When the sample

analyses were completed, an availability session was held at which residents could pick up their

sample results and talk to representatives of USEPA and UDEQ about the results. Fact sheets

were mailed to interested parties, and a public informational meeting on the status of the site was

held on 2 May 1991.

Additional sampling of residential yards in late 1993 was preceded by meetings between UDEQ

and the trailer park manager who subsequently notified the residents of the planned field

activities. The results of the second round of sampling were mailed to individual residents.

A Proposed Plan, outlining USEPA's and UDEQ's preferred remedy and the public participation

process, was mailed on 7 July 1994. An advertisement was placed in the Salt Lake Tribune

providing notice on the availability of the Proposed Plan, the time and location of the public

meetings and the duration of the public comment period (11 July through 10 August 1994).

A public meeting was held on 27 July 1994 at the Midvale City Hall in the city council

chambers. Approximately 35 members of the community were present with questions focusing

on the compatibility of the preferred remedy with future development plans for OU1. Prior to

the public meeting the Citizens For A Safe Future For Midvale (Citizens Group) requested a 30-

day extension of the public comment period so.that an independent contractor could review the FS Report for technical accuracy. The contractor would be hired by the Citizens Group using

funds provided by USEPA Technical Assistance Grant. The extension was granted and an

ut*hdeq\rod\tcxt.ipr Page 26
advertisement was placed in the Salt Lake Tribune providing notice that the close of the public

comment period was extended to 10 September 1994.

A second extension was requested by the Citizens Group on 9 September 1994, and was denied

by USEPA on 12 September 1994. The basis for the denial was the fact that the documents to

be reviewed by the Citizens Group had been available to the public for several months prior to

the issuance of the Proposed Plan. At the close of the public comment period, written and oral comments had been received from

the Citizens Group; Mr. David Ovard of the Salt Lake County Water Conservancy District; Mr. Bruce Nieveen, Environmental Engineer for Midvale City; Mr. Volney Wallace, a private

citizen, Ms. JoAnn Seghini, Midvale Councilwoman; Mr. Wayne Harper, West Jordan Councilman; Ms. Jean Barbuto, a private citizen; Ms. Cindy Merril, a private citizen; Mr. Garth Pimm, manager of Winchester Estates; Mr. Leon Hansen, a private citizen; and Mr. Bob Davis, Director of Development Services for the City of West Jordan. Responses to these comments

are presented below.

RESPONSES TO PUBLIC COMMENTS RECEIVED DURING

PUBLIC COMMENT PERIOD

Part I. — Summary and Response to Local Community Concerns

Note: Some of the following comments and questions were received verbally at the 27 May

1994 Public Meeting in Midvale, Utah. The responses presented here are modified in some

cases from the responses provided at the public meeting. This was done to more clearly

represent UDEQ's and USEPA's position on these issues.

Adequacy of RI/FS

>• Comments by "Citizens For A Safe Future For Midvale"

Comment No. 1

The Citizens for a Safe Future for Midvale indicated they had asked for an extension and would be submitting written comments, once their consultants had had an opportunity to look at the data.

Response to Comment No. 1

USEPA acknowledges these comments and responded to the written comments submitted.

Comment No. 2

My name is Alien Lister and I am addressing this public hearing tonight

representing Citizens For A Safe Future For Midvale, an organization formed to

monitor the findings of USEPA in behalf of the Citizens of Midvale.

Dtahdeq\rod\text»pr Page 27
We thank the USEPAfor the opportunity to comment on the RI/FS as it relates to the OU1 area of the Midvale Slag Superfund Site. We also appreciate USEPA 's immediate response in granting us a 30-day minimum extension of the Public Comment period to allow us to prepare the study authorized in our USEPA TAG

grant to validate the findings of the RI/FS. The objective of the extension is to

gain independent assurance that the USEPA preferred alternative (#3) for the remediation of the OU1 portion of the Midvale Slag Superfimd Site will property

protect the health and safety of the citizens of Midvale. Preparation of this documentation may necessitate us to request a Junker extension of the public

comment period.

We have carefully reviewed the USEPA fact sheet and other information available from state and local offices and will proceed to engage an independent consultant

to review the RI/FS to evaluate its content and the USEPA's conclusions. During

our consultants' renew we will expect them to carefidfy consider the following matters. We will share with the USEPA any concerns which may arise from our consultants' evaluation of their report and its conclusions.

1) A determination will be made of the adequacy of the evaluations of the "hot spots" located in the Midvale Slag site relative to their potential for surface and subsurface contamination.

2) A careful evaluation will be made of the institutional controls that would be in place to ensure contamination is contained on-site.

3) Procedures to ensure satisfactory site monitoring of the potential

contamination of the upper and lower aquifers will be evaluated.

4) The adequacy of the testing for existing contamination of the Jordan River's surface water as well as of its sediment will be evaluated. Similarly, the testing methods used to evaluate water contamination in the

upper and lower aquifers and conclusions made from the data will be substantiated or concerns identified.

5) An evaluation will be made of the reasonableness and consistency of standards that were utilized in all aspects of testing for contamination.

6) An assessment will be made of the adequacy of the grid pattern used as the basis for testing and evaluating the information used in the final RI/FS for OU1.

Response to Comment No. 2 (Items 1-6)

The reviewer indicates that Citizens for a Safe Future For Midvale believe that the purpose of

a TAG grant is to validate the findings of the RI/FS. This is incorrect. The purpose of the TAG grant is to allow a public interest group to acquire technical assistance to "interpret"

information developed during the investigation of a Superfund Site listed on the National Priorities List to "facilitate the public's overall understanding" of Superfund activities.

utahdeq\rod\text.ipr Page 28
Alternative Remedial Actions

»• Comments by Mr. Bruce A. Nieveen, Environmental Engineer for Midvale City

Comment No. 1

The USEPA and DEQ have determined that certain environmental hazards exist

on the properties designated as Midvale Slag Superfund OU1 and OU2. It is known that there are several localized areas which have very high concentrations of arsenic and lead.

Inasmuch as these problems exist and both the City of Midvale and Valley Materials would like to see the property developed. Midvale proposes the following plan. We believe that there are simple precautions which can be taken

to prevent human and wildlife exposure or ingestion. Since these properties will be designated industrial and commercial, the USEPA has conceded that the action level can be higher than residential is acceptable. This action level for exposed soil is likely to be designated around I,300ppmfor arsenic.

Regulations will be enforced by either Administrative Orders, building permits, and oversight by the appropriate and assigned individual on the Midvale Staff.

Import or fill material brought on to the site shall not exceed 5,000ppmfor lead

and 1,200ppm for arsenic.

A tiered approach for the site will be used. This tiered approach shall be similar

to the post remedial regulation which are used in the residential clean up of the Sharon Steel OU2 area, except that the contaminant levels are different.

Testing will be required as part of the development to determine what actions are

to be taken for the soil. Each section will be tested individually, and approval

actions will be taken individually for contaminated soil within that section. This

means because one section of the property is required to a certain set of guidelines, the entire property is not bound by those same actions. More specifically, although a specific area within the boundaries of the property may

require certain remedial actions or capping or other involved procedures, the

entire property will not necessarily have to follow that pattern.

Midvale ordinance requires that 5% of an industrial or commercial area be

landscaped. In the area near the Jordan River and the Jordan River Parkway,

we intend to increase the required landscape area to be 10%. Elimination of the landscaped area is not practical nor acceptable from Midvale's perspective. It

is because Midvale requires a minimum area to be landscaped that we have used

the tiered approach. It can be readily assumed that children will not play in these

areas, and if that occurs on a rare basis, there is certainly not the probability that this could occur on a weekly basis because the area is one of either offices or

industry. Grass cover significantly reduces the dust which can occur from soil.

utahdcq\rod\lcxt.apr Page 29
In those areas where the landscape area may consist of flowers with some exposed soil, the maximum contaminant level has been set at 5,000for lead and 750ppm for arsenic. These levels would also pertain to certain types of bushes or trees which would leave large open areas of bare soil Those shrubs which would adequately cover the ground are would be able to conform to the same

contaminant levels as grass. Shrubs and trees will be designated under the regulations specifically stated for the site. Clean import material (from off-site) for the Industrial/Commercial zone will be designated as 3,000 ppm lead and 750

ppm arsenic. Furthermore, if fill material were needed then the levels would be raised to 1,200 ppm for arsenic and 5,000 ppm for lead; these, however, would have to be placed beneath a cap of "clean" material. Where necessary and when applicable, the most contaminated material will be placed under the foundations of the buildings or under the driveways and parking lots.

ACTION A

ACTION B

ACTION C

ACTION D

ACTION E (Import Material)

(Fill Material)

ARSENIC LEVELS

Greater Than

Oppm

750 ppm

1,850 ppm

15,000 ppm

0 ppm

750 ppm

Equal to or Less Than

750 ppm

1,300 ppm

15,000 ppm

No Limit

750 ppm

1,200 ppm

LEAD LEVELS

Greater Than

Oppm

NA

NA

NA

0 ppm

3,000 ppm

Equal to or Less Than

5,000 ppm

NA

NA

NA

3,00 ppm

5,000 ppm

No restrictions on-site.

Grass cover.

6 inches of earthfill cover on

top for grass cover or

landscaped cover. Minimum of 12 inches of

cover with liner or barrier.

Open soil used for flowers

or open shrubs.

Used for fill to be covered.

Drawing of proposed landscape areas and a sample ordinance or administrative order would be similar to that of Park Gty (enclosed).

Special precautions will be taken in the event of development of businesses or buildings like condominiums or a day care. Though this particular type of development will be discouraged, it would be allowed with additional

requirements and precautions. Any similar business which would have children that may spend a regular routine or daily amount of time on the site would

require a variance. Further, the additional safety requirements would be to place

24 inches of fill material with contaminate levels below 1,000 ppm lead and 130

ppm arsenic on top of a membrane barrier unless the proposed site already meets that criteria to the depth of 4 feet, 4 feet being a practical depth that occur with placement waterlines and other utilities. If soil at depths greater than 4 feet exceeds limits, and it is necessary for removal for such activities as building foundations or footing, then the contaminated material must be disposed of and handled in a manner conforming to the regulations to be put in place. In the

utihdcq\rod\lcxt.ipr Page 30
planning stages of these types of businesses, specific processes witt be outlined for the building and construction processes.

In all cases strict adherence to landscaping codes will be required. Midvale's code enforcement officer -will make certain that the proper vegetation be placed

and remain in healthy condition.

Groundwater monitoring is a concern for both DEQ and USEPA. We proposed that the DEQ place a sum of money into a fund which would cover the cost of

testing, maintaining the wells, and personnel costs. Test results will be sent directly to the USEPA for their review. Knee the State of Utah is responsible for Operation and Maintenance, any future costs for the treatment of groundwater would fall under their jurisdiction.

Considering that Superfimd has and will continue to discourage the investing of

money and buying of property that falls within the Superfimd boundaries, we

believe that by implementation of these regulations the Superfimd listing can be removed from this property.

Slag on-site will be used in certain specifically designated circumstances. Those

situations would be a soil which does not have a soil acidity pH below 6.3. The slag could be placed under a future hard surface only. These would be areas such as concrete or asphalt, which, in effect, would be a cap and prevent water from coming into contact with it. The material would also not be allowed in wetlands or where flooding may regularly occur. Further restrictions would not allow the slag to be ground and used as blasting material. It should be noted that after the failure ofSyncrete on Interstate 15, the material was considered to be hazardous by the USEPA. At that time the UDEQ went to considerable lengths

to find a use for the material. It was able to be used as an encapsulated base material in concrete which was used for roadways. We believe that the slag can be used for similar purposes. Slag dust would remain on-site and be placed in

a centralized location that would be permanently capped. Areas on top would

remain open space and building would not be allowed.

Response to Comment No. 1

Some of Mr. Nieveen' s comments appear to be directed toward remedial action at the Midvale Slag OU2 site, e.g., suggestions for remediation of the slag pile. Those comments will be

considered as USEPA and UDEQ develop a final remedy for Midvale Slag OU2, but will not

be responded to in the context of this OU1 ROD. Mr. Nieveen has also made comments regarding the proposed establishment of institutional

controls by Midvale. Institutional controls will be addressed and developed during Remedial Design, and will not be incorporated in detail in the ROD. USEPA and UDEQ will work with Midvale during the Remedial Design process to assure that the institutional controls implemented

are appropriate and workable.

Btahdeq\rod\text«pr Page 31
Acceptability of Preferred Remedy

»• Comment by City of West Jordan

Comment No. 1

Pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act of 2980, the City of West Jordan respectfully submits the following formal comments on the preferred alternative for remedial action to be included

in the decision-making process leading to the final Record of Decision by the United States Environmental Protection Agency (USEPA) on the Midvale Slag Superfimd Site, OU-1.

