<PAGE>   1
          As Filed with the Securities and Exchange Commission on April 14, 2000
                                                           Registration No. 333-
--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D. C. 20549
                            -------------------------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                           --------------------------

                                ELECTROPURE, INC.
             (Exact name of Registrant as specified in its charter)

              CALIFORNIA
     (State of Other Jurisdiction                      33-0065212
  or Incorporation of Organization)        (I.R.S. Employer Identification No.)

               23456 South Pointe, Laguna Hills, California 92653
                                 (949) 770-9347
          (Address and telephone number of principal executive offices)
                           --------------------------

                    Electropure, Inc. 1999 Stock Option Plan
                            (Full title of the plan)
                           --------------------------


                           FLOYD H. PANNING, President
                                ELECTROPURE, INC.
                               23456 South Pointe
                         Laguna Hills, California 92653
                                 (949) 770-9347
      (Name, address and telephone number of Agent for service of process)
                            --------------------------

                          Copies of communications to:
                             Ronald P. Givner, Esq.
                    SKADDEN, ARPS, SLATE, MEAGHER & FLOM, LLP
                       300 South Grand Avenue, 34th Floor
                          Los Angeles, California 90071
                                 (213) 687-5329
--------------------------------------------------------------------------------


<PAGE>   2

                         CALCULATION OF REGISTRATION FEE

<TABLE>
<CAPTION>
                                        Proposed      Proposed
                                        Maximum       Maximum        Amount of
Title of Securities   Amount to be      Offering     Aggregate     Registration
 to be Registered      Registered      Price Per      Offering          Fee
                                      Share(1)(2)      Price
--------------------------------------------------------------------------------
<S>                   <C>            <C>            <C>            <C>
Class A Common Stock,
par value $0.01       1,000,000 (3)      $1.25      $1,250,000.00     $368.77
  per share
</TABLE>

----------


(1)     Calculated pursuant to Rules 457(c) and (h) under the Securities Act of
        1933, as amended (the "Securities Act"), based on the closing sale price
        as reported on the Electronic Bulletin Board on March 28, 2000.

(2)     Estimated solely for the purpose of calculating the registration fee.

(3)     Pursuant to Rule 416(c) under the Securities Act, this registration
        statement also covers an indeterminate number of additional shares of
        Class A Common Stock that may become issuable pursuant to the
        antidilution provisions of the Plan.

================================================================================


                                      II-1
<PAGE>   3

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

        The document(s) containing the information specified in Part I of the
Form S-8 have been or will be sent or given to employees as specified by Rule
428(b)(1) under the Securities Act of 1933, as amended (the "Securities Act").


                                     PART II


               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

        The following documents previously filed with the Securities and
Exchange Commission (the "Commission") by Electropure, Inc. ("ELECTROPURE"),
pursuant to the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), are incorporated by reference in this registration statement.

(1)     Electropure's Annual Report on Form 10-KSB for the year ended October
        31, 1999; and

(2)     The description of the Class A Common Stock contained in Electropure's
        Registration Statement on Form S-1 (File No. 33-10669) filed on December
        15, 1986, including any amendment or report filed for the purpose of
        updating such information.

        All documents subsequently filed by Electropure pursuant to Sections
13(a), 13(c)14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which deregisters all securities then remaining unsold, shall be deemed
to be incorporated by reference herein and to be a part hereof from the date of
filing of such documents. Any statement contained in a document incorporated or
deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this registration statement to the extent that a
statement contained herein or in any other subsequently filed document which
also is incorporated or deemed to be incorporated by reference herein modifies
or supersedes such statement. Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
registration statement.

ITEM 4. DESCRIPTION OF SECURITIES.

        Not Applicable.

ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.

        Not Applicable.


