Unitwj Sum
                Envtronmonul Protection
            Office of
            Solid Waste and
            Emergency ReeponM
s s a - i A
                      Permit-Exempt Status of Sludge Dryers
                      Added to Wastewa'ter Treatment Units
                APPROVAL DATE: January 2, 1986
                EFFECTIVE DATE:
                ORIGINATING OFFICE: office of solid waste
                Q FINAL
                D DRAFT

                REFERENCE (other documents):
                    9503.51-1A(85) written to Region VI Dec. 24, 1985
  OSWER       OSWER      OSWER

- - - —:.c n A r,cy
Washington DC 20460
,EPA OSWER Directive Initiation Request 7Sc3, i -//‘c
Originator Informaton
me of Contact Person
Mail Code Telephone Number
Irene Homer
WH—565A 382—2550
Lead Office OUST Approved for Review
Signature of Office Orector Date
Permit—Exempt Status of Sludge Dryers Added to Wastewater
Treatment Units
Summary of Directive
Sludge dryers added to wastewater treatment units exempted from permitting
under RCRA are also exempt from permitting even though they have no
discharge subject to regulation under 402 or 307(b) of the Clean Water Act.
Type of Directive (Manual Policy Directive. Announcement. e rc) Status
I 0 Draft : 0 New
Regulatory Interpretive Letter
I L J Final Revision
Does this Directive Supersede Previous Directive(s 1 ) Yes No Does It Supplement Previous 0irectivels ’ Yes
If Yes to Either Question. What Directive (number title)
9503 .51—1A(85)
RD&D Permit for a Sludge Drying Process in a Wastewater System
Review Plan
0 AA-OSWER 0 OUST 0 OECM 0 Other ;SpecifyJ
0 OSW 0 Regions 0 OPPE
This Request Meets OSWER Directives System Format
gnature of Lead Office Directives Officer Date
Signature of OSWER Directives Officer Date
EPA Form 1315.17(10.851

C. T. PhiliPP, P.E.
Pres ide nt
Water Management, Incorporated
2300 Highway 70 East
Hot Springs, Arkansas 71901
Dear Mr. Philipp:
In your letter of December 5, 1985 you requested that the
AgenCy identify the Resource Conservation and Recovery Act
(RCRA) status of sludge dryers that are part of a converttional
treatment system not regulated by RCRA. You questioned whether
adding a sludge dryer to a wasteWater treatment unit exempted
from RCRA permitting will jeopardize the exemption. The RCRA—
superfund Hotline correctly identified sludge drying for you as a
treatment process according to the definition of treatment in
40 CFR 5260.10. However, when sludge dryers meet the definition
of wastewater treatment units, they qualify for the wastewater
treatment exemption of 55264.1(g)( 6 ). 265.1(c)(lO), and
270.1(C)(2)(V). In your case, adding a sludge dryer to treat
sludge generated by a treatment system operating under a wastewater
treatuEnt exemption does not subject the treatment system to RCRA
As you know, sludge dryers must meet the three criteria in
the definition of wastewater treatment unit in order to be
part of a wasteWater treatment ex luSiOfl. First, the information
you sent shows that your sludge dryer qualifies as a tank as
defined in 5260.10, that is, it is designed to contain hazardous
waste and is constructed primarily of nonearthen materials that
provide structural support. Furthermore, the Agency has clarified
the definition of tank-fOr this exempt ion——to include unit
operations such as presses filters, Bumps; and many other types
of processing equipment. (See the attached met randU1fl dated
July 31, 1981, fran John Lehman to Region I.) In addition,
the preamble of the November 17, 1980, proposed rule (45 FR
76077—76078) clarified the definition of a wastewater treatment
unit as follows:
This definitiOn...Cover3..t sludge digesters.
thickeners, dryers and other sludge processing tanks...
in which hazardous wastewater treatment sludge is
treated; and any...tanks used for the storage of
such sludge.

