STEEL SLAG LEACHATE
-
Upload
christopher-wallace -
Category
Documents
-
view
78 -
download
1
Transcript of STEEL SLAG LEACHATE
STEEL SLAG LEACHATEA Brief Overview of Steel Slag Leachate on the Environment (Sheffield Village, Ohio)
Chris J. Wallace | Cleveland State University | November 27, 2007
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
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.)
WHAT IS SLAG? (CONTINUED)
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
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
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
PH SCALE
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
COMMON SLAG PILE PROBLEMS
Chemical leachate
Airborne particulates
Maintenance
Cleanup
HEALTH ISSUES
Ecological – high pH values kill fish and flora (much unknown)
Human – drinking water, air particulates
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)
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
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
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
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
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
US REPUBLIC STEEL SLAG PILES
Concentrated leachate flow area of study:
Leachate flow to the north (red line)
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
OBSERVED ISSUES
Chemical leaching into pools and surrounding waterways
OBSERVED ISSUES (CONTINUED)
OBSERVED ISSUES (CONTINUED)
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
OBSERVED ISSUES (CONTINUED)
Area used by ATVs and campers
Creates lots of dust and more particulates
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.)
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”
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
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