Thanks for the reply. I do have other areas that I could plant. The best other area is a fence line bordered by a ditch and then an asphalt road. This area is on a north-west slope and would be well drained and even dry in the hot season, with full sun. Any suggestions for either areas?

If it does damage your lines you probably will not find out till you have a dense interwoven net of bamboo rhizomes over your septic field. Then just imagine the trouble, smell and insanity of finding equipment that will be able to dig through the rhizome layers without wrecking the whole septic field. Might work nice but I wouldn't take that gamble.

Depending on the soil, bamboo can have very shallow rhizomes or they can dig deep. If you have poor or wet soil way down, but add good compost near the top, the plant will focus its growth close to the surface in the good soil, and is less likely to go down below 24."

No guarantees, but that has been my experience.

greg-
I've dug a lot of bamboo and have yet to see any rhizomes go deeper than 12"-15". Bamboo rhizomes are not like tree roots where they fan out and go downward and get bigger as time goes on: they like to spread laterally in a relatively narrow zone under the surface. If your septic lines are deeper than a couple of feet, I wouldn't worry. The only issue is that if you need to repair your lines for some other reason in the future you'd probably be advised to use a back hoe to tear through the rhizomes, because hand digging would be a chore.

Concur with Kudzu on rhizome depth, done lots of digging in mature groves. I have never encountered rhizomes deeper than 18".

Also agree about the backhoe...

Even if a stray rhizome did manage to get down and enter your drain line, it couldn't get very far unless it could send up a culm, which it couldn't do easily from within a 4" drain line (any shoots would run along the length of the drain line until they ran out of energy). The main problem would be 20 years down the road if you had to dig up some of the lines to do maintenance on them. You would have a dense rhizome mat to have to cut through. Now you wouldn't want to plant moso on the drain field, but if you planted Arundinaria gigantea, A. tecta, Pleioblastus chino, of one of the other small-mid sized bamboos, you should be all right.

The question looks pretty well answered but did anybody happen to see what he said about the asphalt road, at another place that he might plant it? I lost the picture that I had on my computer, that showed a culm coming straight up through an asphalt road. I wonder just how much they, the county or the city or whatever, will charge him for that repair. Just a thought.

I remember the picture, and that looked to me like an opportunistic rhizome coming up through a crack in the thin asphalt shoulder. It was interesting nonetheless, but I'm of the opinion that bamboo is not likely to punch through full thickness asphalt.

I remember seeing it here, also: http://www.bambootexas.com/php2/viewtopic.php?t=40

Rhizomes will find a way to squeeze through existing cracks, but they can't penetrate solid asphalt. At least, I've never heard of a bonafide documented case.

Seedlings of many plants are reputed to be able to "sprout through concrete," but closer observation always shows that the seedlings were actually taking advantage of a fissure that was already there. Once they get into it, their expanding circumferance can cause more of the pavement to break away and enlarge the crack, but the plant can't create a crack.

On the other hand, if bamboo gets planted in a container that is less than durable, such as a planter made of wooden slats, an expanding rhizome mat can rupture the container. I've seen photos of that! Same with trees in concrete or wooden planters. The concrete can be broken by the outward constant force of an expanding root system.

Thanks for starting this post which will give me a place to vent! Our septic field stopped draining correctly and the official in charge of the repair permit determined that we needed a shallower system. SO, we got a new tank AND a whole new field. After about a months wait, and days of "soon" they showed up unexpectedly Tuesday at about 8:45 in the morning. By 9:05 they had not only knocked over two 20+ft trees and a shrub exceeding 10ft in diameter, they completely demolished the most concentrated and diverse (not to mention polished) area of my garden near the foundation of my home. Its like a martian landscape out there now. Ironically, they then proceeded to come knock and tell us that they would have to temporarily remove two boards from our weathered decking. Big deal! What about the hundreds of dollars of plant life that can't be replaced with a couple of hits with the hammer! I hadn't cut anything back in the fall because I wanted to be able to identify plants when I move in a month or two, so it should have been glaringly obvious that I had a garden there. We had never specifically talked about plant or landscape damage control (never put a non-gardener in charge of these things), but it was layed out and diagramed in such a way that it appeared the plantings would be spared. Last minute talks between the contractor and the inspector apparantly dictated that it be done a little differently and the new tank would be placed closer to the house. To be honest, I hadn't even thought of doing precautionary relocation because our house is under contract and presumably the garden should look as it did when it was photographed and viewed by the buyers. What a mess! One of the plants was a clump of Golden Goddess bamboo. It was my first bamboo ever and I had grown it as a dieback plant for 5 years or so. No sign of it. Anyway, when it comes to plantings and septic tanks, be afraid- be VERY VERY afraid!

I can't imagine mature rhizomes NOT interfering with a drainage field. Won't they just find the little tunnels and run wild, sprouting at every hole, either blocking it or cracking the line material creating new entry points for not only rhizomes, but soil?

"Other opinions are that the bamboo will actually help by wicking excess moisture from the septic system."
People are always suggesting/exploring the use of plants to solve drainage issues. I don't think this EVER works with any plants. The problem is, when it rains it POURS and there is only so much a plant can wick. However, you will likely want to continue taking baths and doing laundry during your local monsoon season. Have you ever heard someone complain they planted so many pond plants that they wound up with a non-pond?

Don't Do it!

You are in zone 5 which covers a lot of geography. In Massachusetts, I was told, before a home is sold, the septic system MUST be dug up and its good condition verified or restored. I would not put anything around a septic field which might make such a chore overwhelming. I shudder to think of the damage the workmen might do!!

What's wrong with installing a metal barrier driven into the ground around the space you allocate to the bamboo?

Unreinforced concrete (i.e. no rebar in it) will likely crack way before 20 years, so IMHO that's not a good example. Bamboo will just be able to take advantage of the existing cracks.