I have an old septic system with 2 clay tile septics. each holds about 250 gal. it then goes to a 1000 gal. leech tank with gravel around it. 10 years ago I had them pumped and the leech was not draining well. I had a second leech tank installed after the first one. 2 weeks ago I had all tanks pumped, they were full. the pumper said there were some solids in the leech tanks. all the ground in my area is sand and gravel, so it should leech away good. any info on opening up the gravel around the leech tanks would be appreciated. thank you