Update
New Jersey Zinc/Mobil Chemical Superfund Site
Fact Sheet #9
September 2003
DePue, Illinois
South Ditch
What is the Illinois EPA's decision about the remedy for the South Ditch unnatural
sediments? The Illinois Environmental Protection Agency (Illinois
EPA or Agency) has chosen removal of the South Ditch unnatural sediments
and on-site storage of the sediment in an interim containment cell. The U.
S. Environmental Protection Agency (U.S. EPA) concurs with this decision.
The agencies signed a record of decision in September 2003 to document this
decision. The Illinois EPA has written a responsiveness summary that summarizes
the comments received during the comment period and the Illinois EPA and
U.S. EPA's responses to these comments. This summary, as well as the South
Ditch Record of Decision, is in the Selby Township Library in DePue for public
review.
What were the events leading to this decision? May
1998. The PRPs submitted a proposal to remedy the South Ditch
sediments by leaving them in place and constructing a cap over the
sediment.
Illinois EPA rejected this proposal for several reasons including the
fact it did not comply with state and federal regulations.
February 2001. At Illinois EPA request, the PRPs submitted
a revision of the initial plan as a presumptive remedy. In this revision,
the unnatural sediments would be dredged from the South Ditch and placed
in an on-site interim containment cell. The PRPs assumed that a waiver
of water pollution control laws and regulations would be necessary and
the Illinois EPA had the authority and would support that waiver. The
Illinois EPA does not have this authority at this time.
September 9, 2002. The Illinois EPA issued a proposed plan
to remove the unnatural sediments from the South Ditch and deposit them
in an on-site interim containment cell. This proposed plan required compliance
with federal and state water pollution control laws and regulations or
validation that relief from these laws and regulations is necessary.
The Agency opened a public comment period on the proposal and other studied
alternatives. At the PRPs' request, the Illinois EPA extended the closing
date of the comment period from November 12 to December 20, 2002.
October 9, 2002. The Illinois EPA held a public hearing to
receive oral comments on the proposed plan and other studied alternatives.
Who submitted comments to the Illinois EPA during the public
comment period? The Illinois EPA received oral comments from
citizens and Viacom International Inc. at the public hearing. The DePue
Village Board of Trustees and the Bureau County Board submitted written
resolutions supporting removal of the South Ditch sediments and hauling
the sediments to a permitted off-site landfill. Two citizens supported
this same position with written comments. One citizen submitted written
comments on different issues, and the potentially responsible parties1 (PRPs)
submitted extensive legal and technical written comments.
Why did the Illinois EPA choose removal of the sediments and
on-site storage in an interim containment cell? After carefully
considering all questions and comments, the Illinois EPA, with U.S.
EPA concurrence, chose the remedy proposed in the September 2002 proposed
plan for a number of reasons including the following:
- The remedy meets all federal and state laws and requirements.
- An on-site containment cell will be as safe as an off-site landfill
permitted for similar material, because they both must meet similar
standards.
- The nearest landfill suitable for the South Ditch sediments is about
60 miles from DePue. Hauling the sediment 60 miles, compared to one
mile from the ditch to an on-site interim containment cell, is an increased
safety hazard. The greater transportation distance increases the risk
of accident and accidental release of contaminants to the environment.
- The 1995 Interim Consent Decree signed by the PRPs and the State
of Illinois requires that all investigations and remedies complement
one another if possible. The Interim Consent Decree presumes that the
most likely remedy for the slag pile is on-site closure because of
its large volume. Selection of any remedy will go through the standard
remedy selection process including submitting a proposed plan to the
public for comment.
- By maintaining the South Ditch sediments in an on-site containment
cell, the sediments remain a candidate for technologies such as metals
recovery. This alternative and other resource recovery alternatives
may prove viable during the remedy selection process for other units
such as the primary zinc slag pile.
