EXHIBIT 11 CLEAN HARBORS, INC. AND SUBSIDIARIES COMPUTATION OF NET INCOME (LOSS) PER SHARE FOR THE THREE YEARS ENDED DECEMBER 31, 1995 (IN THOUSANDS EXCEPT PER SHARE AMOUNTS) FULLY TYPE OF SECURITY PRIMARY DILUTED ---------------- ------- ------- 1993 Weighted average common stock outstanding in 1993............ 9,327 9,327 Stock options exercised in 1993.............................. 82 82 Stock options and warrants outstanding during 1993........... 475 475 ------- ------- Weighted average shares of common stock outstanding.......... 9,884 9,884 ======= ======= Net income................................................... $ 3,131 $ 3,131 Less preferred stock dividends accrued....................... 350 350 ------- ------- Adjusted net income.......................................... $ 2,781 $ 2,781 ======= ======= Earnings per share........................................... $ .28 $ .28 ======= ======= 1994 Weighted average common stock outstanding in 1994............ 9,426 9,426 Stock options exercised in 1994.............................. 4 4 Stock options and warrants outstanding during 1994........... 205 205 ------- ------- Weighted average shares of common stock outstanding.......... 9,635 9,635 ======= ======= Net income................................................... $ 475 $ 475 Less preferred stock dividends accrued....................... 441 441 ------- ------- Adjusted net income.......................................... $ 34 $ 34 ======= ======= Earnings per share........................................... $ .00 $ .00 1995 Weighted average common stock outstanding in 1995............ 9,457 9,457 Stock options exercised in 1995.............................. 3 3 Stock options and warrants outstanding during 1995........... 15 15 ------- ------- Weighted average shares of common stock outstanding.......... 9,475 9,475 ======= ======= Net loss..................................................... $(6,893) $(6,893) Less preferred stock dividends accrued....................... 447 447 ------- ------- Adjusted net loss............................................ $(7,340) $(7,340) ======= ======= Loss per share............................................... $ (.77) $ (.77) ======= =======