What was found
AIRCRAFT WAS GROUNDED: AN EMERGENCY WAS DECLARED DUE TO: A STRONG ODOR IN THE BACK OF THE PLANE THAT CAUSED PASSENGERS AND FLIGHT ATTENDANTS TO BECOME SICK. AIRCRAFT AIR INTERRUPTED, BACK TO AND LANDED SAFELY AT MDE. ACCOMPLISHED SMOKE ODOR FUMES CARD 09L00021001. FOUND ODOR COMING FROM AFT SILL DRAIN CLOGGED WITH COFFEE GROUNDS. REMOVED AND REPLACED FLOAT VALVE AND FLUSHED LINES. PER AMM 38-31-06-400-802. OPERATIONAL CHECKED GOOD ODOR IS GONE.