Water Filtration

Southland Plumbing and Pumps can offer a filtration system to suit your individual needs, whether it is for your home or business, we have the system for you.

We supply and install filters for 'Point of use' (under the bench) and filters for your whole house including ultra violet filtration, for bacteria elimination. We also supply and install Longveld Iron Out filtration systems.

Cartridge Filters

Different media cartridges can be used to filter whole household water and as under the sink 'Point of use' filters; they can filter various substances and undesiribles from the water, such as sediment and chlorine.

Ultra Violet Filtration

UV filtration units are used for the removal of bacteria in the water as well as removing other un-wanted substances with filter cartridges of various materials.

Longveld Iron-out System

The Longveld Iron Out system is the ultimate solution for iron removal from water in New Zealand; it is based on proven iron filtration technology developed in Western Australia. Iron Out filters are manufactured in New Zealand and are specifically designed to cope with the high concentrations of iron in our water in problem areas around New Zealand.

Left - Bottle water sample Right - Iron-out water sample taken day of unit installation

Left - Bottle water sample
Right - Iron-out water sample taken day of unit installation

left - Bottle water sample Right - Iron-out water sample a month after installation

left - Bottle water sample
Right - Iron-out water sample a month after installation


Understanding Water Test Results

Understanding a Water Test - Poster A3 Land.jpg

Information Guide:

Bacteria Testing

It is too exhaustive to test for individual types of bacteria that are pathogenic (disease causing) in water supplies. Some bacteria are considered as Indicator Bacteria in that they indicate the possible presence of faecal pathogens. Total Coliforms, Faecal Coliforms, Escherichia coli, and Enterococcus are indicators of faecal contamination and the possible presence of faecal pathogens and/or cleanliness of the water supply. Total Coliforms, Faecal Coliforms, Escherichia coli, and Enterococcus are not generally pathogenic although some species do have pathogenic characteristics.

Total Coliforms
Total Coliforms are a group of bacteria many of which are inhabitants of the gastrointestinal tract (gut) of warm-blooded animals. They will be frequently found in untreated water and may be environmental or faecal in origin depending on the source of the water. When Total Coliforms are found, but faecal coliforms are not found, this usually indicates that the total coliforms were not of faecal origin. There is no limit for these bacteria in drinking water.

Faecal Coliforms
Faecal Coliforms are a sub group of the Total Coliform group and are much more likely to indicate that contamination in the is faecal in origin. Amongst the Faecal Coliforms, Escherichia coli is the most likely to be associated with faecal contamination of a water supply. To be suitable as a potable water this reading must be ‘less than 1’ per 100ml.

Escherichia coli
Escherichia coli (E. coli) is increasingly used as an alternative to faecal Coliforms as an indicator of faecal pollution and is the bacterial indicator of choice in the NZ drinking water Standards. However when E. coli is not specifically tested for, faecal Coliforms are an excellent indicator of faecal contamination. To be suitable as a potable water this reading must be ‘less than 1’ per 100ml.

Enterococcus are used as an indicator of faecal contamination in seawater but presence of the group in drinking water may also give some clues to the cleanliness of the water supply. Enterococci are generally considered as inhabitants of the gastrointestinal tract of a variety of organisms including man and birds. They are however also inhabitants of drains and water that may not be subject to faecal contamination. The significance of Enterococci can be interpreted in conjunction with the Faecal Coliforms and/or E. coli results. There is no limit for these bacteria in drinking water.

The results indicate the number of bacteria that grew from a 100ml sample that was tested. If the result is expressed as ‘less than 1’ this means that no bacteria of that type grew from the 100ml of sample tested. Because of the way bacteria are reported the result will never be 0 – In effect ‘less than 1’ per 100ml has the same meaning as 0 per 100ml.


Chemical Testing

As with bacterial testing, it is too exhaustive to test for all chemicals that would be hazardous or give problems to a water supply. The tests carried out will give an indication of the levels of the main chemicals that may give problems in water supplies in NZ.

pH is a measure of the hydrogen ion concentration of water. It is measured on a scale of 0 to 14. A pH of 7 is neutral, greater than 7 is alkaline and less than 7 is acidic. A pH of 5 is ten times more acidic than a pH of 6. Yoghurt and beer are around pH 4 while household cleaners are generally above pH 11. The acceptable pH in drinking water in NZ are slightly acidic due to dissolved carbon dioxide in the water. The pH of drinking water should normally be between 6.5 and 8.5. However at a pH of 6.5, water can corrode some metals at an unacceptable rate. Values at this end of the range should therefore be avoided if possible. A more appropriate range would be pH 7.5 to 8.5.

pH after Aeration
For water containing excess carbon dioxide the pH can be raised by aeration. This test will give some idea of the effect of stripping the carbon dioxide from the water. Aeration can often bring the pH into a more desirable range. The pH can also be adjusted by the addition of lime, soda-ash, caustic soda and carbon dioxide.

