Here are some other sites which seem to have specific information about the repair / maintenance of onsite wastewater disposal systems.
Septic Tank Info dot com Lots of good information.
On-Site Wastewater Treatment Resources Council
Texas Water Resources Institute
Remediating Failed Septic Tanks Near Lake Livingston Texas
Remediating Failed Septic Systems with Microbubble Aeration Units
National Onsite Wastewater Recycling Association, tel. 1-800-966-2942.
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