Water Softener Drain Line Help

[Handy Man]

My house is “pre-plumbed”. Two water softener installers gave me quotes. Each determined that the water softener drain line (1-5/16” OD) just went out the garage wall into the side yard grass, which won’t work, as would flow to neighbor’s yard. They reviewed for other nearby drain lines within the house to tie into, but not feasible. Each person came up with a drain line proposal, both of which tied directly into the 5” Sewer Main Riser Pipe near the front corner of my garage. My house is located in Houston TX area. See attached drawing / pictures. See further explanation and questions below pictures.

Quote #1 – Install an above grade drain with P trap in the front inside corner of the garage wall. He would drill through garage wall, drop the drain line underground and connect into Main Sewer Riser by front of garage. The Water Softener drain would be tubing along wall of the garage supported by mounting clips, and discharge into P trap with an air gap.

Quote #2 – Connect an Air Gap fitting to end of current installed drain line going into yard. From bottom of Air Gap fitting, install new drain line and bury it all underground to the Sewer Main Riser. He would install a P trap buried underground right before the drain pipe goes into the Sewer Main Riser.

My questions - Will these 2 approaches work from a Practical and Plumbing Code perspective.
- #1 would be inside the garage wall and have an open drain.
- #2 would have a buried P trap – Is that allowable; or do you even need one?
- #1 & #2 would not have any vent lines
- What type of inspections are needed
- What could go wrong over time that I need to worry about

I like #2 better from the standpoint that there’s no plumbing along the garage inside walls, and it’s buried and out of sight.

I would appreciate comments and any other suggestions. Thanks

 

[Bannerman]

In version #1, you show a water heater in the corner beside the intended location for the softener. Is there a floor drain below the WH? If no floor drain is nearby, where would the WH T&P valve discharge if it were to release?

As to plumbing code compliance, I anticipate your county's building dept will have authority over plumbing permits and inspections including the determination of the permissibility of connecting a drain trap to a cleanout access riser, or if a softener may discharge into the environment such as directly beside your home's foundation wall.

 

[Sponsor]

 

[ditttohead]

Without some sort of air vent you will likely siphon the water from the trap. Maybe add a simple (albeit sometimes controversial) AAV (Air admittance Valve). These tend to work very well but they should not be used in occupied spaces in my opinion. They can fail and if they do sewer gas may be allowed to enter the area.

 

[Handy Man]

No drain by water heater. The water heater is on a raised platform and gravity drains outside through a separate pvc line, and relief valve also has a separate pipe out. I asked last installer about permits, and he didn't have a definitive answer. I live in unincorporated portion of county which doesn't seem to have anything about plumbing permits on website, just permits related to new house construction.