1
 
                                                                    EXHIBIT 99.1
 
                             LETTER OF TRANSMITTAL
 
                                AQUA-CHEM, INC.
                           OFFER FOR ALL OUTSTANDING
                   11 1/4% SENIOR SUBORDINATED NOTES DUE 2008
                                IN EXCHANGE FOR
                   11 1/4% SENIOR SUBORDINATED NOTES DUE 2008
                        WHICH HAVE BEEN REGISTERED UNDER
                     THE SECURITIES ACT OF 1933, AS AMENDED
               PURSUANT TO THE PROSPECTUS DATED DECEMBER 31, 1998
 
   
AQUA-CHEM, INC. WILL ACCEPT ALL EXISTING NOTES (AS HEREINAFTER DEFINED) TENDERED
AND NOT WITHDRAWN PRIOR TO 5:00 P.M., NEW YORK CITY TIME, ON FEBRUARY 5, 1999
UNLESS EXTENDED (THE "EXPIRATION DATE"). TENDERS MAY BE WITHDRAWN AT ANY TIME
PRIOR TO 5:00 P.M. NEW YORK CITY TIME ON THE EXPIRATION DATE.
    
                             THE EXCHANGE AGENT IS:
                UNITED STATES TRUST COMPANY OF NEW YORK ("USTC")
 


          By Mail:             Facsimile Transmission Number:    By Hand up to 4:30 p.m.:
          --------             ------------------------------    ------------------------
                                                         
     United States Trust              (212) 780-0592                United States Trust
     Company of New York               (For Eligible                Company of New York
        P.O. Box 844                Institutions Only)                 111 Broadway
       Cooper Station                                                   Lower Level
New York, New York 10276-0844      Confirm by Telephone:         New York, New York 10006
    Attn: Corporate Trust                                          Attn: Corporate Trust
          Services                    (800) 548-6565                     Services
  (Registered or Certified
      Mail Recommended)

 


                                 By Overnight Courier and
                                by Hand after 4:30 p.m. on
                                 the Expiration Date Only:
                                --------------------------
                                                        
                                    United States Trust
                                    Company of New York
                                       770 Broadway
                                        13th Floor
                                 New York, New York 10003
                                   Attn: Corporate Trust
                                         Services

 
     DELIVERY OF THIS LETTER OF TRANSMITTAL TO AN ADDRESS OTHER THAN AS SET
FORTH ABOVE OR TRANSMISSION OF INSTRUCTIONS VIA A FACSIMILE NUMBER OTHER THAN
THE ONE LISTED ABOVE WILL NOT CONSTITUTE A VALID DELIVERY. THE INSTRUCTIONS SET
FORTH IN THIS LETTER OF TRANSMITTAL SHOULD BE READ CAREFULLY BEFORE THIS LETTER
OF TRANSMITTAL IS COMPLETED.
   2
 
   
     The undersigned acknowledges receipt of the Prospectus dated December 31,
1998 (the "Prospectus") of Aqua-Chem, Inc., a Delaware corporation ("Aqua-Chem"
or the "Company"), and this Letter of Transmittal (the "Letter of Transmittal"),
that together constitute the Company's offer (the "Exchange Offer") to exchange
an aggregate of up to $125,000,000 principal amount of its 11 1/4% Senior
Subordinated Notes due 2008 which have been registered under the Securities Act
of 1933, as amended ("Exchange Notes") for a like principal amount of its issued
and outstanding 11 1/4% Senior Subordinated Notes due 2008 (the "Existing
Notes"). Recipients of a Prospectus should read the requirements described in
such Prospectus with respect to eligibility to participate in the Exchange
Offer. Capitalized terms used but not defined herein have the meanings ascribed
to them in the Prospectus.
    
 
   
     The Letter of Transmittal is to be completed by a holder of Existing Notes
in order to tender Existing Notes. Certificates representing Existing Notes must
be forwarded with this Letter of Transmittal, unless tender of Existing Notes is
made (i) by book-entry transfer pursuant to the procedures set forth in the
Prospectus under the caption "The Exchange Offer -- How to Tender" and
"-- Exchanging Book-Entry Notes" or (ii) according to the guaranteed delivery
procedures set forth under the caption "The Exchange Offer -- How to Tender" in
the Prospectus; in any case, instructions may be transmitted through the
Automated Tender Offer Program ("ATOP") of the Depository Trust Company ("DTC"
or the "Book-Entry Transfer Facility").
    
 
     Holders of Existing Notes that are tendering by book-entry transfer to the
Exchange Agent's account at DTC can execute the tender through ATOP for which
the transaction will be eligible. DTC participants that are accepting the
Exchange Offer must transmit their acceptances to DTC which will verify the
acceptance and execute a book-entry delivery to the Exchange Agent's account at
DTC. DTC will then send an Agent's Message to the Exchange Agent for its
acceptance. Delivery of the Agent's Message by DTC will satisfy the terms of the
Exchange Offer as to execution and delivery of a Letter of Transmittal by the
participant identified in the Agent's Message. DTC participants may also tender
their Existing Notes by submitting a Notice of Guaranteed Delivery through ATOP.
 
     Any beneficial owner whose Existing Notes are registered the name of a
broker, dealer, commercial bank, trust company or other nominee and who wishes
to tender should contact such holder of Existing Notes promptly and instruct
such holder of Existing Notes to tender on behalf of the beneficial owner. If
such beneficial owner wishes to tender on his own behalf, such beneficial owner
must, prior to completing and executing this Letter of Transmittal and
delivering his Existing Notes, either make appropriate arrangements to transfer
record ownership of the Existing Notes in such beneficial owner's name or obtain
a properly completed bond power from the record holder of Existing Notes. The
transfer of record ownership may take considerable time.
 
