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                                 Promissory Note



Date December 14, 1999 [x] New [] Renewal Amount $5,000,000.00 Maturity Date
June 30, 2001

Bank:

Bank of America, N.A.
Banking Center:

Mid-Atlantic Commercial
1070 W. Patrick Street
Frederick, Maryland 21702

County: Frederick



Borrower:

Total Containment, Inc.,
TCI Environment NV/SA,
Rene Morin, Inc. and
American Containment, Inc.
A130 North Drive
Oaks, Pennsylvania 19456

County: ___________________




FOR VALUE RECEIVED, the undersigned Borrower unconditionally (and jointly and
severally, if more than one) promises to pay to the order of Bank, its
successors and assigns, without setoff, at its offices indicated at the
beginning of this Note, or at such other place as may be designated by Bank, the
principal amount of Five Million and 00/100 Dollars ($5,000,000.00), or so much
thereof as may be advanced from time to time in immediately available funds,
together with interest computed daily on the outstanding principal balance
hereunder, at an annua1 interest rate, and in accordance with the payment
schedule, indicated below.

[This Note contains some provisions preceded by boxes. If a box is marked, the
provision applies to this transaction; if it is not marked, the provision does
not apply to this transaction.]

1. Rate.

     Eurodollar Daily Floating Rate. The Rate shall be the Eurodollar Daily
Floating Rate plus 1.50 percent, per annum. The "Eurodollar Daily Floating Rate"
is a fluctuating rate of interest equal to the one month rate of interest
(rounded upwards, if necessary to the nearest 1/100 of 1%) appearing on Telerate
Page 3750 (or any successor page) as the one month London interbank offered rate
for deposits in Dollars at approximately 11:00 a.m. (London time) on the second
preceding business day, as adjusted from time to time in Bank's sole discretion
for then-applicable reserve requirements, deposits insurance assessment rates
and other regulatory costs. If for any reason such rate is not available, the
term "Eurodollar Daily Floating Rate" shall mean the fluctuating rate of
interest equal to the one month rate of interest (rounded upwards, if necessary
to the nearest 1/100 of 1%) appearing on Reuters Screen LIBO Page as the one
month London interbank offered rate for deposits in Dollars at approximately
11:00 a.m. (London time) on the second preceding business day, as adjusted from
time to time in Bank's sole discretion for then-applicable reserve requirements,
deposits insurance assessment rates and other regulatory costs; provided,
however, if more than one rate is specified on Reuters Screen LIBO page, the
applicable rate shall be the arithmetic mean of all such rates.

Notwithstanding any provision of this. Note, Bank does not intend to charge and
Borrower shall not be required to pay any amount of interest or other charges in
excess of the maximum permitted by the applicable law of the State of Maryland;
if any higher rate ceiling is (lawful, then that higher rate ceiling shall
apply. Any payment in excess of such maximum shall be refunded to Borrower or
credited against principal, at the option of Bank.

2. Accrual Method. Unless otherwise indicated, interest at the Rate set forth
above will be calculated by the 365/360 day method (a daily amount of intereat
is computed for a hypothetical year of 360 days; that amount is multiplied by
the actual number of days for which any principal is outstanding hereunder). If
interest is not to be computed using this method, the method shall be: N/A.

3. Rate Change Date. Any Rate based on a fluctuating index or base rate will
change, unless otherwise provided, each time and as of the date that the index
or base rate changes. If the Rate is to change on any other date or at any other
interval, the change shall be: N/A. In the event any index is discontinued, Bank
shall substitute an index determined by Bank to be comparable, in its sole
discretion.

4. Payment Schedule. All payments received hereunder shall be applied first to
the payment of any expense or charges payable hereunder or under any other loan
documents executed in connection with this Note, then to interest due and
payable, with the balance applied to principal, or in such other order as Bank
shall determine at its option.

Single Principal Payment. Principal shall be paid in full in a single payment on
June 30, 2001. Interest thereon shall be paid monthly, commencing on January 31,
2000, and continuing on the last day of each successive month, quarter or other
period (as applicable) thereafter, with a final payment of all unpaid interest
at the stated maturity of this Note.

