Wash. Admin. Code § 173-340-355 - Development of cleanup action alternatives that include remediation levels
(1)
Purpose. A cleanup action often relies on a combination of cleanup
action components to remediate an environmental medium. For example, to
remediate soil, a cleanup action may rely on treatment of some soil
contamination and containment of the remainder. The purpose of a remediation
level is to specify when the various components are used as part of a cleanup
action.
(2)
Applicability. Remediation levels must be established as part of a
cleanup action if the cleanup action relies on a combination of cleanup action
components to remediate a hazardous substance in an environmental
medium.
(3)
Types.
Remediation levels may be based on a concentration (e.g., all soil above a
specified concentration will be treated), or other method of identification,
such as the physical appearance or location of the contamination (e.g., all of
the green sludge will be removed from the northwest quadrant of the
site).
(4)
Development. Remediation levels must be developed and evaluated as
part of a cleanup action alternative during the feasibility study conducted
under WAC
173-340-351. Quantitative or
qualitative methods may be used to develop remediation levels. The methods may
include a human health or ecological risk assessment. The methods may also
consider fate and transport issues. The methods may be simple or complex, as
appropriate to the site. Where a quantitative risk assessment is used, see WAC
173-340-357.
(5)
Selection. The remediation
levels selected as part of a cleanup action must be specified in the cleanup
action plan under WAC
173-340-380(5).
(6)
Relationship to cleanup levels and
cleanup standards. Remediation levels are not the same as cleanup levels
or cleanup standards.
(a) A cleanup level
defines the concentration of a hazardous sub-stance above which a contaminated
environmental medium such as soil) must be remediated in some manner such as
treatment, containment, or institutional controls). A remediation level, on the
other hand, defines the concentration (or other method of identification) of a
hazardous substance in an environmental medium at which a particular cleanup
action component such as soil treatment versus containment) will be used.
Remediation levels, by definition, exceed cleanup levels.
(b) Cleanup levels must be established for
every site. Remediation levels, on the other hand, must be established only if
a cleanup action relies on a combination of cleanup action components to
remediate an environmental medium.
(c) Cleanup actions, including those relying
on a combination of cleanup action components to remediate an environmental
medium, must meet each of the requirements in WAC
173-340-360, including compliance
with cleanup standards. If a remedial action does not comply with cleanup
standards, the remedial action is an interim action, not a cleanup
action.
(7)
Examples. The following examples of cleanup actions that use
remediation levels are for illustrative purposes only. All cleanup action
alternatives in a feasibility study, including those using remediation levels,
must be evaluated to determine whether they meet each of the requirements in
WAC 173-340-360.
(a)
Example of a site meeting soil
cleanup levels at the point of compliance. Assume the soil cleanup level
for a hazardous substance at a site is 20 ppm. This means any soil exceeding 20
ppm at the applicable point of compliance must be remediated. Further assume
the cleanup action consists of treating soil above 100 ppm and removing to an
offsite landfill soil between 100 and 20 ppm. In this case, 100 ppm is a
remediation level that defines which soil will be treated and which soil will
be removed from the site. The cleanup action may be determined to comply with
the cleanup standard because the 20 ppm soil cleanup level is met at the
applicable point of compliance.
(b)
Example of a site not meeting soil cleanup levels at the point of
compliance. Assume the soil cleanup level for a hazardous substance at a
site is 20 ppm. This means any soil exceeding 20 ppm at the applicable point of
compliance must be remediated. Further assume the cleanup action consists of
treating soil above 100 ppm and containing soil between 100 and 20 ppm. The 100
ppm concentration is a remediation level that defines which soil will be
treated and which soil will be contained at the site. Even though contamination
above the 20 ppm cleanup level remains at the site, if the cleanup action meets
the requirements specified in WAC
173-340-740(6)(f)
for soil containment actions, the cleanup action may be determined to comply
with cleanup standards.
(c)
Example of site meeting groundwater cleanup levels at the point of
compliance. Assume the groundwater cleanup level for a hazardous
substance at a site is 500 ug/l and a conditional point of compliance is
established at the property boundary. This means any groundwater exceeding 500
ug/l at the point of compliance must be remediated. Further assume the cleanup
action consists of: Removing the source of the groundwater contamination such
as removing a leaking tank and associated soil contamination above the water
table); extracting free product and any groundwater exceeding a concentration
of 2,000 ug/l; and utilizing natural attenuation to restore the groundwater to
500 ug/l before it arrives at the property boundary. The 2,000 ug/l
concentration is a remediation level that defines which groundwater will be
actively treated and which groundwater will be naturally attenuated at the
site. As long as the groundwater meets the 500 ug/l cleanup level at the
conditional point of compliance, the cleanup action may be determined to comply
with cleanup standards.
(d)
Example of a site not meeting groundwater cleanup levels at the point of
compliance. Assume the groundwater cleanup level at a site is 5 ug/l and
a conditional point of compliance is established at the property boundary. This
means any groundwater exceeding 5 ug/l at the point of compliance must be
remediated. Further assume the remedial action selected for the site consists
of: Vapor extraction of the soil to nondetectable concentrations (to prevent
further groundwater contamination); extraction and treatment of groundwater
with concentrations in excess of 100 ug/l; and installation of an air stripping
system to treat groundwater at a water supply well beyond the property boundary
to less than 5 ug/l. Further assume the groundwater cleanup level will not be
met at the conditional point of compliance (the property boundary). The
concentration of 100 ug/l is a remediation level that defines which groundwater
will be treated on site. In this example, the remedial action is an interim
action, not a cleanup action, because it does not comply with cleanup standards
(that is, it does not achieve the 5 ug/l cleanup level at the conditional point
of compliance.
Notes
Statutory Authority: Chapter 70.105D RCW. 01-05-024 (Order 97-09A), § 173-340-355, filed 2/12/01, effective 8/15/01.
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