&EPA
           United States
           Environmental Protection
           Agency
         Office of
         Solid Waste And
         Emergency Response
DIRECTIVE NUMBER: 9355.0-28

TITLE:  Control of Air Emissions From Superlund Air Strippers
     at Superlund Groundwater Sites
            APPROVAL DATE: 06/15/89

            EFFECTIVE DATE: 06/15/89

            ORIGINATING OFFICE:  OSWER/OERR/HSCD


            0C FINAL

            D DRAFT

              STATUS:


            REFERENCE (other documents):
 OSWER   OSWER   OSWER
VE  DIRECTIVE DIRECTIVE Dl

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            UNITED STATES ENVIRONMENTAL PROTECTION AGEV
                           AASHiNGTCN DC  2C-J6C


                            JUM I  5  '.939
                                        OSWER  Directive  9355.0-28
 MEMORANDUM

 SUBJECT:


 FROM:
Control of Air Emissions From Superfund Air
Strippers at Superfund Groundwatar Sites
TO:
Henry L. Longest II, Director
Office of Emergency and Remedi
Gerald Emison, Dir
Office of Air Quality 'plin

Addressees
                                                     nse
                                              and  Standards
PURPOSE

    This memorandum  establishes guidance  on  the  control of air
emissions  from air strippers used at  Superfund sites  for
groundwater treatment  and  establishes procedures for
implementation.  Under this guidance,  Regions should  continue to
make air emission control  decisions on a  case-by-case basis
using the  nine remedy  selection criteria  and the remedy
selection  process set  forth in the proposed  National  Contingency
Plan (NCP).  As described  below, however,  the evaluation and
weighing of the criteria in a Mto be  considered" (TBC) context
will differ according  to the air quality  status  of the site's
location.

BACKGROUND

    Approximately 35%  of the Records  of Decision (RODs) signed
to data have involved  sites which use a pump and treat technique
to either  partially  or fully remediate groundwater
contamination.  Close  to 45% of these pump and treat  sites have
selected air stripping.  For the foreseeable future,  OERR
expects to use air stripping at about the same rate.  This
treatment  technique  relies on volatilization to  remove volatile
organic compounds (VOCs) from the groundwater, i.e. it transfers
the contaminants from  the  liquid to vapor phase.  One known side
effect of  air stripping is the emission of VOCs,  many of which

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                             -2-


 are  toxic, to  the  ambient  air.  The Superfund Program uses
 control devices  such  as vapor phase carbon adsorption and
 incineration to  control these emissions.

     In response  to a  request from Regional Air Division
 Directors  for  a  policy to  guide the selection of controls for
 air  strippers, OERR and OAQPS conducted a joint study.  The
 results showed that historically close to half of the Superfund
 air  stripper sites had adopted controls during remedy
 selection.  Another 25 percent deferred the decision to the
 remedial design  phase.  At sites with RODs signed after the
 enactment  of the Superfund Amendments and Reauthorization Act,
 approximately  two-thirds of the air strippers are controlled.
 At these sites,  control decisions were based on an analysis of
 the  cleanup standards established in Section 121 of CERCLA and
 the  other  statutory considerations which together comprise the
 nine remedy selection criteria:  overall protection of human
 health and the environment;  compliance with Applicable or
 Relevant and Appropriate Requirements (ARARs); long-term
 effectiveness/permanence;  reduction of mobility, toxicity or
 volume (MTV);  short-term effectiveness; implementability; cost;
 State acceptance;  and community acceptance.  Control decisions
 to date have been  driven largely by protectiveness and State
 ARARs for  both air toxics  control and VOC control for ozone
 reduction.  Other  criteria such as MTV, short-term
 effectiveness, cost,  and community acceptance, have also
 influenced the inclusion of  controls.

     Despite the  trend towards increased control of air emissions
 from Superfund air strippers, the Agency remains concerned with
 the  control of these  air emissions.  This concern underlies the
 vigorous efforts by EPA, States, localities, and industry across
 the  country to control air toxics and reduce VOCs in ozone
 nonattainment  areas.  The  adoption of this policy responds to
 these concerns,  reflects an  overall Agency concern with
 preventing the cross-media transfer of pollutants, and
 recognizes that  the number of Federal, state, and local ARARs
 for  both VOCs  and  air toxics appears to be rapidly increasing.

     The following  policy has been adopted to guide Regional
 decisionmaXers on  the use  of controls for air emissions from
 Superfund  air  strippers, and other vented Superfund sources of
VOCs.  This policy is grounded in the remedy selection process
 and distinguishes  between  sites located in attainment and
 nonattainment  areas.

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                             -3-
 STATEMENT OF  POLICY

     For  sites located  in  areas that are attaining the National
 Ambient  Air Quality  Standards for ozone, Regions should continue
 applying controls  based on existing Agency policy.  In most
 cases, this will mean  the adoption of controls largely in
 response to State  ARARs,  risk management (i.e., protective-
 ness) guidelines,  and  other requirements of CERCLA Section 121.

