EXHIBIT 10.26

                           NOTE MODIFICATION AGREEMENT
                                       OF
                           FIRST RENEWAL AND EXTENSION
                                       OF
                                  INTEREST ONLY
                           NONRECOURSE PROMISSORY NOTE
                             AND SECURITY AGREEMENT

     THIS  AGREEMENT  made the 10th day of April, 2004 between H.E.R.C. PRODUCTS
                               ----        -----------
INCORPORATED, a Delaware corporation, with its principal office at 1420 Columbus
Avenue,  Portsmouth, Virginia 23704 (hereinafter referred to as the "Maker") and
R.  JOHN  ARMSTRONG, with his principal office address at 3975 University Drive,
Suite  400,  Fairfax, Virginia 22030 (hereinafter referred to as the "Holder" or
"Secured  Party").


                              W I T N E S S E T H:

     WHEREAS,  Holder  is  the  holder of that certain INTEREST ONLY NONRECOURSE
PROMISSORY  NOTE  AND SECURITY AGREEMENT, dated February 23, 2003, from Maker to
Holder,  evidencing  an  indebtedness  in  the  original  principal  amount  of
$400,000.00  as  secured  by  that  Security  Agreement  made  a  part  thereof
(hereinafter  referred  to  as  the  "Indebtedness");

     WHEREAS,  the due date of that certain INTEREST ONLY NONRECOURSE PROMISSORY
NOTE AND SECURITY AGREEMENT, dated February 23, 2003, for the original principal
indebtedness  of  Four  Hundred  Thousand  ($  400,000.00) Dollars with interest
thereon  was  first  extended  by  that  certain  FIRST RENEWAL AND EXTENSION OF
INTEREST ONLY NONRECOURSE PROMISSORY NOTE AND SECURITY AGREEMENT to February 23,
2005;  and

     WHEREAS,  the Maker and the Holder have mutually agreed to modify the terms
of  the  Indebtedness.

     NOW  THEREFORE,  in pursuance of said agreement and in consideration of the
sum  of  Ten  ($10.00) Dollars and other good and valuable consideration each to
the  other  in  hand  paid, receipt of which is hereby acknowledged, the parties
hereto  mutually  covenant  and  agree  that  the Indebtedness evidenced in that
certain  note and first renewal and extension in the total amount of $400,000.00
is  hereby  divided  equally so as to hereinafter constitute two notes each of a
principal  amount  of  $200,000.00  (hereinafter  referred  to  together  as the
"Notes"),  which  Notes  evidence  an  original  principal  indebtedness of Four
Hundred  Thousand  ($400,000.00)  Dollars.

     The terms of payment of the Indebtedness evidenced by that certain INTEREST
ONLY  NONRECOURSE  PROMISSORY  NOTE  AND  SECURITY AGREEMENT, dated February 23,
2003,  is  hereby  modified  and  extended,  and that note restated, as follows.

     FOR  VALUE  RECEIVED, the undersigned Maker promises to pay to the order of
Holder  at  his  principal office, or at such other place as the Holder may from
time to time designate in writing, the principal sum of the Indebtedness of FOUR
HUNDRED  THOUSAND  DOLLARS  ($  400,000.00)  payable  in  the  following manner:

     1.     Interest  only  at the rate of eight percent (8.0%) per annum on the
principal of TWO HUNDRED THOUSAND DOLLARS ($200,000.00) shall be due and payable
                                            ----------
on  the  first  day  of the first month after the date of this Note Modification
Agreement,  with  the  entire  unpaid  balance  of  the principal of TWO HUNDRED
THOUSAND  DOLLARS  ($200,000.00) with interest thereon to be paid in full on the
                     ----------
date  one  (1) year from the date of the FIRST EXTENSION AND RENEWAL OF INTEREST
      -------------
ONLY NONRECOURSE PROMISSORY NOTE AND SECURITY AGREEMENT, dated February 23, 2004
(hereinafter  referred  to  as "One Year Term Note"), on February 23, 2005. This
                                                         -----------------
One  Year Term Note is delivered and accepted not in payment but for the purpose
of  and  in consideration of the extension of time of payment of one half of the
original  Interest Only Nonrecourse Promissory Note and Security Agreement. This
Note  Modification  Agreement  incorporates  by  specific reference that certain
Interest Only Nonrecourse Promissory Note and Security Agreement, dated February
23,  2003,  by  and  between  its  Maker, H.E.R.C. Products Incorporated and its
Holder  and  Secured Party, R. John Armstrong, and specifically incorporates all
the  terms,  conditions  and  secured party interests stated therein as modified
hereby.


