Grey Water Disposal

   / Grey Water Disposal #1  

IHDiesel73L

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May 13, 2010
Messages
168
We've been in our place almost a year now-150 year old farmhouse on acreage with lots of updates to various systems (electrical, heat, etc...), but when we bought it, it had a cesspool and no water treatment. As a condition of the sale the previous owner put in a brand new septic, pH balancer and water softener. At some point, (I'm guessing since the PO knew the cesspool was on borrowed time) the following waste lines were diverted into separate line which ran to daylight in a meadow about 20 yards from the house:

  • Washing machine
  • Kitchen sink
  • Dishwasher
  • Downstairs bathroom sink
  • Downstairs bathroom tub
  • Basement slop sink
  • pH balancer backwash
  • Softener backwash
  • Basement dehumidifier condensate

This of course was all tied back into the main waste line when the new septic was installed. The septic is a 1300 gallon two chamber tank with an effluent filter at the outlet, but since this is our "forever" house, we want to make sure that the septic has a good long life. Now, just to start things off, yes, I know that diverting grey water is not legal or code compliant in most places. However, I also know that lint, coffee grounds, and water treatment backwash salts and minerals are very bad for septic drainfields. As far as I'm concerned, septic drainfields should be reserved for dealing with poop and poop only. Obviously discharging human waste directly into the ground uncontrolled and untreated is not a good idea, but I fail to see the harm in discharging any of the things I listed above out into an open field. I live on quite a bit of acreage and I know for a fact that there is not another well (besides mine) within 1000' of the proposed area of disposal. That said, what is the best way to handle this? Drywell? Trench?
 
   / Grey Water Disposal #2  
Research the requirments for your jurisdiction,everything you named except kitchen sink is often allowed to be drained onto surface. If surface disposal is forbidden,dry wells are usually forbbiden as well. It come's down to your local officials and how aggressively they inforce it. If I were in a corner and local officials weren't acting like the gestapo,I would install arobic treatment then distrubite with sprinklers.
 
   / Grey Water Disposal
  • Thread Starter
#3  
Research the requirments for your jurisdiction,everything you named except kitchen sink is often allowed to be drained onto surface. If surface disposal is forbidden,dry wells are usually forbbiden as well. It come's down to your local officials and how aggressively they inforce it. If I were in a corner and local officials weren't acting like the gestapo,I would install arobic treatment then distrubite with sprinklers.

I'm not going to post my jurisdiction, but I've read the regulations and know for a fact that grey water disposal anywhere other than a sewer or septic system is forbidden. As far as enforcement, it will only become an issue when the house is eventually sold, which, God willing, won't be until my wife and I are six feet under in our very own "zone of disposal." :p Even if we did find ourselves having to sell the house for some reason it would be easily put back to the way it was with a few fittings and some lengths of PVC. The County Health Department would be responsible for any type of enforcement, and the only way they find out about this type of stuff is when they are doing inspections for new installs or repairs, (not happening anytime even remotely soon) or when investigating complaints-Its not as if I'm looking to dump it onto my neighbor's lawn. I'm a 1/4 mile off of the road in the woods, so there is no one to see anything or to complain.

Interestingly, I just went back through my files and found the septic plan with our closing documents. In it, the engineer that designed the system specifically stated "Garbage disposals and water softening equipment shall NOT be discharged to this system." In doing a bit of research I found that I can buy a lint filter for the washing machine, which is my biggest worry (the system should be adequately sized to handle the water), but it sounds like I really need to get the water softener discharge out of there ASAP.
 
   / Grey Water Disposal #4  
Personal what I would do is run a separate drain line out to a couple of dry wells with some stone around them, concrete covers on the dry wells and enjoy knowing that my septic system was going to do the job it was supposed to and my dry wells there job. If you wanted to add a septic tank before the dry wells and plan on having it pumped as necessary for solids. Maybe every few years.
Using a septic tank and dry wells could even meet rules.
 
   / Grey Water Disposal #5  
If you think the septic is for poop and poop only I’d spend some time reading up on septic systems. The gray water isn’t going to “overload” a properly designed system and typically it’s beneficial to move the fluid through the system. I’d leave it as designed and find the next hobby to occupy your time and resources.
 
   / Grey Water Disposal
  • Thread Starter
#6  
Under the state code a 4 bedroom system must be designed to handle 650 GPD. I used an online water usage calculator that pegged us at about 550 GPD for usage, but this doesn't take into account any water discharged to the system by the dehumidifier or the water treatment. Obviously as you said the system needs a certain amount of water to move effluent out to the field, but the biggest worry is moving effluent out to the field before enough solids have been settled out. I would feel a little better about that if I wasn't within less than 100 GPD of the design limit.
 
   / Grey Water Disposal #7  
but it sounds like I really need to get the water softener discharge out of there ASAP.

What is it about the salt in a water softener that is so awful for a septic system? Our house was built in 2004 with all drains connected to the septic system with mound and everything has been operating happily, at least as evidenced by the nearly 3 years we've lived here. The system has a filter between the two septic tanks which prevents solids from reaching tank 2 and the mound system. Our septic guy that has pumped the system several times has said it looks like everything is great.

Is the salt supposed to harm bacteria and make decomposition go too slowly? Not happening in our case.

Rob
 
   / Grey Water Disposal #8  
As long as all bathroom fluids (sinks, tubs, showers) go into the system, you should have enough to keep it running. The rest (kitchen, laundry, etc.) aren't needed.
 
   / Grey Water Disposal
  • Thread Starter
#9  
Is the salt supposed to harm bacteria and make decomposition go too slowly? Not happening in our case.

I think it has more to do with what happens when the highly concentrated brine makes it out to the drainfield. I've read about a couple of instances where the salts crusted around the effluent filter enough to clog it, so you can imagine what could be happening in the laterals. Here's an article that I would argue is rather inconclusive:

GWSofteners
- Center for Watershed Science and Education | UWSP
 
   / Grey Water Disposal #10  
Septic systems in MS have aerator pumps. These have air plumbing that is resting on the bottom of the tank and the air bubbles keep the bacteria working and also aid in breaking down solids.
The discharge you see could be just run off from the system and not real grey water from the house.

There is septic treatments for bacteria.
Is there not a cover for the new system where you can see inside?
 
 
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