     In ozone  nonattainment areas, however, the adoption of
 controls is more likely to be indicated even if they are not  •
 mandated by current  Federal or State laws and regulations or
 indicated by  a cancer  risk analysis.  Aside from cancer risk'
 from air toxics, VOC emissions contribute to non-cancer health
 risks in nonattainment areas because most are precursors to the
 formation of  ozone.  Consideration of these non-cancer risks
 when applying the  remedy  selection criteria generally will show
 that in  nonattainment  areas Superfund air strippers, except
 those with the lowest  emissions rates as indicated below,
 generally merit controls.  In determining the need for air
 stripper controls  at a particular Superfund site in a
 nonattainment area,  the Regions should be guided by the
 emissions limit goals  in  the document entitled, "Issues Relating
 to VOC Regulation  Cutpoints, Deficiencies, and Deviations,"
 issued in May 1988 by  the Office of Air Quality Planning and
 Standards (OAQPS)  to aid  States in revising their State
 Implementation Plans (SIPs) to incorporate post-1987 ozone
 attainment strategies.  The OAQPS guidance indicates that the
 sources  most  in need of controls are those with an actual
 emissions rate in  excess  of 3 pounds per hour  (Ib/hr) or 15
 Ib/day or a potential  (i.e., calculated) rate of 10 tons per
 year (TFY)  of total  VOCs.  The calculated rate assumes 24-hour
 operation,  365 days  per year.  Regions should note that control
 levels are applied on  a facility basis.  For the purposes of
 this guidance, facility is defined as a contiguous piece of
property under common  ownership.

     This guidance  applies to air strippers at Superfund sites.
 In establishing the  policy, however, the potential for
 applicability to other VOC sources is recognized.  Generally,
 the  guidelines described  for air strippers are suitable for VOC
 air  emissions from other  vented extraction techniques (e.g.,
 soil vapor extraction) but not from area sources  (e.g., soil
 excavation).

    This guidance  applies to future remedial decisions at
Superfund sites.   The  policy is not explicitly designed for

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                             -4-


 actions  taken by the  removal  program  in  the case of emergency or
 time critical removal actions.  However, where time and other
 response circumstances permit, such as for non-time critical
 actions,  adherence  to this  policy  is  expected.

     The  control  levels referred to above serve as guidelines
 only if  ARARs do not  exist  or are  less stringent than presented
 here.  They are  not intended  to preclude or replace State
 proposals for more  stringent  levels of control in pursuit of
 Clean Air Act goals as part of SIP revisions  in nonattainment
 areas.

 IMPLEMENTATION

     This guidance seeks to  incorporate air quality concerns into
 the Superfund remedy  selection process.  In particular, the use
 of  controls for  Superfund air strippers  in nonattainment areas
 demonstrates the Agency's commitment  to  reducing VOCs and thus
 progressing toward  attainment of the  ozone standard.
 Additionally,  the guidance  is consistent with both the current
 NCP and  proposed revisions.   Where ARARs do not exist, EPA may
 consider TBCs in setting target cleanup  levels.  This guidance
 constitutes a TBC.

     The  Remedial Investigation/Feasibility Study (RI/FS) should
 generate  the data needed to support control decisions for both
 attainment and nonattainment  areas.   At  a minimum, the five
 major  types of information  needed  are:

          Estimated  cumulative uncontrolled air emissions rate
          from all air strippers at the site

          Consideration of health risks from the execution of the
          remedy  as  well as  from the uncontrolled site

          Control alternatives and  their  costs

          Ozone attainment status

          Air ARARs

     For purposes of this guidance  "nonattainment area" means any
county included  in a  formal post-1987 ozone SIP deficiency
notification  (SIP call) or any other  county where the ozone
National Ambient Air Quality  Standard was exceeded during the
previous three-year period.   EPA's initial SIP calls were issued
pursuant to Section 110(a)(2)(H)  of the  Clean Air Act and were
described  in the  September 7,  1988 Federal Register.

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    The RI/FS scoping phase and work plan development should
describe the specific data to be generated and the methods for
doing so.  Remedial Project Managers should consult with the
designated Air Superfund Coordinator for technical assistance.
Additional assistance is available from National Technical
Guidance Manuals developed jointly by the Air and Superfund
program offices for estimating air emissions and conducting air
pathway analyses.  The ROD should summarize this information as
appropriate and clearly document the basis for the air emissions
control decision.

Addressees:
Regional Waste Management Division Directors
Regional Superfund Branch Chiefs
Regional Air Division Directors
Regional Air Branch Chiefs
OERR Division Directors
OAQPS Division Directors

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     REPORT DOCUMENTATION PAGE
                    Form Approved OMB No. 0704-0188
   PB90-272667
2.  Report Date:
   06/15/89
3. Report Type And Dates Covered:
   DIRECTIVE
4. Title And Subtitle: Control of Air Emissions
From Superfund Air Strippers at Superfund Groundw
ater Sites
6. Author(s):
                               5. Funding Numbers:
   Performing Organization Names And Addresses:
   Environmental Protection Agency
   Office of Solid Waste and Emergency Response
   401 M Street, SW
   Washington, DC  20460
                              8. Performing Organization
                                 Report Number:
                                 EPA/9355.0-28
   Sponsoring/Monitoring Agency Name(s)
   And Address(es):
   Environmental Protection Agency
   Office of Emergency and Remedial Response
   401 M Street, SW
   Washington, DC  20460
                               10. Sponsoring/Monitoring
                                   Agency Report Number:
11. Supplementary Notes:
12a. Distribution/Availability Statement:
                               12b. Distribution Code:
13. Abstract: .Establishes guidance on control of air emissions from air
strippers used at Superfund sites for groundwater treatraent.  This joint
memorandum from Office Directors, OERR, and Air Quality Planning and Standar
ds, establishes procedures for implementation.-
14. Subject Terms:
    SUPERFUND DOCUMENT:
    Remedial
             15. Number Of Pages:
                   8
                                                   16. Price Code: A02
17. Report Security
    Classication:
 18. Page Security
     Classication:
    19. Abstract Security
        Classication:
20. Media:

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