(1) GENERAL.
(a) Responsible parties shall use information
from the sources listed in s.
NR 720.05(1) to determine the residual
contaminant levels or performance standards for each exposure or migration
pathway of concern for each soil contaminant of concern at a site or facility
in accordance with this chapter.
(b) In addition to meeting the requirements
of par. (c), responsible parties shall establish the soil cleanup standard for
each soil contaminant of concern at the site or facility as one of the
following:
1. The residual contaminant level
of each contaminant in soil which is the lowest concentration from among the
following as applicable: the ceiling limit concentration, the soil saturation
concentration if the contaminant is a volatile, a land use specific direct
contact level, a groundwater quality protective level, a concentration
calculated for a pathway of concern set forth in s.
NR 720.13 all of which are determined in accordance with
the requirements of this chapter.
Note: For a single contaminant, a numeric land
use specific residual contaminant level is determined based on aggregate
exposure through incidental ingestion of soil, inhalation of soil vapors and
particulates, and dermal contact with soil. When more than one contaminant is
present, the residual contaminant level is determined based on cumulative
exposure and may have to be adjusted downward so that the cumulative risk does
not exceed an excess cancer risk of 1-in-100,000 or a hazard index of 1 for
non-carcinogens.
2. A
performance standard determined in accordance with s.
NR 720.08.
(c) In addition to meeting the requirements
of par. (b), a soil cleanup standard developed under this chapter shall comply
with all the following requirements:
1.
Residual soil contamination at the site or facility may not adversely affect
surface water.
2. Residual soil
contamination at the site or facility may not adversely affect a sensitive
environment.
3. Residual soil
contamination at the site or facility may not concentrate through plant uptake
and adversely affect the food chain.
4. Residual soil contamination at the site or
facility may not result in vapor concentrations reaching a substance's lower
explosive limit.
(2)COMPLIANCE WITH SOIL CLEANUP STANDARDS.
(a) Contaminant concentrations in soil
samples shall be determined using a department-approved and appropriate
analytical method and reported on a dry weight basis. An appropriate analytical
method shall have limits of detection or limits of quantitation, or both, at or
below soil cleanup standards where possible. Responsible parties shall report
the limit of detection and the limit of quantitation with sample results. The
department may require that supporting documentation for the reported limit of
detection and limit of quantitation be submitted
(b) Unless an alternative approach for
determining standards exceedances is approved by the department, if a soil
contaminant concentration in a sample exceeds the soil cleanup standard at or
above the limit of quantitation for that soil contaminant, the soil cleanup
standard shall be considered to have been exceeded.
Note: When evaluating the direct contact
pathways, it may be possible to average measured soil sample concentrations to
determine whether the calculated residual contaminant level has been exceeded
or not. If averaging of soil concentrations is being considered, the department
recommends seeking department approval of the proposed sampling plan and
analysis methodology as soon as possible, but prior to submitting a case
closure request in order to avoid delays and other potential problems.
Note: Averaging soil concentrations is not
appropriate as the sole method for addressing sites with areas of significant
soil contamination.
(c) If
a soil cleanup standard for a soil contaminant is between the limit of
detection and the limit of quantitation, the soil cleanup standard shall be
considered to be exceeded if the soil contaminant concentration is reported at
or above the limit of quantitation.
(d) The following applies when a soil cleanup
standard for a soil contaminant is below the limit of detection:
1. If a soil contaminant is not detected in a
sample, the soil cleanup standard shall not be considered to have been
exceeded.
2. If a soil contaminant
is reported above the limit of detection but below the limit of quantitation,
the responsible party may accept the results and the soil cleanup standard
shall be considered to have been exceeded, or the responsible party may choose
to have the soil sample reanalyzed by the use of an appropriate analytical
method. If the soil contaminant is confirmed to be present between the limit of
detection and the limit of quantitation, the soil cleanup standard shall be
considered to have been exceeded. If the soil contaminant is not detected upon
reanalysis of the soil sample, the soil cleanup standard shall not be
considered to have been exceeded.
(3)BACKGROUND. If the background
concentration for a substance in soil at a site or facility is higher than the
residual contaminant level for that substance determined using the procedures
in this section, the background concentration in soil may be used as the
residual contaminant level for that substance. The background concentration for
a substance in soil shall be determined using a department-approved and
appropriate method.
Naturally occurring background concentrations of arsenic
in soil, for example, may be higher than the calculated residual contaminant
level for arsenic. In such instances, the naturally occurring background
concentration could be used as the soil cleanup level.