Second, the sludge dryer treats or stores a wastewater
treatment sludge which is a hazardous waste as defined in S261.3
(i.e., the sludge itself is a listed waste, derived from treatment
of a listed waste, or is hazardous on the basis of characteristics
identified in S26l Subpart C). This means that the treatment of
sludges generated from wastewater treatment units is also exempt
from regulation under the RCRA treatment standards.
Tanks (here a sludge dryer) that do not themselves have any
discharge subject to regulation under Sections 402 or 307(b) of
the Clean Water Act, but that are part of the wastewater treatment
systems qualify for the exemption if other tanks in the treatment
train have discharges that are subject to these Clean Water Act
provisions. So the third condition, being part of a wastewater
treatment unit subject to regulation under Section 402 or 307(b)
of the Clean Water Act, can be met by sludge dryers in certain
circumstances. Sowever, as the November 17, 1980 preamble stated
(45 FR 76077), even the proposed regul&tiOnS.... aY not provide
adequate envirOluDonta] protection where treatment of the hazardous
was tewater tends to result in the escape of hazardous waste
constituents into the atmosphere (e.g., the treatment of highly
toxic volatile wastes in open tanks). Unless the Administrator
promulgates regulations covering wastewater treatment units,
wastewater treatment tanks that qualify for exemption under
current RCRA standards may volatilize their contents and retain
the exemption.
Sludge dryers may be used as part of a program to meet the
waste minimization requirements of Section 3002(b) of RCRA without
requiring permitting if the above conditions are met. Of course,
although exempted from permitting requirements in the wastewater
treatment units, any hazardous waste sludge that is removed from
the tanks is subject to applicable regulations under SS260-2 66 ,
such as manifesting off site, permitted storage after 90 days,
and so on. If you have any additional questions regarding this
exemption for wastewatet treatment units, please do not hesitate
to call Irene Homer at 202—382—7917.
sincerely yours,
- . V O LuGra
J. Winston Porter
Assistant Administrator

2300 H OHWAV 70 EAST
($01) 23-2221
December 5, 1985
Mr. Lee M. Thomas, Administrator
Mail Code A-100
401 M. St. S.W.
Washington, DC 20460
RE: Sludge Dryers - Metal Finishing Industry
Waste Minimization Program
Dear Mr. Thomas:
As you may know, your Agency notified industry in the Federal
Register, 7/15/85, P. 28733-34 that Waste Minimization was a definite
goal of your Agency. We support this goal.
There is a definite problem of interpretation that is delaying
the use of sludge dryers to accomplish waste minimization. I hope
that your office can clear this up as soon as possible. We and many
of our potential customers have contacted the Hotline and have been
advised that drying is a form of treatment per Section 260.10 under
RCRA. This is technically true; however, the sludge dryer can also
be considered as an extension of the conventional treatment system.
I am enclosing several copies of our sales literature on our
dryer. Please note the back page where we illustrate four solids
concentration devices in the following order:
1. Clarifier to separate solids from water.
2. Sludge thickener to seperate solids from water.
3. Filter press to separate solids from water.
4. Dryer to separate solids from water.
It is very important that your Agency define a sludge dryer as
an extension of a conventional treatment system because of insurance
premiums! The minimum cost for liability coverage (40 CFR 264.147)
is $50,000 annual premium. Therefore, how can a generator purchase
a dryer to save $30,000/yr. in disposal costs if the regulations
change his generator classification to a TSD classification? The
goal of waste minimization will be deterred if dryers are classified
as a RCRA regulated unit operation. Dryers should be regulated under
NPDES or state/local permit regulations.

Page Two
DeCember 5, 1985
Will OU please review this problem and advise me at your
earliest convenience. It is most important that the personnel
at the Hotlifle give accurate uniform answers to this questiOn.
C.T. PhilipP, P.
cc: Marcia Williams,
Director of Office of Solid Wastes
Governor Bill Clinton,
State of Arkansas