                                      II-2
<PAGE>   4

ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

        Electropure's Charter limits the liability of Electropure's directors
and officers to Electropure and its stockholders to the fullest extent permitted
from time to time by California law. California law presently permits the
liability of directors and officers to a corporation or its stockholders for
money damages to be limited, except (i) to the extent that it is proved that the
director or officer actually received an improper benefit or profit in money,
property or services for the amount of the benefit or profit in money, property
or services actually received, or (ii) if a judgment or other final adjudication
is entered in a proceeding based on a finding that the director's or officer's
action, or failure to act, was the result of active and deliberate dishonesty
and was material to the cause of action adjudicated in the proceeding. This
provision does not limit the ability of Electropure or its stockholders to
obtain other relief, such as an injunction or recission.

        Electropure's Charter and Bylaws require Electropure to indemnify its
directors, officers and certain other parties to the fullest extent permitted
from time to time by California law. The California General Corporation Law
permits a corporation to indemnify its directors, officers and certain other
parties against judgments, penalties, fines, settlements and reasonable expenses
actually incurred by them in connection with any proceeding to which they may be
made a party by reason of their service to or at the request of the corporation,
unless it is established that (i) the act or omission of the indemnified party
was material to the matter giving rise to the proceeding and (x) was committed
in bad faith or (y) was the result of active and deliberate dishonesty, (ii) the
indemnified party actually received an improper personal benefit in money,
property or services or (iii) in the case of any criminal proceeding, the
indemnified party had reasonable cause to believe that the act or omission was
unlawful. Indemnification may be made against judgments, penalties, fines,
settlements and reasonable expenses actually incurred by the director or officer
in connection with the proceeding; provided however, that if the proceeding is
one by or in the right of the corporation, indemnification may not be made with
respect to any proceeding in which the director or officer has been adjudged to
be liable to the corporation. In addition, a director or officer may not be
indemnified with respect to any proceeding charging improper personal benefit to
the director or officer in which the director or officer was adjudged to be
liable on the basis that personal benefit was improperly received. The
termination of any proceeding by conviction, or upon a plea of nolo contendere
or its equivalent, or an entry of any order of probation prior to judgment,
creates a rebuttable presumption that the director or officer did not meet the
requisite standard or conduct required for indemnification to be permitted. It
is the position of the Securities and Exchange Commission that indemnification
of directors and officers for liabilities arising under the Securities Act is
against public policy and is unenforceable pursuant to Section 14 of the
Securities Act.

        Electropure has entered into agreements with certain of its officers and
directors, pursuant to which Electropure has agreed to indemnify such officers
and directors to the fullest extent permitted by applicable law.

        Section 8.6 of the 1999 Stock Option Plan of Electropure, Inc. (the
"Plan"), specifically provides that, to the fullest extent permitted by law,
each of the members of the Board of Directors of Electropure (the "Board"), the
Administrator of the Plan and each of the directors, officers and employees of
Electropure, and any successor of Electropure shall be held harmless


                                      II-3
<PAGE>   5

and indemnified by Electropure for any liability, loss (including amounts paid
in settlement), damages or expenses (including reasonable attorney's fees)
suffered by virtue of any determinations, acts or failures to act, or alleged
acts or failures to act, in connection with the administration of the 1999 Plan
so long as such person is not determined by a final adjudication to be guilty of
willful misconduct with respect to such determination, action or failure to act.

ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.

        Not Applicable.

ITEM 8. EXHIBITS.

        4.1     Specimen certificate for Class A Common Stock (incorporated by
                reference from Electropure's registration statement on Form S-1
                filed on December 15, 1986)

        5.1     Opinion of Skadden, Arps, Slate, Meagher & Flom, L.L.P.
                regarding the validity of the Securities offered hereby.

        23.1    Consent of Kelly & Company.

        23.2    Consent of Skadden, Arps, Slate, Meagher & Flom, L.L.P.
                (included in its opinion filed as Exhibit 5.1).

        24.1    Power of Attorney (included on page II-6).

ITEM 9. UNDERTAKINGS.

               a. The undersigned registrant hereby undertakes:

                      (1) To file, during any period in which offers or sales
are being made, a post-effective amendment to this registration statement and to
include any prospectus required by Section 10(a)(3) of the Securities Act; to
include any material information with respect to the plan of distribution not
previously disclosed in the registration statement or any material change to
such information in the registration statement;

                      (2) That, for the purpose of determining any liability
under the Securities Act, each such post-effective amendment shall be deemed to
be a new registration statement relating to the securities offered therein, and
the offering of such securities at that time shall be deemed to be the initial
bona fide offering thereof.

