HAMILTON TAP WATER
It seems Hamilton City sources 100% of their drinking water from the Waikato River.
We refer readers to our Waikato River web site page HERE
We also refer readers to the detail on our Auckland Tap Water page HERE, as much of the information there is relevant to Hamilton city water.
Details of the treatment the Hamilton City does to the Waikato River water is set out on their web site and on pdf pages called from 'River To Tap', the latter being here: http://www.hamilton.govt.nz/ourservices/water/water/Documents/A%20Guide%20to%20Hamilton%E2%80%99s%20Water%20Supply.pdf
Hamilton City do state the quantum of fluoride they add to the water, being 0.5 mg/l. They state the Waikato River already has 0.2 mg/l fluoride in it at source (perhaps from super phosphate leaching from adjoining farmland?), suggesting that the drinking water ex taps has about 0.7 mg/l of fluoride. They do not state the source or type of fluoride they add.
It is noted by NZ Food Safety in 2005 ('NZFSA 2005 non-commercial wild food report') that the health effects from the intake of chemical hazards are difficult to quantify, as they might only arise over long periods of low exposure.
SUMMARY of RIVER WATER TREATMENT
Hamilton city has a 'modern' drinking water treatment system. In 2007 $22 million was spent upgrading the existing intake station south of the city at Riverlea. This was proposed to meet Hamilton City's tap water demand until 2016.
The Hamilton City drinking water is pre-treated as follows:
- YES --- Chlorine is added to kill any pathogenic bacteria that might be in the water after filtration. They do not advise the quantum or type or source of chlorine.
- YES --- Fluoride is added at a rate of 0.5 mg/l , and the Waikato River already has 0.2 mg/l of fluoride. They do not advise the type or source of fluoride.
- YES --- Aluminium Sulphate (Alum) is mixed into the water, said to remove some unwanted substances, as Alum breaks weak bonds that hold small particles in suspension.
- NO --- There is no mention of any added cooper, so one assumes this is not added.
- YES --- Lime is also added to help prevent the water supply pipes from corroding and as they note it will lift an earlier acid pH and/or create a softening of the water. They do not advise the quantum or type or source of lime.
- YES --- Another chemical called polymer is added to the Hamilton water treatment process, as this assists particulate matter to clump together for later separation and discarding. They do not advise the quantum or type or source of polymer.
- YES --- UV Disinfection is another system used in this treatment process.
- YES --- There is a process called 'Residual Disinfection' listed of their web site- but not described.
- NO or NOT SURE--- about the use of Reverse Osmosis processing. Seems this water structure damaging system is not used.
- YES --- Sedimentation, screening, sand filtration and GAC - carbon filtration are other protective measures taken in treating the river water pre-drinking. There is no mention of where the sand is sourced from.
- Nothing else is stated to be added-done, so we assume nothing else is.
The Hamilton City water treatment process adds POLYMERS. What are polymers?
To understand what the polymers added to Hamilton City treatment processes are and their possible dangers....see/read the first 5 pages of this 1993 NZ Government commissioned report HERE.
Or refer to this web page about NZ Ministry of Health POLYMER information:
Here are a few words of caution on those pages --- and we ask our readers who drink Hamilton City water to enquire if any safeguards raised, as being required in the 1993 report we refer to, have been implemented and/or investigated --- prior to the city using this chemical in as part of treatments for Hamilton's drinking waters:
- "The extent of polyelectrolyte (also known as polymers) use in NZ is unknown and furthermore there are no NZ drinking water guidelines covering these diverse additives."
- "As a result the potential health risk associated with this sort of water treatment to the NZ public is unknown."
- "The major limiting factor in controlling residual polyelectrolyte and associated contaminants in the final water is likely to be does rate control."
- "NZ has no regulatory requirements for these chemicals."
- "Acrylamide (a polyacrylamide residual monomer) AND epichlorohydin (an epi-DMA polymer contaminant residual reactant) are recognised as toxic to humans."
- "Chloronated by-products of acrylamide and ozonated by-products of acrylic acid are also toxic."
- "Analytical methods are available for the analysis of acrylamide in water; for acrylamide in polymer; for polyacrylamide in water; and for acrylic acid in water. Many of the methods require sophisticated equipment or highly trained analysts, except for the method for polyacrylamide in water."
Some of the tests that are done by Hamilton City Council's ('HCC’s') internal Internationally Accredited Laboratory and subcontracted Laboratories include Giardia, Cryptosporidium, Coliforms, E.coli, Algae, Fluoride, Chlorine, pH, turbidity and other various inorganic and organic compounds.
These Laboratories along with water technicians test water from the treatment plant and check the distribution network to ensure that the water is safe for drinking.
Sophisticated ‘online’ technology also ensures water quality is continuously monitored and maintained. This includes parameters such as pH, turbidity, chlorine, fluoride, flow, pressure, transmissivity and UV intensity.