Septic Tank

In North America approximately 25% of the population relies on septic tanks; this can include suburbs and small towns as well as rural areas. (Indianapolis is an example of a large city where many of the city's neighborhoods are still on separate septic systems)

http://en.wikipedia.org/wiki/Septic_tank

http://home.howstuffworks.com/home-improvement/plumbing/sewer2.htm

Alternatives

• Composting Toilet (not really alternatives, but kinda)
• BobCrosby’s waste water plant can turn about 400 gallons of sludge water every 24 hours into PH neutral, oxygen rich, and oderless water that is ready for irrigation – or – some additional treatment that will make it potable. Bob’s Di Y design requires about $300 for some simple materials and a couple of weekends to build.

Can you plant a Kitchen Garden in a septic field?

• If you must plant vegetables, take the following precautions. Do not plant root crops over drain lines. Leafy vegetables could be contaminated by rain splashing soil onto the plant, so either mulch them to eliminate splashing or don't grow them. Fruiting crops are probably safe; train any vining ones such as cucumbers or tomatoes onto a support so that the fruit is off the ground. Thoroughly wash any produce from the garden before eating it. Do not construct raised beds over the field; they might inhibit evaporation of moisture.
• http://inspectapedia.com/septic/fieldplants8.htm
• http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=12963