5. Revolving Feature.

[X] Borrower may borrow, repay and reborrow hereunder at any time, up to a
maximum aggregate amount outstanding at any one time equal to the principal
amount of this Note, provided, that Borrower is not in default under any
provision of this Note, any other documents executed in connection with the
Note, or any other note or other loan documents now or hereafter executed in
connection with any other obligation of Borrower to Bank, and provided that the
borrowings hereunder do not exceed any borrowing base or other limitation on
borrowings by Borrower. Bank shall incur no liability for its refusal to advance
funds based upon its determination that any conditions of such further advances
have not been met. Bank records of the amounts borrowed from time to time shall
be conclusive proof thereof.

     [] Uncommited Facility. Borrower acknowledges and agrees that,
     notwithstanding any provisions of this Note or any other documents executed
     in connection with this Note, Bank has no obligation to make any advance,
     and that all advances are at the sole discretion of Bank.

<PAGE>

     [] Out-Of-Debt Period. For a period of at least _ consecutive days during
     [] each fiscal year, [] any consecutive 12-month period, Borrower shall
     fully pay down the balance of this Note, so that no amount of principal or
     interest and no other obligation under this Note remains outstanding.

6. Automatic Payment.

     [] Borrower has elected to authorize Bank to effect payment of sums due
     under this Note by means of debiting Borrower's account number __________ .
     This authorization shall not affect the obligation of Borrower to pay such
     sums when due, without notice, if there are insufficient funds in such
     account to make such payment in full on the due date thereof, or if Bank
     fails to debit the account.

7. Waivers, Consents and Covenants. Borrower, any indorser, or guarantor hereof
or any other party hereto (individually an "Obligor" and collectively
"Obligors") and each of them jointly and severally: (a) waive presentment,
demand, protest, notice of demand, notice of intent to accelerate, notice of
acceleration of maturity, notice of protest, notice of nonpayment, notice of
dishonor, and any other notice required to be given under the law to any Obligor
in connection with the delivery, acceptance, performance, default or enforcement
of this Note, any indorsement or guaranty of this Note, or any other documents
executed in connection with this Note or any other note or other loan documents
now or hereafter executed in connection with any obligation of Borrower to Bank
(the "Loan Documents"); (b) consent to all delays, extensions, renewals or other
modifications of this Note or the Loan Documents, or waivers of any term hereof
or of the Loan Documents, or release or discharge by Bank of any of Obligors, or
release, substitution or exchange of any security for the payment hereof, or the
failure to act on the part of Bank, or any indulgence shown by Bank (without
notice to or further assent from any of Obligors), and agree that no such
action, failure to act or failure to exercise ally right or remedy by Bank shall
in any way affect or impair the obligations of any Obligors or be construed as a
waive, by Bank of, or otherwise affect, any of Bank's rights under this Note,
under any indorsement or guaranty of this Note or under any of the Loan
Documents; and (c) agree to pay, on demand, all costs and expenses of collection
or defense of this Note or of any indorsement or guaranty hereof and/or the
enforcement or defense of Bank's rights with respect to, or the administration,
supervision, preservation, protection of, or realization upon, any property
securing payment hereof, including, without limitation, reasonable attorney's
fees, including fees related to any suit, mediation or arbitration proceeding,
out of court payment agreement, trial, appeal, bankruptcy proceedings or other
proceeding, In the amount of 15% of the principal amount of this Note, or such
greater amount as may be determined reasonable by any arbitrator or court,
whichever is applicable.

8. Prepayments. Prepayments may be made in whole or in part at any time on any
loan for which the Rate is based on the Prime Rate or on any other fluctuating
Rate or Index which may change daily. All prepayments of principal shall be
applied in the inverse order of maturity, or in such other order as Bank shell
determine in its sole discretion. No prepayment of any other loan shall be
permitted without the prior written consent of Bank. Notwithstanding such
prohibition, if there is a prepayment of any such loan, whether by consent of
Bank, or because of acceleration or otherwise, Borrower shall, within 15 days of
any request by Bank, pay to Bank any loss or expense which Bank may incur or
sustain as a result of such prepayment. For the purposes of calculating the
amounts owed only, it shall be assumed that Bank actually funded or committed to
fund the loan through the purchase of an underlying deposit in an amount and for
a term comparable to the loan, and such determination by Bank shall be
conclusive, absent a manifest error In computation.

