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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