     In order to properly complete this Letter of Transmittal, a holder of
Existing Notes must (i) complete the box entitled "Description of Existing
Notes"; (ii) if appropriate, check and complete the boxes relating to book-entry
transfer, guaranteed delivery, Special Issuance Instructions and Special
Delivery Instructions; (iii) sign the Letter of Transmittal by completing the
box entitled "Sign Here"; and (iv) complete the Substitute Form W-9. Each holder
of Existing Notes should carefully read the detailed instructions below prior to
completing the Letter of Transmittal.
 
     Holders of Existing Notes who desire to tender the Existing Notes for
exchange and (i) whose Existing Notes are not immediately available; (ii) who
cannot deliver their Existing Notes and all other documents required hereby to
the Exchange Agent on or prior to the Expiration Date; or (iii) who are unable
to complete the procedure for book-entry transfer on a timely basis, must tender
the Existing Notes pursuant to the guaranteed delivery procedures set forth
below. See Instruction 2.
 
     Holders of Existing Notes who wish to tender their Existing Notes for
exchange must, at a minimum, complete columns (1) through (3) in the box below
entitled "Description of Existing Notes" and sign the box below entitled "Sign
Here." If only these columns are completed, such holder of Existing Notes will
have tendered for exchange all Existing Notes listed in column (3) below. If the
holder of the Existing Notes wishes to tender for exchange less than all of such
Existing Notes, column (4) must be completed in full. In such case, such holder
of Existing Notes should refer to Instruction 5.
                                        2
   3
 

                                                                                          
  ---------------------------------------------------------------------------------------------------------------------
                                              DESCRIPTION OF EXISTING NOTES
  ---------------------------------------------------------------------------------------------------------------------
                           (1)                                   (2)                  (3)                  (4)
  ---------------------------------------------------------------------------------------------------------------------
                                                                                                     PRINCIPAL AMOUNT
                                                             CERTIFICATE      AGGREGATE PRINCIPAL      TENDERED FOR
  NAME(S) AND ADDRESS(ES) OF REGISTERED NOTE HOLDER(S),     NUMBER(S)(1)      AMOUNT REPRESENTED    EXCHANGE (ONLY IF
              EXACTLY AS NAME(S) APPEAR(S)                 (ATTACH SIGNED             BY           DIFFERENT FROM COL.
                 ON NOTE CERTIFICATE(S)                  LIST, IF NECESSARY)  SUCH CERTIFICATE(S)        (3))(2)
  ---------------------------------------------------------------------------------------------------------------------
  ---------------------------------------------------------------------------------------------------------------------
  ---------------------------------------------------------------------------------------------------------------------
  ---------------------------------------------------------------------------------------------------------------------
  ---------------------------------------------------------------------------------------------------------------------
  ---------------------------------------------------------------------------------------------------------------------
  ---------------------------------------------------------------------------------------------------------------------
  ---------------------------------------------------------------------------------------------------------------------
                  TOTAL PRINCIPAL AMOUNT OF EXISTING NOTES:
  ---------------------------------------------------------------------------------------------------------------------
    (1) Column (2) need not be completed by holders of Existing Notes tendering Existing Notes for exchange by
        book-entry transfer. Please check the appropriate box below and provide the requested information.
    (2) The minimum permitted tender is $1,000 in principal amount of Existing Notes. All other tenders must be in
        integral multiples of $1,000 of principal amount. Column (4) need not be completed by holders of Existing Notes
        who wish to tender for exchange the principal amount of Existing Notes listed in Column (3). Completion of
        Column (4) will indicate that the holder of Existing Notes wishes to tender for exchange only the principal
        amount of Existing Notes indicated in Column (4).
  ---------------------------------------------------------------------------------------------------------------------

 
                                        3
   4
 
                            TENDER OF EXISTING NOTES
- --------------------------------------------------------------------------------
 
[ ] CHECK HERE IF TENDERED EXISTING NOTES ARE DELIVERED HEREWITH.
 
[ ] CHECK HERE IF TENDERED EXISTING NOTES ARE BEING DELIVERED BY BOOK-ENTRY
    TRANSFER MADE TO THE ACCOUNT MAINTAINED BY THE EXCHANGE AGENT WITH USTC AND
    COMPLETE THE FOLLOWING (FOR USE BY ELIGIBLE GUARANTOR INSTITUTIONS (AS
    HEREINAFTER DEFINED) ONLY).
 
    Name of Tendering Institution:
                                  ----------------------------------------------
 
    Account Number:
                   -------------------------------------------------------------
 
    Transaction Code Number:
                            ------------------------------
 
    By crediting the Existing Notes to the Exchange Agent's account at USTC in
    accordance with USTC's procedures with respect to the Exchange Offer,
    including transmitting a computer-generated message (an "Agent's Message")
    to the Exchange Agent in which the holder of the Existing Notes acknowledges
    and agrees to be bound by the terms of this Letter of Transmittal and
    confirms on behalf of itself and the beneficial owners of such Existing
    Notes all provisions of this Letter of Transmittal applicable to it and such
    beneficial owners as fully as if it had completed the information required
    herein and executed and transmitted this Letter of Transmittal to the
    Exchange Agent.
 
