<ARTICLE> 5 <CIK> 0000847468 <NAME> WASTE SYSTEMS INTERNATIONAL, INC. <MULTIPLIER> 1 <CURRENCY> US DOLLARS <PERIOD-TYPE> 3-MOS 12-MOS <FISCAL-YEAR-END> DEC-31-1999 DEC-31-1998 <PERIOD-START> JAN-01-1999 JAN-01-1998 <PERIOD-END> MAR-31-1999 DEC-31-1998 <EXCHANGE-RATE> 1 1 <CASH> 36,816,693 193,613 <SECURITIES> 0 0 <RECEIVABLES> 6,256,875 5,457,562 <ALLOWANCES> 125,816 222,028 <INVENTORY> 0 0 <CURRENT-ASSETS> 46,250,254 10,198,432 <PP&E> 82,232,920 48,948,513 <DEPRECIATION> 5,410,617 4,262,778 <TOTAL-ASSETS> 173,884,122 96,116,699 <CURRENT-LIABILITIES> 12,110,540 16,718,221 <BONDS> 0 60,000,000 <PREFERRED-MANDATORY> 0 0 <PREFERRED> 0 0 <COMMON> 134,651 117,184 <OTHER-SE> 0 37,810,712 <TOTAL-LIABILITY-AND-EQUITY> 173,884,122 96,116,699 <SALES> 8,862,258 21,044,584 <TOTAL-REVENUES> 8,862,258 21,044,584 <CGS> 7,868,030 12,399,529 <TOTAL-COSTS> 7,868,030 19,000,952 <OTHER-EXPENSES> 1,913,609 4,482,478 <LOSS-PROVISION> 0 0 <INTEREST-EXPENSE> 2,006,467 (4,073,693) <INCOME-PRETAX> (8,473,625) (6,205,925) <INCOME-TAX> 0 43,174 <INCOME-CONTINUING> (8,473,625) (6,249,099) <DISCONTINUED> 0 0 <EXTRAORDINARY> (223,008) (246,539) <CHANGES> 0 0 <NET-INCOME> (8,696,633) (6,495,634) <EPS-BASIC> 0.74 (1.00) <EPS-DILUTED> 0.74 (1.00)