Our house is approximately 3 years old and we bought it last August 2004.
It has a septic system with drain fields, and a large candycane shaped vent
over the drain fields. Records show the previous owner had it pumped out
April 2004, and I had it pumped out earlier this month. There are 6 of us
in the house.

The weather has been rather dry lately, and I have noticed that the grass
over the septic system and drain fields is a bit greener than the other
parts of the yard. I have heard this can be a sign of a problem (but not
necessarily so) and I looked around the neighborhood and saw many similar
situations--perhaps this is the norm. Still a bit concerned, however, I
walked our yard yesterday (checking to see if the greener areas were spongy
or had an odor) and was unpleasantly surprised by a strong sewage odor
coming from the yard vent. We've been here 10 months, and spend
considerable time in the yard, and this is a first.

What should be my next step? Continue to monitor the situation or get an
assessment? A quick Google indicates this is not all that uncommon to have
an odor from the house or yard vent, and there are various recommendations
for carbon filters. Should I call the septic guy back and have an
inspection?

Thanks in advance.

John