We understand that the Feasibility Study Report leading to the final Record of Decision (ROD) represents an abbreviated remedial investigation and feasibility study process. This abbreviation is the result of a request by the USEPA to the State of Utah Department of Environmental Quality and its contractor, WESTON, Inc., that a "focused''feasibility study be conducted "that would develop and analyze remedial alternatives appropriate for a limited number of contaminants

in a limited number of environmental media." (WESTON 1994)

The City of West Jordan'sprofessional staff, Department of Development Services Director D. Robert Davis, P.E., and City Engineer, Clarke MacFarland, P.E., and our professional consultants, Jim Horrocks, P.E., Russell Youd, P.E., and Pamela Dee Parldnson, J.D. have reviewed the abbreviated process and have found it to be efficient, comprehensive, and cost effective.

The City, therefore, is in agreement with the process that the USEPA and the State of Utah Department of Environmental Quality have chosen to utilize. The following represents our comments on the results of that process.

Part I. Introduction

The City of West Jordan has been involved with the Valley Materials site since the mid-1980s. That involvement springs from the City's interest in constructing a six-lane roadway across the site at 7200 South on the east side of the site, and

connecting with 7000 South on the west side of the site. This is a road length of approximately 1.37 miles.

The Midvale Slag Superfimd Site encompasses approximately 500 acres. The site

is located 12 miles south of Salt Lake City, Utah, and is within the municipal limits of Murray and Midvale Cities, Utah. Parcel OU-1 of the Midvale Slag Superfimd Site encompasses approximately 330 acres and is bounded by the following: an arbitrary tine north of the smelter slag deposits marks the southern border; the Jordan River marks the western border; 5400 South Street marks the norther border; and South Main Street (700 West) marks the eastern border. OU1 also includes the Winchester Estates area and the abandoned Midvale Wastewater Treatment Plant (WWTP) and lagoon areas.

utahdcq\rodUcxt-»pr Ptge 32
The western border of the site, the Jordan River, is also the eastern municipal boundary of West Jordan. As such, the City of West Jordan is directly impacted

by the decisions made and actions taken -with regard to the site. Although minimal actual, physical contamination has migrated to West Jordan, the public's

perception of the site in relationship to our City has contaminated the manner in which residents, area citizens, agencies, and organizations relate to and deal with

our city.

The remedial action that the USEPA and UDEQ take on the site will only help alleviate the misconceptions that the public hold about the safety, cleanliness, and

security of West Jordan. We are further encouraged by the minimalist stance that has been adopted with regard to the threat posed by the contaminants of concern. This attitude has been encouraged by the City for the past three years and we are gratified to see the findings of our professional staff verified and implemented.

The proposed Jordan River Boulevard will provide a desperately needed

connecting corridor for the east-west commuters in the Salt Lake Valley. Between

5400 South and 9000 South there is no other east-west roadway enabling the

motorist to travel directly from the Wasatch Range to the Oquirrh Range. This

east-west travel ability is crucial because the most dramatic Salt Lake Valley

growth and expansion is in the southwestern comer of the Valley, to wit: West Jordan, South Jordan, Draper, and Riverton. An aerial view of the Valley shows that only in this corner is there land and room for growth. This view is evidenced by the State of Utah's Department of Transportation's investment in the Bangerter Highway and the development and expansion of 5600 West.

Jordan River Boulevard is the mainstay of West Jordan's economic development master plan for Juture quality growth and development. The proposed roadway allows the commuter, the traveler, the consumer quick, safe, and easy access from the 1-15 freeway directly into the heart of West Jordan's rapidly expanding commercial district. As the limited access currently exists, there is confusion, hazards, and congestion when the motorist tries to wend their way from 1-15 down

7200 South, onto 700 West, then to 7800 South, and finally reaching the city limits of West Jordan. Not only is the motorist at risk due to the poor conditions, they are bombarded with the sight ofMidvale Slag and Sharon Steel abandoned

sites and left with the perception that they are entering a filthy, rundown, industrial park rather that the clean, dynamic, residential and commercial

community that is the City of West Jordan.

Part n. Analysis of Alternative

The feasibility study, even in its abbreviated form, was designed and conducted

to investigate and evaluate alternatives, utilizing best management technology, to clean up OU-1 and address the current health risks identified on the site.

Lifeline Systems, Inc., an USEPA contractor, performed the Baseline Risk Assessment (BRA) for OU-1 in 1992. A BRA is prepared to identify and estimate

current and potential risks evaluating the manner in which humans may have

«tahdcq\iDd\textapr Page 33
contact -with site contamination. Based on the information provided by the BRA, preliminary recommendations for clean up can be made by USEPA.

To be classified as a "risk," three criteria must be met:

1) Site contamination must be present;

2) a media must exist to bring that contamination in contact with the population; and

3) there must be a resident population that may be exposed to the site hazards.

The BRA showed that there existed contaminants of lead, arsenic, cadmium, and others in the soils. These compounds were present in such numbers that their levels could present a risk to human health. Ingestion and inhalation are the most

common ways that human health is put at risk by contaminated soils.

The OU-1 site is surrounded by residential and commercial populations. In fact, the Winchester Estates Mobile Home Park has contamination within its boundaries. This residential area is populated by many very young children and

many older retired individuals. These are the two population bases most at risk from contaminated soils and water.

Based on these findings, a wide range of remedies were considered. Those remedies most protective, feasible, and cost effective were assessed by the following nine evaluation criteria.

1) Overall protection of human health and the environment addressed whether or not

a remedy provides adequate protection and describes how risks are eliminated,

reduced, or controlled.

2) Compliance with applicable or relevant and appropriate requirements (ARARs) addresses whether or not a remedy will meet all federal and state environmental laws and/or provide grounds for a waiver.

3) Short-term effectiveness addresses the period of time needed to complete the remedy and any adverse effects to human health and the environment that may be

caused during the construction and implementation of the remedy.

4) Long-term effectiveness and permanence refers to the ability of a remedy to provide reliable protection of human health and environment over time.

5) Reduction oftoxicity, mobility, or volume through treatment refers to the preference for a remedy that reduces health hazards, the movement of

contaminants, or the quantity of contaminants at the site.

6) Implementabittty refers to the technical and administrative feasibility of a remedy. This includes the availability of materials and services needed to carry out a

utahdeq\rod\teit.apr Page 34
remedy. It also includes the coordination of federal, state, and local governments

to work together to clean up the site.

7) Cost evaluates the estimated capital and operation and maintenance costs of each alternative in comparison to other equally protective alternatives.

8) State acceptance indicates whether the State agrees with, opposes, or has

no comment on the preferred alternative.

9) Community acceptance includes determining which components of the alternative interested persons in the community support, have reservations about or oppose. This assessment may not be completed until public

comments on the alternatives are received.

The City of West Jordan, after evaluating the criteria and the six alternatives presented for final consideration, agrees with and supports USEPA's decision to

pursue remediation through the implementation of Alternative #3. We believe that the two-foot layer of compacted soil placed over exposed native soils, and the removal of contaminated soils from the Winchester Estates Mobile Home Park is compatible with the protective cap of clean fill currently in place over the majority of acreage comprising OU-1.

Part m. Comments on USEPA CERCLA RI/FS Process

The City Council of West Jordan is proud to have been a contributing member of the precedent setting inter-agency cooperative effort that has highlighted this

process. We are not aware of any other Superfund project of this complexity and

size that has brought together so many professional and talented people in an effort to complete a remedial action. It is gratifying to see the respect that our City staff was accorded by the fine members of your staff, UDEQ, the USEPA's legal counsel, the Utah Attorney General's office, the Federal Highways Administration, the Army Corps of Engineers, the Interior Department's Fish and Wildlife staff, the Utah Department of Transportation, URS, WESTON, and the Salt Lake County Commission and Board of Health.

Although this process has been, for the City, many years in length, the twists and

turns, highs and lows, stops and starts of it have made this City more aware of and sensitive to the requirements, rules, and administration involved in the

intricate processes of environmental regulation and cleanups. We will never

again be so naive as to believe that the "feds" can solve it all or that the State or the City alone will know what is the only action to be taken in any given environmental situation.

The Technical Advisory Grant (TAG) program implemented by USEPA is an

attempt to ensure that the lay population is provided with non-agency information

in a manner designed to communicate the most technical data in non-technical language. Bruce Nieveen, the Midvale Environmental Engineer, is charged with that very task for Midvale City, as his job description makes clear. Therefore, the

uUhdeq\rod\tcxLipr Page 33
City of West Jordan finds the latest TAG to "Citizens for a Safer Midvale ° (CSM)

a redundant and possibly non-efficient use of tax-payer monies. We also find CSM's repeated demands for additional time to examine the USEPA 's findings to be unwarranted and untimely. We would encourage the USEPA to deny any Junker such delaying tactics and to advise CSM that this project has been in the works for more than a decade and that their fervent, but misguided, attempts to

engage the USEPA in a dialogue at this late date is neither timely, nor credible.

Part IV. Conclusion

The City of West Jordan is already experiencing a tumbling from the economic development and investment sector because Jordan River Boulevard is not in place

to allow access to the Redwood Road corridor of the City. The Bateman Family and other prominent and innovative City families are worried that any more delays in the Boulevard's construction will cost them investment opportunities that they have relied upon for decisionmoMng over the past decade. Not only are their

private funds being expended in anticipation of the remedial action and the resulting construction of Jordan River Boulevard, but there are governmental funds appropriated and being held for dispersement that face redistribution if the

project is not begun during the 1994 construction period.

Due to the uncertain nature of federal monies in these tight budgetary times, there

is a real danger that the funding for the bridge across the Jordan River will disappear. There is also the specter of permits issued by federal agencies expiring and not being renewed based on the lengthy time frame involved to date.

The most precarious of all of the funding involved is those monies appropriated

by the legislature of the State of Utah. The budget for the Jordan River Boulevard was set during Governor Norman Bangerter's administration in the

early 1980s. Because the appropriation originated in the Executive Branch, the Legislature has not had a firm hand in the dispersement of these monies and therefore, with the uncertainty of the project's start date, there is a real and

present danger of these monies being reappropriated for another state-funded

project.

We cannot overemphasize the commitment of the City of West Jordan to both the remedial action and the Jordan River Boulevard construction project.

 To date, the City has invested over one million dollars in planning, engineering, staffing, and consulting services on Jordan River Boulevard. For a city the size of West Jordan, this is a massive commitment of resources. But, have no doubt,

our commitment is ongoing and we will see this project to fruition as a

participating, cooperative partner.

The City Council and the City's administration and staff are ready, willing, and able to continue their 100% commitment to Ms project, and stand ready to assist

and support the federal and state agencies involved in any way that we can.

utahdeq\rod\texi.ipr Page 36
What we ask in return for our commitment is the USEPA 's commitment to use the fall force of its Congressionalfy mandated powers to continue its forward course

in remediating the OU-1 portion of the Midvale Slag Superfund site and to support the construction of the Jordan River Boulevard project.

Once again, we commend the staff and management of Region VIII of the United States Environmental Protection Agency for their cooperative and supportive relationship with the Gty of West Jordan's officials and administrative staff.

We look forward to the completion of this task and to the day when your agency's

very existence will no longer be necessary to the citizens of our country because

we have all grown to respect our environment and the role we each play in it.

Response to Comment No. 1

Comment is acknowledged.

*• Comment by Mr. Wayne Harper — West Jordon Councilman

Comment No. 1

Councilman Harper said West Jordan was pleased with the progress being made. He said the property owners echoed Councilmember Seghini's comments and that the cities wanted total access for the property owners to develop the site industrially and commercially.

Response to Comment No. 1

USEPA acknowledges the comment.

> Comment by Ms. Jean Barbuto — Resident

Comment No. 1

An eight-year time frame is cited for removing the soil in Winchester Estates. Why wait eight years?

Response to Comment No. 1

The Selected Alternative, Alternative Three, will take less than one year to implement soil

removal at Winchester Estates. The eight year time frame is associated with Alternative Six, which was not selected. It is the most expensive alternative and would involve excavation of

all contaminated materials, even underneath the existing fill .

utahdcq\rod\textapr Page 37
Dissemination of Information

»• Comment by Ms. JoAnn Seghini — Midvale Councilwoman

Comment No. 1

Several people are trying to figure out if they are at risk. "Whom might they address after the meeting to identify the properties in Winchester Estates that need to be remediated? There are only twelve properties that need to be remediated. All the rest are safe?