                      (3) To remove from registration by means of a
post-effective amendment any of the securities being registered which remain
unsold at the termination of the offering.

               b. The undersigned registrant hereby undertakes that, for
purposes of determining any liability under the Securities Act, each filing of
the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act, (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in the registration statement shall be deemed to be a
new


                                      II-4
<PAGE>   6

registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

               c. Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the registrant of expenses incurred
or paid by a director, officer or controlling person of the registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.


                                      II-5
<PAGE>   7

                                   SIGNATURES

        Pursuant to the requirements of the Securities Act, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Laguna Hills, State of California, on this 28th day
of March, 2000.

                                      ELECTROPURE, INC.

                                      By /S/ CATHERINE PATTERSON
                                        ----------------------------------------
                                      Name: Catherine Patterson
                                      Title: Chief Financial Officer


                                POWER OF ATTORNEY

        KNOWN TO ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Catherine Patterson and Floyd H. Panning,
jointly and severally, his attorneys-in-fact, each with the power of
substitution, for him in any and all capacities, to sign any amendments to this
registration statement (including post-effective amendments), and to file the
same, with exhibits thereto and other documents in connection therewith, with
the Securities and Exchange Commission, hereby ratifying and confirming all that
each of said attorneys-in-fact, or his substitute or substitutes, may do or
cause to be done by virtue hereof.

        Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
date indicated.


<TABLE>
<S>                                              <C>                         <C>
/S/  WILLIAM F. FARNAM                                Director               March 28, 2000
------------------------------------------
WILLIAM F. FARNAM

                                                      Director
------------------------------------------
RANDALL P. FRANK

/S/  RANDOLPH S. HEIDMANN                             Director               March 28, 2000
------------------------------------------
RANDOLPH S. HEIDMANN

/S/  ARTHUR LIPPER III                                Director               March 28, 2000
------------------------------------------
ARTHUR LIPPER III

/F/  FLOYD H. PANNING                          Chief Executive Officer       March 28, 2000
------------------------------------------          and Director
FLOYD H. PANNING

/S/  CATHERINE PATTERSON                           Chief Financial           March 28, 2000
                                                 Officer (Principal
                                                    Financial and
------------------------------------------       Accounting Officer)
CATHERINE PATTERSON
</TABLE>


                                      II-6
<PAGE>   8

                                  EXHIBIT INDEX


<TABLE>
<CAPTION>
Exhibit No.    Description of Exhibit
-----------    ----------------------
<S>            <C>
        4.1    Specimen certificate for Class A Common Stock (incorporated by
               reference from Electropure's registration statement on Form S-1
               filed on December 15, 1986).

        5.1    Opinion of Skadden, Arps, Slate, Meagher & Flom, L.L.P. regarding
               the validity of the Securities offered hereby.

        23.1   Consent of Kelly & Company.

        23.2   Consent of Skadden, Arps, Slate, Meagher & Flom, L.L.P. (included
               in its opinion filed as Exhibit 5.1).

        24.1   Power of Attorney (included on page II-6).
</TABLE>
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 17705}]
{"company-data": {"conformed-name": "ELECTROPURE INC", "cik": "0000808015", "assigned-sic": "6794", "irs-number": "330056212", "state-of-incorporation": "CA", "fiscal-year-end": "1031"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-34858", "film-number": "602355"}, "business-address": {"street1": "23456 S POINTE DR", "city": "LAGUNA HILLS", "state": "CA", "zip": "92653-1512", "phone": "9497709347"}, "mail-address": {"street1": "23456 S POINTE DR", "street2": "SUITE A", "city": "LAGUNA HILLS", "state": "CA", "zip": "92653"}, "former-company": {"former-conformed-name": "HOH WATER TECHNOLOGY CORP", "date-changed": "19920703"}}
1
          As Filed with the Securities and Exchange Commission on April 14, 2000
                                                           Registration No. 333-
--------------------------------------------------------------------------------

                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D. C. 20549
                            -------------------------

                                    FORM S-8

                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                           --------------------------

                                ELECTROPURE, INC.
             (Exact name of Registrant as specified in its charter)

              CALIFORNIA
     (State of Other Jurisdiction                      33-0065212
  or Incorporation of Organization)        (I.R.S. Employer Identification No.)

