<ARTICLE>                     5
<LEGEND>
THIS  SCHEDULE  CONTAINS  SUMMARY  FINANCIAL   INFORMATION  EXTRACTED  FROM  THE
CONDENSED  CONSOLIDATED  STATEMENTS OF INCOME AND CONSOLIDATED BALANCE SHEETS ON
PAGES 3, 4 AND 5 OF THE  COMPANY'S  FROM 10-Q FOR THE  QUARTERLY  PERIOD  ENDING
OCTOBER 31, 1998 AND IS QUALIFIED IN ITS ENTIRETY BY REFERENCE TO SUCH FINANCIAL
STATEMENTS.
</LEGEND>
<CIK>                                       0000044764
<NAME>                                    HACH COMPANY
<MULTIPLIER>                                     1,000
       
                             
<PERIOD-TYPE>                   6-MOS
<FISCAL-YEAR-END>                          APR-30-1999
<PERIOD-START>                             MAY-01-1998
<PERIOD-END>                               OCT-31-1998
<CASH>                                           5,987
<SECURITIES>                                       910
<RECEIVABLES>                                   18,134
<ALLOWANCES>                                       351
<INVENTORY>                                     14,589
<CURRENT-ASSETS>                                45,058
<PP&E>                                          89,726
<DEPRECIATION>                                  50,634
<TOTAL-ASSETS>                                 101,643
<CURRENT-LIABILITIES>                           12,931
<BONDS>                                              0
<PREFERRED-MANDATORY>                                0
<PREFERRED>                                          0
<COMMON>                                        23,246
<OTHER-SE>                                      23,023
<TOTAL-LIABILITY-AND-EQUITY>                   101,643
<SALES>                                         70,190
<TOTAL-REVENUES>                                70,190
<CGS>                                           34,874
<TOTAL-COSTS>                                   34,874
<OTHER-EXPENSES>                                25,166
<LOSS-PROVISION>                                     0
<INTEREST-EXPENSE>                               1,046
<INCOME-PRETAX>                                  9,364
<INCOME-TAX>                                     3,364
<INCOME-CONTINUING>                              6,000
<DISCONTINUED>                                       0
<EXTRAORDINARY>                                      0
<CHANGES>                                            0
<NET-INCOME>                                     6,000
<EPS-PRIMARY>                                      .35
<EPS-DILUTED>                                      .35