[ ] CHECK HERE IF TENDERED EXISTING NOTES ARE BEING DELIVERED PURSUANT TO A
    NOTICE OF GUARANTEED DELIVERY ENCLOSED HEREWITH AND COMPLETE THE FOLLOWING
    (FOR USE BY ELIGIBLE GUARANTOR INSTITUTIONS (AS HEREINAFTER DEFINED) ONLY):
 
    Name of Registered Holder of Existing Note(s):
                                                  ------------------------------
 
    Date of Execution of Notice of Guaranteed Delivery:
                                                       -------------------------
 
    Window Ticket Number (if available):
                                        ----------------------------------------
 
    Name of Institution Which Guaranteed Delivery:
                                                  ------------------------------
 
    Account Number (if delivered by book-entry transfer):
                                                         -----------------------
 
[ ] CHECK HERE IF YOU ARE A BROKER-DEALER AND WISH TO RECEIVE 10 ADDITIONAL
    COPIES OF THE PROSPECTUS AND 10 COPIES OF ANY AMENDMENTS OR SUPPLEMENTS
    THERETO.
 
    Name:
         -----------------------------------------------------------------------
 
    Address:
            --------------------------------------------------------------------
 
[ ] CHECK HERE IF THE BENEFICIAL OWNER OF THE EXISTING NOTES IS A PARTICIPATING
    BROKER-DEALER AND SUCH PARTICIPATING BROKER-DEALER ACQUIRED THE EXISTING
    NOTES FOR ITS OWN ACCOUNT AS A RESULT OF MARKET-MAKING ACTIVITIES OR OTHER
    TRADING ACTIVITIES.
 
                                        4
   5
 
                       SIGNATURES MUST BE PROVIDED BELOW
 
              PLEASE READ THE ACCOMPANYING INSTRUCTIONS CAREFULLY
 
Ladies and Gentlemen:
 
   
     Pursuant to the offer by Aqua-Chem, Inc. (the "Company") upon the terms and
conditions set forth in the Prospectus dated December 31, 1998 (the
"Prospectus") of the Company and this Letter of Transmittal (the "Letter of
Transmittal"), that together constitute the Company's offer (the "Exchange
Offer") to exchange an aggregate of up to $125,000,000 principal amount of its
11 1/4% Senior Subordinated Notes due 2008 which have been registered under the
Securities Act of 1933, as amended ("Exchange Notes") for a like principal
amount of its issued and outstanding 11 1/4% Senior Subordinated Notes due 2008
(the "Existing Notes"), the undersigned hereby tenders to the Company for
exchange the Existing Notes identified above (hereinafter the "Tendered Existing
Notes").
    
 
     Subject to, and effective upon, the acceptance for exchange of the Tendered
Existing Notes, the undersigned hereby exchanges, assigns, and transfers to, or
upon the order of, the Company, all right, title, and interest in, to, and under
the Tendered Existing Notes.
 
     Unless otherwise indicated under "Special Issuance Instructions," above,
please issue the Exchange Notes exchanged for Tendered Existing Notes in the
name(s) of the undersigned. Similarly, unless otherwise indicated under "Special
Delivery Instructions," above, please send or cause to be sent the certificates
for the Exchange Notes (and accompanying documents, as appropriate) to the
undersigned at the address shown below.
 
     The undersigned understands that tenders of Existing Notes pursuant to the
procedures described under the caption "The Exchange Offer" in the Prospectus
and in the instructions hereto will constitute a binding agreement between the
undersigned and the Company upon the terms and subject to the conditions of the
Exchange Offer, subject only to withdrawal of such tenders on the terms set
forth in the Prospectus under the caption "The Exchange Offer -- Withdrawal
Rights." All authority herein conferred or agreed to be conferred shall survive
the death or incapacity of the undersigned and any obligation of the undersigned
or any Beneficial Owners hereunder shall be binding upon the heirs,
representatives, successors, and assigns of the undersigned and such Beneficial
Owner(s). The undersigned hereby irrevocably constitutes and appoints the
Exchange Agent as the true and lawful agent and attorney in fact of the
undersigned with respect to the Tendered Existing Notes, with full power of
substitution (such power of attorney being deemed to be an irrevocable power
coupled with an interest), to (i) deliver the Tendered Existing Notes to the
Company or cause ownership of the Tendered Existing Notes to be transferred to,
or upon the order of, the Company, on the books of the registrar for the
Existing Notes and deliver all accompanying evidences of transfer and
authenticity to, or upon the order of, the Company upon receipt by the Exchange
Agent, as the undersigned's agent, of the Exchange Notes to which the
undersigned is entitled upon acceptance by the Company of the Tendered Existing
Notes pursuant to the Exchange Offer, and (ii) receive all benefits and
otherwise exercise all rights of beneficial ownership of the Tendered Existing
Notes, all in accordance with the terms of the Exchange Offer.
 
     The undersigned hereby represents and warrants that (i) the undersigned is
the registered owner of all the Tendered Existing Notes; (ii) it has received
from each beneficial owner of the Tendered Existing Notes ("Beneficial Owner") a
duly completed and executed form of "Instruction to Registered Holder and/or
Book-Entry Transfer Facility Participant from Beneficial Owner" accompanying
this Letter of Transmittal, instructing the undersigned to take the action
described in this Letter of Transmittal; and (iii) the undersigned has full
power and authority to tender, exchange, assign, and transfer the Tendered
Existing Notes and the Company will acquire good and unencumbered title thereto,
free and clear of all liens, restrictions, charges, encumbrances, and adverse
claims when the Tendered Existing Notes are acquired by the Company as
contemplated herein. The undersigned and each Beneficial Owner will, upon
request, execute and deliver any additional documents reasonably requested by
the Company or the Exchange Agent as necessary or desirable to complete and give
effect to the transactions contemplated hereby.
 
