I looked into this before building my beds and what I found was that most of the treated wood these days is not treated with the toxic chromium and arsenic that was used in the past. Supposedly, they are today treated with mostly non-toxic substance but I can't tell you what that is. I never went that far into it. I have difficulty believing that somehow, the trace amount of chemicals that may leach out of the treated wood are going to be transmitted into the flesh of various vegetables any more than substances contained in dog, cat, or horse feces is transmitted through the root system and into the fruit, leaf or vegetables. I suppose root crops could possibly absorb some amount through direct contact if concentrations were high enough but still, I find it hard to believe that it would absorb more than negligible amounts. Considering all the added unnatural chemicals/preservatives/dyes etc, we consume daily in our food and beverages, not to mention everything we breath, I concluded that, for me and my family at least, any chemicals in treated lumber is a non-issue vs. the benefits of eating fresh vegetables. YMMV

This year I started with containers, had tomatoes among several othere things. My containers had 10" deep dirt. Soon I found that it was not enough. The tomatoes get roots taht are 3-4 feet deep. Basil on the other hand has pretty shallow roots. Then I moved my plnats to true raised beds, 1 foot deep fill plus dirt ground below. They grew fine. Had good crop of veges that are heat tolerant but not others. See, the high heat this year was not a conventional garden year. I had lots of eggplants, okra, yard long beans, cucrbits (until temps went over 100), almost no tomatoes even though had flowers but no fruit set and my understanding is that temps over 95 are not good for setting tomatoes. Your one foot deep contianer will do fine for the leafy veges, beans, peas, herbs, short varieties of carrots and radishes, turnips, etc. If you search the net for "depth of plant roots" you will find plants that have very deep roots (3-4 feet), medium (1-2 feet) and shallow roots. Another problem with your container may be: plywood is resting on the concrete without spacers (feet). So, the plywood even though has holes, is not actually draining. Raise the whole container up on couple of 4X4s so the plywood is not resting on the concrete, like a container is supposed to have free draining hole in the bottom. Giid luck.

Hi Gabe from a fellow PNWer. Don't know how much further you are in the raised beds, but here's a suggestion anyway. Do you have any place locally that gathers recycled building materials? We do have such a place locally. They have old windows, doors, toilets, bricks, etc. On any given day you could find who knows what. Perhaps this is not common elsewhere, but it is here. I was thinking such a place could be quite a source for you. Prices on materials would be much more reasonably priced than at Lowes, Home Depot, etc. Cinder blocks would be quite the ticket for me. Resiliant and long lasting. Another thought would be to visit your county extension service. If there is not an office nearby that you can visit, perhaps they are on-line. I am lucky to live in a town with a local extension office and they serve a wide area of Oregon. They are really good. Not the case for everybody, so I have been told. But it's something you might look into. Our local office promotes alternative gardening for those who may need a little help. A year or two ago they displayed a big table filled with dirt. I think it was about 4 feet wide, 8 feet long. Maybe a foot deep. Obviously, such a table would stand in place once it was built. Your mom could stand and garden. For someone in a wheelchair, it could be built a bit lower to the ground. We get about 40 inches of rain a year. I don't know if they use anything special to protect the tables. The local extension agents know and practice organic gardening as much as possible as near as I have been able to tell. anyway, such a place may provide you with some good ideas. Best wishes. It's neat what you are doing for your mom. Mary

Nathanhurst: Would you like to share your data? I have the same data as you or Stuart or most anyone else these days. It is the information on the web that I researched and reviewed that lead me to my decision to use ACQ lumber. My job involves understanding the degree of risk posed by constituents like metals and pesticides in the environment. When I was looking into ACQ I needed to look beyond the leaching studies that just focus on the copper concentration of ACQ leachate, i.e.: ".but it(ACQ) does have triple the amount of coppera substantial increase." I can agree with that quote to a point. But just because it leaches doesnt mean it is bio available. In the current dialogue, your premise for copper being a concern appears to stem from the mere fact that copper is present in ACQ leachate, period. What appears to be missing is an understanding of coppers fate and transport in the soil from its source (ACQ leachate) through the soil column to a receptor (a vegetable plant root system), the resulting exposure concentration (copper in a tomato) and the frequency at which tomatoes are consumed by the ultimate receptor (us). Soil organic matter, silt and clay particles, cation capacity all serve to attenuate, minimize or limit the migration of copper in the environment. For me, the data supported no adverse risk My statement was used out of context in your response since it did not include "under my garden use and consumption scenario". The latter text is where fate and transport and receptor exposure concentration come into play to describe the actual risk posed by copper. I can find articles calling ACQ into question without even trying (the first hit on google with ACQ): "Though this preservative mix has proven to be the most effective so far, ACQ poses its own concerns. soil and sediment. ACQ doesnt have the arsenic or chromium issues of CCA, but it does have triple the amount of coppera substantial increase." -- http://www.nadra.org/industry_news/acqarticle.html (and that from a body trying to promote ACQ use!) For someone who takes that statement at face value, they would believe it to be a case against ACQ unless they looked deeper into the source. NADRA is the North American Deck and Railing Association whose mission as stated on their website is to "promote outdoor living at its best, in safe and creative environments for the enjoyment of every homeowner". They are not promoting ACQ use anymore than they are promoting redwood or composite decking. The article mentioned is at best a third or fourth order source for ACQ info since its author, a fastener manufacturer, was discussing the compatibility of decking screws with ACQ chemistry. NADRA was however providing it members and web surfers a service by mentioning the ACQ copper study so the user could make their own informed decision. Saying that quaternary ammonium salts are the same as ammonia demonstrates a lack of chemistry knowledge and makes me doubt the rest of what you are saying. True, I am not a chemist but I did pick up a few things from my organic chem, inorganic chem, biochem and geochem courses. However, I was not specific enough. I referenced quaternary ammonium compounds in general when I was specifically thinking of DDAC, the quaternary ammonium compound used in ACQ. DDAC is an anti-microbial compound also found in household disinfectants, laundry detergents, fabric softener dryer sheets and swimming pool disinfection to name a few. My point in mentioning it was that DDAC is more common as an active ingredient in products we touch, breath and swim in everyday. As good gardeners we all know that AMMONIA found naturally in high concentrations in raw manures will burn a plant until soil microbes convert it to nitrate, the nutrient plants need. And IF we add too much nitrate-based fertilizer it can leach to groundwater. And IF it reaches a groundwater concentration greater than 10mg/L it can produce methemoglobinemia or "blue baby" syndrome in infants. Organic animal manure. Copper poisoning is not pleasant, I've had it. Having experienced copper poisoning first hand its understandable you would be cautious of any product containing copper. Comparing with copper pipes is like saying that sarin nerve poison is harmless because its got carbon in it. My plumbing analogy was to point out that receptor exposure concentration (trace copper) and duration (a lifetime of daily drinking/bathing) is equally important in determining risk in addition to the mere presence of copper. Few folks would list pure drinking water as an acute toxin, yet last year in California a young college student died tragically in a fraternity hazing incident by drinking too much water (not alcohol) in a short period of time. The water essentially diluted the electrolytes in his blood and he died of a heart attack. Pure drinking water. There is a lot of information on the web. Some confusing, some misleading and some conflicting especially when it comes to an emotional topic like human health. I offer my opinion in response to a question by dgriff as to what to make of ACQ. This was my personal decision, based on my review of the literature and my professional experience. Were I a Wall Street type, I would offer my personal perspective on a financial web forum to a non-financial type who wanted to sort out conflicting info about different investment products. Ultimately, its up to the individual to glean what they can from the various experiences expressed here and make an informed decision they are comfortable with.