Response to Comment No. 1

Fourteen properties will be remediated in Winchester Estates. All others tested below the health

based action levels for soils. Justification for the action levels can be found in the RI/FS and in

the Risk Assessment. These documents are included in the site's administrative record. Representatives from USEPA and UDEQ are happy to talk to those with concerns about the

levels on their properties or in the area. Property owners have been notified of then- results and

will be consulted before work begins.

* Comment by Unidentified Private Citizen

Comment No. 1

When mil work begin?

Response to Comment No. 1

Once the Record of Decision is published, the project moves into the Remedial Design phase

which addresses how, from an engineering standpoint, the work will be done. This phase will

take two or three months. The agencies will then begin work in the following construction

season.

Part n. — Comprehensive Response to Specific Legal and Technical Questions

Impacts to Deeo Princioal Aauifer

* Comments by Mr. David 6. Ovard, General Manager of the Salt Lake County Water Conservancy District (SLCWCD)

Comment No. 1

We have reviewed the report entitled "Final Feasibility Study Report, Operable Unit #7, Midvale, Utah, Volume 1 — Text." We are also familiar with the

groundwater conditions in this vicinity, as weU as throughout the Salt Lake Valley. As a result of our review, we offer the following comments:

ntahdeq\rod\texupr Page 38
1. "Utah's policy is that water, as well as the property of the public, should be so managed by the public that it can be put to the highest use for public benefit" (State Water Plan, Utah Division of Water Resources, Section 6.1).

2. In 1984, Governor Matheson issued an executive order defining Utah's groundwater policy. The State Groundwater Protection Strategy was then prepared, and is a part of the State Water Plan. The strategy reviews the

importance ofgroundwater as a resource, the need to protect groundwater quality, and reviews management alternatives for protecting groundwater (State Water Plan, Section 7.7). Groundwater is a necessary supplement

to surface water supplies for the urban areas of Utah (State Water Plan, Section 19.2.2).

3. The Utah Legislature issued a finding "that the conservation, development,

treatment, restoration, and protection of the waters of this arid state are

a State purpose and a matter of Statewide concern " (UCA 70-10C-1). All

waters in the State, whether above or under the ground, are declared to be the property of the public (UCA 73-1-1). Beneficial use shall be the basis, the measure and the limit of all rights to the use of water in the State (UCA 73-1-3). The use of water for beneficial purposes is declared

to be a public use (UCA 73-1-5).

4. The Salt Lake County Water Conservancy District (SLCWCD) was

established by the Legislature under the Water Conservancy Act. The duties and obligations of water conservancy districts are explained in Section 17-A of the Utah Code. "It is declared that to provide for the

conservation and development of the water and land resources of the State of Utah and for the greatest beneficial use of water within this State, the

organization of water conservancy districts and the construction or works

. . . by such districts are a public use" (UCA 17A-2-1401). The

organization of water conservancy districts is essentially for the public benefit and advantage of the people of the State of Utah and promotes their comfort, safety and welfare (UCA 17A-2-1401).

5. UCA 17A-2-1401 declares the policy of the State of Utah to be:

a. To control, make use of and apply to beneficial use att unappropriated waters in this State to a direct and supplemental use of such waters for domestic, manufacturing, irrigation, power and other beneficial uses; and

b. To promote the greater prosperity and general welfare of

the people of the State of Utah by encouraging the

organization of water conservancy districts.

utahdc4\rod\tcxuapr Page 39
6. The SLCWCD currently serves municipal "water to a population of approximately 500,000 people.

7. SLCWCD believes that comments 1-6 represent pertinent State policies and

statutes to be considered under evaluation criterion 8 of the NCP (40CFR Part 300) in evaluating feasibility study alternatives.

8. SLCWCD relies heavily upon groundwater from the deep, principal aquifer

in the Salt Lake Valley as a municipal supply. SLCWCD delivers approximately 20,000 acre-feet from this source.

9. SLCWCD operates 21 production wells throughout Salt Lake Valley to

extract and deliver groundwater for municipal purposes. One of these wells, located at approximately 500 West 6400 South, is located only

1,100 feet from Operable Unit #1 (OU1).

10. The feasibility study for OU1 only involved groundwater monitor wells which penetrated the shallow, unconfined aquifer. No sampling or

investigation of the deep, principal aquifer was performed. Although the

report acknowledges that the clay layer separating the shallow aquifer and

the deep aquifer "may not be laterally continuous throughout the Midvale slag Superfundsite area" (FSReport, page 2-1), no discussion regarding

exposure of the principal aquifer is included.

11. In its recent groundwater study work in the Midvale Superfund site area, the U.S. Geological Survey (USGS) studied shallow and deep aquifer

waters by means of oxygen isotope analyses. The USGS has identified the

existence of waters in the deep, principal aquifer with a similar isotopic

"signature'' as those existing in the shallow aquifer beneath OU1, indicating downward travel of shallow water.

Response to Comment No. 1 (Items 1-9)

Comments are acknowledged.

Response to Item No. 10

USEPA has not performed sampling or investigation of the deep principal aquifer because the

shallow groundwater under OU1 does not appear to be contaminated. Only one well out of 25

has water with concentrations of lead greater than the lead standard of IS ug/1. The vertical

gradient in the vicinity of the site is probably upward from the deep principal aquifer to the

shallow unconfined aquifer. However, even if the gradient between the two aquifers was

reversed, there could be no contamination of the deep principal aquifer without contamination

of the shallow unconfined aquifer. USEPA and the state will be monitoring the shallow

unconfined aquifer for five years to ensure that there is no contamination in the shallow

utahdeq\rod\tcxLipr Page 40
unconfined aquifer. If contamination is detected, deeper wells and additional action may be

required.

Response to Item No. 11

The Midvale OU1 site team has been in contact with the USGS regarding their many studies the USGS is conducting in the Valley. We are awaiting the USGS interpretation of these data and

also other studies currently being conducted in the Valley. However, the presence of a downward gradient is not problematic in terms of deep aquifer contamination, as long as the

shallow ground water is not contaminated.

Comment No. 2

We believe that the deep, principal aquifer is endangered by the contaminated

waters underlying OU1. In fact, it is likely that downward vertical travel through the discontinuous clay layer is occurring, based upon the recent USGS findings. The SLCWCD encourages USEPA and UDEQ to contact the USGS and review

their findings.

Response to Comment No. 2

See Response to Comment No. 1, Item No. 11.

Comment No. 3

We believe that the Feasibility Study is flawed by not investigating the principal aquifer. We recommend that the decision process be halted at this time to allow the Feasibility Study to be supplemented with this information. This effort should include drilling of deep monitor wells, and sampling of the principal aquifer

water.

Response to Comment No. 3

See Response to Comment No. 1, Item Nos. 10 and 11.

Comment No. 4

Monitoring the principal aquifer water quality over a period of several years should be included with any alternative which is finally selected.

ntahdeq\rod\text.apr Page 41
Response to Comment No. 4

As it is not possible to contaminate the principal aquifer without first impacting the shallow

aquifer, only the shallow aquifer will be monitored during the five year ROD review period. Also, see the Response to Comment No. 1, Item Nos. 10 and 11.

Comment No. 5

We realize that the cost of alternatives 5 and 6 rises dramatically above the costs of alternatives 1-4. However, based upon the future findings of the principal aquifer investigation, these costs may be warranted if the protection of the principal aquifer municipal water supply for the public relies upon implementation of alternatives 5 or 6.

Response to Comment No. 6

See Response to Comment No. 1, Item Nos. 10 and 11.

ARARs

+ Comments by Mr. David 6. Ovard, General Manager of the Salt Lake County Water Conservancy District (SLCWCD)

Comment No. 1

The feasibility study report eliminates groundwater as a "medium of concern" (FS Report, page 3-3). This is based on shallow groundwater metals concentrations

not exceeding drinking water maximum contaminant levels (MCLs). However, the MCL for lead is incorrectly listed. The former lead MCL of 50 micrograms per liter was replaced by the lead action level of 15 micrograms per liter in 1991. The shallow groundwater lead concentration at monitor well LF-08 exceeds the lead action level, with a concentration of 23.7 micrograms per liter.

Response to Comment No. 1

As noted by the reviewer, the lead groundwater protection standard under the Utah Groundwater Protection Rule (Rule) was incorrectly listed in Final FS Report. This error was identified by

the authors and an errata sheet was issued to all of the original recipients of the FS Report on

2 June 1994.

USEPA and UDEQ are working together to determine how and under what circumstances the Utah Groundwater Quality Protection Rule, R317-6, Utah Admin. Code, is applicable or

relevant and appropriate. Those determinations have not yet been made; however, since USEPA

and UDEQ have agreed that, even if the Groundwater Quality Protection Rule is an ARAR in

this situation, an alternate concentration limit shall apply and the ARAR will be met as set forth

otahdcq\rod\tcxt.«pr Page 42
below, a final determination on the status of UDEQ's Groundwater Quality Protection Rule will

not be made for the purposes of this ROD.

Utah's Groundwater Protection Standard (Rule) for lead is IS micrograms per liter (jtg/t). R317-6-2.1, Utah Admin. Code. A sample from one of the 25 groundwater monitoring stations

on OU1 (Well No. LF-08) was found to exceed this standard by 8 /*g/l . In response to this

occurrence, the USEPA and UDEQ have agreed to the application of an Alternate Corrective Action Concentration Limit (ACACL) for OU1 that will bring OU1 into compliance with the Rule. An ACACL is permitted under the Rule provided that it meets certain requirements,

including requirements that the ACACL is protective of human health and the environment, and

is justified by site-specific circumstances. R317-6-15.G, Utah Admin. Code.

USEPA's and UDEQ's decision to apply an ACACL for Well No. LF-08 in this case is based

on the following:

(1) The magnitude of the exceedance.

(2) The very limited spatial distribution of exceedances indicates that Well No. LF-08 is not

representative of groundwater under the entire site.

(3) The relatively high cost of implementing a remedy to address this small suspect area, and

the small benefit of doing so.

Risk Estimations

*• Comments by Mr. Volney Wallace, resident of the City of Murray

I am a retired Ph.D. research chemist. I have examined the Superfimd study final

report of the north end of the Midvale Superfimd site (Operable Unit No. 1) and find it wanting. I recommend that no remedial action be taken -without better data.

This study overlooked the simple fact that the soil studied is loaded with slag gravel. This completely invalidates the study.

Two Basic Errors

This Superfimd study is not valid because of sampling error and misuse of

statistics.

Sampling:

The trailer park is on fill, it is not native land surface. There is no possibility for

contamination to have migrated to the present surface of the park by flow of

water. If there is a serious wind deposition of lead and arsenic there, there is much housing much closer that is more susceptible and would be more seriously affected. That more susceptible area has been studied already as to blood lead

otabdeq\rod\texLapr Page 43
level in children (Midvale Community Lead Study, "Chemical Spedation" and "Bioavailabittty, * 3 (3/4) 2991, pp 149-162 by Bomschein, Pan and Succop, a study by the University of Cincinnati). It reported that the strongest correlation of blood level was with socioeconomic status and highest lead assay of vicinal soil samples. "The effect of soil lead on blood lead was both small and weak." Lead

in house paint was indicted as a cause of the elevated levels of lead that were

seen (the blood levels found were essentially national average and none of the higher levels were alarmingly high by present (1994) standards). Since this is a

problem in older housing and since the older housing is near the site there ought

to be a correlation with distance from the site. A "small" statistical difference

was found. There is no indication in this of a serious wind-carried contamination of lead and arsenic in the vicinity of the smaller.

Slag gravel is ubiquitous in the trailer park and occurs in afield immediately south of the southern extension of the trailer park, in afield immediately to the

east of the park and on the levee between it and the Jordan River. There are

areas within the park that are solidly covered with slag gravel. I noticed on

inspection of the site that the slag gravel content of the soil was especially high

in the west end of the trailer park where the reported lead and arsenic values

were especially high. The "soil" lead and arsenic values in this study appear therefore to be simply measurements of the amount of slag admixed with the soil. This is further indicated by the lack of particle size control in the study and the high correlation between lead and arsenic assay values. The correlation of lead and arsenic was noted oho in the Midvale blood lead study. The correlation of

these two metals indicates that they are intimately associated rather than separate and distinct components of the soil mixture.

The lead and arsenic were assumed to be of high biological availability. This was

an unwarranted assumption. It might be true in other situations but in slag the

great majority of the contamination is present in the interior of the fragments of slag, sequestered as a component of glass, as mineral grains with atomic substitution of lead and arsenic and possibly as lead and arsenic mineral particles contained within a matrix of glass. The slag would have to be dissolved by body fluids for the lead and arsenic in it to be biologically available. From the

viewpoint of a chemist that is so unlikely as to require strong, positive demonstration to establish the contrary.

