If it is Hydrogen Sulfide you will get a rotten egg smell. Have you ever been around sulfur water? What you smell with sulfur water is Hydrogen sulfide. My uncle's house had so much hydrogen sulfide inside the house that any thing that was silver quickly turned black. They lived in the house for many years. There were many similar house in the area, with more or less Hydrogen Sulfide in the air from the water. You mentioned Hydrogen Sulfide as being a poison. It is, but the concentration has to be many times the smell threshold. Because of the smell you will leave the area long before you reach a toxic level. http://www.airgas.com/documents/pdf/001029.pdf

I can vouch for what creekside said about scams. I posted a long time ago about Roy Roy the Water Boy (I am not kidding, that is his marketing name) who came out to my house just when it was being finished to do his 50 dollar water test. Gee - i thought - what a great deal. When the Water Boy turned to me and said, "well, i have some good news, and some bad news" I should have known what was coming. The good news was that we had very clear water and no bacteria. The bad news, it was very hard water and had some iron. And for the mere pidance of "fouty nine ninety five" he could fix it. I turned to my wife and said, what the heck, we can splurge for the 49.95 right now to fix this. And she said, "ah, you need to move the decimal point over a bit - he is talking about 4995!" And that was just for the hard water. To do the iron and the hard water, it was over 8 grand!!! DW then proceeded to ask the Water Boy for his pamphlet, and told him we would get back in touch with him if we decided to treat the water. After he left, she ripped the builder for yet another unforseen oops which we later discovered he knew about and was setting us up (probably getting a kick back from the water boy too). Luckily I had this forum and did a lot of searching over on Plumbing. We wound up doing the water treatment ourselves after I read a bunch of posts - see posts from justalurker and aliceinwonderland - great info. I took the water test results from the Water Boy and called Abundant Water Flow to order the water softener - see link below. They were very helpful and helped me size the unit. I had a water softener delivered to the house site within a few days after Water Boy left and the plumbers were still here to hook it up for a small fee. I put in the resin myself which is the hardest part. FYI - have two people put the resin the tank as spilling it on the floor is not a good idea - very hard to clean up. After I fixed the water hardness issue, i later added a Big Blue water filter to take out the small bit of iron we had plus remove an aftertaste from the Potassium Chloride we used as the brine. In the end I did the entire water treatment for under 1500 bucks and our water is great. I am now my own water treatment maintenance guy and it isn't that hard. I test the water myself once per year with a DIY test kit just to make sure things are still OK. I make sure the brine tank is filled with pellets. I make sure the system is re-generating on the schedule. That's about it. Hopefully this info will hlep others. If your water is not too bad (hardness and moderate iron, no bacteria), then a DIY approach works just fine. if you have really bad water and bacteria - then you probably want a pro to handle it. Here is a link that might be useful: Abdundant Water Flow

According to the same webpage you referenced earlier in the thread (EERE), 80-90% of the energy used to heat the water goes back down the drain,DWHR. It also gives a payback of 2.5-7 yrs. Even at 7yrs, that is an ROI of over 10% per year, not too many investments can give you that. The DOE also supports it ,DOE-OIT. Shower drain water is 85-95, the avg cold water temp is 55 in the midwest(probably 45 now). For equal flow rates (drain and supply), at 50% recovery the water would be 72. In effect, your recovering ~40% of the original energy used to heat the water. You save both by heating the water going to the WH, but you use less hot water since the ratio of cold to hot is higher at the shower (since the cold water is now 17 degrees warmer). Its far from a gimmick, its like saying a heat pump can't work when its 45 outside or 55 in the case of geo. It may not be instinctive, but it still works and its almost idiot proof.

Wow, thanks for all the good input. I didn't intend it to become a debate about solar, but found that interesting as well. I'm not familiar with the lease program that is mentioned. I'm looking to have an array installed that will be owned completely by me. I can get a 20kw system installed for about $60,000. There is a new Duke Energy program offering $1 rebate for each kw installed, so subtract $20,000. Then there are 55% state and federal tax credits, reducing the investment further to $18,000. The system should generate about $2,500 in energy per year (assuming 9 cents per kwh), resulting in about a 7 year payback. There is also potentially a benefit I can derive from depreciating the asset, but am not sure that is allowed, so need to check with my tax expert. I think the main different between now and before is the $1 Duke rebate. Without that, I agree the payback period would be too long (about 11 years), but a 7 year payback seems reasonable to me. There is always the possibility of repair costs in the first 7 years which could lengthen the period a bit, but the warranties on the panels at least are much longer than that. In any case, I think it is a worth a try. With regard to the water heater question, I agree that two heat pump units might be too many, as the one in the basement might be idle for long times, so am not considering doing 1 heat pump (for the upstairs which will get used daily, but shouldn't use more than 80 gallons per hour as there is only 1 shower), and then a gas powered tankless for the basement. We have natural gas that will be already piped to the house for the stove/grille. Any other thoughts or suggestions are welcome, thanks for the lively debate!