Indoor mulch basin for kitchen and laundry effluent

Hello, everyone!!

My husband and I are attempting to treat all of our wastewater on-site (while still adhering to PA code!), and have been struggle-busting for awhile trying to find a filter willing to handle kitchen wastewater. I understand that because it is so nutrient rich, it is often seen as 'black water.' However, we see it as a valuable resource! We would like to send our kitchen sink, dishwasher, and laundry water through some kind of filter, and then to an indoor greywater garden wall. In a brief research on mulch basins, we were wondering if an indoor mulch basin would do the trick as that filter? We would need the mulch basin to be indoors, because an outdoor mulch basin could very well not pass PA code on the treatment of wastewater...and if we are able to keep the treatment process indoors, then we have a better chance of passing code. So! My question for the community is this: does anyone have experience with implementing an indoor mulch basin into their home? Is it even possible? And, if it is, what were some common challenges that you faced? And...did you eventually come to wish that you had not even attempted to put a mulch basin indoors in the first place?

Here is our current rough sketch on how we hope to install an indoor mulch basin, as well as our current plan to treating all of our wastewater on-site:

Thank you everyone!!!

What is the PA code please?
Kitchen sink waste is grey water
Toilets are black water.

Even grey water smells a bit in the filter systems, can you have a sealed system outside that does not enter the ground and return the filtered water to the garden?

A bit more details about the indoor garden design may also help me to understand your needs.
Normally grey water systems are not sprayed or trickled down where it is exposed to the atmosphere, its commonly distributed underground via seeping hoses.
Are you trying to get rid of the grey water or reuse it?

There are some basic commonsense rules that have been developed to minimise the risks associated with greywater reuse.
They include:

wash your hands after watering with greywater
divert greywater to the sewer during wet periods
use garden-friendly cleaning products that are biodegradable and low in sodium and phosphorus
don’t use greywater that contains disinfectants and bleaches
don’t store untreated greywater for more than 24 hours
don’t use greywater on vegetables and herbs that are to be eaten raw
don’t use greywater sourced from washing nappies or soiled clothes
don’t use greywater from the kitchen, unless it has been treated
don’t let greywater leave your property
don’t use greywater that is still hot as it will kill beneficial organisms in the soil.

Hello, John!

Thank you so much for your response to our conundrum! We are currently pondering your suggestion of a sealed outdoor system that returns the filtered water to the house....that is a really good idea...

When I say "PA code" I was referring to Pennsylvania State Department of Environmental Protection Code on the treatment of wastewater. Unfortunately, in PA code, they consider all wastewater, including kitchen, laundry, shower, and bathroom sink effluents, to be 'black water.' Many typical greywater treatment systems are illegal in Pennsylvania. Code officials generally advise for septic tanks~ where the black and greywater just all mix together. We really don't want to do that.

First, we don't want to dig. A septic tank requires a lot of disturbance to natural soils, and we want to have as little impact on our land as possible.
Second, we are aiming to achieve Living Building Challenge certification (https://living-future.org/lbc/), so we need to find a way to treat all of our wastewater on-site. A septic tank however, requires regular pumping. And then the waste is taking to a wastewater treatment facility.
Third, we believe that greywater is a thing, and a valuable resource to be reused. This concept is a fairly foreign concept to our local community. Many here see greywater as 'gross,' and should just be sent to the septic with the black water.

If we can find a way to keep the treatment of all of our greywater indoors, then we just might be able to pass code. We do intend on using a Clivus Multrum Composting toilet system, so our human waste can become fertilizer (although, it still may be illegal to distribute our liquid fertilizer onto our land...we may have to create an additional absorption field for the fertilizer instead of actually using it...again, code). For our shower and bathroom sink water we are going to use a Hydraloop system (https://www.hydraloop.com/). It is also indoors, and will treat and then reuse that greywater to flush our foam flush clivus multrums as well as wash our laundry. However, 50% of each load of laundry does need to be discharged. In the Hydraloop system's design, that 50% from each load is designed to go to a septic tank. But we won't have one, so we are hoping that we could send that effluent to our mulch basins instead. Any excess treated greywater from the Hydraloop will go to our greywater pillow which will be hooked up for outdoor use~ wash cars, irrigate garden, etc.

IF the indoor mulch basins could work out, then we may actually be able to keep all of our wastewater treatment indoors, giving us a better chance of meeting code! Fingers crossed! It would also allow us to reuse that treated greywater for our indoor greywater garden wall.

However!!! Your idea on a sealed system outside, that does not enter the ground, and then returns the filtered water back to the indoor garden wall...is pertty genius...that might actually meet code if we do it right and can keep it warm in winter! We shall definitely continue to ponder that one.

Thank you again!!

I have seen sealed evaporation beds with food trees growing in them. The filtered greywater helps the plants which transpire the water to the atmosphere.

Hello, John! Thank you for another suggestion! I have not heard of sealed evaporation beds before, but William and I will certainly look more into them! Thank you again!!