Grey water disposal with a high water table and a cold climate

I am building a new house in a rural area and it looks like they are going to make us put in a holding tank due to our high water table (which is common in our area). In the spring the water table is 6" to 1' from the surface. Now, it seems ridiculous and extremely expensive to have a giant pumping truck come every few weeks to haul away several thousand gallons of mostly water, rather than processing on site. My thought is, if I could limit the holding tank to black water and deal with the grey water separately that would greatly reduce the frequency of holding tank pumping.

I'm trying to figure out what the best way would be to do this. Our big constraints are that we live in a very cold climate (the average high stays below freezing for over 3 months of the year) and of course the high water table. I've been reading about grey water and it seems like many of the grey water systems for freezing climates deal with the effluent in a similar manner to a conventional septic, with a leach field, which is problematic because a leach field below the frost line would be below the water table for much of the year.

But certain techniques, like the constructed wetland, I'm not sure if it will work because of the freezing temperatures? The plants would not be active for half the year.

One constraint we don't have, which many people looking to do grey water do, is that we have no need to reuse the grey water for irrigation, as our problem is not having enough water, it is having too much.

Does anyone have any ideas for me to look into? Thanks.

Hey Justin - welcome to Permies!

I have no solution for you other than allowing that greywater to freeze into giant block and then shipping it down here to Phoenix!

Seriously - I hope someone chimes in with some thoughts on this as your climate is foreign to me, a desert rat. One thing that does come to mind is processing it through a constructed wetland that is protected from the weather somehow as in a walapini. Perhaps you could get some sort of living machine going in a greenhouse like what John Todd does?

Thanks Jennifer, I will watch the video. I know it's funny, I shouldn't complain about having too much water when so many of you don't have enough, but I guess it just shows that there are probably very few places on earth that are perfect, we all just face different challenges.

Justin - we all work with what we've got, that's for sure. And that's how new technologies come into being or old technologies are revived. You might be sitting on the edge of developing technology that works for you and those in analogous climates. Rock on!

I am in a similar situation with cold climate and high water table. Due to the two extremes I’m doing two dispersing manners.  First is like your standard septic leach field for the cold months. It does not need to be below the “frost line” for it takes several months to achieve that if it ever does and only in a shady area. My frost line is identified as 30” here. Rather, have the perf pipe about a foot underground with a foot of leach rock under. From my dispersment tank the water will be diverted there for the winter months when ground water is lower. I will then divert to the other system in spring when table rises. To further aid in dispersment, all plants being watered are in mounds or elevated boxes. Water will be screened and pumped via 1/2” pvc, no emitter heads. The pipe dead ends into a 6” valve box full of rock near the plant to avoid erosion.

I'm going to be in a similar situation. Groundwater is at 19" though. A foot of leach rock will put my perf pipe right under the ground. Is there anyway to calculate how many linear feet of perf pipe I need based on my usage? Thanks!