Misuse of statistics:

If one takes a statistically significant finding as an absolute truth, the blood lead findings showed a distinct problem at Midvale. That study examined a number of possible correlations, none of which proved strong. It is a corollary of statistical analysis that which is statistically significant may be a fluke and that the chance of it mounts with increasing number of trials. The blood level study

was one of those multiple test studies in which one or more of the higher correlation values obtained could be flukes.

utahdcq\rod\text.apr Page 44
As indicated above, the study found a "small and weak" correlation of lead in blood and lead in vicinal soil. Caveats aside, the direct conclusion is that soil lead level is a POOR predictor of blood lead level. Any prediction of blood level

on the basis of soil lead level would have to be accompanied by large ± values. The Superjund study did not take this into consideration. Instead, it treated the correlation as an absolute truth. It took dirt samples from floors, which it incorrectly describes as "dust" samples, and found a highly questionable, very

poor correlation between those values and vicinal soil lead level. Any use of soil lead level to estimate level of lead in floor dirt would have to be accompanied by large ± values. It then speculated a relationship between the suppositional level of floor dirt and blood lead level. This again would have to be accompanied by large ± values. We have thus a compounding of improbable relationships, which led to hard and fast estimates of lead and arsenic contamination in the area. This

is misuse of statistics, exceedingly poor science. It is so poorfy founded and the resulting uncertainty so great that the proposed remedial action could be absolutely unnecessary. If there is indeed a lead and arsenic contamination

problem there, there is very high probability that the study has misidentified the

intensity and extent of it.

The statistical parameters derived in the Superjund study are the locus of the line best fit of regression line. "Best" can be anything. One can get a best fit

regression tine for even a triangular array of data points. One is assured at the

outset that there will be a best fit. The problem is how good the fit is, and the

measure of that is correlation coefficient. The correlation coefficient was horribly

poor. No consideration was given in the Superjund study to correlation coefficient. The study invokes statistical analysis but it appears to be an analysis applied in ignorance.

Bingham Creek

A few miles to the west, Bingham Creek sediment was contaminated by lead from ills on its watershed. Blood tests of children exposed to this contamination showed blood lead levels about half national average with very few. outliers, none

at alarmingly high level. One of the major conclusions from this study is that soil lead level is not necessarily predictive of lead uptake. As in the Midvale

situation, there was correlation of lead and arsenic assays. This correlation implies that the lead and arsenic occurred inseparably together, which is

inconsistent with the supposition that they are separate contaminations, each biologically available.

The lack of serious cases of lead poisoning along Bingham Creek raises further

question of the concern for lead poisoning at the Midvale site.

Jordan River Data

This Superjund study presented a table showing an increase in lead and arsenic

in the Jordan River in its flow past the Superjund site. To me, a chemist, this table is prima facia evidence of prejudiced study.

otahdeq\rod\lext.apr Page 45
Said table shows arsenic in the river increasing from a level oflSppm upstream

to 47ppm downstream. The inference is that groundwater from under the site

seeping into the river caused this rise in arsenic level For it to have done so, the groundwater would have had to be orders of magnitude higher in arsenic

concentration than the river. The table shows it lower, not higher, in arsenic

content. If one assumes that the increase is due to erosion of a contaminated bank, one assumes a feet-per-day rate of erosion of the bank. The situation is similar for the supposed contamination of the river by lead. Cadmium level magically dropped to zero in passage of the river past the mill site. This table is paradoxical, an absurdity.

I do not know if the absurdity of this data was overlooked or if discussion of its

was intentionally withheld. In the one case ineptness and bias are implied, in the other dishonesty. Either way, the basis dependability of the study is brought in

question.

Arsenic

There is no direct data showing the elevated arsenic level at the site is a human health hazard. The treatment of arsenic by the study is suppositional with the basic supposition being that the arsenic present was not as arsenic-containing slag. It is inexcusable that urine samples of the inhabitants were not tested for

arsenic. The correlation of lead with arsenic and the correlation of slag with reported soil contamination implies strongly that it is present in slag. Lead is geochemicalfy immobile while arsenic migrates readily. If they were separate and distinct occurrences, the separator processes of nature should have disproportionated them. Arsenic should have been preferentially leached out of the superficial layer of soil, for example. For the arsenic in the slag to be a

serious presence, the slag would have to be dissolved by body fluids on ingestion. In the laboratory it requires boiling with concentrated acid, fusion with alkali, or

treatment with hydrofluoric acid to get the arsenic out.

Recommendations

I would strongly recommend a determination of particle size distribution of the lead and arsenic contamination in the trailer park area and the extractabitity of those metals under mild extraction conditions. This should provide data showing whether to close down the study and if not what course should be taken.

Response to Comments by Mr. Volney Wallace

Mr. Wallace's expresses concern over several issues. These issues are addressed individually

below.

Response to Comment No. 1

The reviewer states that the mechanisms for transport of contaminants to the Winchester Estates Tailer Park do not include surface water and that wind transport of site contaminants would have

utahdeq\rod\tcxt.apr page 46
impacted residential areas closer to the former smelter than the trailer park. An additional point

was made that blood lead studies in the area show little correlation between lead in soils and lead

in blood.

The FS Report identifies the possible transport mechanisms that would account for contamination

across all of OU1. In addition to surface water transport, the Report listed wind transport of

slag dust, wind transport of smelter stack fume as well as the intentional placement of slag as

fill and for road sanding. We agree that recent surface water transport of slag onto the present

surface of the trailer park is not possible as an east/west oriented ditch separates the trailer park

from the rest of OU1.

The study area for the site characterization effort included a 1,000 to 2,000 foot wide border

around OU1. Within this area samples of soil, groundwater, and surface water were collected

and analyzed. Included in this study area is the "West Zone"; an existing residential area west

of the Jordan River and slightly closer to the former smelter site than the trailer park. The Baseline Risk Assessment (USEPA, 1992) concluded that the excess cancer risk and non-cancer

hazard indices in this area were below a level of concern and lower than the values calculated

for the trailer park. Other residential areas exist immediately east of the former smelter site,

however, these areas are within the OU2 study area.

While we do not dispute the results of blood lead studies in the area, the risk calculation and

remedy selection issues are a matter of the degree of conservatism applied to the protection of

human health and the environment. USEPA and UDEQ have decided to use the Integrated Exposure Uptake Biokinetic Model (ffiUBK) model (USEPA, 1994) to predict the probability

of blood lead levels in excess of 10 micrograms per deciliter (ug/dl). The issue of how lead

risks are derived is more of a philosophical argument rather than a practical one given that the

site risks are driven by arsenic.

Response to Comment No. 2

The reviewer emphasizes that the arsenic and lead measured in taller park soils is primarily

contained within slag particles and not separate and distinct components of the soils.

USEPA/UDEQ suspects that the reviewers observations are correct although this has not been

proven. Circumstantial evidence exists suggesting that a significant portion of the arsenic and

lead detected in trailer park soils derives from visible and microscopic slag particles. The FS Report repeatedly makes this point not only for the trailer park but for all of OU1.

Response to Comment No. 3

The reviewer objects to a presumption by USEPA and UDEQ that arsenic and lead are highly

bioavailable given that a significant proportion of these contaminants occur as slag.

The reviewer incorrectly concludes that the metal components of slag are not biologically

available. Although a portion of the metal contaminants are isolated within a glassy matrix, a

portion of the metal bearing mineral particles are intercepted by the surface of the slag particle.

uUhdeq\rod\texLapr Page 47
The proportion of available metals per unit mass of slag is a function of surface area and

therefore particle size. In addition, the glassy matrix is not entirely inert and can be susceptible

to weathering which will further enhance the availability of the metal bearing portion of the slag.

For the purposes of calculating cancer and non-cancer risk, lead was presumed to be 30%

bioavailable (default value in IEUBK model) and arsenic was presumed to be 80% bioavailable. Studies currently underway (USEPA Phase n Swine Study and others) will help to refine the

bioavailability factors used in future risk assessments at other sites. However, in the absence

of reliable information on the bioavailability of site contaminants, the approved USEPA Region

bioavailability factors were applied to OU1.

Response to Comment No. 4

The reviewer points out that there is a poor correlation between contaminant concentrations in

house dust and in surface soils. The reviewer also expresses concern over the uncertainty

associated with several variables and the potential for large errors when these variables are

combined in a risk calculation.

The plots of contaminant concentrations in house dust vs. surface soils (UDEQ, 1993) do not

show a clear correlation, although a stronger correlation would be expected with a larger sample

size. The plots do show that house dust generally is less contaminated than surface soils. The

dust and soil sampling program was undertaken to permit the use of site specific measurements

rather than the standard default assumption that contaminant concentrations are the same in house

dust and surface soils. In the risk calculation a large portion of the solids ingested by a person

is presumed to be house dust (typically 40% of the solids). Therefore, use of the equation

describing the 95 % upper confidence limit of the best fit line through the paired house dust and

surface soil data resulted in a lowering of the risk posed by lead when compared with the

standard default assumptions used by USEPA in risk calculations.

It is reasonable to conclude that many of the variables used in the risk calculation are estimates

and that when these estimates are combined in a risk calculation the error may be large. When

possible, site specific data is collected (such as house dust chemistry) and when default values

are used they are conservative values to minimize the possibility of underestimating the risk.

The reviewer concluded that the remedial actions proposed may be unnecessary. While this is

a possibility, USEPA and UDEQ as a matter of policy choose to take the conservative position

on issues of human health protection.

Response to Comment No. S

The reviewer questioned the surface water contaminant concentrations summarized in the FS Report.

In response to the comment, the Jordan River data was rechecked (URS, 1992) and the reviewer

is correct. No differences in arsenic and lead concentrations were apparent between the

utahdeq\rod\texuapr Page 48
sampling location up-stream of OU1 and adjacent to OU1. The correct ranges for up-stream

sampling stations and stations adjacent to OU1 are summarized below.

Concentrations of Selected Metals

in Surface Water

Location

Background Stations (Upstream) On-Site Stations (Adjacent to OU1)Range Average

Range Average

Concentration pglt Arsenic

14-16

16

15-17

16

Cadmium

1

1

1

1

Lead

5-22

8

6-11

8

Antimony

20

20

20

20

Beryllium

1-2

1

1

1

Response to Comment No. 6

The reviewer objects to the lack of systematic testing of urine samples from the current residents

of the trailer park for arsenic.

While a study of arsenic in urine may have been useful, it is not certain the results would be meaningful. No children currently reside in the trailer park, therefore, any urine study would

exclude a portion of a hypothetical future population. In addition, arsenic concentrations in

urine can vary significantly within one day, between days and seasonally making such studies

difficul t to design, implement and interpret.

+ Additional Verbal Comment by Mr. Volney Wallace, resident of the City of Murray

Comment No. 1

Mr. Wallace felt USEPA's site investigation was poorly done. He indicated it was his understanding that at first, it was determined there was no problem. Soil levels were relatively low and the ground water had a lower concentration of lead and arsenic than the river had. Mr. Wallace said there was no sign the shallow aquifer had been contaminated and that the deep aquifer; which was under artesian pressure, was not contaminated. Mr. Wallace said the agencies had changed their minds on the basis of

suppositions. He felt that suppositions were not needed because there was a population which could be tested to see if there really is a need for cleanup. He also said the soils analysis was questionable.

Mr. Wallace asked about the distribution of these toxins as a Junction of paniculate size. He said his real concern was with the dust. He also asked about a depth profile. He said the contamination would be superficial if it came out of a smoke stack and landed

on the ground. He recommended rototilh'ng the soil to dilute out the contamination.

utahdeq\rod\text.ipr Page 49
Response to Comment No. 1

Early opinions were based on very preliminary information. The findings referred to in the

proposed plan and detailed in the Remedial Investigation/Feasibility Study and in the Risk Assessment are part of a more exhaustive site investigation.

USEPA agrees with the assessment of the groundwater issue. The concentrations in the upper

aquifer and the lower aquifer are below those in surface water of the Jordan River and pose no

threat to the public.

The practice of risk assessment includes components of science and professional judgement. USEPA uses as much science as is available, and then makes a public health judgement call

based on staf f experience and best professional judgement. Mr. Wallace indicated that biological tissue sampling would be an effective way to assess the

problem on this site. USEPA takes issue with that for a variety of reasons. Epidemiologically,

there are not enough people on the site to get the statistical power and confidence that would

allow a sound public health decision. In addition, the pharmacokinetics distribution of arsenic,

which is the principal contaminant on this site, is such that it is not expected to be found in the

tissue. It moves very quickly through the body and is excreted in urine. It comes in, creates

tissue damage, and leaves quickly. Because exposures are low and arsenic moves quickly to

urine, tissue sampling for arsenic would be essentially fruitless.

