Yesterday my contractor started the septic system for the new house. Definitely some obstacles with limestone bedrock being approximately 8"-12" down from the surface. I decided to go with a sprinkler irrigation system rather than the standard mound system, primarily because I could save $5-8k. At the company I own, we have tried to get clients with poor soils to install these sprinkler systems, but everyone is skeptical of operations, I decided to be the test dummy.
I was able to do the design of the system and get the county approvals which was also a good exercise for future clients. Basically sewage will flow out of my house to a tank that has "biologically accelerated treatment", basically microorganisms that combine with filter media to break down and filter sewage. This tank also has 2 aerators that run 50% of the time to provide oxygen to the microorganisms. The now basically clean water flows through a UV disinfection bulb and into a dosing tank. The pump runs approximately 1 hour per day, dosing the 480 GPD as required for a 4 bedroom house. The clean, disinfected water is sent to two sprinkler heads that each spray a 38' radius half circle. The 480 GPD is the equivalent of getting 0.14" of rain per day, basically such a small amount that there isn't runoff.
Day 1 was excavating for the two tanks that sit in series. The final hole size is approximately 30' long x 9' wide x 7' deep, with 6' being in solid rock. Here's a few pictures from Day 1.
Digging and Hammering in process
(https://forestryforum.com/gallery/albums/userpics/49164/27369.jpeg?easyrotate_cache=1626445230)
(https://forestryforum.com/gallery/albums/userpics/49164/27368.jpeg?easyrotate_cache=1626445233)
This shows the excavator that did the hammering, they took the mini home. It also show 1 of the two big piles of excavated rock. I estimate that about 150 tons of stone came out of the hole which will become the pad for a big patio I'm going to pour and part of my barn pad. And of course the girls dreaming about how the hole could easily fill up with water to be their swimming pool :D
(https://forestryforum.com/gallery/albums/userpics/49164/27398.jpeg?easyrotate_cache=1626445230)
And finally looking down into the 7' deep hole. The paint marks representing where the tanks will sit.
(https://forestryforum.com/gallery/albums/userpics/49164/27400.jpeg?easyrotate_cache=1626445232)
Today they will be setting the tanks, connecting the gravity sewer line, and starting to run the 300' of 1" pressurized line to the sprinkler heads.
neat system!
never seen that before, it's interesting. What happens in winter when the grounds froze up or ya got a bunch of snow and the sprinklers can't poke up through?
"don't eat the brown snow"! :snowball:
So theres no leachfield at all? How many baffles between the mainline and the first tank output? Where is the sprinkler pump located, inside the dosing tank?
Do you have to add anything continuously or just the initial microbe mix?
That's an interesting system and new to me. Seems to be generating a lot of interest and a lot of questions. Can you point us to something that explains the concept and the details?
Here's the summary from the manufacturer's website that explains a lot of the process. I blocked out any of the names of the tank and products as to not violate and advertising restrictions which I hope is adequate because it gives a very good high level summary of the tank. The entire process takes place in a tank that has 3 compartments with the tank being 10'long x 5' wide x 7' deep.
When working with wastewater, the ticket item is always air. Wastewater strength is largely based off of BOD, the amount of oxygen needed to remove the organic matter, and the two aerators take care of the majority of the work. This system is specifically designed for places, like Ohio that have a very shallow limiting condition for septic design (i.e. impermeable clay and glacial till, shallow perched seasonal water table, shallow bedrock, etc.).
(https://forestryforum.com/gallery/albums/userpics/49164/Septic_LI.jpg?easyrotate_cache=1626463563)
@GRANITEstateMP (https://forestryforum.com/board/index.php?action=profile;u=8262) the pump lines drain back to the dosing tank after every run cycle. The sprinkler heads are permanent fixtures that stick 18" out of the ground so no pop-ups. The sprinklers are specific to this function and dose a specific GPM and a specific pressure. This also sets the radius of spray and determines the amount that is dispersed in the ground, ultimately expressed in inches like rainfall.
@mike_belben (https://forestryforum.com/board/index.php?action=profile;u=33722) There is not leach field at all. The water is 100% treated by the time it flows through the first tank and the UV bulb. The above image should help explain the process and shows a section view of the tank. The sprinkler pump is located inside of the dosing tank and is nothing more than a high head, low flow well type pump. The pump runs on a float system and will be set to run one time per day.
@btulloh (https://forestryforum.com/board/index.php?action=profile;u=29962) The Ohio State University has the guidance for the state of Ohio for the design of these systems, we own a copy at work, but they can be purchased for $4.50 (On-Site Sprinkler Irrigation of Treated Wastewater in Ohio).
So its like an underground liquid hot composting container that spits out water instead of top soil.
Quote from: mike_belben on July 16, 2021, 03:45:19 PM
So its like an underground liquid hot composting container that spits out water instead of top soil.
Mike, I'll just nod, smile, and agree with you :D
Well, same kinda action. Aerobic bacteria and microbes are being manipulated to rapidly decompose organic matter.
smiley_thumbsup
We are doing this same type of system, only one 3 compartment tank. Running 1.5" line about same distance. 3 heads with built up cement pads around them so I can keep cattle off them as well as the disc, drag and seeder when I over seed in the fall. Will have back flow valve though.
