I'm on septic tank and once in a while would get a little sewer smell in the house that would seem to poor or linger in the hallway between bath and bedroom or in the utility closet that opens into the bedroom but it would dissipate fairly quickly. Summertime now and instead of firing up old HVAC decided to put in window units in bed and kitchen. At the same time, had to completely replace 50 year old septic system to new high tech, high maintenance ridiculously expensive aerobic drip system. SO...all is good but when I run window units, I get a horrible build up of stench. It's not immediate as it takes a few to 10 minutes before the smell begins to permeate everything. I thought it was the a/c unit itself so hubs removed and cleaned, sanitized both units then reinstalled. Smell still occurring. Called septic company - they said plumbing problem. Called plumber who went under house and said there was a vent pipe not capped so he duct taped it up and there was another plastic pipe that look like it broke due to settling but it had a rubber boot over it that had slipped, so he pulled it back into place and taped it up too. He left and all seemed okay until that night when the smell returned after running a/c. There's no smell in the attic - but there is a smell under the house but not all the time. The vent pipe that runs up to the roof...it actually stops short and then there's another piece of pipe attached to the roof for it. In other words, the pipe is to short to actually go thru the roof and there's about a 5 inch gap. Could this be the problem forcing the vapors to down draft somehow and the window a/c's are sucking in the air beneath the house? If I extend that pipe and put a charcoal vent on it, would that solve the problem?

I posted previously, but some revisions have happened from all the input I got. Also added labels to the diagrams, made the parts list a bit cleaner, and tried to organize this better. Found those water tests too. Anyway, posting here to hopefully get some input/advice/reasons why I'm stupid. Just a couple notes about my mindset: This a definitely overkill for what I need, but I'm okay with that. This has become a bit of a hobby project by now. Total price is about $7,000 (breakdown is on the parts list linked below). Ideally I can reduce that while keeping the same performance, but at the same time I'm willing to spend a bit more for a good reason. Finally, it's important to me to add as little as possible to the water as a byproduct of treatment. Anyway, here it all is. *** [b]Water[/b] Water comes from a well in Maryland. - Well/Pump Depth: Unknown, but in 2001 the pump was replaced and 160' of roll pipe is listed on the service receipt. The pitless adapter is about 10' below the surface, so I'd estimate a pump depth of 170'. - Static Water Level: In 1986 it was 123'. - Flow Rate: Approximately 8 gpm from a 1/2 hp Schaefer pump installed in 2007. I want the system to accommodate a future pump upgrade though. Nothing specific in mind yet. - Treatment system is in the 1st floor of a 3 floor house. 1st floor has 2 sinks, a toilet, and shower. 2nd floor has kitchen sink, dishwasher, laundry machine, bathroom sink and toilet. 3rd floor has 2 sinks, 2 toilets, 1 shower and 1 bath/shower. Two outdoor spigots used in summer for watering. - Hardness: ~7 gpg - Iron: ~13 ppm - Sulfur: "Slight" - pH: Testing has varied over the years from 6.0-7.2 - CO2: ~6 gpg - TDS: ~100 ppm - Temperature: ~55°F - Bacteria: Positive test for Coliform when buying, although I suspect that contamination was from after the well. No E. coli. *** [b]Images, Model, and Parts List[/b] Regarding the images and model, I've used the largest expected dimensions for all components, so the actual build should be a bit more compact. - Here is a 3d model built in SketchUp: [url]https://drive.google.com/file/d/1T1AVCComJo9h0GkxgKYjoGbkOrLz1b4D/view?usp=sharing[/url]. You will need a program like SketchUp or the free SketchUp Viewer [url]https://www.sketchup.com/download/sketchup-viewer/windows/thank-you[/url]. - Here are a few new pictures of the model: [url]https://photos.app.goo.gl/vuB1IYy17rTdscd23[/url] - Here is a spreadsheet with the parts list: [url]https://docs.google.com/spreadsheets/d/1gSxzI95zEVm28iVzqyEXdfcDZ18tf02v_Ocyif1pCm0/edit?usp=sharing[/url]. For pricing, I can get 15% off at Lowe's, 10% at Home Depot, and 5% at Amazon, so I lean toward them. *** [b]Design[/b] I'll post my thoughts on the design, first some general things and then divided by section, with each section being a major treatment component and the plumbing leading to it. This follows the breakdown in the parts list for the CPVC plumbing. [b]General[/b] - CPVC is used within the treatment system, copper is used after treatment and within the house, PEX for outdoor faucets. - I've done my best to minimize flow restriction and simplify the plumbing wherever possible. Would really like to hear ideas regarding that! - Easily disassembly and part reuse is something I'm willing to pay a bit extra for. That said, I have a ridiculous number of union ball valves. I would love to save money and reduce points of failure by eliminating some of those. I definitely want to retain the ability to disassemble the entire system without any cutting though. - A male garden hose threat outlet is present at every point in the treatment to allow for water sampling, pressure testing, and component bypass via a drinking water quality hose. - Copper Tube Size pipes and NPT threads have been used thoughout, except for the connection to the pressure switch. I'm hoping I didn't miss any... - I prefer long sweep elbows and tees where possible, but I can't find any for CTS CPVC. Spears has some for Schedule 80 CPVC, but I don't want to transition just for that. - Pipe supports will be used where needed, but aren't marked in the model. - This might be a bit odd, but I would love to be able to see the water at each stage, even if that't just a short section of transparent pipe. Not sure if anything like that is made though; I couldn't find anything. [b]From Main to Prefilter[/b] - I was thinking about the 1000 or 500 mesh screen for the Rusco prefilter. Might be too fine, but new screens aren't very expensive if I need to switch. - I recently heard about Atlas Filtri and their Hydra prefilter. Finest screen is 50 microns (~300 mesh?). I really like that the DS version can be installed inline on a vertical pipe. I'm trying to find someone to sell me one to use instead of the Rusco, but no luck so far! [b]To Aerator[/b] - I have the pressure switch