9. Delinquency Charge. To the extent permitted by law, a delinquency charge may
be imposed in an amount not to exceed four percent (4%) of any payment that is
more than fifteen days late.

10. Events of Default. The following are events of default hereunder: (a) the
failure to pay or perform any obligation, liability or indebtedness of any
Obligor to Bank, or to any affiliate or subsidiary of Bank of America
Corporation, whether under this Note or any Loan Documents, as and when due
(whether upon demand, at maturity or by acceleration); (b) the failure to pay or
perform any other obligation, liability or indebtedness of any Obligor to any
other party which failure has a material adverse effect on Obligor; (c) the
death of any Obligor (if an individual), (d) the resignation or withdrawal of
any partner or a material Owner/Guarantor of Borrower, as determined by Bank in
________________ its sole discretion; (a) the commencement of a proceeding
against any Obligor for dissolution or liquidation, the voluntary or involuntary
termination or dissolution of any Obligor or the merger or consolidation of any
Obligor with or into another entity, (f) the insolvency of, the business failure
of, the appointment of a custodian, trustee, liquidator or receiver for or for
any of the property of, the assignment for the benefit of creditors by, or the
filing of a petition under bankruptcy, insolvency or debtor's relief law or the
filing of a petition for any adjustment of indebtedness, composition or
extension by or against any Obligor and if against, not dismissed within 60
days; (g) the determination by Bank that any representation or warranty made to
Bank by any Obligor in any Loan Documents or otherwise is or was, when it was
made, untrue in any material respect or materially misleading; (h) the failure
of any Obligor to timely deliver such financial statements, including tax
returns, other statements of condition or other information, as Bank shall
request from time to time; (i) the entry of a judgment a against any Obligor
which Bank deems to be of a material nature, in Bank's sole discretion; (j) the
seizure or forfeiture of or the issuance of any writ of possession, garnishment
or attachment, or any turnover order for any property of any Obligor in excess
of $50,000; (l) the determination by Bank that a material adverse change has
occurred in the financial condition of any Obligor; or (m) the failure of
Borrower's business to comply with any law or regulation ontrolling its
operation.

11. Remedies upon Default. Whe never there is a default, which has not been
remedied after five (5) days notice has been given by the Bank, under this Note
(a) the entire balance outstanding hereunder and all other obligations of any
Obligor to Bank (however acquired or evidenced) shall, at the option of Bank,
become immediately due and payable and any obligation of Bank to permit further
borrowing under this Note shall immediately cease and terminate, and/or (b) to
the extent permitted by law, the Rate of interest on the unpaid principal shall
be increased at Bank's discretion up to the maximum rate allowed by law, or if
none, 15% per annum (the "Default Rate"). The provisions herein for a Default
Rate shall not be deemed to extend the time for any payment hereunder or to
constitute a "grace period" giving Obligors a right to cure any default. At
Bank's option, any accrued and unpaid interest, fees or charges may, for
purposes of computing and accruing interest on a daily basis after the due date
of the Note or any installment thereof, be deemed to be a part of the principal
balance, and interest shall accrue on a daily compounded basis after such date
at the Default Rate provided in this Note until the entire outstanding balance
of principal and interest is paid in full. Bank is hereby authorized at any time
to set off and charge against any deposit accounts of any Obligor, as well as
any money, instruments, securities, documents, chattel paper, credits, claims,
demands, income and any other property, rights and interests of any Obligor
which at any time shall come into the possession or custody or under the control
of Bank or any of its agents, affiliates or correspondents, without notice or
demand, any and all obligations due hereunder. Additionally, Bank shall have all
rights and remedies available under each of the Loan Documents, as well as
rights and remedies available at law or in equity.


