<PAGE>   1
                                                                   EXHIBIT 10.22


                                 PROMISSORY NOTE

$_____________                     Houston, Texas                 March 5, 2001


         FOR VALUE RECEIVED, the undersigned, EARTHCARE RESOURCE MANAGEMENT OF
SOUTH FLORIDA, INC., a Florida corporation, and EARTHCARE ACQUISITION SUB, INC.,
an Illinois corporation, hereby promises to pay to the order of DON A. SANDERS
("Lender") the principal sum of ___________ Dollars ($________), with interest
on the unpaid balance thereof from the date hereof until maturity at the rate of
twelve percent (12%) per annum, both principal and interest payable as
hereinafter provided in lawful money of the United States of America at 600
Travis Street, Suite 3100, Houston, Texas , or at such other place within Harris
County, Texas as from time to time may be designated by the holder of this Note.

         All past due principal and/or interest or installments thereof shall
bear interest at the rate of eighteen percent (18%) per annum.

         All principal and interest shall be due and payable on the first to
occur of (1) April 30, 2001, or (2) the later to occur of the sale by EarthCare
Company, a Delaware corporation of its EarthLiquid division and its EarthAmerica
division (as defined in the Loan Agreement (as hereinafter defined)).

         This Note is one of a duly authorized issue of Notes of the Company
(which term includes any successor corporation under the Loan Agreement
hereinafter referred to) in aggregate principal amount to $2,500,000, issued
pursuant to a Letter Loan Agreement dated as of March 5, 2001 (the "Loan
Agreement"), among the undersigned, EarthCare Company, a Delaware corporation,
and Lender. The terms of this Note include those stated in the Loan Agreement.
Reference is hereby made to the Loan Agreement and all supplements thereto for a
statement of the respective rights, limitations of rights, duties and immunities
thereunder of the Company and Lender and of the terms upon which the Notes are,
and are to be, and delivered.

         This Note is secured by a Security Agreement (the "Security Agreement")
of even date herewith from the undersigned to Lender evidencing a security
interest in certain personal property described therein. Upon the failure to pay
any installment of the principal of or interest on this Note as above promised,
or upon the occurrence of a default under the Security Agreement, the holder of
this Note or any part thereof shall have the option of declaring the principal
balance hereof and the interest accrued hereon to be immediately due and
payable.

         The undersigned shall have the right to prepay, without penalty, at any
time and from time to time prior to maturity, all or any part of the unpaid
principal balance of this Note and/or all or any part of the unpaid interest
accrued to the date of such prepayment, provided that any such principal thus
paid is accompanied by accrued interest on such principal.

         It is the intent of the payee of this Note and the undersigned in the
execution of this Note and all other instruments now or hereafter securing this
Note to contract in strict compliance with applicable usury law. In furtherance
thereof, the said payee and the undersigned stipulate and agree





                                       1
<PAGE>   2

that none of the terms and provisions contained in this Note, or in any other
instrument executed in connection herewith, shall ever be construed to create a
contract to pay for the use, forbearance or detention of money, interest at a
rate in excess of the maximum interest rate permitted to be charged by
applicable law; that neither the undersigned nor any guarantors, endorsers or
other parties now or hereafter becoming liable for payment of this Note shall
ever be obligated or required to pay interest on this Note at a rate in excess
of the maximum interest that may be lawfully charged under applicable law; and
that the provisions of this paragraph shall control over all other provisions of
this Note and any other instruments now or hereafter executed in connection
herewith which may be in apparent conflict herewith. The holder of this Note
expressly disavows any intention to charge or collect excessive unearned
interest or finance charges in the event the maturity of this Note is
accelerated. If the maturity of this Note shall be accelerated for any reason or
if the principal of this Note is paid prior to the end of the term of this Note,
and as a result thereof the interest received for the actual period of existence
of the loan evidenced by this Note exceeds the applicable maximum lawful rate,
the holder of this Note shall, at its option, either refund to the undersigned
the amount of such excess or credit the amount of such excess against the
principal balance of this Note then outstanding and thereby shall render
inapplicable any and all penalties of any kind provided by applicable law as a
result of such excess interest. In the event that the said payee or any other
holder of this Note shall contract for, charge or receive any amount or amounts
and/or any other thing of value which are determined to constitute interest
which would increase the effective interest rate on this Note to a rate in
excess of that permitted to be charged by applicable law, an amount equal to
interest in excess of the lawful rate shall, upon such determination, at the
option of the holder of this Note, be either immediately returned to the
undersigned or credited against the principal balance of this Note then
outstanding, in which event any and all penalties of any kind under applicable
law as a result of such excess interest shall be inapplicable. By execution of
this Note the undersigned acknowledges that it believes the loan evidenced by
this Note to be non-usurious and agrees that if, at any time, the undersigned
should have reason to believe that such loan is in fact usurious, it will give
the holder of this Note notice of such condition and the undersigned agrees that
said holder shall have ninety (90) days in which to make appropriate refund or
other adjustment in order to correct such condition if in fact such exists. The
term "applicable law" as used in this Note shall mean the laws of the State of
Texas or the laws of the United States, whichever laws allow the greater rate of
interest, as such laws now exist or may be changed or amended or come into
effect in the future.

         Should the indebtedness represented by this Note or any part thereof be
collected at law or in equity or through any bankruptcy, receivership, probate
or other court proceedings or if this Note is placed in the hands of attorneys
for collection after default, the undersigned and all endorsers, guarantors and
sureties of this Note jointly and severally agree to pay to the holder of this
Note in addition to the principal and interest due and payable hereon all the
costs and expenses of said holder in enforcing this Note including, without
limitation, reasonable attorneys' fees and legal expenses.

         The undersigned and all endorsers, guarantors and sureties of this Note
and all other persons liable or to become liable on this Note severally waive
presentment for payment, demand, notice of demand and of dishonor and nonpayment
of this Note, notice of intention to accelerate the maturity of this Note,
protest and notice of protest, diligence in collecting, and the bringing of suit
against any other party, and agree to all renewals, extensions, modifications,
partial payments, releases or substitutions of security, in whole or in part,
with or without notice, before or after maturity.



                                       2
<PAGE>   3



         THIS NOTE AND THE RIGHTS AND DUTIES OF THE PARTIES HEREUNDER SHALL BE
GOVERNED FOR ALL PURPOSES BY THE LAW OF THE STATE OF TEXAS AND THE LAW OF THE
UNITED STATES APPLICABLE TO TRANSACTIONS WITHIN SUCH STATE.

                                  EARTHCARE RESOURCE MANAGEMENT
                                  OF SOUTH FLORIDA, INC.


                                  By:
                                      ----------------------------------
                                  Name: William W. Solomon, Jr.
                                  Title: Chief Financial Officer


                                  EARTHCARE ACQUISITION SUB, INC.


                                  By:
                                      ----------------------------------
                                  Name: Williams W. Solomon, Jr.
                                  Title: Chief Financial Officer


                                       3