Water System

'''NOTE: The information on water filtration is not really a "pick what you want" ordeal. Ideally a decent water filtration system will contain EVERY filtration method mentioned.'''

This page presents information on how things currently are and how things could be. Each citation contains a bunch of important/interesting information so I recommend you look into them. If you are building something I STRONGLY recommend that you go through each reference per section so that you understand more about the potential difficulties and pitfalls on this topic.

Please update information on the water system as things are changed and improved so that all FC members can understand the changes and be able to improve them themselves.

Tasks List: https://docs.google.com/document/d/1Fe344s3OBtOI42WewiVQpemarj5QzZUxnHVf9mm45Es/edit?usp=sharing

Materials List: https://docs.google.com/spreadsheets/d/1LxUgaJJZGVzAoqoPE2DO7NCtV0Y0nKfgO_P0DVkeiuw/edit?usp=sharing

Drinking Water
Drinking water has for a long while been sourced from the Goldmine. But on the 6th of September 2017 they said that we will no longer be allowed to take water from the Goldmine. This means that as of now solutions are being brainstormed.

Kitchen Water
Sourced from the roof of the warehouse (Steel) we collect water in large, 1000 liter, cubic containers. As of writing (6/09/17) there are two containers which need to be switched between manually.

When they are full the water is pumped into a water tank which is on the second floor (look left and up when you go into the warehouse) which is then gravity pumped (no mechanical help: just gravity) into the taps in the kitchen and bathroom. In order to pump the water up to the 2nd floor container a pump needs to be plugged in and unplugged before the barrel overflows.

There is no filtration in this system as of yet.

Water pumps
There is a submersible water pump in the outside water tank that pumps the water into the supply tank in the warehouse. It has a float switch that turns the pump on when it is vertical. Often because the water level is below that of the float switch it has to be tied up vertically in order for the pump to turn on.

There used to be a water pump that would then pressurise the kitchen's water system. It would pressurise 3 tanks (I think they are called thermal expansion tanks) that would then apply that pressure to the water system when the tap was opened. This meant that the pump was not active whenever the tap was open.

A sound proof box was made by a volunteer which was an important addition as the pump often

woke people up in the night or was just generally annoying.

This pump, somewhat ironically, died from water damage and there has not been the money or inclination to replace it yet meaning the kitchen uses low pressure, gravity fed water.

Water Consumption
In a European country such as Britain water consumption per capita (per person) is around 150 liters per day. This is much less than the 1115 l/h/d of the average American household.

At Floating City it would make intuitive sense that per capita we use far less. As we don't shower using the rainwater (Or often at all) and we flush the toilet using a bucket of water from a barrel separate from the main water system. This means that we use nearly all our plumbed water in the kitchen which in an average British household (that according to the UK government statistics study is comparable to other European countries) accounts for 42% of water use. According to the UK gov national statistics- 63 liters.

Another statistical map charts water use per person per year by the country. In Denmark it seems the normal person would use 120,900 liters per year, 340 liters a day. ''Though this does not seem to be an average representative of the normal person. But it's pretty interesting to gawk at.''

Either way, the conclusion drawn from this cursory research is that Floating City can expect to use nearly all of its water in the kitchen and even then, due to water pressure, water is generally conserved quite well.

I would estimate that we use roughly somewhere between 60 and 100 liters a day on account of each drinking water barrel being 30 liters and how we generally use two of them every day at least. More precise measurement on water usage would be very valuable.

Off-Grid Rainwater Viability
One off-grid survivalist has a water system of roughly 4500 liters in a tropical climate. He claims that throughout a one month drought, he never ran out of water and that most of his water use went towards his garden.

This is of course an estimate as we don't know the nature of his water usage but it would seem that for FC to run on rainwater we would need at least 4500 liters of water storage.

Integrated Rainwater System
'''NOTE: From here onwards are a lot of links and diagrams featuring imperial pipe measurements. This is a table to help you understand the differences (if not metric standards) of pipe diameters. Btw, if you see Schedule 40 or schedule 80 (SCH) this refers to the interior pipe diameter. 80 can contain more pressure and they fix together just fine.'''

Materials
Copper piping is a damn good standard for plumbing but plastic piping is cheaper and more prevalent. But is it safe!!!!?