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     2.     Interest  only  at the rate of eight percent (8.0%) per annum on the
principal of TWO HUNDRED THOUSAND DOLLARS ($200,000.00) shall be due and payable
                                            ----------
on  the  first  day  of the first month after the date of this Note Modification
Agreement,  with  the  entire  unpaid  balance  of  the principal of TWO HUNDRED
THOUSAND  DOLLARS  ($200,000.00) with interest thereon to be paid in full on the
                     ----------
date  three  (3)  years  from  the  date  of  the FIRST EXTENSION AND RENEWAL OF
      -----------------
INTEREST ONLY NONRECOURSE PROMISSORY NOTE AND SECURITY AGREEMENT, dated February
     --
23,  2004  (hereinafter  referred to as "Three Year Term Note"), on February 23,
                                                                    ------------
2007. This Three Year Term Note is delivered and accepted not in payment but for
 ---
the  purpose  of and in consideration of the extension of time of payment of one
half  of  the  original  Interest  Only Nonrecourse Promissory Note and Security
Agreement.  This  Note Modification Agreement incorporates by specific reference
that  certain  Interest Only Nonrecourse Promissory Note and Security Agreement,
dated  February  23,  2003,  by  and  between  its  Maker,  H.E.R.C.  Products
Incorporated  and  its  Holder  and  Secured  Party,  R.  John  Armstrong,  and
specifically  incorporates all the terms, conditions and secured party interests
stated  therein  as  modified  hereby.

     It is hereby expressly agreed that should any default be made in payment of
any  of  the  principal and interest on the One Year Term Note or the Three Year
Term  Note  on  any day whereon the same, or either of them, is payable as above
expressed,  or  in  the performance or observance of any of the other covenants,
terms or conditions of the Security Agreement or of any other instruments now or
hereafter  securing  these  Notes,  the  balance  of  said  principal  sum  of
Indebtedness,  with  all arrearages of interest thereon, shall, at the option of
the  Holder  of these Notes, become and be due and payable immediately, anything
contained to the contrary thereof in any ways notwithstanding, time being of the
essence.

     By  its  acceptance  hereof,  Holder,  for  himself  and his successors and
assigns,  as  the  owner  and  holder hereof, agrees that no judgment, order, or
execution entered in any suit, action, or proceeding, either legal or equitable,
hereon  or  on  the  Security Agreement shall be enforced personally against the
undersigned  duly authorized corporate officer or against any officer, director,
stockholder,  partner,  or  principal,  disclosed  or  undisclosed,  of  the
undersigned,  for  the purpose of obtaining satisfaction and payment of the debt
evidenced  hereby;  provided, however, that nothing herein contained shall limit
or  be  construed  to  limit  or  impair  the  enforcement  against the property
encumbered  by  the  Security Agreement of the rights and remedies of Holder and
his successors and assigns created under these Notes, the Security Agreement, or
under  any  other  instrument  executed  in  connection  with this Indebtedness.

This  Note  shall  be  construed according to the laws of the State of Virginia.

     IN  WITNESS  WHEREOF, the parties hereto have caused their names signed and
seals  affixed  hereto  as  of  the  day  and  year  first  written  above.

MAKER:  H.E.R.C.  Products  Incorporated
        --------------------------------


   /s/  S.  Steven  Carl
------------------------
S.  Steven  Carl,  Chief  Executive  Officer


HOLDER:  R.  John  Armstrong
         -------------------

   /s/  R.  John  Armstrong
---------------------------
R.  John  Armstrong


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