hey .. mr T .... you ask about a leech field.. and then tell us where the tank is... which is it ... a weep field.. by definition has holes..... else how would it weep?? .. eh?? .. and if there is a source of water and nutrients.. trees will find it ... perhaps just an issue of how many decades .... you are confusing a sealed SEWER ... with the field.. two different worlds ... it doesnt matter how new a leech field is .... and you dont mention how deep the field is.. mine is only about 24 inches down.. and i bet the gravel is only 12 inches down ... but with fields running.. in the 5 to 10 thousand dollar range.. i really dont know what you are thinking.. especially with a tree that has GIANT ... in its name ... are you really this starved for space.. that you have to plant in this area??? i have no sources.. but would think.. a nice mini collection could be had in the area... but not things i think of as forest trees ... aka species trees.. ken

The suggestion for curing new concrete to ready it for plants or pond plants is to flush with water 3 - 5 times a day with the hose for two weeks. Then allow to thoroughly dry and apply two coats of concrete sealer inside, allowing to dry over night between coats. Some will suggest a third step in between flushing and sealing: Mix up a solution of 1 quart of ordinary kitchen vinegar and 10 quarts of water. (you may need more with the length of your planter) With a stiff brush (or old broom) and generous sloshings of the solution, scrub vigorously over every square inch of the vessels inside surface. "The surfaces may bubble up a bit as the vinegar works on the free lime, but don't worry, it will not weaken the concrete." Rinse well, allow to dry, then apply the concrete sealer.

Nice link. But if you follow this further after reading your link, you will find that many plant β-glucosides are carcinogenic to rats and humans and toxic to our liver. It seems that the hazard is only from eating (vs. touching, injecting, etc.) since the bacterial flora in our gut further digest man of the class of plant chemicals called β-glucosides. So the original question still stands. Just because something doesn't have a recycle symbol or number on it, doesn't mean it is hazardous, although cheaper generally means less regulation. Check with the manufacturer online or find them from your retailer and call their customer service line and try to get more info. Usually they readily can give you the recycle code, although hazard info is more difficult to get since everyone who knows about it seems to have an axe to grind and you might as well be arguing about the greenhouse gases or politics before you can reach a consensus... Good luck. Just keep in mind that recycle codes are not everything. Code 7 for example has everything from poisonous to approved for repeated food contact. HDPE is code 2 always, but what it is mixed with will determine its suitability for food contact. Even if someone says it is 'virgin' material, that doesn't mean anything if they use some hardener or UV stabilizer that is unsafe for food contact, so you can start in tyhe US by asking the manufacturer if it is FDA, USDA or NSF approved or certified and the manufacturer will know that since they pay about $5000 to get the certification. NSF 61 is lead and other dangerous chemical free, ok for potable water (so irrigation should be fine) but not necessarily for single or repeated food contact which is really FDA approved. Good luck. Learning about plastics is something you can never do completely and all feelings of safety are really not dictated, conditions of use vary so much and there is still a lot that is unproven. It comes down once tyou weed out the obvious one to your risk aversion mentality. Personally, I think eating more veggies from a PVC hydroponic system is healthier than eating less veggies grown naturally in the Garden of Eden, but that is what you run up against. The best we can do is just buy FDA approved (usually PP and HDPE without regulated additives) and hope for the best. To give you an example I am making a similar choice for a possible home hydroponic system in the future with square PVC. Here's the problem: Go to a home improvement store and get a square PVC piece and you don't even know where it is made. My risk aversion says, no way. The reason is that most cheap stuff comes from China and so that is the centers majority of product and they probably couldn't trace a upplier if they tried they way they buy many of these commodities PVCs. So go on line and read, "Virgin Monolayer PVC" ... that must be better, right? They say it is better than the higher cheaper recycled content coextruded stuff, but if it isn't for food, who really knows since it hasn't been tested - what are the stabilizers going into the virgin PVC? So actually - they scared you that co-extruded was a problem, but I personally would prefer coextruded "virgin PVC substrate". Coextruded is cheaper because minimal additives go on the inside layer, the additives are what costs, and the outer shell has the recycles, etc, content with eg UV stabilizers etc additives. Well if you need stabilizers, but don't want additives overwhelmingly contacting the inside, co-extruded seem the way to go...

We literally just signed a contract yesterday to abandon our 30yr septic because we now can connect to city sewers. The length we have to bore is about 50’ to tap into the line that was brought into our neighborhood this summer. After bidding 5 contractors the one we chose is charging us close to 20k for this and the city is charging us close to 5k for TAP fees. This is their way to recoup the costs to bring the city sewer line into our neighborhood. It’s also important to note that if your property can not do a gravity system you will have to have a grinder pump which you will have to maintain every year and replace every 5 yes or so usually at a cost of about 5k each time. We bought this house 3 years ago and have been fixing it up. Knowing what we know now we realize we got our house for a song because most people don’t want to deal with this. Live and learn.