Water
See Also
Water Infrastructure
Our water infrastructure consists of:
- Well
- Submersible Pump
- Long Hoses
- Float Switch Instructions
- Many (under 20) 55 gallon barrels
- Reverse Osmosis Filtration System
- Surface Pump (with Pressure Switch at 50psi and strainer)
System Summary
- The well draws water in from its surroundings.
- The submersible pump pushes water from the well through long hoses to a 55 gallon barrel.
- Once the water level reaches the height of the float switch, the float switch turns off the submersible pump to prevent overflow (once the water level drops below the float switch, the float switch turns on the submersible pump).
- The 55 gallon barrels are linked to each other so as to become a single large water reserve.
- The surface pump pushes water from the reserve through the long hoses to the residential areas.
- The residential area has a reverse osmosis filtration system that cleans some of the received water for drinking. The rest of the water is used for general purpose applications without such filtration.
- Notes When atmospheric temperatures drop below freezing, the water inside exposed infrastructure will freeze and expand. The freezing will block water from moving past that point; the expansion may cause serious damage to the water infrastructure.
The temperature-time functions of the air in both the general region and specific areas are a significant factor of where and if the water system will freeze. Also, how closely packed the volume of water is and their insulation are other major factors.
Hoses are vulnerable because the cross-sectional area of the water volume is low and the volume of water within a hose line is spaced apart hence cannot effectively transfer thermal energy throughout the line. Hoses are most vulnerable when flow is zero and progressively less vulnerable as flow rate increases (because water movement improves thermal transfer within the water and new water transfers thermal energy into the insulation). Hoses should be insulated (ex. buried into the ground).
Large reserves of water are resilient to freezing because their heat capacity and rate of thermal transfer are high, but given severe freezing temperatures, long durations, and little insulation, these reserves will freeze as well. Fortunately, when large reserves of water begin to freeze, the most exposed part of the reserve freezes first to become an insulating layer of ice between the air and the water. Hence it becomes progressively harder for the air to freeze the water volumes that are deeper within the reserve. Small enough reserves should be insulated (ex. partially or fully buried into the ground).
Active parts of the water infrastructure such as surface pumps are especially in need of insulation. The submersible pump is already well insulated by being inside the ground.
A further step past insulation to prevent freezing is to add a thermal energy machine with a temperature switch to turn it on or off at designated temperatures. A critical consideration here is to ensure that fires do not occur by fireproofing the heated area (ex. with stone around) in addition to the temperature switch.
An ergonomics and energy consideration regarding water use is to insulate and heat the water infrastructure more than just to prevent freezing. Excessively cold water is detrimental for comfortable use, hence it makes sense to keep the water at or close to optimal use temperatures as practically possible. Furthermore, more energy is required to heat a colder volume of water than a warmer one, hence it makes sense to keep water cold using passive insulation techniques rather than by active heating that required energy.
Overall, extremely high levels of passive insulation are desirable to prevent freezing, improve water use, and reduce energy requirements. In extreme conditions, thermal energy machines may be required throughout the water infrastructure.
Storage System Research
Due to recent realizations of safety hazards with our current water storage system, we will be exploring other options for large scale storage of water for 10-20 people living at FeF (mostly at HabLab).
Our goals are reliable storage (well insulated and enough volume), high quality clean water, and cost effectiveness.
Current Water Usage
Current use for 15 people=400 gallons per day
12,000 gallons per month
146,000 gallons per year
Roof Runoff for HabLab
Catchment Calculations
To calculate we use this equation:
Catchment area (ft^2) x Annual Rainfall (ft) x 7.48 gallons = Total Rainwater (gallons)
3200 ft^2 x 3.42 ft x 7.48 gallons = 81,861 gallons per year
That means we are short 64000 gallons per year if there are 15 people living at FeF year round (and we are only using HabLab runoff).
If we get equal amounts of rain every month, we will have 7000 gallons per month from HabLab's roof (5000 gal short of current usage).
Water Quality
The following taken from Rainwater Harvesting for Drylands and Beyond: Vol 1 (.PDF download)
"Rainwater is naturally distilled prior to cloud formation, and thus is one of our purest sources of water. Rain is considered soft due to lack of calcium carbonate and magnesium found in solution, and is excellent for cooking, washing, and saving energy. Rainwater use reduces soap and detergent requirements, and eliminates soap scum, hardness deposits, and the need for a water softener (sometimes required for well water systems), besides being a natural hair conditioner."
A note on current well water quality: the well water is not the source of pathogens. Our storage technique is the problem, and is better suited for agriculture. I propose cisterns for short term storage of well water, and also if we choose rainwater catchment later.
Life Cycle Cost
10,000 gallons of cistern storage
Burial and/or Insulation of Cistern(s)
pipes
gutters
downspouts
screens
Timeframe
We need large scale, sealed storage whether we use rain or well water. Cisterns would be a fast solution to large volume water storage, as opposed to barrels.
This is an immediate solution to water storage, it would be a large cost to buy them, and also require renting an excavator to bury the cistern and pipes before winter.