ANSWER -- Go back to the crawl space and make sure that you have cleaned all visible surface residue left by the leak. It is wise to dig down about a third of a metre or so in the area where the sewage ponded.
Once that's done, thoroughly soak the entire area with pure bleach to kill bacteria and the smell it leaves. Make sure to take proper precautions when using bleach and other cleaning materials in a closed space. Cover the bleached area with a 30-kilogram bag or two of powdered lime. You will also want to check for any damaged ducts in your air system, and you may want to consider having a contractor do a professional cleaning of the ducts. They have special machines designed for this purpose.
-- Associated Press