Exhibit (10)(ff)
                                               JW Letter Agreement dated 9/27/01


                                             Bank of America Plaza
Jefferson Wells [LOGO]                       101 South Tryon Street, Suite 2450
               INTERNATIONAL                 Charlotte, North Carolina 28280
                                             Phone 704.377.8850 Fax 704.377.8883
                                             www.jeffersonwells.com




September 27, 2001

Mr. Larry W. Singleton
Senior Vice President Finance and Chief Financial Officer
Safety-Kleen Corp.
1301 Gervais Street, Suite 300
Columbia, SC  29201

Dear Larry:

Jefferson Wells International ("Jefferson Wells") appreciates the opportunity to
present you with this engagement letter to provide Safety-Kleen Services, Inc.
("Safety-Kleen") with professional services in support of your finance,
accounting, internal audit and tax department needs.

OBJECTIVES

Safety-Kleen is operating under Chapter 11 bankruptcy provisions. The company
has recently restructured by hiring a new executive management team and is
implementing recommended business improvements across its businesses. Many of
these business improvements are directly related to the financial infrastructure
of the company with regard to needed accounting and controls processes,
establishment of improved management reporting tools, and expansion of the
internal audit function.

Among the many challenges to improve the business, the new executive team and
its partners have identified three key objectives:

     1)   Safety-Kleen  needs to timely file 10-Ks and 10-Qs with confidence and
          accuracy.
     2)   Safety-Kleen  needs to improve its  financial  systems,  processes and
          related  internal  controls such that its external auditor can endorse
          the controls during the annual audit.
     3)   Safety-Kleen  requires the  implementation  of processes  and controls
          that support and deliver accurate management reporting data to support
          the new business structure and executive team.

In addition, management has indicated that it has and will continue to identify
a number of accounting and tax-related areas where additional support will
likely be needed in the coming months in order to meet its business objectives.

STRATEGY SUMMARY

Our initial recommended strategy is two-fold:

     1)   Pursue the ultimate goal of long-term business process improvement and
          controls.
     2)   Execute immediate improvements identified by Safety-Kleen's Accounting
          Procedure  and  Control  Initiative  (ACPI)  and  Financial  Reporting
          Integrity Projects (FRIP).



<PAGE>

Mr. Larry Singleton
September 27, 2001
Page 2 of 4

This mix will be obtained through the use of several teams focused upon
different initiatives across all areas of the company. Our project managers will
ensure a cohesive, consistent approach throughout the Safety-Kleen business
units. The specific timeline for implementing immediate improvements will be
defined as an initial priority.

To elaborate further, we recommend the use of a "Strategic" team focused on the
design and implementation of an end-to-end process and control environment to
deliver accurate management and financial reporting and internal controls. To
implement real change as swiftly as possible, the Strategic team will be
responsible for recommending the formation of "Tactical" teams to attack
immediate needs identified.

For the first two key company objectives outlined above, Safety-Kleen has begun
to address the deficiencies identified by the APCI and FRIP projects. These
teams have made significant progress in documenting the existing
accounting-related procedures in place throughout the company. However, to
assist in the design and implementation of improved processes and controls,
Safety-Kleen is requesting Jefferson Wells to:

     o    Review  and  assess   data   currently   collected   and   defined  by
          Safety-Kleen's APCI effort.
     o    Design  and  implement  required  process   modifications  to  improve
          accuracy, efficiency and offset risk.
     o    Design and implement required controls, monitoring, and internal audit
          functions to ensure continued efficiency and risk management.

For the third key company objective outlined above, we will adapt and leverage
the work performed to date in both the FRIP and APCI projects. During our
discussions, the following concentrated areas for improvement in management
reporting were identified:

     o    Review of standard costing systems and methodology  utilized by branch
          support groups including,  the machine  manufacturing  plant,  solvent
          recycling plants, and oil re-refining plants.
     o    Evaluate  branch  accounting  allocation  of  overhead  costs  such as
          disposal, transportation, warehousing, and corporate.
     o    Assess the  integrity of overall data  including the areas of chart of
          accounts,   payroll  recording,   intercompany  accounts,  and  branch
          expenses.

