The Good Life - Off Grid Water Solutions
eIf you're thinking of escaping the smog of modern day commercial living in exchange for a more peaceful existence we've prepared a quick guide for those essential water supply and treatment considerations.
The vast majority of homes in the UK are connected to a central water supply, operated by their local utility company. However, around 1% of the population in England and Wales use a private water supply (PWS) which would generally be a borehole; in Scotland this figure increases to 3%.
Groundwater as a Water Supply
Many properties with a PWS have a ground water supply usually fitted with a borehole well pump. If a new borehole is to be sunk this will be subject to building control and the Environment Agency (or SEPA) will be involved at the early stages to ensure the borehole has no negative impacts on the existing groundwater.
Rainwater as a Water Supply
Capturing Rainwater is something that any household or business can do but if you are thinking of living off grid this becomes particularly important. Any roof space can become source of water supply. By simply installing a water storage tank, whether that be above or below ground, a large amount of water that would otherwise go to waste can quickly be collected and stored until necessary and delivered on demand to where it is required using a rainwater harvesting system.
Whilst rainwater itself is not suitable for drinking directly after harvesting, there are a number of products that will divert and filter the rainwater to an acceptable standard for flushing toilets which typically represents 30% of total household demand increasing to 45% if washing machine usage is added. Splitting out potable and non potable demand has a significant effect of reducing the demand and sizing of the potable water system and often pays for itself.
In terms of sizing our online rainwater harvesting calculator will help for most domestic and smalls scale projects. If the project is more substantial you may wish to consider a level 3 rainwater harvesting assessment.
Storage of Water.
Once a source has been identified the water can be stored in its raw form or after treatment. If stored after treatment a potable water tank will be required. A combined potable tank and booster pump set can be incorporated into the system to ensure short durations of high water demand are well managed. This tank is typically much smaller than a main raw/source water tank.
Water Treatment for Drinking
In some cases however a total off grid solution is required since no other source of water exists and so rainwater purification system is required.
Water that is intended for drinking understandably comes under the most stringent of regulations.
Typically treatment for drinking water starts with analysis of the incoming water to establish the baseline using water quality testing.
Once the baseline has been established the treatment can tailored to suit.
In all cases a particle/sediment filter(s) followed by a carbon filter will be required. This will remove all particles typically down to 5 micron and the carbon filter will remove taste and odour issues.
This will be followed by a Ultraviolet (UV) light to kill bacteria - the size on this will depend on the maximum flow rate required typically 20-30 lpm in a domestic setting.
A WRAS approved booster pump set maybe required to store water and balance demand and maintain pressure.
Further water treatment may applied depending on the basline assessment, this may include Reverse Osmosis membrane filters.
The above treatment chain can be supplied in an "all in one package" such as the Rainsafe, an innovative rainwater to drinking water package solution for treating rainwater into drinking water, storing it and delivering it on demand.
Waste Water Treatment and Grey Water Recycling
There are a number of activities that result in wastewater being created, domestically these could include cooking, bathing, washing, using the toilet.
As with the benefit of splitting out incoming water into potable and non potable uses it is worth considering the different types of waste water.
Grey water represents up to 70% of wastewater output resulting from showers, baths and taps and thus a potentially great resource. We supply the Hydraloop which is a package system which treats grey water to a non potable standard suitable for flushing toilets.
96% of the UK’s wastewater is treated at large scale waste water treatment plants. This is completed in the following stages:
- Preliminary treatment
- Primary treatment
- Secondary treatment
- Tertiary treatment
In an off grid scenario the waste water must be treated to a standard where it can be discharged to a drainage field or a water course. New legislation in the UK requires all new properties and existing properties with a septic tank to be upgraded to a package treatment plant or a small sewage treatment plant.
There are also a number of solutions that can be installed on a more local level, such as a GRAF One2Clean domestic sewage treatment plant which treats wastewater to a very high standard allowing it to be discharged to the water course with minimal environmental impact.
Living in the 'sticks' is dream for many but it does present some challenges: where will the water come from, how should it be treated for drinking and how will the wastewater be dealt with. Whatever the challenges we have a solution. Most the technologies described above are available for inspection at the Centre for Water Saving technology.
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