PA
United SIMM
Environmental Protection
Agency
Off ice of
Solid Waste ana
Emergency Respons*
DIRECTIVE NUMBER:
9441.08(85)
TITLE: Use of a Secondary Wastewater Treatment System
to Remove Biological Solids from an Activated
Sludge Unit
APPROVAL DATE: 2-22-35
EFFECTIVE DATE: 2-22-85
ORIGINATING OFFICE, office of Solid Waste
m FINAL
D DRAFT-
LEVEL OF DRAFT
DA — Signed by AA or DAA
Q B — Signed by Office Director
DC — Review & Comment
REFERENCE (other documents):
OSWER OSWER OSWER
VE DIRECTIVE DIRECTIVE Dl
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261 SUBPART A - GENERAL
DOC: 9441.08(85)
Key Words:
Regulations:
Subject:
Addressee:
Originator:
Source Doc:
Date:
Summary:
Refinery Wastes, Wastewater Treatment
Use of a Secondary Wastewater Treatment System to Remove Biological
Solids from an Activated Sludge Unit
Mr. Walsh, Placid Refining Company, 3900 Thanksgiving Tower,
Dallas, TX 75201
Matthew A. Straus, Chief, Waste Identification Branch
#9441.08(85)
2-22-85
Secondary wastewater treatment refers to the reduction of organic consti-
tuents via biological oxidation. It differs from primary treatment which
involves physical methods of oil/solids/water separation which occurs prior to
secondary treatment. In some cases, two (or more) methods of primary treatment
are used consecutively. In the K051 listing, the Agency referred to the latter
of two primary treatment units as "secondary treatment," which was misleading.
The Agency intended that the K051 hazardous waste listing address only oil/
solids/water separation from primary treatment. Therefore, the sludge generated
from secondary treatment is not a listed hazardous waste. It would be hazardous
only if it exhibits one or more of the hazardous waste characteristics.
The Agency, however, is currently evaluating secondary sludges from
biological treatment of refinery wastewaters to determine whether they should
be listed.
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9441.08 (83)
22
Placid Refining Company
3900 Thanksgiving fewer
DallAS, IX 75201
Dear NT. Walsh:
This letter is written in response to your February 14 correspondence
which requests that EPA clarify whether a particular refinery wastawatar
treatment sludge is a listed hazardous waste (K048). The waste in question
is generated by a dissolved air flotation Oevice in use at the Placid Refinery
in Port Allen, Louisiana, that is used as part of the secondary wastewater
.treatment systea to renove biological solids froa an activated sludge unit.
•.•-.•" * •' "* - • ' " '
In a recent federal Register notice (see enclosure), the Agency has
maintained that the K048 and K051 listings were intended only to address
oil/sol ids/water separation from primary treatment. The word •secondary*
was used in the background document and subsequently in the* K048 listing
to describe configurations where two primary wastewater treatment methods
were used consecutively as compared to secondary treatment consisting of
biological oxidation. The sludge from this unit is not currently a listed
hazardous waste because the dissolved air flotation unit at the Placid
Refinery is used to remove biological sludge from the treated effluent.
Therefore, under the Federal hazardous waste nanagenent system, this waste
would be hazardous only if it exhibits one or wore of the hazardous waste
characteristics.
At the sane tirre, you should also be aware that CPA is concerned about
secondary sludges trora biological treatment of refinery wastewaters.
Consequently, we are currently evaluating these wastes as part of the
petroleur. refining industry studies to determine whetiier they should be
listed as hazardous. Please feel free to give rae a call at (202) 475-8551
if you have any further questions.
Sincerely,
Matthew A. Straus, Cniet
Waste Identification Branch
Enclosure
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