A New Casa 2017 - Bio-Cell Construction

Early on in the construction design process we knew we had to make an effort to reduce the impact our new home would have on the town's infrastructure.  The lot is essentially north facing so the idea of solar to help offset our electrical use was not something we considered.  Off street parking to help traffic flow?  Yes, we have that covered.  Recycle?  Of course.  Water/sewer?  High efficiency toilets etc are a no brainer but what else can we do?  Perhaps we can help there.

A facebook page dedicated to Ecological sustainability solutions for Sayulita had been started about the time we began construction.  It had been discussing how even in a downtown setting there are things we can do to help wastewater contributions.  As ridiculous as it sounds, our new house will have 2 kitchens, 2 laundry rooms with utility sinks, a bar and 4 bathrooms. Granted the amount of water we will use and waste water we will generate won't be much more than we do currently, the potential contributions and usage are much higher with a full house and occasional renters/family/ friends in the apartment.  So, we decided to look up the folks who seemed to be in charge of designing a grey and black treatment system for our property.  What could we do on the lot in the space we had that would help reduce the impact we would have on an already overloaded water/sewer infrastructure.

Design by Budd Adams

Essentially, the house's plumbing needed to separate "grey water" from "black water".  Liquid waste water which comes from sinks and showers from solid waste which comes from toilets.  The solid waste, "black water", would be distributed into what is called a Bio-Digester.  This is essentially a large plastic tank(see the small round circle in white on plan above) that would be buried in the driveway.  In the bio-digester, solid waste would be broken down anaerobically as micro-organisms naturally took care of the decomposition of solids.  It would have to be emptied once in a while but it would prevent "black water" waste from most of the house from having to be treated by the facility in town.

The liquid waste, "grey water", would be filtered and sent to a garden in the front yard.  The light blue area of the diagram above shows the location.  Once filtered the grey water would slowly be treated by micro organisms, used by select garden plants and then recirculated again within the garden by a pump.

To pull this off we had to essentially plan three separate plumbing systems.  1.  The totally separate apartment system which will be tied into the the town's main sewer.  Why separate?  Honestly, we really wouldn't have any control over what occupants sent down the drain.  The concern was that some products occupants used may be damaging to the system rendering the treatment process less effective.  Something we could control in our living space upstairs  2. A system separating of all the main house(our house) toilets to distribute to the "black water" bio digester in the driveway.  3.  A system separating of all the "main house" showers, sinks and drains to distribute to a filter and then to the garden for treatment.

Design by Budd Adams

This all going on in the front yard of the small 330 square meter lot with a house on it.  Here is a photo of the front yard showing some of the formed up walls for the system.  The green section is the concrete slab to the right.  The blue section begins at what looks like a open box in the photo and the area by the plastic sheeting will actually be one more garden area that will act as a overflow should we see a big rain or something goes wrong with the system for some reason.  Excess water should infect be pumped up to the green section of the diagram to filter through the system again.  We are told the system does not smell and we are counting on that.  Our old neighbor used to water his garden with "grey water" from his house by hose and it did stink. If it does smell the system's designer has a few tricks to help with that but the system is mostly underground.  A similar system to this was actually supposed to go into a small hotel kitchen here in Sayulita to take care of grey water .  If it would work in the tight location with people eating and lodging then we hope we won't have a problem either.

The front yard Bio Cell taking shape.  The large wall to the right is just a separation wall from the neighbors's property.

So the question remains about what happens with the apartment waste water since we cannot hook into the main sewer system just yet.  Since the apartment has a single discharge line and does not mix with the Bio-cell, the only option is to collect it and have the collection container pumped out every few weeks as needed.  The collection container will be stored in a bodega(the smaller of the two green sections on the map) and hidden then removed when it is time to hook the apartment into the town system.

 Well, that is our solution for now anyway.