Yes. Yes it is. '''

The three biggest problems facing a rainwater system are as follows The 3rd one, at least until we can make a blimp to seed clouds, is beyond our control and theoretically can be compensated for entirely through increased capacity.
 * 1) Contamination
 * 2) Capacity/Collection
 * 3) Crap, where's the rain gone?

Capacity/Collection
Our capacity can be increased relatively easily and for free. Using Adblue barrels which are usually given away for free, we could make a series of barrels, connected with bulkhead fittings, with a spigot in the final one from which we get our water.

The barrels have a capacity of roughly 200 liters each and are made from HDPE. HDPE stands for high density polyethylene which doesn't thermally degrade until 120 degrees celsius and takes roughly 100 years to photodegrade. As these barrels are so thick, it would take much longer meaning that within all possible reason, HDPE barrels would be safe to drink from. Another big plus is that algae couldn't grow inside the opaque barrels.

FInally, it is no use having barrels without the ability to collect the water effectively. The larger the collection surface the more effective the water system will be. Loch Ness has a huge catchment area meaning that relatively little rain adds up to quite a lot of water going into the Loch. That's why we need the warehouse roof to collect water. It catches far more water than an open topped barrel.

The larger the catchment area, the more water we get.

Contamination
Contamination and water treatment is the most severe concern. FC avoids drinking rainwater at the moment and our collection system has for a very long time been at high risk to contamination. However, no one has ever gotten a waterbourne illness. Doubly however, it has always been a risk- a rat just has to swim through or someone accidentally flick something nasty in there.

More recently (July 2017 onwards) the water collection has become far more safe, being properly covered.

Still, there are many factors that need to be considered in order to make the rainwater, beyond any doubt, safe to drink and water obtained through these means

Testing
NEEDS to be tested semi regularly by being sent to a lab (info on that procedure pending.)

Important parameters for testing are as yet, unknown but here is some tips.

Screens
At each point leading to the main filters every effort should be made to reduce the particulate in water before it gets into the filter.

This means putting metal gauze over the gutters and funnels and buckets that the water travels through before reaching the water storage tank in order to prevent the bigger stuff from blocking the finer filter.

First Flush Diverter
A First flush diverter prevents the first rush of rainwater from the roof/gutters going into the water container thus removing, as far as possible: bird shit, leaves, slime, goo, guck and bugs until the rain has sort of cleaned the roof for you.There are m any ways of making one of these and this picture is a good demonstration of how one (easy to make) model could work. In many of the references on this page there are youtube videos and related videos that show a flush diverter in practice. The principal with this design is that the vertical section fills with crappy water thus floating the ball and sealing the section when full up to a certain point. The diverter can be drained and probably should be every now and then.

Slow Sand
A slow sand filter for drinking water is shown in this video where it is explained in decent detail. It basically comes down to the barrel of sand developing a biological film of bacteria that kill harmful bacteria. The biggest problem that might exist with this system, and other filters, would be the water flow. Solutions pending given more research.

The amazing thing is the water tests the video maker did. The roof water went from 35,000 CFU (Colony Forming Units i.e. groups of bacteria or fungus that would be able to reproduce and potentially make you sick) to 10 CFU after filtering. A drastic reduction.

The biofilm is supposed to develop naturally over 3 weeks and it seems they can be highly effective.

Beach sand is NOT the best idea according to a longterm developer of slow sand filter tanks. It would need to be extensively rinsed, sterilised and sifted in order to put a layer of fine sand on top that would cause bad bacteria to be held in the natural biological filter (A.k.a. Smutzdecke/biofilm) for longer, thus making it more effective.

FILTRATION DIAGRAM LIBRARY 

Drawbacks
This filter system takes a decent while to get going, if the bacterial film is left dry it will die and the time it takes for water to make its way through the filter can be up to 30 hours in an older system (where the bacteria is thick) and 5 hours in a new system (where filtering is not as effective). It relies on a strong storage system to give the filter barrel a decent margin.

Charcoal Filter Active/Plain
Active charcoal is different to just charcoal. It is treated with either steam or a chemical in such a way that the surface area of the charcoal increases to a very large extent. This kind of carbon is called Buckmisterfullerene and has "phenomonal adsorptive capacity".