after the prefilter to protect the switch a bit. I know this is generally not recommended, but I do have the pressure relief valve before it. - Pressure switch is set at 40-60 psi, but I am thinking about upping that to 50-70 if my pump doesn't object. I understand that means less buffer capacity in my pressure tank and therefore more wear on the pump. I'm betting I'll be wanting to replace the pump before it would reach it's then hastened end-of-life anyway. - Speaking of the pressure tank, I'm reusing the one already installed. It is 20 gallons, so undersized anyway. I'll upgrade that when I get a new pump. - Regarding the odd plumbing here, I'm trying to keep a small water column above the check valve to keep air from the aerator from traveling back down the pipes. - The aerator is primarily to oxidize iron, but should also take care of much of the radon that seems so common around here. - The aerator is based on the Aer-Max system and uses some of their parts, but with a few changes I hope turn out to be upgrades. Compressor with tank for air delivery, air filters, 'bubbler' pipe (small holes drilled in the end to get more air/water contact), more robust solenoid... Sort of an experiment at this point. - That said, I'm hoping to find a better way to diffuse the air than drilling holes in some CPVC. - Also want to find a quieter compressor if possible. California Air Tools advertises one that is apparently 56 db (opposed to the B&S's 60 db). I don't know about their reliability though. - 240 V solenoid would be nice - could more easily tie its operation in with the well pump on the pressure switch. - I would really like to use their tank head with larger ports, but unfortunately it only comes with a 4" base, and I can't find any good 4" opening tanks for a reasonable price. [b]To Backwashing Katalox Light Filters[/b] - Katalox Light is marketed for very good iron removal, and will apparently also filter sediment down to about 3 microns. - I'm hoping that with all the dissolved oxygen in the water I won't need any sort of regenerate for the Katalox Light and can simply backwash it. - These will probably be set so one tank backwashes every night, on an alternating schedule. They will use Fleck 2510 control valves, timer version. - I've attempted to balance flow through the two filters. Plumbing look alright? - Had thoughts about using some sort of stacked tank setup, or the mid-Vortech tanks, to have the KL on top of softener resin, but I can't think of any way to make that work well. Would be really nice to save the space and money for extra tanks and control valves though... - I've heard the Vortech tanks planned for here and for the softeners have potential issues with the plate breaking. I'm willing to give it a shot though, especially with the warranties some have. [b]To Softeners[/b] - Again, tried to balance the flow between the two softeners. Plumbing okay? - Outdoor lines break off here to skip softening. One valve for the spigots on the house, and another for a line which will go to a pasture. The separate valve for the pasture will be actuated by a smart-home enabled motor to facilitate work out there. - The softeners will run in parallel and will have their backwashing offset. - Will use Fleck 5800 control valves for the soft-water brine tank refilling and counter-current regeneration. Trying to decide between the SXT and XTR2 controls. - I've been told the 2510 valves used for the filters don't let untreated water past while backwashing. That's good - do the 5800's act the same while regenerating/backwashing? If not, I'll probably rig up something that accomplishes that. - Resin... Probably one of the harder decisions, but I am thinking of going with the SST-60 from Purolite. My backup was going to be Resintech's CG10-Na. If the SST-60 will perform just as well or better than the competition, I'm okay with the extra price even if it just for the experiment. If there's a better performer for the money though, please let me know! - Salt: Probably going to go with Diamond Crystal's Hardi-Cube. I was getting a lot of residue in my old brine tank with whatever salt I found at Home Depot/Lowe's and would hope to change that. The Hardi-Cube salt is apparently 99.8+% NaCl. Anyone able to beat that without going into crazy prices? [b]To Carbon Filters[/b] - One last time, tried to balance the flow. Not happy with with one though, mostly because of how the pipes join up downstream from the carbon filters. I also want to get the filters closer to the softener tanks so the whole thing can be closer to the wall. - Atlas Filtri also has a product I'd like to use here instead, if only I could find them for sale. [b]To Micron Filter[/b] - Again, Atlas Filtri has a very competitive micron filter, and even a sub-micron option... But where? - If I do go with the Penteks, I might double up on them to avoid having the restriction of the 3/4" ports on a single filter. That would make this section of plumbing even more of a mess though, and I'm not sure how much benefit I'd see anyway. - This is the only section that doesn't have complete bypass capabilities, due to space limitations. So if someone takes an ax to the sediment filter, I'll have to bypass the carbon filters too. Oh well. [b]To UV Disinfection[/b] - As I explained in the beginning, I'm pretty sure the well is not contaminated with bacteria. Still, I'll disinfect the well and my plumbing with chlorine bleach before I do all this work, and I'll use the UV lamp for the lifespan of its bulb before retesting. If there's bacteria, good thing I had the UV. If not... well now I have an extra UV lamp. I'll put it in an air duct or something. [b]Heating[/b] - This will be my first time with a tankless heater. I'm pretty sold on the Stiebel Eltron Tempras. Probably won't get the Plus version though, since as I understand it, the main benefit is that it limits flow if necessary to maintain a constant output temperature. This seems like it would only be helpful if you only wanted straight hot water, and a lot of it. Either you have a smaller amount of hotter water with the Plus, or you have a larger amount of less-hot water without... Either way you will need to adjust your mixture at the point of use to maintain a stable temperature there, right? - Where the red/blue copper lines split, the ones that go straight into the wall service only the kitchen sink, dishwasher, and washing machine. I'm thinking of putting a separate smaller Tempra under the kitchen sink to get those three more immediate hot water and to take the load off the 36.