Water Problems

pH Correction

Low pH or acidic water can cause corrosion of copper pipe fittings. In extreme cases the copper the water dissolves from pipework can react with soaps causing water to turn blue and with hair dyes giving unpredictable results, e.g. blondes go green.

The CleanStream® filter uses a media in the filter which corrects the acidic nature of water without the need for mixing or dosing of chemicals. The media slowly reacts with water and the filter media is topped up, usually once a year.

Iron & Manganese Removal

Both iron and manganese in water can cause staining of laundry. The CleanStream® filters use a unique air entrainment device within the filter to oxidise these metals, together with filter medias to enhance the reaction. They also use an air/water backwash to maintain the filter performance and give very high rates of reduction. Filters can be designed for either pressure or float switch controlled appliances.

Softening

Softening of water, exchanging calcium ions for sodium ions operates similar to nitrate removal.

The media within the filter is a "cation" resin whilst nitrate media is "anion". Using water, sodium in salt (NaCl) is swapped for the calcium in the water. In nitrate the chloride (Cl) is swapped for the nitrate in the water. Thus, in water softening sodium is added to the water. Sodium levels should be checked to ensure they do not exceed the maximum allowable value of 150mg/l. Current advice from the UK Department of Environment is that softened water should not be used for drinking and an unfiltered drinking supply should be taken off prior to a water softener.

Taste and Odour

Water supply companies maintain a low level of chlorine in mains water to inhibit bacterial growth in the distribution network. Chlorine and naturally-occurring organic materials create a taste and smell that many people dislike.

Plumbed-in activated carbon filters work on the same principle as the jug filter to remove chlorine and organic substances but are not so effective on inorganics such as salts and metals. They consist of a filter head for connection to the water supply with a detachable bowl housing a filter cartridge incorporating a mechanical filter, which excludes grit, dirt, sand and so on.

The effectiveness of an activated carbon filter can be extended through additions to the basic filter material and different types of cartridge are now available, capable of removing or reducing a variety of additional substances. Activated carbon filters are also often used as the main element of a larger combination filter system, capable of removing heavy metals and nitrates.

Bacterial growth can occur in filters if they are left unused for a long period of time, as they would be, for instance, at a holiday home. To reduce potential bacterial problems, some activated carbon filters are impregnated with silver, which is known to inhibit bacterial growth. Any treated water not used immediately should be refrigerated.

All filter cartridges should be changed regularly, in accordance with the manufacturer's instructions. The maximum filter cartridge life recommended by BRITISH WATER is 6 months for standard filters and 12 months for those containing silver.

Nitrates

Nitrates from plant decay or nitrate-based fertilisers can sometimes find their way into natural water supplies.

There's been considerable discussion over the years about the possibly harmful effects of nitrates in the water supply. On one hand, there is talk of a link between nitrates and cancer in animals. On the other hand, in East Anglia, where nitrate levels are relatively high, stomach cancer levels are lower than average for the UK. Nitrates have also been linked in the past to a very, very rare condition that affects some bottle-fed babies. There is, however, little hard evidence on either side.

The drinking water regulations call for a maximum of 50 milligrams per litre of nitrate in drinking water supplies. There may have been some infringements of this regulation in the past by some water supplies. Generally speaking, though, the necessary equipment has been, or is being, installed across the country to keep within the limit and infringements in mains water supplies are now rare.

If consumers are concerned about possible excessive nitrate levels in their water supply, they should contact their water supply company for an analysis of the water, or, in the case of a private (non-mains) supply such as a borehole or well, the local Environmental Health Officer.

If a consumer chooses to reduce nitrate levels, there are several plumbed-in drinking water filters available to do the job. Be aware, though, that there are many types of drinking water filters available, with different capabilities and only some will remove or reduce nitrate.

Nitrate removal filters use the ion exchange principal as with water softening, where media is "charged" with chloride from brine which are exchanged for nitrate ions in the water. When all the chloride ions have been used up, the system is "regenerated" automatically using brine, the nitrates being washed out of the filter, it is then ready to treat the next batch of water. Regeneration can be set up on either a time or flow basis dependent on the filter selected.

So, it is essential to use a reputable supplier to ensure you select a filter of suitable capacity and nitrate reduction capability. You should also ensure that the filter is supported by a performance validation and that you adhere rigorously to any maintenance instructions.

Turbidity

Turbidity is a measure of the cloudiness of water and can often be a problem in water with a high iron content, often removing the iron will remove the turbidity.

Water cloudiness is caused by material, such as dirt and residue from leaves, which is suspended (floating) in the water. If you look at a river after a storm, it will be full of sediment and definitely not clear, you are seeing all of the suspended soil in the water. Usually the materials that cause turbidity in our drinking water either settle out or are filtered before the water arrives in our drinking glass at home.

Turbidity may be composed of organic and/or inorganic constituents. Organic particulates may harbour high concentrations of bacteria, viruses, and protozoan, therefore, turbid conditions may increase the possibility for waterborne disease.

Cryptosporidium

Cryptosporidium is a waterborne parasite found widely distributed around the world including Europe. When ingested it can cause an unpleasant illness referred to as cryptosporidiosis. Infections are transmitted by tiny pore- or egg-like cells called oocysts. Cryptosporidium oocysts are small, roughly spherical in shape and about 4 to 6 µm in diameter; a µm is a micrometre, one millionth of a metre.