In addition, Jefferson Wells will make available from time-to-time, as
requested, professionals to assist with various accounting and tax-related
support needs to assist the Company in meeting its business objectives.

ENGAGEMENT TEAM

A Jefferson Wells National Director will be assigned and regularly on site at
Safety-Kleen in Columbia. Also, Engagement Managers will document a weekly
status report to summarize and communicate status of each identified project to
Safety-Kleen management. The objectives of tracking and formally reporting
status are to:

     o    Provide a consistent technique for monitoring progress against plan.
     o    Identify  problems/issues  quickly  to  allow  for  maximum  time  for
          corrections.
     o    Provide an objective  rather than subjective  evaluation of status.  o
          Provide you with timely information on a regular basis.
     o    Provide assistance in communicating recommendations.


<PAGE>


Mr. Larry Singleton
September 27, 2001
Page 3 of 4


An agreement will be established regarding content and format of status
reporting, schedule of status meetings, and other engagement criteria.

PROFESSIONAL FEES

Jefferson Wells proposes a unique solution to provide Safety-Kleen with maximum
expertise while remaining sensitive to cost constraints. The hourly professional
fees for this engagement are as follows:

            National Director(s)                                    $175
            Practice Director/Managing Director(s)                  $150
            Engagement Manager(s)                                   $140
            Team Leader(s)                                          $115
            Information Technology Professional(s)                  $125
            Accounting, Internal Audit and Tax Professional(s)      $105

Jefferson Wells does not charge a premium for overtime hours worked. Note that
Jefferson Wells may utilize certain professionals who are paid on an hourly
basis. These professionals are required to be paid for travel time, subject to
certain legal limitations. Where compensatory travel time is incurred, Jefferson
Wells will invoice Safety-Kleen at 50% of the normal rates outlined above.

In order to meet the reporting requirements of the Bankruptcy Court, Jefferson
Wells is expected to incur significant administrative time in preparing invoices
and supporting documentation. We will utilize administrative personnel whenever
possible to reduce the expense associated with these tasks. Accordingly, our
charge for administrative services will be $35 per hour.

EXPENSES

Safety-Kleen will reimburse Jefferson Wells for all reasonable travel and actual
out-of-pocket expenses incurred while performing the services described in this
proposal and approved by the company. Jefferson Wells will provide receipt
documentation as required by the Bankruptcy Court, except for the following:
travel per diems for meals, telephone expense and mileage reimbursement.
Wherever possible, Jefferson Wells will utilize professionals from our network
of offices across North America to minimize travel expenses in visiting branch
locations.

Safety-Kleen will reimburse Jefferson Wells for all reasonable legal expenses
incurred by Jefferson Wells associated with Jefferson Wells' retention and
compensation in Safety Kleen's bankruptcy case, including, but not limited to,
preparing retention applications and fee applications and responding to any
objections thereto.

TERMS

Jefferson Wells invoices and fee applications will be sent and filed monthly in
accordance with the terms of any standing orders of the Bankruptcy Court for the
District of Delaware or any orders entered by the Bankruptcy Court presiding
over Safety-Kleen's bankruptcy case (the "Court"). Payments on the invoices and
fee applications are due 30 days from the approval date by the court (subject to
any holdback requirements imposed by the Court). Once Safety-Kleen emerges from
Bankruptcy protection, all invoices are due 30 days from invoice date in the
normal course of business.

<PAGE>

Mr. Larry Singleton
September 27, 2001
Page 4 of 4


Jefferson Wells salaried professionals' standard workweek is 45 hours.
Professionals will be available to work additional hours as required to meet key
deadlines. Any activities such as vacations, holidays and training will be
communicated on a timely basis.

This engagement letter is subject to the terms and conditions of the Jefferson
Wells Master Service Agreement between Safety-Kleen Services, Inc. and Jefferson
Wells International, dated September 27, 2001 (the "MSA", see attached). This
engagement letter and the MSA are subject to approval by the Court.

JEFFERSON WELLS' BENEFITS

Jefferson Wells is a unique professional services firm that provides process
improvement, internal audit, finance/accounting, tax, and technology services.
Many of our highly seasoned professionals hold CPA, CIA, CFE, CISA and MBA
designations. Clients find we are affordable, effective, and committed toward
providing total satisfaction on every engagement. To date, Jefferson Wells has
completed thousands of engagements for over 1,600 major organizations.