                                        5
   6
 
     The undersigned hereby represents and warrants that the information set
forth above under "DESCRIPTION OF EXISTING NOTES" is true and correct.
 
     By accepting the Exchange Offer, the undersigned hereby represents and
warrants that (i) the Exchange Notes to be acquired by the undersigned and any
Beneficial Owner(s) in connection with the Exchange Offer are being acquired by
the undersigned and any Beneficial Owner(s) in the ordinary course of business
of the undersigned and any Beneficial Owner(s); (ii) the undersigned and any
Beneficial Owner(s) are not participating, do not intend to participate, and
have no arrangement or understanding with any person to participate, in the
distribution of the Exchange Notes; (iii) except as otherwise disclosed in
writing herewith, neither the undersigned nor any Beneficial Owner is an
"affiliate," as defined in Rule 405 under the Securities Act, of the Company;
and (iv) the undersigned and any Beneficial Owner(s) acknowledge and agree that
any person participating in the Exchange Offer with the intention or for the
purpose of distributing the Exchange Notes must comply with the registration and
prospectus delivery requirements of the Securities Act in connection with a
secondary resale of the Exchange Notes acquired by such person and cannot rely
on the position of the Staff of the Securities and Exchange Commission (the
"Commission") set forth in the no-action letters that are discussed in the
section of the Prospectus entitled "The Exchange Offer." In addition, by
accepting the Exchange Offer, the undersigned hereby (a) represents and warrants
that, if the undersigned or any Beneficial Owner of the Existing Notes is a
Participating Broker-Dealer, such Participating Broker-Dealer acquired the
Existing Notes for its own account as a result of market-making activities or
other trading activities and has not entered into any arrangement or
understanding with any person to distribute the Exchange Notes to be received in
the Exchange Offer; and (b) acknowledges that, by receiving Exchange Notes for
its own account in exchange for Existing Notes, where such Existing Notes were
acquired as a result of market-making activities or other trading activities,
such Participating Broker-Dealer will deliver a prospectus meeting the
requirements of the Securities Act in connection with any resale of such
Exchange Notes.
 
                                        6
   7
 
                                PLEASE SIGN HERE
          (TO BE COMPLETED BY ALL TENDERING HOLDERS OF EXISTING NOTES
 REGARDLESS OF WHETHER EXISTING NOTES ARE BEING PHYSICALLY DELIVERED HEREWITH)
 
X
- --------------------------------------------------------------------------------
X
- --------------------------------------------------------------------------------
Date:
- -------------------------------------------------
 
     Must be signed by the registered holder(s) of Existing Notes exactly as
name(s) appear(s) on certificate(s) representing Existing Notes or on a security
position listing or by person(s) authorized to become registered holder(s) by
certificates and documents transmitted with this Letter of Transmittal. If
signature is by a trustee, executor, administrator, guardian, attorney-in-fact,
officer, or other person acting in a fiduciary or representative capacity, such
person must set forth his or her full title below (see Instruction 6).
 
Name(s)
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
                                 (Please Print)
 
Capacity (full title)
- --------------------------------------------------------------------------------
Address
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
                           (Include Zip/Postal Code)
 
Area Code and Telephone No. (
- ---------)
- --------------------------------------------------------------------
Tax Identification or Social Security Number
- ----------------------------------------------------------------
                                         Please complete Substitute Form W-9
 
                         MEDALLION SIGNATURE GUARANTEE
         (SIGNATURE(S) MUST BE GUARANTEED IF REQUIRED BY INSTRUCTION 1)
 
Authorized Signature
- --------------------------------------------------------------------------------
Dated
- ------------------------------------------------
Name and Title
- --------------------------------------------------------------------------------
                                 (Please Print)
 
Name of Firm
- --------------------------------------------------------------------------------
                               (PLACE SEAL HERE)
 
                                        7
   8
 
     Unless otherwise indicated below under "Special Issuance Instructions" or
"Special Delivery Instructions," the undersigned hereby request(s) that any
Notes representing principal amounts not tendered or not accepted for purchase
be issued in the name(s) of, and delivered to, the undersigned (and in the case
of Notes tendered by book-entry transfer, by credit to the account of DTC).
 
     In the event that the "Special Issuance Instructions" or "Special Delivery
Instructions" box is completed, the undersigned hereby request(s) that any Notes
representing principal amounts not tendered or not accepted for purchase be
issued in the name(s) of, and be delivered to, the person(s) at the address(es)
therein indicated.
 
                         SPECIAL ISSUANCE INSTRUCTIONS
                           (SEE INSTRUCTIONS 1 AND 8)
To be completed ONLY (i) if (a) Exchange Notes issued in exchange for Existing
Notes or (b) certificates for Existing Notes in a principal amount not exchanged
for Exchange Notes are to be issued in the name of someone other than the
undersigned, or (ii) if Existing Notes tendered by book-entry transfer which are
not exchanged are to be returned by credit to an account maintained at the
Book-Entry Transfer Facility.
 
Issue: [ ]
Name:
- -----------------------------------------------
                                 (Please Print)
 
Address:
- ---------------------------------------------
 
- -------------------------------------------------------
 
- -------------------------------------------------------
                           (Include Zip/Postal Code)
 
- -------------------------------------------------------
              (Taxpayer Identification or Social Security Number)
 
[ ] Credit Existing Notes not exchanged and delivered by book-entry transfer to
    the account set forth below:
 
- -------------------------------------------------------
                 (Book-Entry Transfer Facility Account Number)
 
                         SPECIAL DELIVERY INSTRUCTIONS
                           (SEE INSTRUCTIONS 1 AND 8)
To be completed ONLY if certificates for Existing Notes in a principal amount
not exchanged for Exchange Notes are to be mailed or delivered to someone other
than the undersigned, or to the undersigned at an address other than the address
shown below the undersigned's signature.
 