- The South Ditch remedy is only an interim remedy, so the final fate
of the South Ditch sediments will be made when a decision is made about
all the on-site contamination. The South Ditch sediment is only about
0.4 percent of the total on-site contaminated materials2,
so its relatively small volume will have little or no influence on
the final decision about the site remedy.
What are the next steps for remedying the South Ditch unnatural
sediments? Beginning this fall and finishing in the year 2004,
the PRPs will construct the South Ditch remedy designated in the Record
of Decision. Completion in 2004 is dependent upon normal seasonal lake
and river levels that affect surface water levels in the South Ditch.
Overall Remedial Investigation of the Plant Property
What is the status of the overall investigation of the plant
property? The following are actions accomplished in the last
two years:
December 2000. The PRPs for the site completed the fieldwork
for the Phase I investigation of the plant property.
June 2002. The PRPs submitted a draft three-inch report describing
and interpreting sample results. This report is called a remedial investigation
(RI) report.
February 2003. The Illinois EPA and its contractor thoroughly
reviewed this document and returned substantial comments to the PRPs.
One of Illinois EPA's more significant comments was that the PRPs used
an inappropriate method to determine which chemicals on the site are
of concern. The PRPs will soon be submitting alternative methods for
determining chemicals of concern and these will be reviewed by the Illinois
EPA.
What are the next steps in the remedial investigation of the
plant property? The following are anticipated next steps for
the plant property investigation.
- This winter, the Illinois EPA anticipates that the PRPs will submit
a revised copy of the RI report that will meet Agency approval. At
that time, the Agency will summarize the report in a fact sheet to
be distributed to the project mailing list and place the full report
in the project repository located in the Selby Township Library in
DePue.
- The Illinois EPA and the PRPs will identify data gaps. Data gaps
are questions that need to be answered before the remedy is designed.
For example, if present data showed contamination at 10 feet and no
samples were collected below 10 feet, then an unanswered question would
be, "Is contamination present at depths greater than 10 feet?"
- If there are data gaps, the PRPs will develop a Phase II work plan
to gather information to fill these data gaps.
- After the Illinois EPA approves the Phase II work plan, the PRPs
will conduct the fieldwork described in the approved work plan.
- The PRPs will repeat this process until they have gathered the information
necessary to develop a study of alternatives (feasibility study or
FS). They will then prepare an FS, which must be approved by the Illinois
EPA.
- The Illinois EPA will designate one of the alternatives studied
in the approved FS as a proposed plan and submit the FS and the proposed
plan to the public for comment.
- After considering public comments, the Illinois EPA will choose
a remedy for the plant property. The Illinois EPA will document this
remedy in a record of decision.
- The Illinois EPA and PRPs will negotiate a second consent decree.
If negotiations are successful, the PRPs will agree to construct the
remedy designated in the record of decision.
Lake DePue
What is the status of the Lake DePue investigation? The
PRPs are preparing a work plan for the lake and the southeast area. See
the map on the first page. When the PRPs submit a work plan that Illinois
EPA can approve, the PRPs will begin the fieldwork described in the work
plan.
Water Treatment Plant
What is the status of the water treatment plant? The
water treatment system continues to collect groundwater (water beneath
the ground) and surface runoff from the plant property and remove high
levels of metals before the water is discharged into the Illinois River.
The water treatment plant is operating as expected. During heavy rainfall,
there have been several bypasses of the system. The system cannot handle
the volume of water generated during these unusual events. In almost
six years of operation, however, there is no indication that the more
heavily contaminated water from the slag pile area bypassed the treatment
system. Instead, the water that bypasses the system during these storm
events is water from the North Ditch, which has significantly lower concentrations
of metals. The improvements to the collection system and management of
uncontaminated water have significantly reduced the frequency of bypasses.
July 2002. The PRPs submitted a proposal to the Illinois EPA
for additional surface water studies. These studies ultimately will lead
to diversion of additional clean water around the site, enhanced storm
water retention or other improvements to storm water management.