               23456 South Pointe, Laguna Hills, California 92653
                                 (949) 770-9347
          (Address and telephone number of principal executive offices)
                           --------------------------

                    Electropure, Inc. 1999 Stock Option Plan
                            (Full title of the plan)
                           --------------------------

                           FLOYD H. PANNING, President
                                ELECTROPURE, INC.
                               23456 South Pointe
                         Laguna Hills, California 92653
                                 (949) 770-9347
      (Name, address and telephone number of Agent for service of process)
                            --------------------------

                          Copies of communications to:
                             Ronald P. Givner, Esq.
                    SKADDEN, ARPS, SLATE, MEAGHER & FLOM, LLP
                       300 South Grand Avenue, 34th Floor
                          Los Angeles, California 90071
                                 (213) 687-5329
--------------------------------------------------------------------------------
2

                         CALCULATION OF REGISTRATION FEE
Proposed      Proposed
                                        Maximum       Maximum        Amount of
Title of Securities   Amount to be      Offering     Aggregate     Registration
 to be Registered      Registered      Price Per      Offering          Fee
                                      Share(1)(2)      Price
--------------------------------------------------------------------------------
Class A Common Stock,
par value $0.01       1,000,000 (3)      $1.25      $1,250,000.00     $368.77
  per share
----------

(1)     Calculated pursuant to Rules 457(c) and (h) under the Securities Act of
        1933, as amended (the "Securities Act"), based on the closing sale price
        as reported on the Electronic Bulletin Board on March 28, 2000.

(2)     Estimated solely for the purpose of calculating the registration fee.

(3)     Pursuant to Rule 416(c) under the Securities Act, this registration
        statement also covers an indeterminate number of additional shares of
        Class A Common Stock that may become issuable pursuant to the
        antidilution provisions of the Plan.

================================================================================

                                      II-1
3

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

        The document(s) containing the information specified in Part I of the
Form S-8 have been or will be sent or given to employees as specified by Rule
428(b)(1) under the Securities Act of 1933, as amended (the "Securities Act").

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3. INCORPORATION OF DOCUMENTS BY REFERENCE.

        The following documents previously filed with the Securities and
Exchange Commission (the "Commission") by Electropure, Inc. ("ELECTROPURE"),
pursuant to the Securities Exchange Act of 1934, as amended (the "Exchange
Act"), are incorporated by reference in this registration statement.

(1)     Electropure's Annual Report on Form 10-KSB for the year ended October
        31, 1999; and

(2)     The description of the Class A Common Stock contained in Electropure's
        Registration Statement on Form S-1 (File No. 33-10669) filed on December
        15, 1986, including any amendment or report filed for the purpose of
        updating such information.

        All documents subsequently filed by Electropure pursuant to Sections
13(a), 13(c)14 and 15(d) of the Exchange Act, prior to the filing of a
post-effective amendment which indicates that all securities offered have been
sold or which deregisters all securities then remaining unsold, shall be deemed
to be incorporated by reference herein and to be a part hereof from the date of
filing of such documents. Any statement contained in a document incorporated or
deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this registration statement to the extent that a
statement contained herein or in any other subsequently filed document which
also is incorporated or deemed to be incorporated by reference herein modifies
or supersedes such statement. Any such statement so modified or superseded shall
not be deemed, except as so modified or superseded, to constitute a part of this
registration statement.

ITEM 4. DESCRIPTION OF SECURITIES.

        Not Applicable.