Our unique business model leverages our strengths in designing and implementing
process improvements and controls. We currently have over 1,500 professionals in
28 offices throughout North America. We believe the following attributes make
Jefferson Wells a strong fit to your team:

     o    EXPERIENCE  -  Utilizing   professionals   with  real  world  industry
          experience,  we require  five  years  minimum  experience  and have an
          average of over ten years.

     o    INDEPENDENCE -  Jefferson Wells is not a public  accounting firm. Our
          core competencies are internal audit and process improvement.

     o    TEAMWORK  - We do not  work in a  vacuum.  Our  team-based  approach
          ensures  that  skills,  knowledge  and  data are  transferred  to your
          employees throughout the engagement.3

Jefferson Wells appreciates this opportunity to begin building a long-term,
mutually rewarding business partnership with you and Safety-Kleen.

Sincerely,


/s/ Alan G. Atwell Jr.

Alan Atwell
Managing Director

Please indicate your acceptance by signing below.


         Signature:     Larry W. Singleton
                    --------------------------------------

         Title:          CFO                Date:   10-24-01
                    ---------------------         ------------------


<PAGE>

                        JEFFERSON WELLS INTERNATIONAL
                            MASTER SERVICE AGREEMENT
                              TERMS AND CONDITIONS

THIS  MASTER  SERVICE  AGREEMENT  is made and  entered  into  this  27th day of
September,  2001 between  SAFETY-KLEEN  SERVICES,  INC. ("CLIENT") and JEFFERSON
WELLS INTERNAT1ONAL,  a Delaware corporation ("JEFFERSON WELLS"). This agreement
sets forth the general terms and conditions  pursuant,  to which JEFFERSON WELLS
will provide services to CLIENT. The specific  engagement scope and pricing will
be separately  documented in the  Proposal(s).  This agreement is subject to the
approval of the United States Bankruptcy Court for the District of Delaware.

1.  Location.  Services will be performed at sites  established by CLIENT unless
otherwise agreed to in the Proposal(s).

2. Rights of Title. All reports,  workpapers,  programs,  manuals, discs, tapes,
listings  and any  other  material  prepared  solely  under  this  Agreement  by
JEFFERSON WELLS'  employees shall belong  exclusively to CLIENT and CLIENT shall
have the right to obtain from JEFFERSON WELLS and/or JEFFERSON WELL' employees,
and to hold in CLIENT's name all copyrights, trademark registrations, patents or
whatever protection CLIENT may deem appropnate to the subject matter.  JEFFERSON
WELLS agrees to give CLIENT reasonable assistance, at CLIENT's expense, required
to  protect  the rights  defined in this  paragraph.  All  reports,  workpapers,
programs, manuals, discs, tapes, listings and any other material prepared solely
under this Agreement by JEFFERSON  WELLS'  employees is intended  solely for the
use of CLIENT's internal  management and is not intended to be and should not be
used by any other parties without the prior written consent of JEFFERSON  WELLS,
which consent shall not be unreasonably withheld.

3. Termination.  Unless otherwise provided for in the Proposal(s),  either party
may  terminate  this  Agreement  for any reason at any time.  Upon  termination,
CLIENT shall pay  JEFFERSON  WELLS' final  invoice for all amounts due under the
terms of section 4 below.

4.  Payment.  JEFFERSON  WELLS shall be paid at the billable  rates set forth in
each  Proposal(s).  JEFFERSON WELLS' employees' daily working hours shall be the
same as worked by CLIENT's employees,  unless otherwise directed and/or approved
by CLIENT.

     (a)  While  CLIENT  remains  in  bankruptcy,   payment  shall  be  made  in
          accordance with any orders governing  compensation of professionals or
          JEFFERSON WELLS in CLIENT's bankruptcy case.

     (b)  Upon such time as CLIENT emerges from bankruptcy  protection,  payment
          shall be made within 30 days from invoice date in the normal course of
          business.  If payment is not  received  with 30 days from the  invoice
          date in the normal course of business,  JEFFERSON  WELLS  reserves the
          right, in addition  to any other  rights it may have,  to suspend  the
          services until such payment is made in full.


