The purpose of this thesis is, with the laws regarding drinking water filter up to 50 P.E. as the basis, to create a routine for how the tests should be for the filters in a test-bed facility. How will a common test routine be designed for better assessment of drinking water filters today?
The thesis is based a literature study in the form of both websites and legislations. The information have been retrieved from the websides of relevant companies such as, the National Food Agency (NFA) and similar organizations working on drinking water issues. While the legislations have been taken from, for example, National Public Investigation and/or likewise. Several of the references that are used have backing from several other sources which should mean that the information is reliable. The legislation is the starting point for a functioning Sweden which should mean that it is reliable.
It has also been conducted a survey through email, where approximately 50 companies in the drinking water filter industry were asked what they think about various statements. The questions were based on an already developed proposals for a test routine that the author developed earlier. This method was chosen because it is difficult to get a clear picture of what the market is interested in examining without asking them.
Water in its raw form H2O does not taste or smells anything. It can, however, change when it is in contact with other materials. This is because water is highly soluble and thus dissolves other substances. Therefore it is important that materials used in drinking water treatment should be safe where the consumer might otherwise ingest unhealthy substances through drinking water. Building and Planning Agency together with the National Food Administration and the Swedish Chemicals Agency will design a platform where stakeholders can easily find information regarding approved materials in contact with drinking water.
There are approximately 1.2 million households in Sweden (both permanenta- and leisure accommodations) who receive their drinking water from private well. It is therefore the well owner's responsibility to make sure that the drinking water has a good quality. There is no legislation on the control of its own drinking water. The recommendation suggest sampling every three years on the well if it only supplies a household but every year if there are more than one household that are supplied. Approximately 1/5 of all drinking water is estimated to be unfit.
There are many different types of filters and methods which can make it confusing and difficult for people to choose the right one. Some of those types are ion exchange, activated carbon, reverse osmosis, sand filters, air filters, cartridge filters, UV light and scale filter. The filters have different characteristics and work in different ways. According to WHO guidelines for safe drinking water. Many substances are not regulated with any limits as long as the WHO does not consider that the concentration of that substance will be sufficient enough to affect people negatively. Examples of these are pH, iron chloride, manganese and potassium. Although EU has a list of safe drinking water which NFA base their limits on.
The proposed test routine became somewhat shorter and less strict than the routine as it was based on. It is reported in Appendix 2 together with the questionnaire sent out to businesses to find out what they thought about the proposal on the test routine. Drinking water filters should be tested in 32 weeks during which a power failure will be simulated. It is even recommended that the capability of the filter should be tested at high flow and no flow for a certain number of hours during each week.