August 2002. The Illinois EPA returned written comments on
the proposal to the PRPs.
December 2002. The PRPs submitted a revised proposal in response
to Illinois EPA concerns.
February 2003. The Illinois EPA returned comments on the PRPs'
December 2002 proposal. One Illinois EPA comment was that the PRPs must "present
a new list of analytical parameters3 and a rational for each
sample point where a reduced parameter list is proposed."
July 2003. The PRPs submitted a revised plan and it is under
review at this time.
Next steps. After the PRPs submit a plan for additional surface
water studies that the Illinois EPA can approve, the PRPs will conduct
the fieldwork to implement the plan.
Gypsum Stack
What is the status of work on the gypsum stack? The
PRPs are ahead of schedule in regrading, seeding and dewatering the gypsum
stack located north of Route 29. The PRPs anticipate completing the regrading
and seeding of the gypsum stack by late 2004. The PRPs have completed
excavation of phosphogypsum from the Clearwater Pond (the pond at the
base of the stack that is visible from Highway 29) and have placed it
in the southwestern section on top of the stack. Rebuilding or reconstruction
of the Clearwater Pond is expected to be completed this fall.
What are the next steps for work on the gypsum stack? The
final remaining pond in the southeast quadrant of the phosphogypsum stack
will be emptied this fall and the southeast quadrant will be regraded,
seeded and vegetated during 2004. The PRPs also are proceeding with a
hydrogeological study that will complete characterization of subsurface
conditions and groundwater quality. The data from the hydrogeologic study
will help guide final closure options and will be used to implement a
long-term monitoring program.
Off-Site Soil--Including Residential Soil
What about off-site soil sampling including sampling of residential
soil? This fall, the Illinois EPA will meet with the PRPs
to begin planning for off-site soil sampling. In 1992, the Illinois
EPA detected elevated levels of metals in 20 residential soil samples.
The purpose of future sampling is to determine if the elevated levels
pose a health threat to residents exposed over the long term. The Illinois
Department of Public Health (IDPH) evaluated the 1992 soil samples
and concluded that metals concentrations in these samples did not pose
a risk over the short term. In the meantime, IDPH recommended that
residents take common sense precautions to limit their exposure to
soil. These precautions included not allowing children to eat outside,
washing hands before eating and keeping windows closed during windy
days when dirt could blow into the house.
Land Use Committee
What is the Land Use Committee? The Village of DePue
was awarded a grant of services in July of 2002 by the U. S. EPA. The
purpose of the grant was to assist the community in developing a set
of future land use recommendations for the New Jersey Zinc/Mobil Chemical
Superfund site. These recommendations are intended to provide guidance
to the Illinois EPA and the U.S. EPA on the community’s reuse goals
for the site. The consultant team guiding this process, E2 Inc., has
helped assemble a committee consisting of a diverse group of community
members as well as the PRPs since the PRPs are major landowners. This
committee, referred to as the Land Use Committee, met in late March and
again in late May to discuss the community’s preferences for reuse
of the Superfund site. A number of community interests and ideas for
the site’s reuse were touched on at the first meeting, including:
- the importance of Lake DePue as a tourist attraction and an ecological
resource,
- the need for new economic growth in the Village and
- the potential for expanding recreational opportunities in DePue.
Based on this discussion, E2 Inc. conducted and presented research to
the Land Use Committee on the potential economic benefits of marketing
the Village as an ecotourism destination with hiking, biking and wildlife
viewing opportunities. The consultant team also presented the committee
members with a variety of resources that can aid the Village in marketing,
designing and funding the development of recreational facilities in the
community. E2 Inc. is currently crafting a Draft Conceptual Reuse Plan
for the site based on suggestions and issues raised at the two meetings
and will present this plan to Village of DePue officials for review in
the coming months before delivering the final plan to the U.S. EPA and
Illinois EPA.
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