5.  Taxes.  CLIENT  shall be  responsible  for  payment of all taxes  (excluding
payroll and income taxes),  if any, levied upon the services provided under this
Agreement.

6. Insurance. JEFFERSON WELLS agrees to maintain the following insurance for its
employees.

     (a)  Worker's   compensation   insurance   covering  all  JEFFERSON   WELLS
          employees;

     (b)  Employer's liability insurance;

     (c)  Comprehensive  automobile  liability  insurance  for  combined  bodily
          injury and property damage;

     (d)  Comprehensive  general liability  insurance for combined bodily injury
          and property damage; and

     (e)  Professional liability insurance.

     JEFFERSON  WELLS agrees to provide CLIENT with  certificates  of  insurance
upon request.

7. Independent Contractor Relationship.    The parties understand and agree that
the  personnel  assigned by JEFFERSON  WELLS to CLIENT under this  Agreement are
JEFFERSON WELLS' employees or agents.  Under no circumstances are such personnel
to be considered  CLIENT employees or agents.  JEFFERSON WELLS shall perform its
obligations  under this  Agreement as an  independent  contractor  and not as an
agent or joint  venture  partner  of CLIENT.  No individual  providing  services
pursuant to this  agreement  shall be  entitled  to benefits  provided to client
employees,   including   but  not  limited  to,   compensation,   insurance  and
unemployment insurance.

8. Mutual Indemnification.   To the fullest extent  permitted by applicable law,
each party will  indemnify,  defend and hold the other  harmless for any and all
actual and alleged claims, damages, liabilities, losses and expenses, including,
but not limited to reasonable attorney's fees, arising out of, resulting from or
in  connection  with that other  party's (i)  intentional  and  willful  acts or
omissions in connection with this Agreement, (ii) gross negligence in connection
with this Agreement or (iii) breach of this Agreement. This Article 8 is subject
to the  provisions  of  Article  10 of this  Agreement.   This  Article  8 shall
survive termination of this Agreement.

9. Warranty.  JEFFERSON  WELLS warrants that the services will be performed in a
workmanlike and professional manner by individuals who have skill and experience
commensurate  with the requirements of the services.  Other than those contained
in this section,  JEFFERSON WELLS makes no other  representations  or warranties
with respect to the services.

10. Limitation of Liability.  CLIENT understands and agrees that JEFFERSON WELLS
will not be liable  for any  punitive,  incidental,  consequential  or  indirect
damages.  CLIENT agrees that JEFFERSON WELLS' liability for any damages, if any,
including  any  liability to CLIENT  pursuant to Article 8. shall not exceed two
times those charges paid to JEFFERSON WELLS by CLIENT pursuant to any individual
proposal  for the  services  rendered by  JEFFERSON  WELLS that gave rise to the
liability. This Article 10 shall survive termination of this Agreement.

11. Confidential Information.   Each party agrees that during and after the term
of this  Agreement it will keep secret and will not,  without the prior  written
consent of the other,  use or disclose to any third  party any  confidential  or
proprietary  information  relating  to the  business  of the other party or that
party's customers learned by such party or disclosed to such party in connection
with this Agreement.  The restrictions of this section 11 shall not apply to any
information which (i) is or becomes generally available to the public other than
as a result of a breach of this  section  11 by the  receiving  party,  (ii) was
available  to the  receiving  party  on a  nonconfidential  basis  prior  to its
disclosure  under this  Agreement or (iii)  becomes  available to the  receiving
party on a  nonconfidential  basis from a third party which was not itself bound
by a confidentiality  obligation and was free to disclose the information.  This
Article 11. shall survive  termination of this agreement.

12. Entire Agreement. This Agreement and the Proposal(s) referred to, as well as
any  written  amendments,  shall  constitute  the entire  Agreement  between the
parties   and   supersedes   all   previous   communications,   representations,
understandings,  concurrent  or  subsequent  purchase  orders,  and  agreements,
whether oral or written, between the parties or any officer or representative of
the parties, CLIENT has not relied upon any representations other than those set
forth in this Agreement.

