1. STEEL SLAG LEACHATE
A Brief Overview of Steel Slag Leachate on the Environment (Sheffield Village, Ohio)
Chris J. Wallace | Cleveland State University | November 27, 2007

2. WHAT IS SLAG?
 In the steel-making industry, it is the materials left over after separating the
valuable fraction from the worthless fraction of ore
 General Composition:
 Varies greatly, but usually includes:
 Calcium Oxide
 Magnesia
 Silica
 Aluminum
 Sulfur
 Iron Oxide
 Various heavy metals

3. WHAT IS SLAG? (CONTINUED)
 Most slag piles contain not only slag, but other wastes of the steel-making
industry, such as:
 Leftover coke
 Lime
 Coal
 Ore
 Iron pieces
 And other miscellaneous wastes
(machinery parts, scrap metals, tires, etc.)

4. WHAT IS SLAG? (CONTINUED)

5. USES OF SLAG
 Many commercial uses, so it is rarely thrown away
 Is often “re-mined” by outside companies to extract any
valuable materials (often metal) still contained in the waste
 Has been used for the construction of road and as a fill material
 Used as a cement additive for a range of construction
applications
 Used for snow and ice control (instead of sand), driveways, and
roofing granules
 In 2006, 12.6 million tons of US slag was consumed, valued at
$375 million dollars

6. SLAG PILE LEACHATE PROBLEM
 Leachate – When rain or melting snow percolate through the porous gravel,
collecting trace substances of the substrate and making them mobile
Leachate

7. SLAG PILE LEACHATE PROBLEM (CONTINUED)
 Leaching causes highly alkaline ponding water (with pH up to 13)
 Can encourage the mobilization of heavy metals and toxic substances contained
within the waste, such as:
 Mercury
 Cadmium
 Lead
 Arsenic
 Aluminum
 All of the above substances have been found in varying amounts in ground water
near slag piles

8. PH SCALE

9. REGULATIONS & MANAGEMENT
 Ohio EPA states that surface waters should be between pH 6.5 and 9.0 for Warm
Water Habitats
 No slag type exceeds Ohio EPA standards of hazardous materials
 However, leachate and heavy metals in ground water can exceed EPA levels
Leachate

10. COMMON SLAG PILE PROBLEMS
 Chemical leachate
 Airborne particulates
 Maintenance
 Cleanup

11. HEALTH ISSUES
 Ecological – high pH values kill fish and flora (much unknown)
 Human – drinking water, air particulates

12. SPECIFIC EXAMPLES
 Sharon Steel Slag Pile (Average Composition of a “Slag Pile”) 400 acres
 Contains arsenic, lead, and chromium at unsafe levels
 Slags deposited since 1900
 Included on National Priorities List of hazardous waste sites (July 1998)

13. SHARON STEEL SLAG PILE (PA)
 Study done by Agency for Toxic Substances and Disease Registry (division of CDC)
 Stated that “slag pile” is a public health hazard to site visitors because of
potential irritation from highly alkaline ponding water (pH up to 13) and physical
dangers from sliding and slumping piles

14. SHARON STEEL SLAG PILE (PA) (CONTINUED)
 Since inclusion on National Priorities List, water pollution control stations (below)
have been added until more funds are available to fully contain and cleanup the site

15. NINE MILE RUN
 Stream near industrial area outside of Pittsburgh, PA
 Suffered from severe chemical pollution, mainly in the
form of highly alkaline water entering the stream
from slag piles
 Slag was dumped here from 1920-1980 as high as 20
stories
 Water seeping through the slag and into the stream
was found to have a pH as high as 11
 In 2003, a seep wall was constructed at the base of
the slag pile and intercepts the leachate into a series
of drains, from there the leachate is transported to a
sewer and onto a WWTP
 Restoration took 3 years and $7.7 million dollars

16. CLEVELAND HOPKINS AIRPORT
 In 2001, after complaints from local citizens, the
Ohio EPA forced Cleveland Hopkins Airport’s
contractors to remove slag that was being used as
fill during a runway extension.
 Local citizens and environmentalists noticed that
leachate from this fill slag was discharging directly
into Abram Creek and then into the Rocky River
 The leachate exceeded the levels of a prior
discharge permit acquired by the airport, and the
slag was completely removed

17. MY FOCUS: US REPUBLIC STEEL SLAG PILES
 Near Lorain, Ohio on Black River mainstream
 East side of river between river mile (RM) 4.8 and 6.1
 177 acre site (dumping began after 1894, until 1994)
Leachate flow
to the north

18. US REPUBLIC STEEL SLAG PILES
Concentrated leachate flow area of study:
Leachate flow to
the north (red line)

19. BACKGROUND
 Located on the Black River
 Only Area of Concern (AOC) in the state of Ohio
that encompasses an entire watershed
 Site of massive industrial wastes in the past
 Water quality has improved with the closing of
USS/Kobe’s coking facilities in 1983, and the
dredging of the bottom toxic sediments in 1990
 The bottom sediments were disposed of in a
hazardous waste disposal site on US Republic
Steel’s property

20. OBSERVED ISSUES
 Chemical leaching into pools and surrounding waterways

21. OBSERVED ISSUES (CONTINUED)

22. OBSERVED ISSUES (CONTINUED)

23. OBSERVED ISSUES (CONTINUED)
 Ohio EPA 1996 – mentions the slag piles as a “possible factor resulting in the
degradation of the biological community”
 Ohio EPA 1998 – states that the slag piles could be the reason for why this area
of the river “displayed some of the highest DELT anomalies recorded in the
Black River basin”
 DELT:
 Deformities
 Erosion
 Lesions
 Tumors

24. OBSERVED ISSUES (CONTINUED)
 Area used by ATVs and campers
 Creates lots of dust and more particulates

25. OBSERVED ISSUES (CONTINUED)
 Area used as junk yard since 1900 (What else could be buried?)
 Observation wells were installed in 1996 to monitor ground water, but they are
in disrepair and unused (missing camps, locks, etc.)

26. PROPOSED HIKE & BIKE TRAIL
 Lorain Morning Journal reports that the
Lorain County Metroparks have secured
an easement on the property to construct
a hike and bike trail ($2.3 million dollar
phase)
 Over this winter, they plan to construct a
2.8 mile extension that “will traverse
these piles and show the history of
Lorain’s steelmaking past”

27. RECOMMENDED ACTIONS
 Contact the Ohio EPA of the observed issues
 A site specific risk assessment is needed to validate the issue
 Hold the owner of the property responsible, if possible
 Lorain County Metroparks must take further precautions before opening hike and
bike trail (further studies, fencing, etc.)
 Suggest capping the piles with soil and collecting leachate (similar to Sharon Steel
Slag pile and Nine Mile Run)
 Send leachate polluted waters to a WWTP that the City of Lorain is building by 2011
on a site across the river on former US Republic Steel property

28. CONCLUSION
• Slag piles are industrial waste landfills and should be dealt with accordingly
• Overall, not much is known about slag because of the differences in composition
(have to be studied on a case-by-case basis)
• Since slag is not on the Ohio EPA’s hazardous materials list, it is not given much
thought
– i.e., City of Cleveland’s Brownfield Development Director “we can just build over the
slag”
• However, through many examples around the country, other agencies have
discovered the problem and are taking appropriate actions
• Slag leachate needs to be studied more in depth