There is a great deal of history and many projects that lead to the development of the BioSand Water Filter technology and spin-off technologies presently marketed by Davnor Water Filters Ltd. and Manz Engineering Ltd. The primary purpose of this web site is to share this history and provide guidance how to build the original concrete units. (And there are new developments here too.)
Photo shows the production from a filter factory in the Dominican Republic.
After the discovery in Temuco, Chile that the BioSand Water Filters were very effective in removing iron, the BSF technology was demonstrated in First Nation households in Saskatchewan and farms and acreages throughout Western Canada.
This photo is of a large community scale project consisting of three ten meter diameter BSF's in Honduras. These are used to treat water from a nearby stream. The importance of strong local technical support for these types of projects cannot be over emphasized.
It is also important to note that the original designs of the BSF technology for community scale projects was only partially successful when it came to treating surface water with high sediment loads. These difficulties have largely been overcome in the technologies marketed by Davnor Water Filters Ltd. and Manz Engineering Ltd.
In 1990 the first ideas for the development of the BioSand Water Filter or BSF were born. Since then numerous individuals and supporting organizations have been trained in the use and application of models specifically designed for humanitarian projects around the world. These individuals passed on their training to others, and over the past decades hundreds (thousands?) have been established.
Most BSF's are used by individual families, often shared with extended family members, friends and neighbors. The safe water produced is used for drinking, food preparation, personal hygiene and sanitation. Most of these BSF's have a capacity to produce between twenty and sixty liters of water per hour. Several health impact studies were conducted around the world demonstrating that use of the BSF could be expected to reduce gastro-intestinal disease by 50% or more.
Several community scale BSF systems have been developed over the years, originally by my old company, Davnor Water Treatment Technology Ltd., with some of this technology being copied and modified by several not-for-profit organizations into what are known as 'school based systems'. Several of the original Davnor filters are still operating after more than twenty years, similar to some of the household concrete filters. The smallest BSF systems provide water for several families while the largest provide water for tens of thousands of people (Current versions of household and community scale filters are described in this web site in the Davnor and Manz Engineering Ltd sections)
The BSF technology is used alone or in combination with pre- and post-treatment to remove water borne pathogens (helminths, parasites, bacteria and viruses), particulate matter, color, iron, manganese, arsenic and in certain cases dissolved toxins such as fluoride).
There is substantial reference material pertaining to the history, designs, implementation and early evaluations on the BSF listed below. As well, there is detailed information on the construction of the original Manz BSF or Manz Design as it has come to be known.
My personal history which resulted in the development and dissemination of the BioSand Water Filter technology was recognized in a recent Alberta Order of Excellence award details of which may be found in the following web site: https://www.lieutenantgovernor.ab.ca/aoe/community-service/david-manz/index.html
I am told by people who should know that there are more than 2,000,000 BSF's operating around the world with many hundreds, perhaps thousands, being produced every day.
There is a tremendous amount of information regarding the construction, use, and performance of the BioSand Water Filter on web sites too numerous to list.
The following list of references provide a very good introduction to the history of the development of the BioSand Water Filter. It is understood that there has much, much more been written; but, this information documents some of the original struggles.
2019-01-22 There has been a great deal happening in the 'BioSand Filter World' since the filters were first introduced in the very early 1990's. There are many, many web sites supported by very good organizations providing top quality information and guidance. A simple internet search will produce several tens of thousands of hits. Of course some of the stuff is garbage or of questionable utility.
The purpose of this editorial section is to provide commentary and views pertaining to the BioSand Water Filter technology and its implementation in a fashion that not-for-profit organizations might not wish to articulate because of perceived risks to funding and other support.
I have no such constraints. I simply want to advocate for those organizations who are trying to provide the BSF technology correctly where it is needed.
MUST HAVE CHARACTERISTICS to be CALLED a BIOSAND WATER FILTER
It has come to my attention that filters are claiming to be a variation of the BioSand Water Filter technology which would not be a problem if in fact they met the minimum requirements. These are:
1. The filter container, diffuser, standpipe, lid and media are constructed using food grade quality materials.
2. The filter will contain a filtering layer consisting of a minimum of 15 cm of clean rock particles, also known as media, as measured down from the top surface of the media. Layers of larger diameter rock particles may underlie the filtering media to provide support for the filtering layer and drainage of filtered water.
3. The rock particles comprising the filtering layer will have a mean diameter less than 0.35 mm.
4. The filter outlet system is normally a pipe that should be located such that it removes filtered water from the bottom of the filter into a vertical pipe, called the standpipe, that is located inside the filter container wall or securely attached to the filter on the outside the filter wall. The standpipe must not be located inside the filter media to avoid accidental occurrence of untreated water reaching the bottom of the media by flowing along the outside of the standpipe. Filtered water must flow freely from the filter when in operation (no valves or anything else that might restrict the flow of filtered water). When the flow of filtered water stops, there must be a layer of water at least 5 cm deep above the filter media – known as the paused depth. There should be no extensions to the standpipe outlet that would result in siphoning action that might drain all of the water from the filter.
5. A diffuser plate or basin with a flat bottom must be located 10 cm above the top of the filter media when leveled. All water that is poured into the filter must pass through the diffuser. The holes in the bottom of the diffuser must be no smaller than 3 mm diameter spaced no closer than 25 mm (so as not to disturb the surface of the media when water is added to the filter). The number of holes is dependent on the diameter or width of the filter container (must cover more than one-half the area of the bottom of the diffuser). The space above the paused depth of water in the filter should be large enough to allow convenient addition of water to the filter with minimum user attendance.
6. Filter height must be one meter or less (convenient for household use).
7. Filter can be used as required without reduction in filter effectiveness to remove bacteria and viruses.
8. Routine cleaning of the media should not require removal of any media from the filter.
9. Only the top 5 cm or less of the media should be disturbed during cleaning using surface agitation methods.
10. Maximum surface loading of a BSF used to remove bacteria and viruses is 400 Liters per square meter of media surface.
Filters that do not exhibit any one of the features 1 to 10 cannot be called a variation of the BSF technology.
Note that these manuals were used for the original design (Manz design) of the concrete filter. There are many other designs available that are easily discovered using a simple internet search. Most of these 'new' designs still adhere to the basic principles of the original design allowing them to be part of the 'intermittently operated slow sand filter family'. Books 1 to 7 describe how the steel mold is used to make a filter body, diffuser and lid, media selection and preparation and finally installation and commissioning of the filter. Also there is a very detailed description (great drawings) of how to fabricate a steel mold. Additional 'Guidance Manuals' provide greater detail on installation and commissioning, operation, cleaning and protocols for performance evaluation. There is discussion on the problem of sourcing filter media when there is no crushed rock available (e.g. islands). Additional detail is provided on the use of three and four layer filter media installations.
The history of the BioSand Water Filter is well documented in photographs. Awareness of how the BioSand Water Filter developed brings a deeper appreciation for the innovation that it is and recognizes the numerous players in the process.
The short courses were being demanded after the success of the Nicaraguan project was 'discovered'. The short courses and associated projects were very important in the development of concrete BioSand Water Filter and now the plastic BioSand Water Filter being marketed by Davnor Water Filters Ltd. Several short courses had been offered each year in Calgary to anyone who was interested and often they were offered in the country where the projects were going to be implemented. The role of providing training (short courses) and technical support for the BioSand Water Filter now largely falls on organizations such as the Centre for Affordable Water and Sanitation Technology (CAWST).
The preparation of the descriptions takes a bit of effort because of the mass of information that must be worked through; but, it is going to happen and as the documents are produced they will appear on the list below.