[njraddoc]

help...we moved into a new house 6 months ago, with septic system on property, and have an unsolvable problem of intermittent septic smell at a few locations in our house[xx(]. has occurred four times, always in the morning at about 8-11 am, then clears over 1-3 hours. ocurred once during an extremely heavy downpour in september, and the other three times following near-zero nighttime temperatures in january. smell strongest in an upstairs princess bathroom and also occurs in the room (kitchen) directly below. at another site towards the front of our house near a 1/2 bath we can smell it at the same time. the smell seems to permeate into these sites from an unknown origin. it's not the drain traps as we've flushed them recently. the drains function well otherwise. i've consulted a few books at the library to no avail. what's the source, and what's the fix for this problem??