If you collect the rainwater correctly and use for grade tanks the water stored in the tank should be of potable quality. Ceramic water filters can be used to further filter the water http://www.safewaternow.org/?page_id=31
To learn more about rainwater harvesting go to the American Rainwater Catchment Systems Association http://arcsa.org. They have a manual that can be used for reference. The Australians Rain Harvesting http://rainharvesting.com.au have great products for small to medium sized systems. The Germans have several companies Wisy, 3P Technik and Intewa.
I have tested 4 of my systems and they are potable according to Georgia State residential requirements.
Let me know if you have any questions just follow the ARCSA guidelines.
Hi Colin, we manufacure personal/family water filters which could suit you. They need neither any power nor regular change of cartridge, www.naqwa.com. Shall be glad to assist. Best regards, Felix. zfm@petros.ru
Patrick's comments and sources are very complete and valuable to find answers to your specific needs. We are manufacturing and installing the following systems in Mexico: http://www.aquatec.sk/en/. Better check Aquatec's website as it is in English.
The advantage is that you can reuse every liter of household water in irrigation, we are even treating it to a level of quality that allows for reuse in toilets. The disadvantage is the energy consumption. For the same reason I would not even consider installation an aerobic wastewater treatment and recycling system if the use of the off-grid building is very low.
Already available in EU compliant water and waste water treatment plants. www.rsgarrow.co.uk/page9.html or email BobGarrow@rsgarrow.co.uk. Energy requirement could be met by run of river hydro if you have access and enough flow, when it's raining and/or solar when it's sunny.
Thank you for sharing your contact details with Mr. Robison. However, if you would share additional details about solutions (products and services) for the issue, others who have similar problem could see it and benefit from it.
I've got just the right plan for YOU so send us an email globalian@rocketmail.com then I'll forward a tabled report or call in on LinkedIn there in you'll can read my articles or ask me more always it.
I would like to draw your attention to two e-courses the SANDEC department at EAWAG (department for water issues in developing countries in Switzerland) has published. First one is about household water treatment and the second one is about household water treatment.
Both course videos have been published on youtube:
Please note that all this resources are for free, and there is plenty more on the website. This research institute does not only theoretical work, but work a lot in the field to assess the different options. Please follow this link to find all their publications (which also includes sludge and solid waste, topics you might be interested in) :
The pollutants contained in rainwater are mostly microbiological due to the collection system and particular/chemical due to the exchange with atmosphere. The solution with the claypot having silver ions is a solution which might be adapted to your case. The biggest problem you will face is the safe storage of the drinking water produced. Please have a look at the courses.
Since your blackwater stream is already taken care of and you do not want to have stagnant water because of mosquitoes, may be a sceptic tank can be a good solution. The water will go into a tank generally build underground where it will be treated anaerobically, and an overflow will lead excess water to infiltrate into the ground. From time to time you will need to desludge the tank (sludge produced from carbon removal). This sludge should be pathogen free. and can be used in several applications. This solution is well known and is used in a lot of areas for household wastewater treatment. Advantage is it is compact, easy and hidden underground.
If you have a lot of organic waste at the same time, anaerobic treatment with this organic waste can be also used for biogas production. Operation will be more complicated, but gas can be used for kitchen purpose. Please note that for being interesting, organic waste has to be big enough (If only one househould is treated, this is is not interesting for instance).
Anyway, I hope the material offered will help you, it is a great free resource.
If you have any questions, please feel free to ask.
What could be helpful is to know if you plan treatment for just one household, or if you are trying to find a solution for a village for instance.
In your case, you want to separate blackwater and greywater stream, depending on local habits this might not be the best idea.
Cheers and all the best,
Patrick
Published
by Patrick Rambosson, Process and Sales Engineer at Lenntech BV
2 Comments
Hello Patrick,
thank you, this will be really useful. The development is entirely new, but will grow to around 150 households over the next few years - at which point the biogas production from waste becomes an option. In early days the first "settlers" will require a single house solution.
Useful suggestions Patrick, thanks for sharing the resources. We are working on a similar request for a small tropical island where potable water resources are diminishing due to partial urbanisation and tourist activities, the local community has practiced eco friendly practices so far, however with an airport and a small industry coming nearby, the runoff volumes shall become substantial and availability of water for increased population, mostly used to wasteful consumption patterns will pose a potential water crisis.
The green drain solution is a combination of underdrained bioswale and retention tanks build with FRANKISCHE Rigofill-ST geocellular blocks. To resolve the problem of mosquitoes and brackish water collections, the soil cover above the blocks is maintained in a manner that the macrophytic activity in the gravel/sand layers has been substantially augmented by the rootzone. The layering as to be carefully calibrated according to the flow rates so that there is no ponding on the surface and the local flora is allowed to have a well drained soil.
We chose Rigofill-ST blocks as these offer greatest strength and void ratio, expected life is well over 50 years, easy to install and inspect afterwards. Frankische has given us adequate design support, the first few installations in India are showing encouraging results.
Please note that the grey water in these underground trenches will need to be recirculated and is not deemed to be potable, secondary treatment is recommended as per local site conditions
Your requirements can't be readily met in a tropical environment. If you don't want to get sick, you will need disinfection, which requires either chemicals (HYPOCHLORITE) or energy (UV). You could restrict the disinfection to the drinking water only.
Bacterial and algal growth will be your greatest problems, along with the nutrients from the atmosphere in rain water. I survived for 18 years on a farm with untreated rain water, but it was in New Zealand and we were far from a nutrient rich atmosphere. It just rained a lot!
Whatever you do, you will need to exclude light from storages. To reduce nutrients, a first flush system will help.
