Ammonium is derived from ammonia and is widely used as cleaning agents and food additives. Ammonium in water supplies can originate from agricultural and industrial processes, sewage systems and animal waste.
Ammonium is not a health risk itself but it serves as a valuable indicator of source pollution. Ammonia in water can result in corrosion of pipes and fittings which can cause copper stains and sanitary ware.
The limit for ammonium in drinking water is 0.30 mg/l
Aluminium is the most abundant metallic element in the earth’s crust. Different chemical forms of aluminium are commonly used as coagulants and for removal of colour, turbidity and micro-organism during water treatment.
High aluminium content may pose a threat to people with kidney disorders and it may causes neurological problems.
The limit for Aluminium in drinking water is 0.200mg/l Al
Colour in water is caused by the interaction of light with suspended and dissolved particles. As suspended particles (turbidity) are likely to be coloured themselves, the more turbid the water the more colour will appear.
The impact is mainly aesthetic and is deemed acceptable to the customer themselves but it is important to note that if high colour can get through the water treatment process, microorganisms may also be getting through the water supply.
The limit for apparent colour in drinking water is either no abnormal change or acceptable to customers
Clostridium Perfringens is an anaerobic bacterium commonly found in the intestines of humans and animals and in the environment in soil, sewage, crops, dust and decaying vegetation. The presence of these spore-forming anaerobes is an indicator of faecal contamination. Clostridium Perfringens are particularly resistant to chlorination and unfavorable conditions in the environment and can survive in water much longer than organisms of the coliform group. Their presence, especially in well water and borehole supplies, can indicate remote or intermittent contamination.
The ingestion of the bacteria through drinking water does not appear to pose a direct health affect but their presence may indicate that other more harmful bacteria are present in the water.
The limit for Clostridum Perfringens in drinking water is 0 cfu/100ml.
Conductivity is the measure of the ability of an aqueous solution to carry and electric current. Conductivity is a good indicator of hardness and alkalinity and also used to estimate dissolved solids in a water sample.
There are no direct health effects.
The limit for conductivity in drinking water is 2,500 µS/cm @ 20oC
E-coli bacteria are present in warm blooded mammals. They enter the water supply from sewage contamination and their presence indicates recent heavy pollution by human or animal waste.
The consumption of water with E-coli present would possibly cause risk to human health as there are potentially other pathogenic bacteria present in the water supply.
The limit for E.Coli in drinking water is 0 cfu/100ml.
Fluoride present in the majority of water samples is through fluoridation (addition of fluoride) by local authorities. The fluoride limit in Ireland is more stringent than the remainder of Europe. Studies have shown that fluoride levels above 0.6mg/l leads to a reduction in tooth decay in growing children.
Further studies have also shown that levels above 1.5mg/l cause an inverse effect and mottling of teeth. Supplies with naturally occurring fluoride levels should not exceed 1.5mg/l F.
The limit for fluoride in drinking water is 0.8mg/l F in fluoridated supplies.
Different areas of the country will have varying degrees of hardness. Hardness can be temporary (can be removed by boiling) or permanent (cannot be removed by boiling). Total hardness (temporary + permanent hardness) is combined amounts of calcium and magnesium hardness expressed as CaCO3 (Calcium Carbonate).
|Soft||Up to 50 mg/l CacO3||Moderately Hard||151 – 250 mg/l CaCO3|
|Moderately Soft||51 – 100 mg/l CaCO3||Hard||251 – 350 mg/l CaCO3|
|Slightly Hard||101-150 mg/l CaCO3||Excessively Hard||over 350 mg/l CaCO3|
Hardness can actually improve the taste of water and make it more acceptable.
Water with high hardness levels will tend to cause scaling of kettles, pipes, irons etc. It will also reduce the lathering formation from soaps and shampoos.
There is no limit for hardness in drinking water.
Iron is present in high concentrations in soil and rock and this enters the water in a soluble form as it passes through these formations.
There will be reddish-brown staining of laundry, sinks, cisterns etc. It can impart a taste also in water supply.
The limit for Iron in drinking water is 0.2 mg/l.
Lead predominantly enters water from the pipework leading to and within houses. The lead dissolves into the water from the pipework. Because it accumulates within the body tissue, it is important that the levels are low in the water consumed. The concentrations of lead are highest in the morning when the water has been sitting in the pipework overnight.
If you are getting your water testetd for lead concentrations, take the sample from the first draw from the tap in the morning. But if you want to prevent potential lead exposure, then run the tap for a number of minutes before drinking.
The limit for lead in drinking water is 10 micrograms/l.
Manganese is similar to iron in that there are no harmful health effects but more staining of appliances. The source of manganese is also from soils and rocks.
The staining associated with manganese is more severe than iron and will tend to be a black-brown staining. It can have a more detrimental effect regarding imparting a taste on the water.
The limit for mangense in drinking water is 0.05 mg/l.
Nitrate is a tasteless, colourless and odourless compound found naturally occurring in the soil. It is present in water in elevated levels due to human interference such as fertiliser run-off, septic tank contamination etc.
Nitrate is excessive levels can cause Blue Baby Syndrome. This is as a result of infants stomach acid not being as robust as an adult and therefore allows certain bacteria to develop. These bacteria convert nitrate to nitrite which binds the oxygen in the blood. It eventually leads to lack of oxygen to vital organs.
The limit for nitrate indrinking water is 10mg/l.
Nitrite formation is part of the nitrogen cycle and is formed from microbiological activity. It normally exists in low concentrations. High nitrite levels indicate more recent pollution of the water than high nitrate levels, as the production of nitrite is an intermediate stage in the conversion of ammonia to nitrate. Chloramination of water systems during treatment may also give rise to the formation of nitrite.
High levels of nitrite act as a toxicant and are known to cause ‘Blue Baby Syndrome’ (methaemoglobinaemia). In addition, nitrites can give rise to the presence of nitrosamines by reacting with organic compounds giving possible carcinogenic effects.
The limit for nitrite in drinking water is 0.5 mg/l
pH is a measurement of the alkalinity or acid content in water. The optimum range for drinking water is between 6.5 and 9.5. Below 6.5 would likely cause corrosion of water supply pipes leading to higher amounts of metals in the water supply.
Water with high or low pH values may impart unusual taste into the water supply. It has no direct health effects.
The limit for pH in drinking water is ≥6.5 and ≤9.5 pH units
Total coliform bacteria indicate the general level of microbial contamination of a water sample. Total Coliforms include both bacteria of faecal origin and also those which originate in the soil and are non-faecal. They may be present in a water supply where the well is not properly capped and screened letting in animals and insects.
Drinking water with total coliforms present can cause health issues as they indicate that other pathogenic bacteria may be present.
The limit for Total Coliforms in drinking water is 0 cfu/100ml.
Turbidity is the measure of finely divided solids and suspended particles in the water. In general terms it can be described as the cloudiness of a water sample.
The health effects depend on the composition of the turbidity particles, as it is possible that the particles are of sewage origin. The E-Coli test will confirm the presence of sewage. Generally “acceptable to consumers” applies as a limit.