Mail or deliver to:
Name:
- -----------------------------------------------
                                 (Please Print)
 
Address:
- ---------------------------------------------
 
- -------------------------------------------------------
 
- -------------------------------------------------------
                           (Include Zip/Postal Code)
 
- -------------------------------------------------------
              (Taxpayer Identification or Social Security Number)
 
                                        8
   9
 
                     INSTRUCTIONS TO LETTER OF TRANSMITTAL
 
         FORMING PART OF THE TERMS AND CONDITIONS OF THE EXCHANGE OFFER
 
                                  INSTRUCTIONS
 
         FORMING PART OF THE TERMS AND CONDITIONS OF THE EXCHANGE OFFER
 
     1. GUARANTEE OF SIGNATURE. Except as otherwise provided below, all
signatures on the Letter of Transmittal must be guaranteed by, if the holder is
resident in the United States, an eligible institution that is a member of one
of the following recognized signature Guarantee Programs:
 
     (a) The Securities Transfer Agents Medallion Program (STAMP);
 
     (b) The New York Stock Exchange Medallion Signature Program (MSP); or
 
   
     (c) The Stock Exchange Medallion Program (SEMP).
    
 
     Signatures on this Letter of Transmittal need not be guaranteed (i) if this
Letter of Transmittal is signed by the registered holder(s) of the Existing
Notes tendered herewith and such registered holder(s) have not completed the box
entitled "Special Issuance Instruction" or the box entitled "Special Delivery
Instructions" on this Letter of Transmittal or (ii) if such Existing Notes are
tendered for the account of an Eligible Guarantor Institution. IN ALL OTHER
CASES, ALL SIGNATURES MUST BE GUARANTEED BY AN ELIGIBLE GUARANTOR INSTITUTION.
 
     2. DELIVERY OF THIS LETTER OF TRANSMITTAL AND EXISTING NOTES; GUARANTEED
DELIVERY PROCEDURE. This Letter of Transmittal is to be completed by holders of
Existing Notes (i) if certificates are to be forwarded herewith or (ii) if
tenders are to be made pursuant to the procedures for tender by book-entry
transfer or guaranteed delivery set forth in the section of the Prospectus
entitled "The Exchange Offer -- How to Tender." Certificates for all physically
tendered Existing Notes or any confirmation of a book-entry transfer under DTC's
ATOP (a "Book-Entry Confirmation"), as well as a properly completed and duly
executed copy of this Letter of Transmittal or facsimile hereof, and any other
documents required by this Letter of Transmittal must be received by the
Exchange Agent at its address set forth on the cover of this Letter of
Transmittal prior to 5:00 p.m., New York City time, on the Expiration Date.
Holders of Existing Notes who elect to tender Existing Notes and (i) whose
Existing Notes are not immediately available, (ii) who cannot deliver the
Existing Notes or other required documents to the Exchange Agent prior to 5:00
p.m., New York City time on the Expiration Date or (iii) who are unable to
complete the procedure for book-entry transfer on a timely basis, may have such
tender effected if: (a) such tender is made by or through an Eligible Guarantor
Institution; (b) prior to 5:00 p.m., New York City time, on the Expiration Date,
the Exchange Agent has received from such holder or Eligible Guarantor
Institution a properly completed and duly executed Letter of Transmittal (or a
facsimile thereof) and Notice of Guaranteed Delivery, or an Agent's Message with
respect to guaranteed delivery that is accepted by the Company, either by hand
delivery, mail, telegram or facsimile transmission setting forth the name and
address of the holder of such Existing Notes, the certificate number(s) of such
Existing Notes and the principal amount at maturity of Existing Notes tendered
for exchange, stating that tender is being made thereby and guaranteeing that,
within three (3) New York Stock Exchange ("NYSE") trading days after the date of
delivery of the Notice of Guaranteed Delivery, the certificates representing
such Existing Notes (or a Book-Entry Confirmation), in proper form for transfer,
and any other documents required by this Letter of Transmittal, will be
deposited by such Eligible Guarantor Institution with the Exchange Agent; and
(c) certificates for all tendered Existing Notes, or a Book-Entry Confirmation,
together with a copy of the previously executed Letter of Transmittal (or
facsimile thereof) and any other documents required by this Letter of
Transmittal are received by the Exchange Agent within three (3) NYSE trading
days after the Expiration Date.
 
     THE METHOD OF DELIVERY OF EXISTING NOTES, THIS LETTER OF TRANSMITTAL AND
ALL OTHER REQUIRED DOCUMENTS IS AT THE ELECTION AND RISK OF THE TENDERING HOLDER
OF EXISTING NOTES. EXCEPT AS OTHERWISE PROVIDED BELOW, THE DELIVERY WILL BE
DEEMED MADE ONLY WHEN ACTUALLY RECEIVED OR CONFIRMED BY THE EXCHANGE AGENT. IF
DELIVERY IS BY MAIL, PROPERLY INSURED
                                        9
   10
 
REGISTERED MAIL WITH RETURN RECEIPT REQUESTED IS RECOMMENDED. SUFFICIENT TIME
SHOULD BE ALLOWED FOR SUCH DOCUMENTS TO REACH THE EXCHANGE AGENT. NEITHER THE
LETTER OF TRANSMITTAL NOR ANY EXISTING NOTES SHOULD BE SENT TO THE COMPANY.
 