This increased surface area makes the charcoal far more able to adsorb (different to absorb) bacteria, particulate and odours thus preventing it from reaching a human's body. Regular charcoal can be and has been used in water/air filters and historically has been throughout history. If it is not activated it will be unavoidably less effective than its active counterpart but allegedly effective enough for most uses.

Unlike the above slow sand filter the active charcoal filter should be replaced periodically to maintain efficacy. It would also be an addition, not alternative, to the slow sand filter.

Ultra Violet Irradiation
Ultra Violet radiation (light) can kill bacteria by turning them into superheroes that are unable to handle their powers thus resulting in death at the hands of their own inexperience.

The effective range of a UV light is only a couple of centimeters .The most primitive use of this method is seen on the Indian subcontinent and Africa where people will put water out on a screen, making a thin film of water that the UV radiation from the sun can shine through an kill bacteria.

The most effective wavelengths of UV are 300-250 nanometers and these are both damaging to eyesight. A system reported to us from Leipzig used UV LEDs that irradiated a flat, moving film of water.

In more industrial systems there needs to be a filtration to remove large sediment before irradiation as bacteria can hide behind detritus. One way of circumnavigating this problem is to vortex the water whilst it is irradiated so that bacteria are unable to hide behind particulate.

Non-Integrated Rainwater System
Another option for the drinking water system would be to have it not integrated into the collection system where a

filter tower is installed in the kitchen. The Berkey Water Filter can apparently filter ~60 liters per day  and the filters can apparently be cleaned and re-used. A system such as this would cost $200 up front with a filter replacement probably every year. This sort of water filter would be useful to have as the cost of filters would be less than a small one where the filters need to be replaced far more regularly.

It would also be possible to make a filter tower using only the ceramic filter like this guy did. Here are some ceramic filters  that would be usable in a homemade arrangement. It would take 4-6 hours, with one filter to fully filter what looks like 20 liters. The more ceramic filters the better.

The lifespan of a ceramic filter can be very long if they are properly cared for. Some people have claimed 25 years but 1 year, if the water going in is sufficiently clean, would be very possible.

Desalination
Desalination is the process of removing salt from water. Thankfully, this is reeeeally easy. You heat up a container of salt water and the evaporated liquid can distill, along a tube, into another container.

The bad part is that this only removes mineral impurities and many man made impurities will persist. Various hydrocarbons, certain metals and other stuff too, probably. I dunno. I'm not a doctor. Or hydrologist. The point is that it's in your best interests to treat thermally distilled seawater beyond the boiling stage.

Chemical Flocculation
Flocculation is a process that reduces the turbidity of water. Turbidity is where there's a bunch of dirt murking up your water. That stuff's super bad because that's where a lot of nasty bacteria lives.

Flocculation is something that is automatically done by the above filters but for posterity's sake I (Josh Carr) will say that I have made coagulants that have worked to great effect though I didn't do it with the intention to drink the result. It wouldn't have been safe.

The most effective coagulant was aluminium sulphate. I made sulphuric acid (burn sulphur and bubble the smoke through hydrogen peroxide) and dissolved aluminium foil in it. This immensely reduced the turbidity of British canal water and resulted in a much less disgusting looking sample of agar jelly than the control sample or sodium aluminate sample.

Freezing
One of the biggest obstacles to a water system is winter. It is currently unknown if insulation would be enough to prevent freezing in prolonged 0 degrees, as the storage tanks would not be producing heat. It could increase the time it takes to freeze, however.

Burying and Sinking
Another method of preventing freezing is through either burying or sinking the storage tank. The tank must be below the frost line which does vary depending on how cold the winter gets.

In -10 degree weather people are advised to bury pipes at least 1.2 meters deep. In colder weather 1.8m is advised. In Copenhagen 1.2 meters seems to be a good, safe bet.

For floating water storage it might be possible to sink the tanks. In fish ponds there is a recommended depth between 0.45 and 0.76 meters. At this depth goldfish can hang out, be very inactive, and survive the winter. It stands to reason at this depth the water will be warm enough to prevent freezing.

Goldmine Siege
On 06/09/17 (d/m/y) the Goldmine withdrew our access to water, forcing us to find a solution.