ITEM 5. INTERESTS OF NAMED EXPERTS AND COUNSEL.

        Not Applicable.

                                      II-2
4

ITEM 6. INDEMNIFICATION OF DIRECTORS AND OFFICERS.

        Electropure's Charter limits the liability of Electropure's directors
and officers to Electropure and its stockholders to the fullest extent permitted
from time to time by California law. California law presently permits the
liability of directors and officers to a corporation or its stockholders for
money damages to be limited, except (i) to the extent that it is proved that the
director or officer actually received an improper benefit or profit in money,
property or services for the amount of the benefit or profit in money, property
or services actually received, or (ii) if a judgment or other final adjudication
is entered in a proceeding based on a finding that the director's or officer's
action, or failure to act, was the result of active and deliberate dishonesty
and was material to the cause of action adjudicated in the proceeding. This
provision does not limit the ability of Electropure or its stockholders to
obtain other relief, such as an injunction or recission.

        Electropure's Charter and Bylaws require Electropure to indemnify its
directors, officers and certain other parties to the fullest extent permitted
from time to time by California law. The California General Corporation Law
permits a corporation to indemnify its directors, officers and certain other
parties against judgments, penalties, fines, settlements and reasonable expenses
actually incurred by them in connection with any proceeding to which they may be
made a party by reason of their service to or at the request of the corporation,
unless it is established that (i) the act or omission of the indemnified party
was material to the matter giving rise to the proceeding and (x) was committed
in bad faith or (y) was the result of active and deliberate dishonesty, (ii) the
indemnified party actually received an improper personal benefit in money,
property or services or (iii) in the case of any criminal proceeding, the
indemnified party had reasonable cause to believe that the act or omission was
unlawful. Indemnification may be made against judgments, penalties, fines,
settlements and reasonable expenses actually incurred by the director or officer
in connection with the proceeding; provided however, that if the proceeding is
one by or in the right of the corporation, indemnification may not be made with
respect to any proceeding in which the director or officer has been adjudged to
be liable to the corporation. In addition, a director or officer may not be
indemnified with respect to any proceeding charging improper personal benefit to
the director or officer in which the director or officer was adjudged to be
liable on the basis that personal benefit was improperly received. The
termination of any proceeding by conviction, or upon a plea of nolo contendere
or its equivalent, or an entry of any order of probation prior to judgment,
creates a rebuttable presumption that the director or officer did not meet the
requisite standard or conduct required for indemnification to be permitted. It
is the position of the Securities and Exchange Commission that indemnification
of directors and officers for liabilities arising under the Securities Act is
against public policy and is unenforceable pursuant to Section 14 of the
Securities Act.

        Electropure has entered into agreements with certain of its officers and
directors, pursuant to which Electropure has agreed to indemnify such officers
and directors to the fullest extent permitted by applicable law.

        Section 8.6 of the 1999 Stock Option Plan of Electropure, Inc. (the
"Plan"), specifically provides that, to the fullest extent permitted by law,
each of the members of the Board of Directors of Electropure (the "Board"), the
Administrator of the Plan and each of the directors, officers and employees of
Electropure, and any successor of Electropure shall be held harmless

                                      II-3
5

and indemnified by Electropure for any liability, loss (including amounts paid
in settlement), damages or expenses (including reasonable attorney's fees)
suffered by virtue of any determinations, acts or failures to act, or alleged
acts or failures to act, in connection with the administration of the 1999 Plan
so long as such person is not determined by a final adjudication to be guilty of
willful misconduct with respect to such determination, action or failure to act.

ITEM 7. EXEMPTION FROM REGISTRATION CLAIMED.

        Not Applicable.

ITEM 8. EXHIBITS.

        4.1     Specimen certificate for Class A Common Stock (incorporated by
                reference from Electropure's registration statement on Form S-1
                filed on December 15, 1986)

        5.1     Opinion of Skadden, Arps, Slate, Meagher & Flom, L.L.P.
                regarding the validity of the Securities offered hereby.