     No alternative, conditional or contingent tenders will be accepted. By
execution of this Letter of Transmittal (or facsimile hereof, if applicable),
all tendering holders of Existing Notes waive any right to receive notice of the
acceptance of their Existing Notes for exchange.
 
     3. INADEQUATE SPACE. If the space provided in the box entitled "DESCRIPTION
OF EXISTING NOTES" above is inadequate, the certificate numbers and principal
amounts at maturity of the Existing Notes being tendered should be listed on a
separate signed schedule affixed hereto.
 
     4. WITHDRAWALS. A tender of Existing Notes may be withdrawn at any time
prior to 5:00 p.m., New York City time, on the Expiration Date by delivery of
written notice of withdrawal to the Exchange Agent at the address set forth on
the cover of this Letter of Transmittal. To be effective, a notice of withdrawal
of Existing Notes must (i) specify the name of the person who tendered the
Existing Notes to be withdrawn (the "Depositor"); (ii) identify the Existing
Notes to be withdrawn (including the certificate number or numbers and aggregate
principal amount at maturity of such Existing Notes); (iii) be signed by the
holder of Existing Notes in the same manner as the original signature on the
Letter of Transmittal by which such Existing Notes were tendered (including any
required signature guarantees) or be accompanied by documents of transfer
sufficient to have the applicable transfer agent register the transfer of such
Existing Notes into the name of the person withdrawing the tender; and (iv)
specify the name in which any such Existing Notes are to be registered, if
different from that of the Depositor. Withdrawals of tenders of Existing Notes
may not be rescinded, and any Existing Notes withdrawn will thereafter be deemed
not validly tendered for purposes of the Exchange Offer and no Exchange Notes
will be issued with respect thereto unless the Existing Notes so withdrawn are
validly retendered. Properly withdrawn Existing Notes may be retendered by
following one of the procedures described in the section of the Prospectus
entitled "The Exchange Offer -- How to Tender" at any time prior to 5:00 p.m.,
New York City time, on the Expiration Date.
 
     5. PARTIAL TENDERS. (Not applicable to holders of Existing Notes who tender
Existing Notes by book-entry transfer.) Tenders of Existing Notes will be
accepted only in integral multiples of US $1,000 principal amount at maturity,
and only if the remaining untendered portion of such Existing Notes held by the
tendering holder is in a principal amount of $250,000, or any integral multiple
of $1,000 in excess of such amount. If a tender for exchange is to be made with
respect to less than the entire principal amount at maturity of any Existing
Notes, fill in the principal amount at maturity of Existing Notes that are
tendered for exchange in Column (4) of the box entitled "DESCRIPTION OF EXISTING
NOTES," as more fully described in the footnotes thereto. In case of a partial
tender for exchange, a new certificate, in fully registered form, for the
remainder of the principal amount at maturity of the Existing Notes, will be
sent to the holders of Existing Notes unless otherwise indicated in the
appropriate box on this Letter of Transmittal as promptly as practicable after
the expiration or termination of the Exchange Offer.
 
     6. SIGNATURES ON THIS LETTER OF TRANSMITTAL, POWERS OF ATTORNEY AND
ENDORSEMENTS.
 
          (a) The signature(s) of the holder of Existing Note(s) on this Letter
     of Transmittal must correspond with the name(s) as written on the face of
     the Existing Notes without alteration, enlargement or any change
     whatsoever.
 
          (b) If tendered Existing Notes are owned by record by two or more
     joint owners, all such owners must sign this Letter of Transmittal.
 
          (c) If any tendered Existing Notes are registered in different names,
     on several certificates, it will be necessary to complete, sign and submit
     as many separate copies of this Letter of Transmittal and any necessary or
     required documents as there are different registrations or certificates.
 
          (d) When this Letter of Transmittal is signed by the holder of the
     Existing Notes listed and transmitted hereby, no endorsements of Existing
     Notes or separate powers of attorney are required. If, however, Existing
     Notes not tendered or not accepted, are to be issued or returned in the
     name of a
                                       10
   11
 
     person other than the holder of such Existing Notes, then the Existing
     Notes transmitted hereby must be endorsed or accompanied by appropriate
     powers of attorney in a form satisfactory to the Company, in either case
     signed exactly as the name(s) of the holder of Existing Notes appear(s) on
     the Existing Notes. Signatures on such Existing Notes or powers of attorney
     must be guaranteed by an Eligible Guarantor Institution (unless signed by
     an Eligible Guarantor institution).
 
          (e) If this Letter of Transmittal or an Existing Note or power of
     attorney is signed by a trustee, executor, administrator, guardian,
     attorney-in-fact, officer of a corporation or other person acting in a
     fiduciary or representative capacity, such person should so indicate when
     signing, and proper evidence satisfactory to the Company of their authority
     so to act must be submitted.
 
          (f) If this Letter of Transmittal is signed by a person other than the
     registered holder of Existing Notes listed, the Existing Notes must be
     endorsed or accompanied by appropriate powers of attorney, in either case
     signed exactly as the name(s) of the registered holder of Existing Notes
     appear(s) on the certificates. Signatures on such Existing Notes or powers
     of attorney must be guaranteed by an Eligible Guarantor Institution (unless
     signed by an Eligible Guarantor Institution).
 