On the issue of depth: USEPA agrees that exposure occurs at the surface. The agency typically

focuses on the top two centimeters. The concentrations taken from this surface horizon were

analyzed very carefully and are the principal basis for our public health decision making on the

site.

»• Comment by Ms. Jean Barbuto, resident

Comment No. 1

There is a well in Winchester Estates near the river. Who uses the water?

Response to Comment No. 1

No one appears to be using the well as this point. The well was installed by Valley Materials

and has never been hooked up to any domestic system. The residents of Winchester Estates

receive their water from Murray City wells.

Comment No. 2

Do you have reports from the medical community regarding the health of people living

in Winchester Estates?

ntahdcq\rod\text.apr Page 50
Response to Comment No. 2

USEPA does not have any specific medical reports.

»• Comment by Cindy Merril, Winchester Estates resident

Comment No. 1

Has anyone addressed the issue of the material underneath the mobile homes?

Response to Comment No, 1

The issue was addressed during the risk assessment. Since the contaminated material is

underneath the mobile home, people are not regularly exposed to it and there is no need to be

concerned about risk. USEPA's lexicologist felt it would be unnecessarily disruptive and not

in the interest of public health to remove materials underneath the trailers at this time. Institutional controls may be required in the event mobile homes are moved.

K Summary of Comments by Mr. Leon Hansen, area resident

Summary Comment

Mr. Hansen said he was a geotechnical expert who had spent his early years qualifying the chemistry and characteristics of the chemistry of the ores shipped to area smelters. He explained that the area embraced one common, huge aquifer system comprised of

various aquifers which have been disrupted, in part, by recent faulting. He said the aquifer system was injected with the waters of the Wasatch Mountains, including water from the east side of the mountain from Deer Creek and the new Jordanelle Reservoir. Mr. Hansen said Deer Creek was being chlorinated and those waters were then going

into the pristine aquifers. Near the new Jordanelle Reservoir was a regional tailings dump where Mr. Hansen said samples had shown heavy metals contamination in

concentrations tens of thousands of times greater than the concentrations found at Midvale Slag. Mr. Hansen said the agencies hadn't addressed the means that water

was being injected into the common aquifer system along with the Deer Creek water. He said he was concerned about soils from former smelter sites which had water/lowing over them.

Mr. Hansen asked about remedial procedures at the Midvale Slag and Sharon Steel Tailings sites. He asked how long-term ongoing remedial problems from blowing slag and tailings would be addressed? He also asked if there had been a demonstration of any

toxic problems with children or adults? He wondered if there had been any basis for the

risk findings which hadn't been extrapolated from a distance statistically without regard

to analytical proof? Had a medical fraternity been involved?

obhdeq\rod\texUipr Page 51
Response

The global perspective is appreciated. The agencies realize that they are working with a system

and not individual parts. Often, however, one site or one operable unit is focused on. The U.S. Geological Service is currently doing a comprehensive evaluation of the ground water which

should address the issues raised here. Preliminary results should be available within a year.

Remedial action for the Sharon Steel Tailings and the Midvale Slag OU2 will be addressed in

later documents. Problems associated with blowing tailings and other contaminants will be

addressed as part of remedial design for these projects.

A study was completed several years ago for the Sharon Steel project to assess lead exposure

in Midvale. It showed clearly, with a good degree of statistical power, that children living in

proximity to the contamination had elevated blood lead as a result of their proximity to that material. The closer they were to the site, the higher the blood lead. Several other studies

which have recently been completed by the mining and smelting industries in the Salt Lake Valley are currently under evaluation. These epidemiological studies measured metal

concentrations in children and adult blood and urine. Other studies are planned. USEPA

recognizes, however, that these studies are not the final answer. The issue is a little more than making a single measurement. The heavy metals found at these sites are transient through

biological systems. They can come in, cause damage, and then leave. If the timing is not right,

the appropriate measurement isn't made. However, the results are valuable and are assessed as

part of the risk analysis process. Region 8 does use extrapolation. That's generally the

approach used nationally.

> Comment by Ms. JoAnn Seghini, Midvale City Council

Comment No. 1

The lead study done in the Midvale area showed no significant lead levels in children,

in pregnant or lactating females except for one child who only lived in the. community a week.

Response to Comment No. 1

There was a relationship between proximity to the Sharon Steel tailings and blood lead. See also

response to previous question.

» Comment by Unidentified area resident

Comment No. 1

What does USEPA think of Dr. Bill Banner's review from the Primary Medical Center in

matters related to what we're discussing? He was very adamant that there have been no

tests, no indications of any kind, to any toxic damage or risk to anyone in any of these

areas that have been under study.

utahdcq\rod\l£it.apr Page 52
Response to Comment No. 1

The commentor was invited to submit the information for the record. No further information

was received.

Results of Site Investigation

* Comment by Ms. JoAnn Seghini, Midvale Councilwoman

Comment No. 1

Was sampling done west of the Jordan River? Was contamination found?

Response to Comment No. 1

Samples were taken in a half-mile perimeter around the site. Several areas of contamination

were found, primarily north of 6400 South and west of Murray golf course and in an area

between the Jordan River and the Jordan Canal. Detail about the sampling is available in the

1992 URS Site Characterization Report.

Comment No. 2

The site map, LR east section, indicates an arsenic average of280ppm even though the

range was 1.9 to 2,000 ppm. Is the same kind of range found in other areas? Can you demystify the map? How were samples taken in the Winchester Estates area?

Response to Comment No. 2

The map reflects the range from the hottest soil sample to the coldest soil sample. This

concentration range is similar to that found on the southern 2/3 of the site with die highest

concentrations attributable to visible layers of slag. In the residential area (Winchester Estates),

each lot was evaluated. Four to five samples were taken per yard. These samples were then

combined to make one composite sample.

Comment No. 3

Will Winchester Estates residents be told what their sample results are?

Response to Comment No. 3

Sample results and a letter of explanation for each property were mailed to residents. Since the

letters were mailed, UDEQ has responded to several calls from people who wanted more

information. UDEQ and USEPA representatives are available to answer any additional questions

which residents might have.

ntahdcqNrod\tcxt.apr Page 53
* Comment by Garth Plmm, Winchester Estates Manager

Comment No. 1

Define the sampling process. Is the slag the source of contamination or is it the dust accumulation within the soil itself?

Response

Four to five soils samples were taken per yard. The samples from each yard were then

composited into one sample. Dust samples were collected in one out of every five homes. For

adults and children, the principle exposure concern is very small particulate, or dust. Slag

grains and small particles that were emitted from the smelter chimney are the source of

contamination in soils. House dust samples are collected because contaminated soil can be

tracked or blown into a home.

Institutional Controls

»• Comment by Mis. JoAn n Seghini, Midvale City Council

Comment No. 1

Would the only limit on investment for the site be to remove contaminated soils? Would those have to be tested by the builder? Would that cost be assumed by the builder? Will USEPA define the depth of the cap or would that be defined by the local ordinance which establishes the institutional control? Will there be any limit to the length of foundation for any kind of building or structure?

Response to Comment No, 1

During the Remedial Design phase, USEPA and UDEQ will work with the property owner and

the appropriate city to develop institutional controls. The primary focus will be to assure the

contaminant exposure pathway is broken. Any excess contaminated soils which are removed

during excavation would need to go to a Subtitle D landfill. Excavated, contaminated soils could

be left on site, provided they are adequately covered when construction is completed. If a residential development is to be built, the developer would need to assure that soil levels met

the residential requirements outlined in the ROD.

Comment No. 2

Would there be restrictions on OU2 since the highway and that operable unit are

contiguous or will OU2 be open to development once it is remediated? Afidvale is reluctant to build a highway that would restrict any development on our properties and literally funnel everything to other communities. You say no restrictions north of your OU dividing line?

ulahdeq\rod\text.apr Page 54
Response

OU2 issues will be addressed in a later decision document. If institutional controls are required

for OU2, USEPA and UDEQ will work with the property owner and the appropriate city to

develop them during that portion of the site's Remedial Design phase.

Xm. REFERENCES

Camp, Dresser, and McKee. 1990. Remedial Investigation Addendum for Sharon Steel/ Midvale Tailings Site, 1989-1990. "Ground Water/Geochemistry Data Report Vols. 1,

2,3."

Hely, A., R. Mower, and C. Harr. 1971. Water Resources of Salt Lake County, Utah. State

of Utah Department of Natural Resources Technical Publication #31.

LSI, 1992. Baseline Risk Assessment-Human Health Evaluation, Midvale Slag Superfund Site, Operable Unit 1, Midvale, Utah.

URS. 1992. Site Characterization Report, Midvale Slag Superfund Site, Operable Unit No. 1 (OU1), Midvale, Utah.

UDEQ. 1994. Feasibility Study Report, Operable Unit No. 1, Midvale Slag Site, Midvale, Utah.

utahdeq\rod\textapr Page 55
Table 1

Exposure Point Concentrations

Parcel

LR(West)

LR(East)

LF

LG

WESE

WENW*

Exposure Point Concentration*

(rag/kg)

Arsenic

210

280

240

£60

390

16-520

OidTpfaif n

28

32

18

48

20

N S6

Lead

793

1545

492

505

619

120 - 2,300

* Exposure Point Concentrations (EPCs) for arsenic and cadmium are the 95 % Upper Confidence Limit of the arithmetic mean of a log normal

distribution or maximum detected concentration, whichever it smaller. EPC for lead is the arithmetic mean.

b

 Parcel WENW is current residential development; each residential lot was individually aampled, range of values presented is range of

concentrations detected. c

 NS - Not aampled; previous work performed at OUI indicated mat the health risks due to cadmium are amall when compared with arsenic.

mg/kg ** milligrams per kilogram
Table 2

Summary of Human Exposure Parameters

Exposed Population

Resident Adult

Resident Child

Worker

General Parameters

Body weight = 70 kg

Exp. Freq. = 350 day/yr Exp. Duration = 30 yr

Body weight = 15 kg

Exp. Freq. = 350 day/yr Exp. Duration — 6 yr

Body weight = 70 kg

Exp. Freq. = 250 day/yr Exp. Duration «= 25 yr

Exposure Medium

Groundwater

Soil

Groundwater

Soil

Groundwater

Soil

Exposure Route

Oral

Oral

Oral

Oral

Oral

Oral

Route Parameters (RME)

2 //day

100 mg/day (24 yr)

200 mg/day (6 yr)

l//da y

200 mg/day

l//da y

50 mg/day

kg «= kilogram

//day = liter per day

mg/day — milligrams per day RME — Reasonable Maximum Exposure

yr - year
Table 3

Total Site Risk Estimates

Parcel

LRWes t

LREast

LF

LG

WESE

Population

Worker

Worker

Worker

Worker

Resident

RME*

Non-Cancer Hazard Index

fjidmiiirq

0.06

0.05

0.05

0.06

0.4

Arsenic

0.3

0.3

0.3

0.8

3

RME Cancer Risk

5E-5

6E-5

6E-5

IE-4

8E-4

P C

10

NE

NE

NE

NE

3

* Total site risk refers to the risk posed by contaminants in soils, house dust, and groundwater. The relationship between toil and house dust

for arsenic, cadmium, and lead is defined by Cdust - 0.2 Csoil+20 , Cduct - Csoil and, Cdust - 0.2 Csoil + 290, respectively, where

Cdust and Csoil » contaminant concentrations in dust and soil, respectively. These relationships were developed from paired house dust

and surface soil chemistries. In addition, for computation of non-cancer risk the effect s of arsenic and cadmium are presumed not to be

additive. Additional discussion on soil/dust ratios and additrvity of health effect s is presented in the Feasibility Study Report (UDEQ, 1994)

and Baseline Risk Assessment Report (LSI, 1992).

b

 Total site risks are presented by parcel assuming the typical groundwater contaminant levels using the calculation method described in RAOs

(95% UCL of the mean (assuming a lognormal distribution) for all of OU1 I At- 3.1 w>lt, Cd-2.1 fig", and Pb-2.1

c

 P,, - Probability fin percent) that a child exposed would have a blood lead concentration > 10 ng/dt. Only evaluated for residential setting

(WESE). NE * Not Evaluated RME « Reasonable Maximum Exposure
Table 4

Soil Clean-Up Levels

(Contaminant

Arsenic

fy^mh' m

Lead

Health Criterion

Risk = IE-4

Hazard Index = 1

Pw

b

 <5%

Soil Clean-up Level* (mg/kg)

Resident

73

49

650

Worker

960

2980

NE

* Soil clean-up levels are calculated assuming die typical groundwater contaminant levels. The typical contaminant

levels used are the exposure point concentration (EPCs) using die calculation method described in RAGS,

namely the 95% UCL of die mean (assuming a lognormal distribution) for all of OU1 [As=3.1 ftglt, Cd=2.1

fig/t, and Pb=2.1 jtg//]). Additional discussion on soil/dust ratios and additivity of health effect s is presented

in the Feasibility Study Report (UDEQ, 1994) and Baseline Risk Assessment Report (LSI, 1992).

b

 P10 corresponds to die probability that a child exposed would have a blood lead concentration of > 10 pg/dl ,

estimated using die lead 6.0 UBK model, as discussed in die text.

mg/kg = milligrams per kilogram NE = Not Evaluated
Table 5

Reduction in Soil Contaminant Concentrations Under the Selected Remedy*

Exposure Point Concentration

(iag/kg)b

Parcel

WESE

WENW

Arsenic

Pre-Remedial

390

16-520

Post-Remedial

11"

16-70

f-p^inii"1?