The symptoms of cryptosporidiosis are diarrhoea (circa 92% of patients), mild abdominal pain (circa 45% of patients), nausea and vomiting (circa 51% of patients), mild fever (circa 63% of patients) and fatigue. No drug has been shown to be effective against Cryptosporidium infection and recovery from the illness is dependent on the body's immune system. As a consequence cryptosporidiosis can be very serious in people whose immune system is weakened or less effective such as the very young, the elderly, AIDS sufferers and those on immuno-suppressant drugs. The oocysts of Cryptosporidium are passed in huge quantities in the faeces of infected people and animals (which is why oocysts are found in sewage effluent and sewage sludge). When animal slurry is spread on farmland oocysts may well be present, and as a consequence runoff from rain can carry oocysts into streams, rivers, lakes and reservoirs. It has been reported that most waterborne outbreaks of cryptosporidiosis occur during and after heavy rainfall. Cryptosporidiosis is routinely observed in the population. Since the causal agent was identified in 1976 there have been a number of outbreaks of cryptosporidiosis caused by poor hygiene, contact with farm animals, contaminated drinking water and contaminated swimming pools. Cryptosporidium is resistant to the normal methods used to disinfect drinking water such as chemical dosing with chlorine, chloramines, chlorine dioxide and/or ozone. Fortunately a well-operated water treatment plant using conventional coagulation and filtration can reduce oocysts by as much as 99% or even 99.8%. However, sudden changes in flow rates dislodge some of the solids retained within the filters, including oocysts so the careful operation of the filters is of great importance. This fact is recognised in the UK by the adoption of treatment regulations, which stipulate that there should be less than 1 oocyst in 10 litres with a sample flow-rate of at least 40 litres per hour taken over a day. The ROCK explains that this regulation is not a health standard but an operational standard to ensure that the processes for physical removal of particles (including oocysts) are working efficiently at the supplier's treatment works.

Although Cryptosporidium is frequently waterborne in natural waters and infections have occurred from drinking contaminated water supplies most outbreaks of cryptosporidiosis in the UK appear to be associated with swimming pools (an 'outbreak' of cryptosporidiosis or intestinal disease is defined as a level of disease above the normal background level). In the period January 1999 to December 2000 there was a total of 18 outbreaks of cryptosporidiosis of which 2 were attributed to public water supplies, 1 to a private water supply, 1 uncertain and 14 were attributed to swimming pools. The total number of people infected in these outbreaks was 667, of whom 405 were infected by the public water supply, whereas the total number of individual cases notified to the Communicable Disease Surveillance Centre for the same period in England & Wales was 10,037.

In the year 2000 the total number of reported cases of cryptosporidiosis in England & Wales was 5279 out of total population of 52.94 million of whom 51.2 million are connected to the public water supply. However, drinking the public water supply did not cause most of these cases.

Giardia

Like Cryptosporidium, Giardia is a parasite that can be waterborne and is found widely distributed around the world including Europe. When ingested it can cause an unpleasant illness referred to as giardiasis. Infections are transmitted by tiny pore- or egg-like cells called cysts which are oval in shape with a length of 9-12 µm (a µm is a micrometre, one millionth of a metre).

The symptoms of giardiasis are acute diarrhoea, abdominal cramps, bloating and excessive flatulence. The severity of the illness can vary considerably and only about a quarter of infected people show symptoms of the illness. Malabsorption of food can lead to considerable loss of weight and in children it can be a cause of failure to thrive. The incubation period can be anything from 1 to 75 days, but on average is 7-10 days. Treatment with drugs can be effective, but if untreated the illness may persist for 3-4 years.

Giardia is found in man, dogs, cats, pigs, sheep, beavers and many other domestic and wild mammals and also in birds. Cysts are passed in the faeces of infected animals, including humans, and are found in cattle slurry, untreated sewage and treated sewage. They are widely found in lakes and rivers especially where there is wildlife which uses these water sources.

Giardiasis is routinely observed in the population. Giardia is frequently waterborne in natural waters and infections have occurred from drinking contaminated water. However, there are many other possible ways of becoming infected with Giardia such as person-person contacts, animal-person contacts, contaminated food and contaminated swimming pools and other recreational waters (rivers and lakes), or foreign travel - giardiasis is also known as "travellers' diarrhoea".

Cysts are particulate and are fairly readily removed by the conventional processes used in drinking water treatment plants such as coagulation, settlement, rapid filtration and slow sand filtration. A well operated treatment plant based on chemical coagulation, sedimentation and filtration should achieve at least 99.9% removal of cysts. The effectiveness of standard chemical disinfectants such as chlorine and chloramine against Giardia cysts is limited. However, they do present a further barrier to the entry of viable cysts into the supply system. There are strong indications that both ozone and UV light may be effective and work is currently in progress to identify the conditions in which UV radiation may be used with confidence.

In the UK there are regulations to control the risk of pathogens getting into the drinking water supply. The total numbers of infections of giardiasis in the UK are small. In the year 2000 the total number of reported cases of giardiasis in England & Wales was 3892 out of total population of 52.94 million of whom 51.2 million are connected to the public water supply. However, there is no evidence that any of these cases were caused by drinking the public water supply. Furthermore, it seems likely that a number of these cases were contracted by people travelling overseas. Data for Scotland and Northern Ireland suggest that the situation there is little different from England & Wales.