DEBTOR AUTHORIZES ANY ATTORNEY ADMITTED TO PRACTICE BEFORE ANY COURT OF RECORD
IN THE UNITED STATES TO APPEAR ON BEHALF OF DEBTOR IN ANY COURT IN ONE OR MORE
PROCEEDINGS, OR BEFORE ANY CLERK THEREOF OR PROTHONOTARY OR OTHER COURT
OFFICIAL, AND TO CONFESS JUDGMENT AGAINST

<PAGE>

DEBTOR IN FAVOR OF THE HOLDER 0F THIS AGREEMENT IN THE FULL, AMOUNT DUE UNDER
THIS AGREEMENT (INCLUDING PRINCIPAL, ACCRUED INTEREST AND ANY AND ALL CHARGES,
FEES AND COSTS) PLUS ATTORNEYS' FEES EQUAL TO FIFTEEN PERCENT (15%) OF THE
AMOUNT DUE. PLUS COURT COSTS, ALL WITHOUT PRIOR NOTICE OR OPPORTUNITY OF DEBTOR
FOR PRIOR HEARING. DEBTOR AGREES AND CONSENTS THAT VENUE AND JURISDICTION SHALL
BE PROPER IN THE CIRCUIT COURT OF ANY COUNTY OF THE STATE OF MARYLAND OR OF
BALTIMORE CITY, MARYLAND, OR IN THE UNITED STATES DISTRICT COURT FOR THE
DISTRICT OF MARYLAND. DEBTOR WAIVES THE BENEFIT OF ANY AND EVERY STATUTE,
ORDINANCE, OR RULE OF COURT WHICH MAY BE LAWFULLY WAIVED CONFERRING UPON DEBTOR
ANY RIGHT OR PRIVILEGE OF EXEMPTION, HOMESTEAD RIGHTS, STAY OF EXECUTION, OR
SUPPLEMENTARY PROCEEDINGS, OR OTHER RELIEF FROM THE ENFORCEMENT OR IMMEDIATE
ENFORCEMENT OF A JUDGMENT OR RELATED PROCEEDINGS ON A JUDGMENT. THE AUTHORITY
AND POWER TO APPEAR FOR AND ENTER JUDGMENT AGAINST DEBTOR SHALL NOT BE EXHAUSTED
BY ONE OR MORE EXERCISES THEREOF, OR BY ANY IMPERFECT EXERCISE THEREOF, AND
SHALL NOT BE EXTINGUISHED BY ANY JUDGMENT ENTERED PURSUANT THERETO; SUCH
AUTHORITY AND POWER MAY BE EXERCISED ON ONE OR MORE OCCASIONS FROM TIME TO TIME,
IN THE SAME OR DIFFERENT JURISDICTIONS, AS OFTEN AS THE HOLDER SHALL DEEM
NECESSARY, CONVENIENT, OR PROPER.

12. Non-waiver. The failure at any time of Bank to exercise any of its options
or any other rights hereunder shall not constitute a waiver thereof, nor shall
it be a bar to the exercise of any of its options or rights at a later date. All
rights and remedies of Bank shall be cumulative and may be pursued singly,
successively or together, at the option of Bank. The acceptance by Bank of any
partial payment shall not constitute a waiver of any default or of any of Bank's
rights under this Note. No waiver of any of its rights hereunder, and no
modification or amendment of this Note, shall be deemed to be made by Bank
unless the same shall be in writing, duly signed on behalf of Bank; each such
waiver shall apply only with respect to the specific instance involved, and
shall in no way impair the rights of Bank or the obligations of Obligor to Bank
in any other respect at any other time.

13. Applicable Law, Venue and Jurisdiction. This Note and the rights and
obligations of Borrower and Bank shall be governed by and interpreted in
accordance with the law of the State of Maryland. In any litigation in
connection with or to enforce this Note or any indorsement or guaranty of this
Note or any Loan Documents, Obligors, and each of them, irrevocably consent to
and confer personal jurisdiction on the courts of the State of Maryland or the
United States located within the State of Maryland and expressly waive any
objections as to venue in any such courts. Nothing contained herein shall,
however, prevent Bank from bringing any action or exercising any rights within
any other state or jurisdiction or from obtaining personal jurisdiction by any
other means available under applicable law.

14. Partial Invalidity. The unenforceability or invalidity of any provision of
this Note shall not affect the enforceability or validity of any other provision
herein and the invalidity or unenforceability of any provision of this Note or
of the Loan Documents to any person or circumstance shall not affect the
enforceability or validity of such provision as it may apply to other persons or
circumstances.