Pre-Remedial

20

NS

Post-Remedial

2

C

2"

Lead

Pre-Remedial

619

120 - 2,300

Post-Remedial

87

120-600

* Under the selected remedy, there is no reduction in soil contaiminant concentrations on Parcels LR-West, LR-East, L F, and LG. b

e

 mg/kg = milligrams per kilogram

6

 concentration values equal to local background (LSI, 1992)

 Post remedial concentrations on treated yards will be flic local background concentration of 2 mg/kg (LSI, 1992)

NS — Not sampled; data not available
Table 6

Total Site Risk Reduction*

Under Selected Remedy

Parcel

LR-WesF

LR-Easf

LP

LG"

WESE

WENW

Population

Worker

Worker

Worker

Worker

Resident

Resident

RME Non-Cancer Risk Hazard Index

Before Remediation

0.3

0.3

0.3

0.8

3

See Figure 6

After Remediation

0.3

0.3

0.3

0.8

0.3

0.2

RME Cancer Risk

Before Remediation

5E-5

6E-5

6E-5

IE-4

8E-4

See Figure 5

After Remediation

5E-5

6E-5

6E-5

IE-4

6E-5

4E-5

pM *O

Before Remediation

NA

NA

NA

NA

3

See Figure 7

After Remediation

NA

NA

NA

NA

<1

<5

* Thia table provide* fummary of risks due to aoila, house dust, and groundwater before and after implementation of the (elected remedy. The relationship between toil and house dint for anenic,

cadmium, and lead ii defined by Cdutt = 0.2 Csoil + 20, Cdust = Csoil and, Cdu«t = 0.2 Csoil + 290, respective^. Oroundwater contaminant concentntiom used for computation of risk.

are typical for all of OUI. These have been calcuUtedutiiig the memod described in RAGs (95 ft UCL of me mean [a**u^ Cd»2.1 ftglt, and Pb— 2.1 ftg/tj). For computation of non-cancer risk the effect s of anenic and cadmium are presumed not to be additive. b

 P)0 corresponds to the probability in percent that a child exposed would have a blood lead concentration > 10 microgram* per deciliter (/tg/dQ. Only evaluated for residential setting (WESE

and WENW Parcels). 0

 Note mat under the selected remedy, the risk to a hypothetical worker remains unchanged on these parcel*.

NA = Not Applicable RME = Reasonable Maximum Exposure
afte

r URS (1992b)

mvcas

215 Union Boulevord Suite 550 Lokewood. CO 80226

(303) 980-6800

UTAH DEPARTMENT OF ENVIRONMENTAL QUALITY SALT LAKE CITY. UTAH

MIDVALE SLA G SUPCRFUND SIT E INDEX MAP

FIGURE

1
8

PARCEL WENW

PARCEL WESE

PARCEL LF

PARCEL LR

PARCEL LG

PARCEL LR-EAST

MURRAY

IflOVALE

7200 S. ST.

SOU: 1 MM -MO rtET

EXPLANATION ..__._.. PARCa BOUNDARIES

•GU I BOUNDAR Y

a.

go

wuass KSOCRS/CONSJlWnS

215 Union Boulevard Suite 550 Lakewood, CO 80228

(303) 980-6800

RECORD OF DECISION

MIDVAL E SLAG SUPERFUND SIT E

O U1 PARCELS

FIGUR E

2
E PA REGION VIII SUPERFUND DOCUMENT MANAGEMENT SYSTEM

DOC ID # PAGE#

IMAGERY COVER SHEET

UNSCANNABL E ITEM

Contact the Superfund Records Center to view this document.

(303-312-6473)

SIT E NAME

REPORT OR DOCUMENT TITLE

<y

DATE OF DOCUMENT

DESCRIPTION OF IMAGERY
MIDVALE SLAG SITE, SEPTEMBER 21, 1987. APPROXIMATE SCALE 1:11,450

o>

2 15 Union Boulevard Suite 550 _ !® Lakewood, CO 80228 KMWH5 V^/DESOOS/MNSUITMS (303) 980-6800

MIDVALE SLAG OPERABLE UNIT 1

INFRARED FALS E COLOR AERIAL PHOTOGRAPH

FIGURE

3
1009247.MBDS100394

CONTAMINATE D MEDIUM EXPOSUR E PATHWA Y

EXPOSE D POPULATION

CURREN T RESIDEN T (WENW ) FUTUR E RESIDEN T FUTUR E WORKER (WESE ) (LF.LR.LG )

DUST INGESTIO N

SOI L INGESTIO N

VEGETABLES INGESTION

GROUNDWATE R INGESTIO N

PATHWAY IS OR MIGHT BE COMPLETE

PATHWAY IS NOT COMPLETE

MWGERS V^/Kswos/cowuiwns

215 Union Boulevard Suite 550

lakewood. CO 80228

(303) 980-6800

RECORD OF DECISION MIDVALE SLAG OU1 SUPERFUN D SIT E

CONCEPTUAL SIT E MODEL OF EXPOSUR E PATHWAY S

FIGURE

4
E PA REGION VIII SUPERFUND DOCUMENT MANAGEMENT SYSTEM

IMAGERY COVER SHEET

UNSCANNABL E ITEM

Contact the Superfun d Records Center to view this document.

(303-312-6473)

DOC ID ft PAGE #

SITENAME middaie. Ska \

REPORT OR DOCUMENT TITLE l)ed£rd>rfafij m /u£ record &T

DATE OF DOCUMENT

DESCRIPTION OF IMAGERY 3 c &l *r+ coded Ma 1>1
J

J

J

J

J

CM

o

R ME Cancer Risk From Arsenic

LEGEND

12 £ IE-4

I —I EE-4 to 5E-4

• S 6E-4

2 15 Union Boulevard Suite 550 Lakewood, CO 80228

(303) 980-6800

UTAH DEPARTMENT OF ENVIRONMENTA L EQUALIT Y MIDVAL E SLAG SUPERFUND SIT E

FIGURE 5 WINCHESTER ESTATES R ME CANCER RISK FROM ARSENI C
JJJJJ

$I

RME Chronic Hazard Index From Arsenic

LEGENDg 1 22 3

2 15 Union Boulevard Suite 550 Lakewood, CO 80228

(303) 980-6800

UTAH DEPARTMENT OF ENVIRONMENTAL EQUALIT Y MIDVAL E SLAG SUPERFUND SITE i FIGURE 6

WINCHESTER ESTATES

ME CHRONIC HAZARD NDEX FROM ARSENIC
J]JJJJ

g 1 , JI 2 3

Probability of Blood Lead Exceeding 10

LEGEND (UNITS = %)

a <= 5

ID > 5 and <= 15

• > 15

N OT TO SCALE

WNNXRS OfiSHCB/CONSUlttNrS

UTAH DEPARTMENT OF ENVIRONMENTA L EQUALIT Y MIDVAl[E SLA G SUPERFUN D SIT E

FIGURE 7 WINCHESTER ESTATES PROBABILITY OF BLOOD LEAD EXCEEDING 10

2 15 Union Boulevard Suite 550 Lakewood, CO 80228

(303) 980-6800
EXPLANATIO

N ..-.-._.. PARCEL BOUNDARIES

OU1 BOUNDARY WOIS

X X X X TOUT Of COUPUANCE

muaas

215 Union Boulevard Suite 550 Lokewood. CO 80228

(303) 980-6800

POINT OF COMPLIANCE F OR GROUNDWATER ARAR

S

O U1 PARCELS

FIGURE 8
91628

6

6287

6288

702269

#16290

7x16291

,516292 MS'1629 3

//1 6294 I 6295

16297

6298

6299

7116301

1 6302 1 6304

#16306

/Vl6307

1^6379

6317

6318

6319

/16321

$6322

^16324

'516326

£16328

5/16329

#16330 J516335

iv

&16381

«'16382

716383

^16387

5^6396

^3520

543550

^3763

^3764

^3765

^3766

^3767

^23770

/5i3771

>823773
APPENDIX A

APPLICABLE, RELEVANT OR APPROPRIATE REQUIREMENTS

L
APPENDIX Al

Groundwater ARARs

L
Table A-l

Chemical-Specific ARARs for Groundwater

(concentration shown in pgfl)

Parameter

Arsenic

Cadmium

Lead

SDWA M CL

50

5

NS

SDWA MCLG

NS

5

0"

C WA Water Quality Criteria*

190

10

50

Utah Drinking Water MCL

50

5

15

Utah Groundwater Protection Standards*

50

5

15

ARAR

50

5

TBD

ARAR Basis

SDWA M CL

SDWA MCLG

TBD

* Not considered «n ARAR u discussed in preceding text.

NS = No Standard SDWA * Safe Drinking Water Act CWA «= Clean Water Act MCL(O) * Maximum Contamination Limits (Goal) TBD - To Be Determined

utahdcq\rod\»ppd-«l .jan
APPENDIX A2

Action-Specific ARARs

L
Appendix A2 Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action

Cappin g

Requirement

Placement of a cap over waste (e.g.,

closing a landfill , or closing a surface

impoundment or waste pile as a landfill ,

or similar action) requires a cover

designed and constructed to:

• Provide long-term minimization migration of liquids through the

capped area;

• Function with minimum

maintenance;

• Promote drainage and minimize

erosion or abrasion of the cover;

• Accommodate settling and

subsidence to that the cover' s

integrity is maintained; and

• Have a permeability less than or

equal to the permeability of any

bottom liner system or natural subtoils present.

• Eliminate free liquids, stabilize

wastes before capping (surface

impoundments)

• Restrict post-closure use of

property as necessary to prevent

damage to the cover.

• Prevent runon and runoff from

damaging cover.

• Protect and maintain surveyed

benchmarks used to locate waste

cells (landfills , waste piles.)

• Eliminate free liquids by removal

or solidification.

• Stabilization of remaining waste

and waste residues to support

cover.

Installation of final cover to provide

long-term minimization of infiltration.

Post-closure care and groundwater monitoring.

Prerequisite

RCRA hazardous waste placed

at site after November 19, 1980,

or movement of hazardous waste

from one unit, area of

contamination, or location into

another unit or area of

contamination will make

requirements applicable. Capping without such movement

will not make requirement

applicable, but technical

requirements are likely to be

relevant and appropriate.

1

Citation

40 CFR 264.258(b); UAC R315-8-12.6(b)

40 CFR 264.3 10(a); UAC R313-8-I4.5(a)

40 CFR 264.228(a), UACR315-8-ll.S(a)

40 CFR 264.1 17(c); UAC R3 15-8-7

40 CFR 264.228(b), UAC R315-8-lI.5(b)

40 CFR 264.3 10(b), UAC R315-8-14.5(b)

40 CFR 264.228(a)(2), UAC R31 5-8-1 1.5(a)(2)

40 CFR 264.228(a)(2) and

40 CFR 264.258(b), UAC R3 15-8-1 1.5(a)(2),

and R315-8-12.6(b)

40 CFR 264.310; UAC R3 15-8- 14. 5

ARAR

N ot ARAR

Comments

Alternative 3 involves the

installation of t

permeable tingle-layer •oil cover, the only

objective of which ii to

prevent direct exposure. Accordingly the intent ic

inconsistent with that oft RCRA cap and these

requirements are not ARAR.
Appendix A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action Requirement Prerequisite Citation ARAR Comments

Excavation Placement on or in land ouUide unit

boundary or area of contamination will

trigger land disposal requirements and

restrictions. Movement of excavated materials lo new

location and placement in or on land will

trigger land disposal restrictions for the

excavated waste or closure requirements

for the unit in which the waste is being

placed.