        23.1    Consent of Kelly & Company.

        23.2    Consent of Skadden, Arps, Slate, Meagher & Flom, L.L.P.
                (included in its opinion filed as Exhibit 5.1).

        24.1    Power of Attorney (included on page II-6).

ITEM 9. UNDERTAKINGS.

               a. The undersigned registrant hereby undertakes:

                      (1) To file, during any period in which offers or sales
are being made, a post-effective amendment to this registration statement and to
include any prospectus required by Section 10(a)(3) of the Securities Act; to
include any material information with respect to the plan of distribution not
previously disclosed in the registration statement or any material change to
such information in the registration statement;

                      (2) That, for the purpose of determining any liability
under the Securities Act, each such post-effective amendment shall be deemed to
be a new registration statement relating to the securities offered therein, and
the offering of such securities at that time shall be deemed to be the initial
bona fide offering thereof.

                      (3) To remove from registration by means of a
post-effective amendment any of the securities being registered which remain
unsold at the termination of the offering.

               b. The undersigned registrant hereby undertakes that, for
purposes of determining any liability under the Securities Act, each filing of
the registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act, (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in the registration statement shall be deemed to be a
new

                                      II-4
6

registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

               c. Insofar as indemnification for liabilities arising under the
Securities Act may be permitted to directors, officers and controlling persons
of the registrant pursuant to the foregoing provisions, or otherwise, the
registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Act and is,
therefore, unenforceable. In the event that a claim for indemnification against
such liabilities (other than the payment by the registrant of expenses incurred
or paid by a director, officer or controlling person of the registrant in the
successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.

                                      II-5
7

                                   SIGNATURES

        Pursuant to the requirements of the Securities Act, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this registration
statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Laguna Hills, State of California, on this 28th day
of March, 2000.

                                      ELECTROPURE, INC.

                                      By /S/ CATHERINE PATTERSON
                                        ----------------------------------------
                                      Name: Catherine Patterson
                                      Title: Chief Financial Officer

                                POWER OF ATTORNEY

        KNOWN TO ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Catherine Patterson and Floyd H. Panning,
jointly and severally, his attorneys-in-fact, each with the power of
substitution, for him in any and all capacities, to sign any amendments to this
registration statement (including post-effective amendments), and to file the
same, with exhibits thereto and other documents in connection therewith, with
the Securities and Exchange Commission, hereby ratifying and confirming all that
each of said attorneys-in-fact, or his substitute or substitutes, may do or
cause to be done by virtue hereof.

        Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities and on the
date indicated.
/S/  WILLIAM F. FARNAM                                Director               March 28, 2000
------------------------------------------
WILLIAM F. FARNAM

                                                      Director
------------------------------------------
RANDALL P. FRANK

/S/  RANDOLPH S. HEIDMANN                             Director               March 28, 2000
------------------------------------------
RANDOLPH S. HEIDMANN

/S/  ARTHUR LIPPER III                                Director               March 28, 2000
------------------------------------------
ARTHUR LIPPER III

/F/  FLOYD H. PANNING                          Chief Executive Officer       March 28, 2000
------------------------------------------          and Director
FLOYD H. PANNING

/S/  CATHERINE PATTERSON                           Chief Financial           March 28, 2000
                                                 Officer (Principal
                                                    Financial and
------------------------------------------       Accounting Officer)
CATHERINE PATTERSON
II-6
8

                                  EXHIBIT INDEX
Exhibit No.    Description of Exhibit
-----------    ----------------------
4.1    Specimen certificate for Class A Common Stock (incorporated by
               reference from Electropure's registration statement on Form S-1
               filed on December 15, 1986).

        5.1    Opinion of Skadden, Arps, Slate, Meagher & Flom, L.L.P. regarding
               the validity of the Securities offered hereby.

        23.1   Consent of Kelly & Company.

        23.2   Consent of Skadden, Arps, Slate, Meagher & Flom, L.L.P. (included
               in its opinion filed as Exhibit 5.1).

        24.1   Power of Attorney (included on page II-6).