15. Waiver of Jury Trial. Obligors waive trial by jury in any action or
proceeding to which Obligors and Bank may be parties, arising out of, in
connection with or in any way pertaining to, this Note or the Loan Documents. It
is agreed and understood that this waiver constitutes a waiver of trial by jury
of all claims against all parties to such action or proceedings, including
claims against parties who are not parties to this Note. This waiver is
knowingly, willingly and voluntarily made by Obligors.

16. Binding Effect. This Note shall be binding upon and inure to the benefit of
Borrower, Obligors and Bank and their respective successors, assigns, heirs and
personal representatives, provided, however, that no obligations of Borrower or
Obligors hereunder can be assigned without prior written consent of Bank.

17. Controlling Document. To the extent that this Note conflicts with or is in
any way incompatible with any other Loan Document concerning this obligation,
the Note shall control over any other document, and if the Note does not address
an issue, then each other document shall control to the extent that it deals
most specifically with an issue.

18. YEAR 2000 REPRESENTATIONS AND WARRANTIES.

     (A) Borrower has (i) begun analyzing the operations of Borrower and its
subsidiaries and affiliates that could be adversely affected by failure to
become Year 2000 compliant (that is, that computer applications, imbedded
microchips and other systems will be able to perform date-sensitive functions
prior to and after December 31, 1999) and; (ii) developed a plan for becoming
Year 2000 compliant in a timely manner, the implementation of which is on
schedule in all material respects. Borrower reasonably believes that it will
become Year 2000 compliant for its operations and those of its subsidiaries and
affiliates on a timely basis except to the extent that a failure to do so could
not reasonably be expected to have a material adverse effect upon the financial
condition of Borrower.

     (B) Borrower reasonably believes any suppliers and vendors that are
material to the operations of Borrower or its subsidiaries and affiliates will
be Year 2000 compliant for their own computer applications except to the extent
that a failure to do so could not reasonably be expected to have a material
adverse effect upon the financial condition of Borrower.

     (C) Borrower will promptly notify Bank in the event Borrower determines
that any computer application which is material to the operations of Borrowor,
its subsidiaries or any of its material vendors or suppliers will not be fully
Year 2000 compliant on a timely basis, except to the extent that such failure
could not reasonably be expected to have a material adverse effect upon the
financial condition of Borrower.

Borrower represents to Bank that the proceeds of this loan are to be used
primarily for business, commercial or agricultural purposes. Borrower
acknowledges having read and understood, and agrees to be bound by, all terms
and conditions of this Note, and hereby executes this Note intending to create
an instrument executed under seal.

<PAGE>

NOTICE OF FINAL AGREEMENT. THIS WRITTEN PROMISSORY NOTE REPRESENTS THE FINAL
AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
CONTEMPORANEOUS, OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO
UNWRITTEN ORAL AGREEMENTS.

                                   Corporate or Partnership Borrower

                                   Total Containment, Inc.

                                   By: /s/ Keith R. Ruck               (Seal)
                                       -------------------------------

                                   Name: Keith R. Ruck
                                         -----------------------------

                                   Title: Vice President Finance & CEO
                                          ----------------------------

                                   -----------------------------------
                                   Attest (If Applicable)

                                   [Corporate Seal]



                                   TCI Environment NV/SA


                                   By: /s/ Keith R. Ruck               (Seal)
                                       -------------------------------

                                   Name: Keith R. Ruck
                                         -----------------------------

                                   Title: Secretary
                                          ----------------------------

                                   -----------------------------------
                                   Attest (If Applicable)

                                   [Corporate Seal]



                                   Rene Morin, Inc.


                                   By: /s/ Keith R. Ruck               (Seal)
                                       -------------------------------

                                   Name: Keith R. Ruck
                                         -----------------------------

                                   Title: Secretary
                                          ----------------------------

                                   -----------------------------------
                                   Attest (If Applicable)

                                   [Corporate Seal]



                                   American Containment, Inc.


                                   By: /s/ Keith R. Ruck               (Seal)
                                       -------------------------------

                                   Name: Keith R. Ruck
                                         -----------------------------

                                   Title: Secretary
                                          ----------------------------

                                   -----------------------------------
                                   Attest (If Applicable)

                                   [Corporate Seal]