Last night I was feeling pretty good about my trenching and being thankful I was never at Dieppe or Vimy or anyplace in a world war. In fact I was happy that my little one foot deep trench was progressing across the yard at the rate it was when I found myself at the pool return line. It was made of thick white plastic, and as soon as I found it I switched from digging with my spade to digging with a trowel, carefully exposing the pipe.
Once the return line was daylighted, I continued with my trench, and a few feet later, I came across the 2 lines running to the jets. Where the return line was of a heavy, white plastic, these lines were black plastic, bundled together. As soon as the soil was lifted from them, the pipes began to weep water and a trickle from them formed a small puddle in the trench.
Ugh. Looks like the lines should be replaced. Its good that I discovered the condition of the lines now, before all the work on the deck and retaining wall are in place, but this will mean extra work with the excavation of the lines, and placement of new ones. On the other hand, with the replacement of the lines, the pool should be in good shape to operate trouble-free for the foreseeable future. Or something.
A surprise with the pool returns was that they were all laid on the clay and backfilled with regular fill. On municipal projects we would backfill a hose with a forgiving material like rock dust or sand. Something without any rocks, and without anything sharp or abrasive in the material. At this point my plan is to expose the pool lines all the way back to the shed, replace with new, and backfill with sand.
This will likely add about $200 to the project, but hopefully will allow us to rest easy about the lines. Also for future yardwork, the sand will act as a warning that we are near the pool lines and prevent us from cutting into them with random backyard digging.
This will add another 25 feet of trenching to the project. I'm getting pretty good at this stuff.