vv EPA
              United States
              Environmental Protection
              Agency
            Office of
            Solid Waste and
            Emergency Response
DIRECTIVE NUMBER:  948i.o~6<84)

TITLE: Clarification of the Definition of Aquifer in
     40 CFR 260.10
APPROVAL DATE: 6-^-84

EFFECTIVE DATE: &-4-84

ORIGINATING OFFICE

0 FINAL

D DRAFT

 STATUS
                              °"i« of Solid Waste
                              A-'' Pending" OMB approval
                              Bf-K Pending AA-OSWER approval'
                              C-*~Forf review" &/or comment
                              DT If ^development" or circulating
               REFERENCf(bt»ier dbcumentsV:
  OS WER      OS WER      OS WER
!E    DIRECTIVE    DIRECTIVE   Di

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 PARTS 264 AND 265  SUBPART F - GROUND-WATER PROTECTION
                                                 DOC:   9481.06(84)
Key Words:

Regulations:

Subject:

Addressee:

Originator:

Source  Doc:

Date:

Summary:
'Aquifer,  Points  of  Compliance,  Ground-Water  Monitoring

 40 CFR 260.10,  264.93,  264.97,  RCRA 3013

 Clarification  of the  Definition of  Aquifer in  40  CFR  260.10

 Jim Scarbrough

 John H.  Skinner, Director,  Office of  Solid Waste

 #9481.06(84)

 6-4-84
     There is confusion in the use of the terms aquifer and ground water in the
regulations.  As stated in the regulations, an aquifer, by definition, provides
a significant yield of water Until Subpart F regulatory amendments are promul-
gated, EPA cannot require owner/operators to place ground-water monitoring
wells in saturated zones above aquifers to meet Part 264's point-of-compliance_
standards.  The monitoring system requirements (§264.97) and the ground-water
protection standard (§264.93) are limited to ground water in the aquifer.
Where there is a clear environmental rationale for requiring the permittee to
monitor the ground water above the aquifer, the Agency suggests using RCRA
§?013.  Finding ground-water contamination above the aquifer, however, does not
indicate that the ground-water protection standard has been- exceeded; imminent
hazard or other provisions must be envoked.

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                                                              9^81.06 (84)
Definition Of An Aquifer In Part 250.10

John H. Skinner, Director
Office of Solid Waste

Jim Scarorough


     In your memo in May 1, 1934, you requested clarification

of the definition of the word aquifer.  There is confusion

which results from the usage of the terms "aquifer" and "ground

water" in the regulations.   As you mentioned, the preamble

indicates our awareness of the issue at the time the regulations

were promulgated.  This subject has been repeatedly raised by

commenters and petitioners; and it is included in our list of.

.items for regulatory amendment.  We are now scheduled to propose

such amendments in the Spring of 1935.

     Meanwhile, we must abide by the current regulations which

do not require placement of ground-water monitoring wells  in

saturated zones above aquifers.  As you point out, §264.93

establishes the "point of compliance" as the entire vertical

plane from the edge of the waste management area down to

the upper surface of the aquifer; this would include, of

course,  ground water above the aquifer.  Similarly,  in  §270.14

(c)(4),  applicants must describe all ground-water contamination,

not just contamination in the aquifer.  However, the monitoring

system requirements, (§254.97), and the ground water protection

standard (§254.93),  are limited to ground water  in  the  aquifer.

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      Guidance  for  implementing the existing regulation is availaols

 in  three manuals:

      1.  Permit Applicant's Guidance Manual (SW 84-004) page 9-17.

      2.  Draft Permit Guidance Manual for Hazardous Waste Land
         Treatment, Storage, and Disposal Facilities (Get 33)
         pages 5-19 to 5-21.

      3.  Draft Permit Writers Manual for Ground Water Protection
         (Sep. 33) page 22


 A copy of  these references  is ate? .aed.  The issue will also

 been  addressed in  the first quarterly Permit and Policy Quarterly

 Report.  In general, we advocate the conservative approach

 where there is discretion in defining what is a s ignificant

 yield.  As expressed in the preamble, we must provide protection

 for individual domestic wells especially when considering that

 such wells typically supply "water  for use without treatment.

      I must caution you that guidance in the draft manuals

 (42 and *3 above)   has been  taken from context and used in a

misleading manner.   It says "In summary, the Agency considers

 the hydrologic unit an aquifer if  it provides a pathway for

migration  to any existing or potential point of use or discharge."

The next edition of these draft manual will clarify that this

must still be within tbe context of "significant, yield."

     With  regard to the facilities you are currently reviewing,

you may make use of the Part 270 requirement to require a

description of the contamination of all ground water beneath

the facility.   However,  with regard to the proposed monitoring

systems,  the regulations will only support the requirement  for

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monitoring the ground water in the aquifer.  Where there is



clear environmental rationale for requiring the permittee to



monitor ground water above the aquifer, we suggest that you



consider using the provisions of Section 3013 of the



Act.  You must keep in mind,  however, that the ground-Water



protectio'n standard for a facility, (§264.92) is only applied in



the aquifer.   Therefore, while we may require information



concerning ground-water contamination above the aquifer, finding



such contamination does not indicate that the ground-water



protection standard has been  exceeded;  imminent hazard or other



provisions must be envoked.

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