UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549


                                    FORM 8-K

                                 Current Report


                       Pursuant to Section 13 or 15(d) of
                       The Securities Exchange Act of 1934

         Date of Report (Date of earliest event reported) March 19, 2004


                              IONICS, INCORPORATED
             (Exact name of registrant as specified in its charter)






                                                                                     
              Massachusetts                            1-7211                              04-2068530
        (State of incorporation)                (Commission File No.)           (IRS Employer Identification No.)
        ------------------------                ---------------------           ---------------------------------

65 Grove Street, Watertown, Massachusetts
                                                        02472                            (617) 926-2500
(Address of principal executive offices)             (Zip Code)                  (Registrant's telephone number,
                                                                                      including area code)




Item 5.    Other Events and Required FD Disclosure
-------    ---------------------------------------

          On  March  19,  2004,  Ionics,  Incorporated  issued  a Press  Release
          announcing  (i) the departure of William J. McMahon,  Vice  President,
          Ultrapure Water Group; and (ii) the appointment of Lester B. Devitt as
          Vice President, Sales and Marketing for the Water Systems Division.


Item. 7.   Financial Statements and Exhibits
--------   ---------------------------------

           Exhibit Number                       Description
           --------------                       -----------

                  99         Press Release dated March 19, 2004 announcing (i)
                             the departure of William J. McMahon, Vice
                             President, Ultrapure Water Group; and (ii) the
                             appointment of Lester B. Devitt as Vice President,
                             Sales and Marketing for the Water Systems Division.





                                   SIGNATURES

Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned duly authorized.

                                  IONICS, INCORPORATED

March 19, 2004                    By:     /s/Stephen Korn
                                          ---------------
                                  Name:   Stephen Korn
                                  Title:  Vice President and General Counsel





                                  EXHIBIT INDEX





                                                                                     
Number                                     Description                                     Page Number

 99            Press Release dated March 19, 2004 announcing (i) the departure                 4
               of William J. McMahon, Vice President, Ultrapure Water Group; and
               (ii) the appointment of Lester B. Devitt as Vice President, Sales
               and Marketing for the Water Systems Division.







                                   EXHIBIT 99

     Ionics, Incorporated Announces Restructuring-Related Personnel Changes

Watertown,  MA, March 19, 2004 . . . Ionics,  Incorporated  (NYSE-ION) announced
today  several  personnel  developments  related  to its  ongoing  restructuring
program.

William J. McMahon,  the Company's Vice  President,  Ultrapure Water Group since
November  2000,  will be leaving the Company as a result of the  elimination  of
that  position.  As disclosed  in the  Company's  recent Form 10-K  filing,  the
Company is combining its Equipment Business Group, its Ultrapure Water Group and
its recently  acquired  Ecolochem Group, to form the new Water Systems Division.
The  Water  Systems  Division  is  headed by Lyman B.  Dickerson,  President  of
Ecolochem,  Inc.,  who now  holds  the title of Vice  President,  Water  Systems
Division.

The  Company  also  announced  the  appointment  of  Lester  B.  Devitt  as Vice
President,   Sales  and  Marketing  for  the  Water   Systems   Division,   with
responsibility  for all sales and  marketing  efforts for that Division in North
and South America. Mr. Devitt, who was trained as an engineer,  has an extensive
background in sales  management  and program  development,  most recently at BEA
Systems  and for over  twelve  years at Silicon  Graphics,  Inc.  Earlier in his
career,  Mr. Devitt worked as a sales engineer involved in the sale of equipment
to customers in the power and process industries, including the Company.

Douglas R. Brown,  Ionics' President and Chief Executive Officer,  commenting on
these  personnel  changes,  noted,  "We all wish Bill McMahon well in his future
endeavors.  He served Ionics well as an effective  leader of the Ultrapure Water
Group, and we appreciate the role he played in helping us restructure Ionics. We
also would  like to  welcome  Les  Devitt to our Water  Systems  Division.  I am
confident  that his  demonstrated  skills and ability in the sales and marketing
arena will prove valuable to the growth of our Company."

About  Ionics,  Inc.
Ionics is a global leader in water  purification and wastewater  treatment.  The
Company has over 50 years of experience in the design,  installation,  operation
and  maintenance  of water and  wastewater  treatment  systems  and is a leading
provider  of  emergency   and   long-term   water   treatment   services.   More
membrane-based  desalination systems have been designed and built by Ionics than
any  other   supplier   worldwide.   Ionics  is  also  a  leader  in   supplying
zero-liquid-discharge  systems,  in providing  ultrapure  water  systems for the
power and  microelectronics  industries,  and in the measurement and analysis of
water  impurities.  The Company also supplies  Point-of-Use  and  Point-of-Entry
water treatment  systems for commercial and residential  applications.  For more
information,  visit  www.ionics.com.

Safe-harbor  statement  under the Private  Securities  Litigation  Reform Act of
1995:   Forward-looking  statements  in  this  news  release  involve  risk  and
uncertainty.  The statements  contained in this release which are not historical
facts  are  forward-looking  statements.   Important  factors,  including  risks
associated with the Company's recently announced  restructuring  program;  risks
associated  with the  integration of the operations of the Ecolochem  group with
those of the Company; overall economic conditions,  demand for Company products,
raw material availability, availability of manufacturing capacity, technological
and product development risks, competitors' actions, and other factors described
in the Company's filings with the Securities and Exchange Commission could cause
actual results to differ materially.

                                   # # # # #

For more information, contact:
John F. Curtis
Vice President, Strategy and Operations, Treasurer
Ionics, Incorporated
Tel: (617) 673-4403
jcurtis@ionics.com