July 10, 2013

Treating Soil Contaminated With Heavy Metals

When heavy metals show up in soil at a generator facility, what sort of management options are available? Does the generator have to ship the waste offsite and pay another company to treat it, typically via stabilization? Or, could the generator treat the hazardous soil themselves? Sure, assuming their state also allows it.

However, generators must be cognizant of the RCRA implications as noted below.

Treatment in 90/180/270-day accumulation units

Although not clearly spelled out in the federal RCRA regs (other than one obscure reference in §268.7(a)(5)), EPA’s guidance indicates that generators may treat hazardous waste in 90/180/270-day accumulation units (i.e., tanks, containers, containment buildings) without a RCRA permit. [March 24, 1986; 51 FR 10168, RO 11163, 11261, 11641, 13782, 14618, 14662] Because the federal regs are not clear on this exemption, generators must verify that their states allow such treatment by generators without a RCRA permit. Some states do allow this form of treatment but have added conditions with which generators must comply in order to use the exemption.

Accumulation units used by generators to treat hazardous waste remain subject to all applicable RCRA standards. Thus, these units are subject to 90/180/270-day clocks, tank/container labeling, and RCRA Subpart J, I, and DD standards for tanks, containers, and containment buildings, respectively. [RO 11261, 11641, 13782, 14618, 14662]

LDR treatment standards for hazardous soil

Because the soil is hazardous at its point of generation, the land disposal restrictions (LDR) standards must be met before the treated soil can be placed in a landfill. There are two treatment standard options for hazardous soil: 1) the soil could be treated to meet the nonwastewater standards of §268.40 for the waste codes that apply; or 2) the facility could treat the soil to achieve the alternative standards in §268.49, which were specifically developed by EPA for hazardous soil. Under the alternative standards of §268.49, the facility must reduce the TCLP concentrations of the contaminants subject to treatment by 90% but would never have to treat these contaminants to a level less than 10 times the universal treatment standards (UTS) of §268.48. This is referred to as “90% reduction capped at 10 times UTS.” A comparison of the §268.40 nonwastewater treatment standards with the alternative treatment standards for soil in §268.49 is found in the following table.


Contaminant
 


Waste code
 

Characteristic
level in §261.24
(mg/L TCLP)

§268.40 NWW
standard
(mg/L TCLP)

§268.49 standard
10 times UTS
(mg/L TCLP)

Arsenic

D004

5.0

5.0

50

Barium

D005

100

21

210

Cadmium

D006

1.0

0.11

1.1

Chromium

D007

5.0

0.60

6.0

Lead

D008

5.0

0.75

7.5

Mercury

D009

0.2

0.025

0.25

Selenium

D010

1.0

5.7

57

Silver

D011

5.0

0.14

1.4

Source: McCoy and Associates, Inc.

From the table, it can be seen that, with the exception of silver-contaminated soil, rendering the soil nonhazardous (i.e., treating it to below the characteristic levels in §261.24) will also meet the §268.49 alternative soil treatment standards. Once the soil is no longer hazardous and meets the standards in §268.49, the stabilized soil can be disposed in a Subtitle D (nonhazardous waste) landfill.

LDR paperwork

For soils characteristic due to heavy metals that are treated onsite by generators, the LDR paperwork is not sent to the Subtitle D landfill. Instead, the LDR paperwork required in §§268.7(e) and 268.9(d) should be prepared and placed in the facility’s onsite files. [May 26, 1998; 63 FR 28620, RO 14283]

In addition, large and small quantity generators are required to develop and follow a waste analysis plan (WAP) if they are treating hazardous waste in a 90/180/270-day accumulation unit for the purpose of meeting an LDR treatment standard. The WAP must include the elements found in §268.7(a)(5) and must be maintained at the generator’s facility and be available for inspection.

 


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Disclaimer

Considerable care has been exercised in preparing this document; however, McCoy and Associates, Inc. makes no representation, warranty, or guarantee in connection with the publication of this information. McCoy and Associates, Inc. expressly disclaims any liability or responsibility for loss or damage resulting from its use or for the violation of any federal, state, or municipal law or regulation with which this information may conflict. McCoy and Associates, Inc. does not undertake any duty to ensure the continued accuracy of this information.

This document addresses issues of a general nature related to the federal RCRA regulations. Persons evaluating specific circumstances dealing with the RCRA regulations should review state and local laws and regulations, which may be more stringent than federal requirements. In addition, the assistance of a qualified professional should be enlisted to address any site-specific circumstances.