     7. TRANSFER TAXES. Except as set forth in this Instruction 7, the Company
will pay all transfer taxes, if any, applicable to the transfer and exchange of
Existing Notes pursuant to the Exchange Offer. If, however, issuance of Exchange
Notes is to be made to, or Existing Notes not tendered for exchange are to be
issued or returned in the name of, any person other than the holder of Existing
Notes, the amount of any transfer taxes payable on account of the transfer to
such person will be imposed on and payable by the holder of Existing Notes
tendering Existing Notes for exchange prior to the issuance of the Exchange
Notes. If satisfactory evidence of payment of such taxes or exemption therefrom
is not submitted with the Letter of Transmittal, the amount of such transfer
taxes will be billed directly to such tendering holder.
 
     8. SPECIAL ISSUANCE AND DELIVERY INSTRUCTIONS. If the Exchange Notes are to
be issued, or if any Existing Notes not tendered for exchange are to be issued
or sent, to someone other than the holder of Existing Notes or to an address
other than that shown above, the appropriate boxes on this Letter of Transmittal
should be completed. Holders of Existing Notes tendering Existing Notes by
book-entry transfer may request that Existing Notes not accepted be credited to
such account maintained at DTC as such holder of Existing Notes may designate.
 
     9. IRREGULARITIES. All questions as to the form of documents and the
validity, eligibility (including time or receipt), acceptance and withdrawal of
Existing Notes will be determined by the Company, in its sole discretion, whose
determination shall be final and binding. The Company reserves the absolute
right to reject any or all tenders for exchange of any particular Existing Notes
that are not in proper form, or the acceptance of which would, in the opinion of
the Company or its counsel, be unlawful. The Company reserves the absolute right
to waive any defect, irregularity or condition of tender for exchange with
regard to any particular Existing Notes. The Company's interpretation of the
terms of, and conditions to, the Exchange Offer (including the instructions
herein) will be final and binding. Unless waived, any defect or irregularities
in connection with the Exchange Offer must be cured within such time as the
Company shall determine. Neither the Company, the Exchange Agent nor any other
person shall be under any duty to give notice of any defects or irregularities
in Existing Notes tendered for exchange, nor shall any of them incur any
liability for failure to give such notice. A tender of Existing Notes will not
be deemed to have been made until all defects and irregularities with respect to
such tender have been cured or waived. Any Existing Notes received by the
Exchange Agent that are not properly tendered and as to which the defects or
irregularities have not been cured or waived will be returned by the Exchange
Agent to the tendering holders, unless otherwise provided in this Letter of
Transmittal as soon as practicable following the Expiration Date.
 
     10. WAIVER OF CONDITIONS. The Company reserves the absolute right to waive
certain of the specified conditions as described under "The Exchange Offer --
Conditions" in the Prospectus in the case of any Existing Notes tendered (except
as otherwise provided in the Prospectus).
 
     11. MUTILATED, LOST, STOLEN OR DESTROYED NOTES. If a holder of Existing
Notes desires to tender an Existing Note pursuant to the Exchange Offer, but the
Existing Note has been mutilated, lost, stolen or
 
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destroyed, such holder of Existing Notes should write to or telephone the
Trustee, at the address listed below, concerning the procedures for obtaining
replacement certificates for such Existing Notes, arranging for indemnification
or any other matter that requires handling by the Trustee:
 
              United States Trust Company of New York
              770 Broadway
              New York, NY 10003
              Corporate Trust Department
              Telephone: (800) 548-6565
              Facsimile: (212) 780-0592
 
     12. REQUESTS FOR INFORMATION OR ADDITIONAL COPIES. Requests for information
or for additional copies of the Prospectus and this Letter of Transmittal may be
directed to the Exchange Agent at the address or telephone number set forth on
the cover of this Letter of Transmittal.
 
   
     13. SUBSTITUTE FORM W-9. Each tendering holder (or other payee) is required
to provide the Exchange Agent with a correct taxpayer identification number
("'TIN"), generally the holder's Social Security or federal employer
identification number, and with certain other information, on Substitute Form
W-9, which is provided under "Important Tax Information" below, and to certify
that the holder (or other payee) is not subject to backup withholding. Failure
to provide the information on the Substitute Form W-9 may subject the tendering
holder (or other payee) to a $50 penalty imposed by the Internal Revenue Service
and 31% federal income tax withholding on any payments made pursuant to the
Exchange Offer. The box in Part 3 of the Substitute Form W-9 may be checked if
the tendering holder (or other payee) has not been issued a TIN and has applied
for a TIN or intends to apply for a TIN in the near future. If the box in Part 3
is checked and the Exchange Agent is not provided with a TIN by the time of
payment, the Exchange Agent will withhold 31% on any payments made pursuant to
the Exchange Offer.
    
 
     IMPORTANT: THIS LETTER OF TRANSMITTAL (OR A FACSIMILE THEREOF, IF
APPLICABLE) TOGETHER WITH EXISTING NOTE CERTIFICATES, OR CONFIRMATION OF
BOOK-ENTRY TRANSFER OR THE NOTICE OF GUARANTEED DELIVERY, AND ALL OTHER REQUIRED
DOCUMENTS MUST BE RECEIVED BY THE EXCHANGE AGENT PRIOR TO 5:00 P.M., NEW YORK
CITY TIME, ON THE EXPIRATION DATE.
 