I have some what the same system. From house to aerator tank then to basically a underground sand mound that has a liner so nothing leaks out then goes thru a clorinator ? Then to two holding tanks 2500 gallon total then gets pumped out to eight spray heads. Been using this for 20 plus years
Day 2 update (Friday 7/16). The tanks are installed and the gravity line from the house is connected. The trench is dug to the spray heads. I will inundate you with pictures.
Here's a shot of the two tanks. The one on the left is the treatment tank, the right is the 2000 gallon dosing tank.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210718_124001206.jpg?easyrotate_cache=1626693749)
A couple shots of the trench going out to where the spray heads will be installed and the sand they are using to bed the spray line so it doesn't sit on the jagged rock.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210718_123932651.jpg?easyrotate_cache=1626693747)
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210718_123934981.jpg?easyrotate_cache=1626693748)
The next pictures are each of the lids opened up, starting at the end of the treatment process. Here's a shot looking down at the pump. Dept of Health requires a union ball valve at the surface. The lid on the bottom side of this picture is where all of the electrical connections are made, I did not get a picture. It is a clusterfu whole mess of wires that I'm sure would make sense to the person who hooked it up.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210718_124022480.jpg?easyrotate_cache=1626693749)
A shot of the UV disinfection bulb housing.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210718_124039166.jpg?easyrotate_cache=1626693749)
The final filter leaving the treatment tank. This was only required because of the shallow bedrock. ODH requires an extra nitrogen treatment, which this filter meets. I looked up the filter and I'm not sure how it meets the requirement. The manufacturer states that it is for fine filtering of solids. Nitrogen is treated with you guessed it, air. Not the battle I wanted to fight though.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210718_124053577.jpg?easyrotate_cache=1626693751)
Top of the aerator that will run 30 minutes out of every hour.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210718_124103641.jpg?easyrotate_cache=1626693750)
A shot of the gravity line coming from the house and the power going to the tanks.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210718_124123967.jpg?easyrotate_cache=1626693751)
And finally a picture of where the hole for the propane tank will go. It costs more, but I hate looking at propane tanks so for a small fee, I am having my contractor excavate the hole so I can bury the tank. Also, you can see in the background where I used a lot of the stone that was excavated to build up what will be a concrete patio off the back of the house. I put about 2' of stone on a 20'x30' area. In hindsight, I should have compacted it in lifts, but a day with a jumping jack should take care of things. I still have probably 40+ tons of stone to use for the shop pad plus what comes out of the propane tank hole.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210718_170355454_28129.jpg?easyrotate_cache=1626693752)
Dwyatt,
That system is similar to a system we use locally for troubled locations with the exception that we still need a leach field to get rid of the water because we live in the glaciated north :D They are expensive though, and usually require a maintenance agreement with a septic service or the company to be approved.
@reride82 (https://forestryforum.com/board/index.php?action=profile;u=14202) This was actually substantially cheaper than my other alternative, a mound system, by about 30%. In Ohio, any systems with mechanical components have to have a maintenance agreement with the county department of health that has a 1 year inspection requirement by a licensed personnel for that type of system. My Installer happens to be certified for this system. He said the maintenance it pumping out the initial baffle of the treatment tank, pulling the aerator and cleaning off any junk on the shaft, replacing the UV bulb which needs done yearly anyways, and cycling the pump to make sure its operating correctly.
Even with a a gravity leaching tile type system, you are now required to have a 5 year maintenance agreement. These regulations just changed <5 years ago. basically the county wants to keep tabs on the new systems in the county and by having this maintenance requirement, they can have a reason to check them out and tell people if they fail prematurely.
Day 3 (7/19) and she's all finished up except for 2 risers that need added to the tanks on the odd ball sized holes.
A couple shots of the tanks backfilled and the trench going out to the sprinkler heads backfilled.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210719_210244980.jpg?easyrotate_cache=1626779492)
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210719_210253614.jpg?easyrotate_cache=1626779492)
A picture inside the control box. The system runs on 2 20 amp 120v circuits. The circuits control the aerator, UV Bulb, pump, and heat tape on the sprinkler heads. This makes my eyes glaze over.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210719_210343470.jpg?easyrotate_cache=1626779489)
The "don't drink this water" sign and a view of the sprinkler heads.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210719_210537159.jpg?easyrotate_cache=1626779490)
A view of the sprinkler heads. The left is a pressure gauge. The middle is the actual sprinkler head which pops up with water pressure and is set to operate at a 180 degree angle. The right is the air bleed off valve that is needed since the line drains back to the tank. Then the electrical box for the heat tape wiring. My contractor has several of these systems without heat tape as it was not standard until recently. He said nobody has had any issues, but the manufacturer must have had issues with them freezing and decided to add it as a standard option.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210719_210555054.jpg?easyrotate_cache=1626779491)
And finally a shot of the propane tank hole and the associated 50 ton of stone that came out of it.
(https://forestryforum.com/gallery/albums/userpics/49164/PXL_20210719_210310824.jpg?easyrotate_cache=1626779489)
Lots of rainwater collected off the gutters and dumped on your new pad will help compact the base layers by washing fines down into the voids.