Slags, steelmaking

Monitoring data

Administrative data

Endpoint:

monitoring data

Type of information:

experimental study

Adequacy of study:

key study

Study period:

before 2005

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

other: Study well documented. Study meets generally accepted scientific principles. Study acceptable for assessment

Data source

Reference

Reference Type:

publication

Title:

Geochemistry of extremely alkaline (pH > 12) ground water in slag-fill aquifers

Author:

Roadcap GS, Kelly WR, Bethke CM

Year:

2005

Bibliographic source:

Ground Water 43(6), 806-816

Materials and methods

Principles of method if other than guideline:

Analytical determination of pH and several ions on site

GLP compliance:

not specified

Type of measurement:

concentration at contaminated site

Media:

ground water

Test material

Test material information

Constituent 1

Reference substance name:

Slags, steelmaking

EC Number:

266-004-1

EC Name:

Slags, steelmaking

Cas Number:

65996-71-6

Molecular formula:

~ Al(n)Ca(m)Fe(o)Mg(p)Si(q)O(3n/2+m+o+p+2q)

IUPAC Name:

Aluminium-Calcium- Iron-Magnesium-Silicium oxide equivalent

Details on test material:

Aquifers contaminated by steelmaking slags used as filling materials for wetlands;
groundwater beneath closed steel mills and slag dumps

Results and discussion

Concentration

Country:

United States (the)

Location:

Lake Calumet region, Chicago, Illinois

Substance or metabolite:

other: pH

Conc.:

<= 12.8 other: pH

Remarks on result:

other: large-scale infilling of wetlands with steelmaking slag

Details on results:

At most sites dominating ions were Ca2+ and OH- in equilibrium with Ca(OH)2. In water bodies with intensive contact with air, calcium carbonate (calcite) was found.

Any other information on results incl. tables

Metals present in the slags (Fe, Mn) were oxidized forming more stable oxides and sulfides, and did not accumulate in elevated concentrations in the groundwater.

Applicant's summary and conclusion

Conclusions:

In the vicinity of former steel mills, slag dumps, and infillings of wetlands, high pH values in the ground water may occur

Executive summary:

In the Lake Calumet region, Chicago, Illinois, 4 contaminated sites were examined. These sites were former steel mills, slag dumps, and a large-scale infilling of wetlands. Due to the presence of Ca²⁺ ions and OH^- ions in equilibrium with the groundwater at these sites the groundwater was basic (up to pH 12.8 at one site), but did not contain toxic levels of heavy metals.