Experts and BHG readers answer.
Thanks for writing. I'd plant your vegetables as far away from a sewage tank as possible to avoid issues with lead and other heavy metals. Or, if you don't have space farther away, try growing them in raised beds over the buried tanks; if you fill the raised beds with good soil, your plants should be fine.
For groundcover ideas, check out our groundcover slideshow!
---Justin, Senior Garden Editor, BHG.com