Ask Mr. Smarty Plants

This is really a plumbing problem, not a plant problem. We will tell you what we know about the plants you know the name of and then see if we can find some information on the septic tank issue.

'Blue Rug' Juniper is apparently a trade name for Juniperus horizontalis (Creeping juniper), which is native to North America but, according to this USDA Plant Profile Map is not native in any of the southern or western states, including Alabama. Lagerstroemia indica (Crape Myrtle) is native to Korea, China and Japan.

Now, on to the septic tank:

From a previous Mr. Smarty Plants answer:

"This article from InspectAPedia.com Guide to Planting Trees or Shrubs Over or Near Septic System Components has a lot of information on planting trees and shrubs over septic fields (don't) or distances from those fields to plant trees (you don't have that much space).

Beyond that information, about all we can tell you is what we have told others who wanted to know what they could plant over septic systems and let you go from there. These are all Mr. Smarty Plants answers to previous questions and some have more links for information. These involve different areas of the country and different plants but all are applicable to your question.

June 28, 2010 Planting over septic tank in California

September 2, 2009 Native flowers from Door County WI

January 25, 2009 Plants that will not clog lateral lines with roots from Bulverde, TX

April 10, 2008 Native plants for septic field from Austin, TX"

Please follow any additional links in any of those linked answers. We would suggest you have someone who specializes in septic tank installation visit the site and make recommendations. Damage may already have been done and the sooner you find out about it, the sooner it can be fixed and the less damage will be done.