Area from which materials are excavated

may require cleanup lo levels established

by closure requirements._________

Materials containing RCRA hazardous wastes subject to land

disposal restrictions are placed

in another unit.

RCRA hazardous waste placed

at site after the effective date of me requirements.___ __

40 CFR 268 (Subpart D) UACR315-13-1

40 CFR 268 (Subpart D) UAC R315-13-1

See Closure in this exhibit.

N ot ARAR Requirements are

applicable for RCRA hazardous waste. OUI soils have been tested and

found not to exhibit any

hazardous waste

characteristics and land

disposal restrictions are

accordingly not identified

as ARARs.

Treatment or

storage in tanks

Tanks must have sufficient shell strength

(thickness), and, for elosed tanks,

pressure controls, to assure that they do

not collapse or rupture.

Waste must not be incompatible with the

tank material unless the tank is protected

by t liner or by other means.

New tanks or components must be provided with secondary containment.

Tanks must be provided with controls to

prevent overfilling, and sufficient

freeboard maintained in open tanks to

prevent overtopping by wave action or

precipitation.

Inspect the following: overfillin g

control, control equipment, monitoring

data, waste level (for uncovered tanks),

lank condition, above-ground portions of

tanks, (to assess their structural integrity)

and the area surrounding the tank (to

identify signs of leakage).

Repair any corrosion, crack, or leak.

RCRA hazardous waste (listed

or characteristic), held in a tank

f or temporary period before

treatment, disposal, or storage

elsewhere, (40 CFR 264.10).

40 CFR 264.190 UAC R315-8-10

40 CFR 264.191 UAC R315-8-10

40 CFR 264.193 UAC R315-8-10

40 CFR 264.194 UAC R315-8-10

40 CFR 264.195 UAC R315-8-10

N ot ARAR None of the alternatives

involve treatment or

storage in tanks.

40 CFR 264.196 UAC R315-8-10
Appendi

x A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action

Treatment or

storage in tanks

(coo't.)

Container Storage (on-site)

Requirement

At closure, remove ill hazardous waste

and hazardous waste residues from tanks,

discharge control equipment and

discharge confinement structures.

Store igniuble and reactive waste so as

to prevent the waste from igniting or

reacting. Igniuble or reactive wastes in

covered tanks must comply with buffer

zone requirements in "Flammable and Combustible Liquids Code,* Tables 2-

1

through 2-6 (National Fire Protection Association, 1976 or 1981).

Containers of hazardous waste must be:

• Maintained in good condition. • Compatible with hazardous waste to be stored; and • Closed during storage (except to

add or remove waste).

Inspect container storage areas weekly

f or deterioration.

Place containers on a sloped, crack-free

base, and protect from contact with

accumulated liquid. Provide containment

system with a capacity of 10 * of the

volume of containers of free liquids. Remove spilled or leaked waste in a

timely manner to prevent overflow of the

containment system.

Prerequisite

Storage of RCRA hazardous

waste (listed or characteristic)

not meeting small quantity

generator criteria held in a

container for a temporary period

greater than 90 days before

treatment, disposal, or storage

elsewhere. A generator who

accumulates or stores hazardous

waste on site for 90 days or less

in compliance with 40 CFR 262.34(a)(l-4); 40 CFR

264.176, UAC R3 15-8-9.6 is

not subject to full RCRA storage

requirements. Small quantity

generators are not subject to the

90-day limit [40 CFR 262.34(c),

(d), and (e); UAC R3 15-5-10).

Citation

40 CFR 264. 197 UAC R315-8-10 40 CFR 264.198 UAC R3 15-8-10 40 CFR 264. 171 UAC R3 15-8-9.2 40 CFR 264.173 UAC R3 15-8-9.3 40 CFR 264.174 UAC R315-8-9.4 40 CFR 264.175 UAC R3 15-8-9.5 40 CFR 264. 175 UAC R3 15-8-9.6

ARAR

NotARA R

Comments

Container ftonge of

hazardous wastes or

similar wictei it not •

put of any alternatives. fcI
Appendi

x A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action Requirement Prerequisite Citation ARAR Comments

Container Storage

(on-site)

(con't.)

Keep containers of igniuble or reactive

waste at least 50 feet from the facility's

property line.

Keep incompatible materials separate. Separate incompatible materials stored

near each other by • dike or other

barrier. At closure

, remove all hazardous waste

and residues from the containment

system, and decontaminate or remove all

containers, liners. 4

0 CFR 264.176 UAC R315-8-9.7 40 CFR 264.177 U AC R315-8-9.8 40 CFR 264.178 UAC R315-8-9.9

Clean Closure General performanc

e standard requires

minimization of need for further maintenance and control; minimization or

elimination of post-closure escape of

hazardous waste, hazardous constituents,

leachate, contaminated runoff , or

hazardous waste decomposition products. Disposal or decontamination of

equipment, structures,and toils.

Removal or decontamination of all waste

residues, contaminated containment

system components (e.g., liners, dikes),

contaminated subsoils, and structures and

equipment contaminated with waste and

leachate, and management of them as

hazardous waste.

Meet health-based levels at unit.

RCRA hazardous waste (listed

or characteristic) placed at site

after November 19, 1980, or movement of hazardous waste

from one unit, area of

contamination, or location into

another unit or area of

contamination. Not applicable

to material undisturbed since November 19, 1980.

May apply to surface

impoundment and container or

tank liners and hazardous waste

residues; contaminated soil,

including soil from dredging or

soil disturbed in the course of

drillin g or excavation, and

returned to land. 4

0 CFR 264.111; UAC R315-8-7 UACR-315-8-11.5 40 CFR 264.111

40CFR 264.178 40 CFR 264.197 40 CFR 264.228(a)(l)

and 40 CFR 264.258 UAC R315-8-9.9 U AC R315-8-11.5 40 CFR 264.111 UAC R315-8-7

N ot ARAR Only Alternative 4 involves removal of

contaminants. These

contaminants ire not

identifiable as hazardous

wastes and clean closure

requirements are

accordingly not ARAR.
Appendi

x A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action

Off-Site Treatmen

t Storage or Disposal

Discharge to Storm Sewers

f

Requirement

In the case of any removal or remedial

action involving the transfer of any

hazardous substance or pollutant or

contaminant off-site, such hazardous

substance or pollutant or contaminant

shall only be transferred to a facility which is operating in compliance with

section 3004 and 3005 of the Solid Waste Disposal Act (or where applicable, in

compliance with the Toxic Substances Control Act or other applicable Federa

l

law) and all applicable State

requirements. Such substance or

pollutant or contaminant may be

transferred to a land disposal facility only

if the President determines that both of

the following requirements are met: • The unit to which the hazardous

substance or pollutant or

contaminant is transferred is not

releasing any hazardous waste, or

constituent thereof, into the

groundwater or surface water or

soil. • All such releases fro

m other units

at the facility are being controlled

by a corrective action program

approved by the Administrator

under Subtitle C of the Solid Waste Disposal Act.

Requires storm water discharges to be

permitted under the Federal (or state) National Pollution Discharge Eliminatio

n Systems (NPDES) program. Different

requirements are applicable for different

classes and types of discharges.

Prerequisite

Transfer off-site of CERCLA hazardous substance, pollutant , or contaminant.

Protection of surface waters

against degradation resulting

from site discharges

Citation

CERCLA section I21(d)(3) 40 CFR 122

40CFR125 UACR317-

8

ARAR

Applicable

Applicable

Comments

Applicable to the off-site

treatment, storage, or

disposal of wastes

generated during on-site

remedial actions.

Off-site disposal is

included as part of Alternatives 4.

Applicable to the

construction phase of Alternatives 3 and 4. Protection of state surfac

e

waters will also be

required during the

implementation phase of

these alternative!.
Appendix A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action

Discharge of Water into Surface Water Bodies

Discharge to Publicly-Owned Treatment Works (POTW)

(off-site activity)

U.S. EPA Oroundwater Protection Strategy

New Source Performance Standards

Construction

Requirement

An NPDES permit is required for

discharging water off-site into surface

water bodies.

All surface water discharges must be in

compliance with promulgated Utah Stream Discharge Standards

Discharge of pollutants mat pass through

the POTW without treatment, interfere

with POTW operation, contaminate POTW sludge, or endanger health/safety

of POTW workers is prohibited.

• Discharge must comply with local POTW pretreatment program,

including POTW specific

pollutants, spill prevention

program requirements, and

reporting and monitoring

requirements.

• RCRA permit-by-rule requirements

(including corrective action where

die NPDES permit was issued

after Nov. (, 1984) must be

complied with for discharges of RCRA hazardous wastes to POTWs.

The strategy includes guidelines on

classifying groundwater for EPA

decisions affectin g groundwater

protection and corrective actions. Criteria include ecological importance,

replaceability, and vulnerability

consideration.

Standards for new sources of air

emissions. Requirements are sourcespecific.

Fugitive dust control.

Prerequisite

Protection of surface waters

against degradation resulting

from site discharges

Discharge to a POTW.

Transport of RCRA hazardous

wastes to POTWs by truck, rail,

or dedicated pipe (i.e., pipe

solely dedicated for hazardous

waste (as defined in 40 CFR

264] which discharges from

within the boundaries of the CERCLA site to within the

boundaries of the POTW). The protection strategy does not

involve applicable ARARs but

does contain policy statements to

be considered.

Need to determine if these

standards apply to potential

remedial actions.

Citation

40 CFR 122 and

40 CFR 125 UAC 317-8

40 CFR 403 .5 UAC R317-S-8.4

40 CFR 270.60(c) UACR315-3-18(b)

C AA Section III UAC R307-1-3

R307-1-3, l.S(A) R307-I-4.5.2, U.A.C.

ARAR

Applicable

N ot ARAR

.

To be

considered

N ot ARAR

ARAR

Comments

Applicable to the

construction phase of Alternative! 3 tnd 4. Protection of Mate surface

waters trill also be

required during the

implementation phase of

these alternatives.

Alternatives do not

involve discharge to POTWa.

Concentrations of COCs

are locally elevated above

apparent background

conditions. All COC

concentrations are below MCLa.

None of the alternatives

involve installation of

new source of air

pollution. Alternatives 3 and 4

require earthwork which

may generate fugitive

dust.
Appendix A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action

Corrective Action Cleanup Standards Policy

forUST , and CERCLA Site

s

Waste Treatment

Underground

injection of

wastes and

treated

groundwater

Closure of Land Treatment Units

Requirement

Lists general requirements to be

considered in establishing cleanup

standards.

Treatment of restricted hazardous wastes

prior to land disposal must attain

concentration-based or technology-based

treatment standards.

U IC program prohibits: • Injection activitie

s that allow movement of contaminants into

underground sources of drinking

water which may result in

violations of MCLs or adversely

affect s health. • Construction of new Clas

s IV

wells, and operation and

maintenance of existing wells.

Class IV wells are banned except for

reinfection of treated groundwater into

the same formation from which it was

withdrawn, as part of a CERCLA cleanup or RCRA corrective action.

Maximize degradation, transformation, or immobilization of hazardous

constituents within the treatment zone,

minimize runoff of constituents, maintain

runon control system and runoff

management system, control wind

dispersal of hazardous waste, maintain

tmsaturated cone monitoring, establish

vegetative cover, and establish

background soil values to determine

consistency with permit values.

Prerequisite

Wastes to be treated must be

identifiable as restricted

hazardous wastes.

Approved UIC program is

required in States listed under SDWA section 1422. (All states

have been listed.) Class I wells

and Class IV wells are the

relevant classifications for CERCLA sites. Class I wells

are used in inject hazardous

waste beneath the lowermost

formation containing, within one

quarter mile, an underground

source of drinking water

(USDW). Class IV wells are

used to inject hazardous or

radioactive waste into or above

die formation which contains,

within one quarter mile of the

well, an underground source of

drinking water.

Closure of land treatment units.

Citation

"AC mil

40CFR268(SubpartD ) UAC R3 15-13 40 CFR 144.12 40 CFR 144.13 UAC R317-7 UAC R315-7-25 40 CFR 264.280 UAC R3 15-8-13.8

ARAR

Applicable

N ot ARAR

N ot ARAR

N ot ARAR

Comments

Applicable tot CERCLA

sites.

Consistent with activities

currently being

undertaken at OUI

pursuant to CERCLA. None of die alternatives

involves treatment of

hazardous wastes or

similar wastes. No underground injectio

n

activities are proposed for

die final remedy.

