PVC drainage questions

This is how my sump pump and down spout system works.

The first PIC is the over all “Christmas Tree” at the back r of the house.

It shows the two downspouts into 4 inch PVC tees and the smaller 2 inch sump pump into a 4x2 inch tee.

The 2 inch goes in under the down spout trash screens. The exit into the larger pipe provides a vacuum break that prevents any back flow. You might be able to make out tee and a ball valve in the 2 inch line. That is because I use that tee in the spring to the sump water for filling the swimming pool.

(I have borrowed the term Christmas Tree from the oil industry. It is their term for a collection point of many underwater wells to a pumping to a station. I am relying on gravity, but I am collecting from 3 sources.)

The two down spouts are from the front and back sides of the house. Between them they collect over 80% of the roof area of a 4 bed room, two story, Colonial. Sorry, I don’t know the SF off the top of my head.

This is what I use to keep leaves and such out of the long pipe. It is meant to be a leaf guard for flat roof drains.

I turned it upside down and slipped it into the 4 inch PVC bell. I did have to whittle away a bit on the flange to get it to fit. I used the wire brush on my bench grinder for this. It is shown right side up, I flipped it over.

This PIC shows the screens in place. I have tied some twine on them to make it easier to take them out for cleaning. They work very well. Even with down spout guards in the gutters some stuff gets through. The peace of mind it gives me by keeping trash out of the long underground run was worth the small cost and effort.

This is where the drain goes. 180 feet away.

This is the end in the woods.

I had to keep the pipe high. It goes over some of my septic system. It is no where near being below the frost line. So I had to keep enough slope in it to drain it dry after each use to prevent a freeze blockage. This was my biggest concern of the whole project. Over the 180 feet of run I did not have more than a foot of elevation to work with.

To maintain that slope I used a 4 foot level with a full bubble off level at each joint. I used the light weight gray pipe because I will never be driving over it with anything but a lawn tractor. It came in 20 foot lengths. To make sure I wouldn’t get low spots in the run I did several light back fills with soaking after each. That settled the dirt under the pipe. I checked the slope a day after each backfill. If I got low spots I had loops of twine that I had put around the pipes as I laid it. This gave me an easy handle to lift the pipe with before throwing in more dirt and soaking again.

The soaking of the backfill is absolutely needed. The pipe will sag without a firm base and you will get low spots that will freeze. I don’t remember how long it took. It may have been a week of small backfills before I felt comfortable covering it up.