P Lyons

In order to calculate the Volume of the wetland:

Using the 5 day recommendation: Required Volume of wetland = 5 days X Volume of Greywater generated per day.

Assuming you will generate 100 L/day of greywater, the required volume would be 100L/day X 5 Days = 500 L.

Technically, in order to achieve 5 days of retention within the wetland you would need to factor in the volume occupied by the gravel, which would result in a design volume of 2 to 3 times larger, depending on the characteristics.  For your application with a final discharge is to a swale system, I think this would result in something unnecessarily large.

A few considerations if you choose to incorporate the constructed wetland as part of your system:

If kitchen wastewater will be part of your greywater, I would recommend using a woodchip filter prior to the wetland to remove any food particles, oils, greases etc. so you don't end up plugging the system.

protect the inlet and outlet piping and ideally allow for inspection.  Using milk crates or upside down buckets with holes drilled in them  surrounded by larger rocks than your gravel material will protect these critical areas from clogging and becoming matted with roots as well as facilitating inspection and maintenance.

For the gravel material, if you have pea gravel,  that is what is typically recommended, but if you have something else available you can use it, best to wash it well prior to use.

The typical recommended depth of a constructed wetland is usually around 0.5 m, so maybe you could use half of your IBC as the wetland reservoir, but any other water tight vessel or liner could also be used.

What area of Indonesia.  I spent 3 years there.  I sent you a PM with some contacts that are involved in the types of development you are considering, they all happen to be based in Bali, but they likely have contacts in other regions as well.

I am not sure if you are designing the entire resort or a greywater system for an existing facility?  

Could you provide more details on the resort such as existing facilities and/or infrastructure, layout of the resort (type of facilities, number of buildings, cabins etc.), area(s) available for the greywater treatment areas, general topography and elevations of the area, plans for future expansion etc.  Also your location would be useful to understand climate considerations and regulations that may apply.  

The amount of water I would like to process is 5000L (15 min duration) at peak use that is water from the wash basin, shower and laundry.  Total grey water per day is estimated at 15,000L.

 Could you provide information on how you arrived at these numbers?  The peak seems high to me...1/3 of total daily estimate used in 15 min?  The daily estimate works out to around 180 L/guest/day, again this may be a little high/conservative as I am assuming that the necessity to truck in water would result in water conservation priority in design of plumbing fixtures and overall water usage practices at the resort?

If the greywater collection plumbing has not been constructed, it would be worth considering individual at-source treatment systems, provided you are in an area where regulations are not strict or non-existent.  For example:

- Individual or small groups of bathroom sinks/showers directed to small treatment systems comprised of mulch basins
- Laundry facilities could have a dedicated system based on number of machines and expected useage
- Kitchen and food prep areas could have a dedicated system - it would be best to use a mulch/wood chip filter to remove food particles and grease (or a conventional grease trap) prior to discharge to greywater treatment system or any collection plumbing infrastructure.

There are several possible advantages of this strategy:

- You may be able to save significant cost on plumbing materials and installation compared to conventional collection plumbing of all facilities to one treatment area.  
- Each system could be designed specifically for the type of greywater to be treated, and would make planning for daily flow rates and peak events would be simpler, with less risk of over or under estimating the actual flows.  
- smaller easier designs for planning, installation and maintenance - would also be able to be more discretely incorporated into the landscaping plan
- facilitate future alterations to the system as individual areas can be maintained/modified/expanded on a smaller simpler scale.  
- Easier troubleshooting of system issues
- mitigation of system failures.  If a combined system fails, the entire resort is affected, where as individual system failure would only affect those locations where the issue has occured.

We have a pet rabbit that is a one year old female, it free ranges a small yard with some chickens.  In the last couple of months it has started using our covered tiled patio as its personal bathroom.  This and has become a real nuissance as we frequently use this area and the urine is staining the tiles.  

I have tried chili flakes to deter it, but they seemed to have no effect.  

Any ideas on how to deter it from this area or make another area more appealing?

A couple more photos

Currently spending some time in Cuba and recently salvaged a couple of mahogany logs (trees being cut down for road works). The logs were debarked and left on a covered patio to dry while I decided what I would build with wood.

I recently noticed that something is boring into the log. The diameter of the hole is about 1mm, I probed the holes with a wire and they extend in about 1 to 2 cm, not sure if the path of the hole then has a turn or not. I have been unable to see any of the boring insects. I am not sure if it is an entrance or exit hole? See photos.


Based on what I was able to quickly find on the internet, it is not termites as they do not produce sawdust/frass, but is more likely some sort of boring beetle?

I would like to identify what the insect is and figure out the best non-toxic treatment to eradicate this pest.

Roberto, I would definitely recommend that you purchase any of Art's books that correspond to your areas of interest. They are affordable and packed with practical useful information.

On my spectrum of cold weather greywater systems, my theoretical design is the most basic system I can think to practically construct and I want to explore the potential of determining how far you can push these minimal design criteria and what elements need to be considered in order to best protect the environment and prevent system failure.