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- -----------------------------------------------------------------------------------------------------------------
                                       PAYER'S NAME:   AQUA-CHEM, INC.
- -----------------------------------------------------------------------------------------------------------------
  SUBSTITUTE                    PART I--PLEASE PROVIDE YOUR TIN IN THE BOX
                                AT THE RIGHT AND CERTIFY BY SIGNING AND       Social Security Number
                                DATING BELOW.
                                                                              OR
                                                                                 Employer Identification
                                                                                 Number
                                -----------------------------------------------------------------------------
 FORMW-9
 DEPARTMENT OF THE TREASURY     PART 2--CERTIFICATION--Under Penalties of Perjury, I certify that:
 INTERNAL REVENUE SERVICE
 PAYER'S REQUEST FOR            (1) The number shown on this form is my correct taxpayer identification
 TAXPAYER IDENTIFICATION        number (or I am waiting for a number to be issued to me), and
 NUMBER (TIN)
                                (2) I am not subject to backup withholding because: (a) I am exempt from
                                backup withholding, or (b) I have not been notified by the Internal Revenue
                                    Service (the "IRS") that I am subject to backup withholding as a result
                                    of a failure to report all interest or dividends, or (c) the IRS has
                                    notified me that I am no longer subject to backup withholding.
                                CERTIFICATE INSTRUCTIONS--You must cross out item (2) in Part 2 above if you
                                have been notified by the IRS that you are subject to backup withholding
                                because of under- reporting interest and dividends on your tax return.
                                However, if after being notified by the IRS that you were subject to backup
                                withholding you receive another notification from the IRS stating that you
                                are no longer subject to backup withholding, do not cross out item (2).
                                SIGNATURE   DATE __________________
                                -----------------------------------------------------------------------------
                                PART 3--AWAITING TIN [ ]
- -----------------------------------------------------------------------------------------------------------------

 
   NOTE: FAILURE TO COMPLETE AND RETURN THIS FORM MAY RESULT IN BACKUP
         WITHHOLDING OF 31% OF ANY PAYMENTS MADE TO YOU PURSUANT TO THE
         EXCHANGE OFFER. PLEASE REVIEW THE ENCLOSED GUIDELINES FOR
         CERTIFICATION OF TAXPAYER IDENTIFICATION NUMBER ON SUBSTITUTE FORM
         W-9 FOR ADDITIONAL DETAILS.
 
         YOU MUST COMPLETE THE FOLLOWING CERTIFICATE IF YOU CHECKED THE BOX
         IN PART 3 OF SUBSTITUTE FORM W-9
- --------------------------------------------------------------------------------
 
             CERTIFICATE OF AWAITING TAXPAYER IDENTIFICATION NUMBER
 
      I certify under penalties of perjury that a taxpayer identification
 number has not been issued to me, and either (a) I have mailed or delivered an
 application to receive a taxpayer identification number to the appropriate
 Internal Revenue Service Center or Social Security Administration Office or
 (b) I intend to mail or deliver such an application in the near future. I
 understand that if I do not provide a taxpayer identification number within
 sixty (60) days, 31% of all reportable payments made to me thereafter will be
 withheld until I provide such a number.
 
 Signature   Date ____________________
- --------------------------------------------------------------------------------
 
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                           IMPORTANT TAX INFORMATION
 
     Under current United States federal income tax law, a holder of Existing
Notes whose tendered Existing Notes are accepted for exchange is required to
provide the Company (as payor), through the Exchange Agent, with such holder's
correct TIN on Substitute Form W-9 or otherwise establish a basis for exemption
from backup withholding. If such holder of Existing Notes is an individual, the
TIN is such holder's social security number. If the Exchange Agent is not
provided with the correct taxpayer identification number, the holder of Existing
Notes may be subject to a penalty imposed by the Internal Revenue Service. In
addition, delivery of such holder's Exchange Notes may be subject to backup
withholding.
 
     Certain holders of Existing Notes (including, among others, all
corporations and certain foreign individuals) are not subject to these backup
withholding and reporting requirements. Exempt holders of Existing Notes should
indicate their exempt status on Substitute Form W-9. A foreign individual may
qualify as an exempt recipient by submitting to the Exchange Agent a properly
completed Internal Revenue Service Form W-8 (which the Exchange Agent will
provide upon request) signed under penalty of perjury, attesting to the holder's
exempt status. See the enclosed Guidelines for Certification of Taxpayer
Identification Number on Substitute Form W-9 for additional instructions.
 
     If backup withholding applies, the Company is required to withhold 31% of
any payment made to the holder of Existing Notes or other payee. Backup
withholding is not an additional federal income tax. Rather, the federal income
tax liability of persons subject to backup withholding will be reduced by the
amount of tax withheld. If withholding results in an overpayment of taxes, a
refund may be obtained from the Internal Revenue Service.
 
SUBSTITUTE FORM W-9; TAXPAYER IDENTIFICATION NUMBER
 
     To prevent backup withholding on payments that are made with respect to
Existing Notes exchanged in the Exchange Offer, each holder of Existing Notes is
required to provide the Exchange Agent with either (i) the holder's correct TIN
by completing the form above, certifying that the TIN provided on Substitute
Form W-9 is correct (or that such holder of Existing Notes is awaiting a TIN)
and that (A) the holder of Existing Notes has not been notified by the Internal
Revenue Service that he or she is subject to backup withholding as a result of a
failure to report all interest or dividends or (B) the Internal Revenue Service
has notified the holder of Existing Notes that he or she is no longer subject to
backup withholding; or (ii) an adequate basis for exemption (for example, in the
case of a Canadian resident holder, by submitting a completed Form W-8).
 
     The holder of Existing Notes is required to give the Exchange Agent the TIN
(e.g., social security number or employer identification number) of the record
owner of the Existing Notes. If the Existing Notes are held in more than one
name or are not held in the name of the actual owner, consult the enclosed
Guidelines for Certification of Taxpayer Identification Number on Substitute
Form W-9 for additional guidance regarding which number to report.
 
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