I had the same problem. I tried the "pea gravel pit", but only went about 12 inches. The humidity is so high here the only thing the pea gravel did was hold the water. The ground around the drain was so saturated, that it would simply sit in the pea gravel pool.... last year I extended the drain to under a group of shrubs about 20" away. The water from the drain is quickly taken up by the shrubs, so I do not have standing water. I make sure to blow the line out every month or so and flush it with a solution of bleach water a few times a year to keep it from clogging up.