IDEM Announces New TPH Default Closure Levels
July 15, 2009
Petroleum fuel and oil products represent the single most common environmental contaminant in Indiana. As of June 2006, Indiana had over 19,000 registered underground storage tanks and over 7,000 confirmed leaks. These leaks ranged from a few gallons to many thousands of gallons of petroleum-based products released into the environment. (IDEM RISC Technical Guide - Chapter 8, dated June 15, 2006.)
Recently, IDEM announced new total petroleum hydrocarbon (TPH) default closure levels for surface and subsurface soils and groundwater. A comparison of the old versus new default closure levels is shown in the chart below. The new closure levels may be implemented immediately.
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TPH Default Closure Levels
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Hydrocarbon
Product
|
Soil (mg/kg)
Direct Contact
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Soil (mg/kg)
Indirect Contact
|
Groundwater
(ug/L)
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Industrial
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Residential
|
Industrial
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Residential
|
Industrial
|
Residential
|
|
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Gasoline
|
|
|
|
|
|
|
|
|
|
Old
|
1,540
|
795
|
330
|
25
|
3,000
|
220
|
|
|
New
|
4,300
|
3,100
|
1,500
|
120
|
14,000
|
1,100
|
|
Diesel
|
|
|
|
|
|
|
|
|
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Old
|
3,912
|
1,590
|
1,000
|
80
|
1,100
|
100
|
|
|
New
|
5,800
|
3,100
|
2,300
|
230
|
2,500
|
260
|
These new relaxed cleanup levels should result in more prompt and cost effective remediation of petroleum contaminated sites.
Any questions about IDEM’s new closure levels should be directed to Frank Deveau, Bill Wagner, or any other member of Taft’s Environmental Practice Group.