On the other end of my spectrum would be the "Solar Greywater Greenhouse" as per Art's book. Chapter 8 details more advanced greywater systems and he provides examples of Solar greywater greenhouses's in operation and provides some general design considerations. If I had unlimited resources and knew that I would be living in my current home longterm, this is definitely the system I would design as part of my house. It would provide year round potential use of the greywater resource and assist in regulating household temperature and humidity. The greenhouse would also provide the ideal location for experimentation of different greywater treatment and reuse concepts year round. It is also a great investment for your home and quality of life, a definite added bonus. I am not sure if this would help in resale value, as not all would appreciate such a system.

I am not including advanced engineering solutions as part of my spectrum of greywater systems: These include mechanical filters, storage tanks and pumps that are being marketed as greywater treatment systems. I think that these systems can be avoided in most applications. Again Art's book and website do a great job of evaluating and discussing.

Thanks Rebecca, your post and photo is a great example of a larger installation operating successfully for many years. I have read a couple of your posts on similar cold weather related topics and your information is what led me to consider designing my system to allow for accumulated ice build up and control of spring melt.

Are you using greywater to create the skating rink or is it coming from the nearby surface water?

There are multiple families living in your community, can you remind me of the numbers?

How deep are your pipes buried, do you do anything additionally to insulate pipes for cold weather periods?

During your winters do you typically get day time temperatures above zero where some melting of the accumualed ice will melt?

How does the photo you included compared to typical and maximum ice build up during cold weather periods?

In winter, to reduce the ice buildup in the swale along the cliff edge, we usually let the greywater just spill out into the garden and soak in and/or sublimate. The garden soil seems to like it just fine.

At some point were there ice build up issues, or was this part of the design to mitigate a potential problem? If you did have ice build up issues, could you provide some information as this would clearly be situations to avoid?

Have you notice or observed any microclimates being developed at the greywater discharge locations. ie. less frost depth in the surrounding soil area during the winter or frost pockets being developed that take a longer time to melt compared to surrounding areas?

In my yard I created a rainwater garden on the north side of our home, due to spring freeze/thaw conditions and the location of the garden, it is usually 2 weeks behind the rest of my yard in melting to exposed ground.

Thanks again, I'm sure that your information is appreciated by many considering greywater systems in colder climates.

Some perspective on my thinking:

For many years, I was building and experimenting with wetland systems for both greywater and combined wastewater systems, mostly in Indonesia. I experimented with many different types of grease traps, different wetland systems (subsurface/horizontal flow and vertical flow) and evapotranspiration concepts. In many cases, the grease traps eventually failed due to lack of maintenance, which resulted in subsequent clogging of the downstream system. It was definitely not install and forget and there were considerable resources used in the construction and a required maintenance component.

I met a permaculture practitioner, also working in the region, and was introduced to the concepts of the banana circle. The resulting system eliminated the grease trap and proved to be much simpler and practical for both the construction and maintenance with respect to most applications I was working on. Soon after, I started reading the information from the Oasis web page, finally ordering a copy of the book. It was at this point I realized that most simple solution possible for effective treatment was far superior to more elaborate designs that tried to replicate what nature effectively accomplishes given the opportunity. There are a couple of key take-aways that I always keep in mind based on Art's material (I am paraphrasing based on memory):

1. The best treatment of greywater occurs in the upper region of the topsoil
2. A well built and maintained mulch basin will not fail even if the system is abused (ie. grease and solids handling capabilities)

I have since tried to simplify all of my designs to best utilize the natural environment available and avoid external inputs and components that can complicate any design or maintenance requirements.

Thanks for the clarification on your plans, I enjoy hearing the ideas and thoughts of others thinking about these issues and the best methods for a sustained winter operation.

I think that your containers will essentially be creating a healthy environment for treatment, similar to what nature creates in healthy topsoil. My perspective is however, that the environment you are creating within the containers will be isolated from the natural environment, essentially limiting the potential of the system to benefit your site. Without the ease of harvesting the nutrient rich resources created, you are eliminating the possibility of easily applying and utilizing this material. I would prefer the design of a system to most effectively use all of the outputs of the greywater resource.

I like the Solviva system and others that I have seen similar to it, your thoughts and ideas included. It is well worth experimenting with in more extreme cold weather situation, something that is definitely more feasible within a greenhouse environment like you are considering. I believe that I read that the system created has not needed any material removed after years of operation, so I think it is possible you could operate the proposed system for many years without issue, providing you can keep the system healthy.

My thinking on the nutrients within the system is that at some point, without plants to uptake the nutrients, there will be a carry over of nutrients, ie. worms digest input materials but release castings, some of which would be carried over as soluble nutrients within the treated greywater outflow. If I understand correctly your discharge would not be directly to the groundwater system but to downstream trees and plants that would happily consume these nutrients, so this is probably a non-factor in potential ground water contamination depending on the soil conditions of your site and distance to groundwater table.

You have a nice large lot to work with and a convenient slope that allows you many options for construction of your ultimate system, so take advantage of the possibilities that are not available in all locations.