None of die alternatives

involve on-site land

treatment. I
Appendi

x A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action

Placement of Liquid Waste in Ltndfil l

Closure with Waste In Plac

e

Operation and Maintenance

Requirement

Liquids in Landfill s Prohibition: No bulk or non-containerized liqui

d

hazardous wute or hazardous waste

containing free liquids, or solid waste

containing free liquid, may be disposed

of in landfills .

Containers holding free liquids may not

be placed in I landfil l unless the liquid is

mixed with an absorbent or solidified.

Eliminate free liquids by removal or

solidification.

Stabilization of remaining waste and

waste residues to support cover.

Installation of final cover to provide

long-term minimization of infiltration (see Capping).

30-year post-closure care and

froundwater monitoring.

30-year post-closure care to ensure that

site is maintained and monitored.

Prerequisite

Placement of a bulk or noncontainerized RCRA hazardous

waste or solid waste in a landfill .

Placement of containerized RCRA hazardous waste in • landfill .

Applicable to land disposal of

hazardous waste. Applicable to RCRA hazardous waste (listed or characteristic) placed at site

after the effective date of the

requirements, or placed into

another unit. Not applicable to material treated, stored, or

disposed only before the

effective date of the

requirements, or if treated in situ

or consolidated within area of

contamination.

Land disposal closure.

Citation

40 CFR 258.28

40 CFR 264.314 UAC R31S-8-14.

8

40 CFR 264.3 14(d) UACR315-8-14.8(a)(2) 40 CFR 264.228(a)<2) U AC R3 15-8-1 1.5(2)0) 40 CFR 264 J28(a)(2) UAC R3 15-8-1 1.5(2)0) 40 CFR 264.258(b) UAC R315-8-12.6(b) 40 CFR 264.3 10 UAC R315-8-14.5 40 CFR 264.310 UAC R3 15-8-14.5 40 CFR 264.3 10 UAC R3 15-8-14.5

ARAR

NotARA R

N ot ARAR

NotARAR

Comments

No free liquids will be

disposed in an on-site

land disposal unit.

OUI toils have been

tested and found not to

exhibit any hazardous

waste characteristics.

Alternative 3 involves the

installation of*

permeable cover, the only

objective of which is to

prevent direct exposures. Accordingly the intent it

inconsistent with that

required under RCRA and RCRA requirements

are not ARAR.

OUI toils have been

tested and found not to

exhibit any hazardous

waste characteristics.

Alternative 3 involves the

installation of a

permeable cover, the only

objective of which is to

prevent direct exposures. Accordingly the intent is

inconsistent with that

required under RCRA and RCRA requirements

are not ARAR. *I
Appendi

x A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action Requirement Prerequiih

e Citation ARAR Comments

Surface Water Control

Prevent runon and control and collect

runoff from a 24-hour, 25-year storm

(waste piles, land treatment facilities,

landfills).

RCRA hazardous waste treated,

stored, or disposed after the

effective date of the

requirements. 4

0 CFR 264.2Sl(c), (d) UACR3l5-8-12.2(c)(d) 40 CFR 264.273(c), (d) UACR3l5-8-I3.4(c)(d)

40CFR264.310(c), (d) UACR315-8-14.2(c)(d)

N ot ARAR Surface water has not

been identified as a pathway of concern fo

r OUI.

Waste Pile Us

e a double-liner and leachate collection

system.

Waste put into waste pile subject to land

disposal restrictions regulations.

RCRA hazardous waste, noncontainerized accumulation of

•olid, nonflammable hazardous

waste that is used for treatment

or storage. 4

0 CFR 264.251 UAC R315-8-12 40 CFR 268.2, UAC R315-13-

I

N ot ARAR Non

e of the alternatives

involve management of

hazardous wastes or

similar wastes in a waste

pile.

Incineration

I

Analyze the waste feed.

Dispose of all hazardous watte and

residues, including ash, scrubber water,

and scrubber sludge. No further requirements apply to

incinerator* that only bum wastes that

are listed a* hazardous solely by virtue of

combination with other wastes, and if the

waste analysis demonstrates that no Appendix VD constituent is present tha

t might reasonably be expected to be

present.___________________

RCRA hazardous waste. 4

0 CFR 264.341 UAC R315-8-15.

2

40 CFR 264.351 UAC R315-8-15.

8

40 CFR 264.340 UAC R315-8-15.

1

Performance standards for incinerators:

• Achieve a destruction and removal

efficiency of 99.99 percent for

each principal organic hazardous

constituent in the waste feed and

99.9999 percent for dioxins. • Reduce hydrogen chloride

emissions to 1.8 kg/hr or 1 percent

of the HCI in the stack gases

corrected for amount of oxygen in

stack gas. • Not releas

e particulate in excess of I SO mg/dscm corrected for amount of oxygen in stack gat. __

RCRA hazardous wastes. 4

0 CFR 264.343 UAC R315-8-15.

4

40 CFR 264.342 UAC R315-8-15.

3

40 CFR 264.343 UAC R315-8-15.

4

N ot ARAR None of the alternative!

involve on-site

incineration.
Appendi

x A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action

Incineration

(con't.)

Requirement

Monitoring of various parameters during

operation of the incinerator ii required. TTie*e parameters include: • Combustion temperature. • Wute feed rate. • An indicator of combustion gas

velocity. • Caibon monoxide.

Control fugitive emissions either by:

• Keeping combustion zone sealed, or

• Maintaining combustion zone

pressure lower than atmospheric

pressure.

Utilize automatic cutoff system to stop

waste feed when operating conditions

deviate.

Special performance standard for

incineration of PCBs: • Achieve t destructio

n and removal

efficiency of 99.9999 percent. • Either 2 second dwell time at

1,200 degrees C (± 100) and 3

percent excess oxygen in stack

gas; or 1.5 second dwell time at

1,600 degrees C, and 2 percent

excess oxygen in (tack gas; and

• For non-liquid PCBs, mass air

emissions from the incinerator

shall be no greater than 0.001 g. KB per kg of the PCBs entering

the incinerator. • Prerequisite

Liquid and non-liquid PCBs at

concentrations of SO ppm or

greater.

Citation

40 CFR 264.343 U AC R315-8-1S.

4

40 CFR 264.345 UAC R3 15-8-15.

6

40 CFR 761 .70

ARAR

NotARA R

Comments

None of the alternatives

involve incineration
Appendix A2 (Continued) Analysis of Action-Specific ARARs

for Remedial Actions at Midvale Slag OUI

Action

Construction of N ew Undfil l On-iite

(see Cloture

with Waste in Place)

Requirement

Minimum Technology Reguirementi:

Install two linen or more, a top liner that

prevents waste migration into die liner.

and a bottom liner that prevents waste

migration through the liner.

Install leaehate collection system above

and between the linen.

Construct ninon and runoff control

systems capable of handling the peak

discharge of a 25-year storm.

Control wind dispersal of particulates.

Operation and maintenance.

Close each cell with a final cover after

the last waste has been received.

Oroundwster Monhorine:

Establish a detection monitoring program

(264.98). Establish a compliance monitoring program (264.99) and

corrective action monitoring program

(2641100) when required by 40 CFR

264.91. All monitoring programs must

meet RCRA genenl groundwater

monitoring requirements (264.97).

Prerequisite

RCRA hazardous waste (listed

or characteristic) currently being

placed in a new, replacement, or

expanded landfill .

Creation of a new landfil l unit to

treat, store, or dispose of RCRA hazardous waste as part of a

response action.

Citation

40 CFR 264.301 UACR315-S-I 4

40 CFR 264.303-304 UAC R315-8-14.3

40 CFR 264.3 10 UAC R315-8. 14.5

40 CFR 264.91 -264.100

ARAR

NotARA R

Comments

None of the alternative!

involve construction of a

new landfill . Wastes tie

not RCRA hazardous

wastes.
1

1

I APPENDIX A3

Location-Specific ARARs

n

a

]

U
Appendix A3

Identification of Potential Location Specific ARARs for the Midvale Slag OUI Site

Standard Requirement, Criteria, or Limitation Citation Description ARAR Comment

Historic Sites, Building

and Antiquities Act

16 USC Sec. 461-467

40 CFR Sec. 6.30(a)

Requires Federal agencies to consider the

existence and location of landmarks on the National Registry of Natural landmarks to avoid

undesirable impacts upon such landmarks.___

N ot ARAR Proposed activities will not adversely

affect historical landmarks.

National Historic Preservation 16 USC Sec. 470

40 CFR Sec. 6.301 (B)

Requires Federal agencies to take into account

me effect of any Federally-assisted undertaking

or licensing on any district, site, building,

structure, or object mat is included in or eligible

for inclusion in the national register of historic

places.______________________

N ot ARAR Proposed activities will not adversely

affect historical district, site,

building, structure or object.

Archaeological and Historic Preservation16 USC Sec. 469 UCA, Tide 63 Chapter 18; UCA R212Establishes procedures to provide for

preservation of historical and archaeological data

which might be destroyed through alteration of

terrain as a result of a Federal construction

project or a Federally-licensed activity or

program. Preservation of archeological,

anthropological, or paleontological landmarks is

provided for by State law.____________

N ot ARAR Proposed activities will not adversely

affect archaeological data or

landmarks.

Endangered Species Act 16 USC Sec. 1531-1543

50 CFR Parts 200.402

33 CFR Parts 320-330

40 CFR Sec. 6302 (ca)

Requires that Federal agencies ensure that any

action authorized, funded, or carried by the

agency is not likely to jeopardize the continued

existence of any threatened or endangered

species or destroy or adversely modify critical

habitat.

N ot ARAR No critical habitat has been identified

in Salt Lake County for endangered

species.

Executive Order on Protection

of Wetlands

Exec. Order #11,990

40 CFR Sec. 6.302(A)

and Appendix A

40 CFR Parts 230,231

Requires Federal agencies to avoid, to the extent

possible, (he adverse impacts associated with the

destruction or loss of wetlands and to avoid

support of new construction in wetlands if a practicable alternative exists.

Actions must not discharge dredged or fill

material into wetlands without permit.______

N ot ARAR Proposed activities will not adversely

affect wetlands.

Area affectin g Stream or River 40 CFR 6.302 Action must protect fish or wildlife N ot ARAR No activities are proposed that will

affect rivers or streams.

Fault Zone 40 CFR 264.18(a) UAC R315-8-2.9(a)

RCRA regulations specify mat hazardous waste

treatment, storage, or disposal must not take

place within 200 feet of a Holocene fault

N ot ARAR No faults displaced during Holocene

times exist within 200 feet of this

site.
Appendix A3 (continued)

Identification of Potential Location Speciflc ARARs for the Midvale Slag OUI Site

Standard Requirement, Criteria, or Limitation

Flood Plain

Underground mine, caves, or

salt dome formations

Wilderness area

Wildlife refuge

Within area affectin g national

wild, scenic, or recreational

river

Citation

40 CFR 264.18(b) UAC R315-8-2.9(b)

40 CFR 264.18(c) UAC R315-8-2.9(c)

Wilderness Act (6 USC

1131 ettea.l; 50 CFR

35.1 et tea.

16 USC 688 dd etseo.;

50 CFR Part 27

Wild and Scenic Rivers Act (16 USC 661 et

seg.; 40 CFR 6.302

Description

Any RCRA treatment, storage, or disposal

facility which lies within • 100-year flood plain

must be designed, constructed, and operated to

avoid washout

RCRA regulations specify that the placement of

non-containerized or bulk liquid hazardous waste

is prohibited.

Area must be administered in such manner as

will leave it unimpaired as wilderness and to

preserve its wildness.

Only actions allowed under the provisions of 16 USC Section 668 DD(c) may be undertaken in

areas that are part of the National Wildlife Refuge System.

Diversion, channeling or other activity that modifies a stream or river and affect s fish or

wildlife is prohibited.

ARAR

NotARA R

N ot ARAR

NotARAR

NotARAR

NotARAR

Comment

RCRA Hazardous Wastes will not be

treated, stored, or disposed of on site.

Hazardous waste will not be placed

within an underground mine, cave, or

salt dome.

Proposed activities will not adversely

affect wilderness areas.

Proposed activities will not adversely

affect wildlife refuge areas.

Proposed activities will not adversely

affect national wild, scenic, or

recreational rivers.
EPA REGION Vin SUPERFUND DOCUMENT MANAGEMENT SYSTEM

DOC ID # PAGE #

IMAGERY COVER SHEET UNSCANNABL E ITEM

Contact the Superfimd Records Center to view this document.

SITE NAME Sf

OPERABLE UNIT

REPORT OR DOCUMENT TITLEfi^«iftrfJfriD<

DATE OF DOCUMENT

DESCRIPTION OF IMAGERY . 2 oP<M

NUMBER AND TYPE OF IMAGERY ITEM(S)\