Turbidity in water is caused by the presence of fine suspended matter such as clay, silt and or colloidal particles. In addition to being displeasing, high turbidites can affect some disinfection processes. Some suspended particles may also have the effect of concentrating some heavy metals or pesticides to their surface. Based on the pleasing properties of water alone, turbidity should not exceed 2.5 NTU. As a guide, water with a turbidity of 5 NTU would appear slightly muddy or milky in a glass. It would not be possible to see through a glass if the turbidity was over 60 NTU. Crystal clear water usually has a turbidity less than 1 NTU.

Hardness – Total, Calcium and Magnesium
Strictly speaking, hardness is a measure of the water’s capability to waste soap. The dominant chemicals that give rise to hardness are calcium and magnesium. For drinking water Total Hardness is defined as the sum of the calcium and magnesium concentrations expresses as calcium carbonate (CaCO₃). Degrees of hardness can be described as follows:

  • Less than 75mg/L CaCO₃                                  Soft
  • 75-150mg/L CaCO₃                                           Moderately hard
  • 150-300mg/L CaCO₃                                        Hard
  • Greater than 300mg/L CaCO₃                          Very hard

Acceptance of hardness can vary considerably and is generally related to the hardness you have come to expect. Soft water may lead to corrosion of pipes. Total hardness above 200mg/L may lead to excessive scaling of pipe fittings, and cause blockages of safety release valves in hot water systems. Total hardness in drinking water should not exceed 200mg/L as CaCO3, to reduce effects on taste, soap lathering, and to minimise undesirable build-up of scale. Hardness can be removed by treatments such as chemical softening, reverse osmosis, electrodialysis or ion exchange.

Alkalinity is a measure of the ability of water to neutralise acids or alkalis. The ability of water to provide buffering against pH changes brought about by corrosion processes or chemical additions is closely related to the alkalinity and pH of the water. Some treatment processes require that the alkalinity of the water is known.

Iron is a common metal found dissolved in Southland groundwater. Iron has a taste threshold of about 0.1mg/L in water and can become objectionable above 1mg/L. iron levels above 0.3mg/L may give water an undesirable rust-brown appearance and can cause staining of laundry and plumbing fittings, fouling of ion-exchange softeners and blockages in irrigation systems. Levels above 1mg/L are certain to give these problems. Ideally, the concentration of iron in drinking water should not exceed 0.2mg/L.

Manganese is a metal sometimes found dissolved in Southland groundwater. Manganese has a taste threshold of about 0.4mg/L. Above 0.05mg/L manganese may give taste and staining problems. Excessive manganese can block filters and irrigations systems. Above 0.5mg/L manganese is considered a health problem. However the greatest exposure to manganese is usually from foo. There is no convincing evidence of toxicity in humans associated with the consumption of manganese in water.

Nitrate (Nitrate + Nitrate)
The nitrate tested is actually the sum of the nitrite and nitrate in the water. Based on health considerations the Nitrate as expressed should not exceed 10mg/L as N. young infants are more susceptible to nitrate than older children and adults. Nitrate enters the water from vegetable and animal debris and animal excrement. It is also used in chemical fertilisers.

Ammonia may be found in surface waters but is more frequently found in ground waters. Many ground waters contain up to 1mg/L ammonia as N. the odour threshold is 1.5mg/L and the taste threshold is 35mg/L. ammonia can be an important indicator of pollution from breakdown of animal and vegetable matter of from human or animal excrement. Ammonia is not of immediate health relevance however based on the odour threshold it should not exceed 1.5mg/L in drinking water.

Chloride is widely distributed in nature. The presence of chloride in drinking water can be attributed to saltwater intrusion in coastal areas, salt deposits, effluent discharges, irrigation drainage or refuse leachate. Seawater has a chloride of around 20,000mg/L. the taste threshold of chloride in water is 200-300mg/L. high chlorides can accelerate corrosion. The concentration in drinking water should not exceed 250mg/L.

A Silica reading above 50mg per litre is bad. For potable water this needs to be below 50mg per litre.

UV Transmission
The higher the percentage the better the UV transmission through the water. This tells you whether a UV filter will be effective at treating bacteria in the water.