A sewage leak under a house is an emergency situation that must be repaired and cleaned up as soon as it is discovered. In addition to the unpleasant odor, bacteria and mold can grow rapidly and cause serious health issues for all of the home's inhabitants. Sewage cleanup is a project that is best handled by a professional but handy do-it-yourselfers can manage much of the remediation on their own if the crawlspace allows enough room to work.
Cordon or fence off the contaminated area to prevent children or pets from gaining access.
Put on protective eyewear, a respirator mask, gloves, boots and coveralls or old clothing.
Remove the topmost layer of heavily contaminated soil, place it in heavy-duty plastic bags and seal them. Discard according to the regulations of your municipality.
Spread a layer of hydrated lime onto the remaining soil to absorb odor and help break down organic matter. Till the soil well so the lime mixes into the soil.
Discard heavily contaminated items in the crawlspace in plastic bags, then seal the bags. Disinfect lightly soiled, hard, non-porous items by submerging them in 1 cup of bleach mixed in 1 gallon of water. Rinse in clean water and allow them to air dry. Porous items should be discarded in sealed plastic bags.
Disinfect or discard clothing and protective gear worn during the cleanup.