13.  Amendments.  No  amendments or other  variation to this  Agreement shall be
effective unless it is in writing,  is signed by an authorized  person on behalf
of each party, and is approved by the court in CLIENT's bankruptcy case.

14.  Governing  Law. The laws of the State of South  Carolina  shall govern this
Agreement.  Both parties consent to the  jurisdiction of the courts in the state
of South Carolina.  No action arising out of this  Agreement,  regardless of the
form,  may be  brought  by either  party  more than one year  after the cause of
action has occurred.

15.  Controversy/Arbitration.  Controversies  and  claims  arising  out  of or
relating to this Agreement shall be resolved as follows:

     (a)  Controversies  or Claims  Arising  During  the  Bankruptcy  Case.  Any
          controversy  or claim that is pursued or arises during the  Bankruptcy
          Case and that  arises  out of or  relates  to this  Agreement,  or the
          breach  of  the  same  shall  be  settled  through   consultation  and
          negotiation in good faith and a spirit of mutual cooperztion. However,
          if those attempts  fail,  any  controversy or claim that is pursued or
          arises during the Bankruptcy Case and that arises out of or relates to
          this Agreement, or breach of the same shall be heard by the bankruptcy
          court presiding over CLIENT's bankruptcy case.

     (b)  Claims  Arising  After  CLIENT's   Emergence  from   Bankruptcy.   Any
          controversy or claim arising out of or relating to this Agreement,  or
          the  breach  of  the  same,   arising  after  CLIENTs  emergence  from
          bankruptcy,  shall be settled through  consultation and negotiation in
          good  faith  and a spirit  of mutual  cooperation.  However,  if those
          attempts  fail,  the  parties  agree  that  any  misunderstandings  or
          disputes  arising from this Agreement  shall be decided by arbitration
          which shall be conducted  upon request by either party,  in Milwaukee,
          Wisconsin,  before three (3) arbitrators (unless both parties agree on
          one (1) arbitrator designated by the American Arbitration  Association
          (the  "AAA"),   in  accordance   with  the  terms  of  the  Commercial
          Arbitration  Rules of the AAA, and, to the maximum extent  applicable,
          the  United  States  Arbitration  Act (Title 9 of  the  United  States
          Code), or if such Act is not applicable,  any substantially equivalent
          state law. Each party shall be  responsible  for its own costs related
          to  arbitration  and shall  bear  half the cost of the  Arbitrator(s).
          Notwithstanding  anything  herein to the  contrary,  either  party may
          proceed  to a court of  competent  junsdiction  to  obtain  injunctive
          relief at anytime.

16.  Severability.  If any  provision  of this  Agreement  is  determined  to be
unenforceable  or invalid,  the  remaining  provisions of this  Agreement  shall
remain in full force and effect.

17.  Force Majeure.  JEFFERSON  WELLS and  CLIENT  shall not be liable  for any
failure  to  perform  or delay in  performance  of its  obligations  under  this
Agreement,  resulting  from the elements,  acts of God or any other cause beyond
the reasonable control of the party failing to perform.

18.  Notices.  Any notices  required under this  Agreement  shall be in writing.
Notices  shall be delivered in person or sent by overnight  courier or facsimile
addressed to the addresses in the  Proposal(s).  Notice shall be effective  when
sent by overnight  courier or facsimile or upon delivery if delivered in person.

19.  Successors  and Assigns.  This  Agreement  may be assigned by either of the
Parties upon written consent of the non-assigning party, which consent shall not
be unreasonably withheld.  This Agreement shall be binding upon and inure to the
benefit of the Parties and their respective heirs, successors and assigns.

20.  Waiver.  No waiver by either  party at any time of any  breach by the other
party of, or compliance with, any condition or provision of this Agreement to be
performed by that other party shall be deemed a waiver of a prior or  subsequent
breach of any similar or dissimilar provisions or conditions of this Agreement.

For JEFFERSON WELLS INTERNATIONAL

By       /s/ Alan G. Atwell  Jr.

Name     Mr. Alan G. Atwell Jr.

Its      Managing Director - Charlotte

For CLIENT

By       /s/ Larry W. Singleton

Name     Mr. Larry W. Singleton

Its      Senior Vice President and Chief Financial Officer