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Pure, clean ... and getting rare
- Water, water…
- Drinking water
- Waste water
- Stormwater
- Air
- PM10 pollution
- Nitrogen dioxide
- Carbon Monoxide (CO)
Air and water - these essential elements need our care.
by Kathleen Blackhurst
Every day we breathe around 11,000 litres of air and use around 300 litres of water. These are normal everyday activities that we usually take for granted. We expect a certain standard for the quality of our air and water and we are not impressed if pollution occurs. But how often do we stop and think about what it takes to ensure that there is enough high-quality air and water for everyone?
Water, water…
Providing and disposing of water is one of the key functions of local authorities. It is a complicated business that requires expensive treatment plants, thousands of miles of pipes, reams of legislation and policy documents, and significant levels of staffing.
Regional authorities oversee the provision and disposal of water in different ways. For example, in Auckland, Watercare is the regional supplier of drinking water and wastewater services. There are also six local network operators (Ecowater Waitakere City Council; Manukau Water; Metrowater; North Shore City Council; Rodney District Council; and United Water), who distribute water and manage the water and wastewater networks for the region’s city and district councils. If a local government body decides to contract out the operation of a water service, it must retain control over water pricing, management and policy development on delivery of water services.
Water use falls into three categories:
- drinking water – this has been treated to remove contaminants so that it complies with New Zealand Drinking Water Standards
- waste water – this has been through our homes and businesses and needs to be treated to have contaminants removed before being discharged to land, estuaries and oceans
- storm water – this is run-off from houses, driveways and roads that is drained without treatment into natural waterways.
Drinking water
All water provided to our homes and businesses is usually taken from
its source (such as a river or lake) and piped to a treatment plant where
it undergoes a costly process to bring it up to New Zealand Drinking
Water Standards. Local authorities are responsible for ensuring that
water supplied to their region meets these standards. If contamination
does occur, they are also responsible for controlling it.
Currently there is much debate about these standards. There is a strong push
to further improve the quality of water provided to homes and businesses. Certainly
this is a very good thing. However, most of the water provided to our homes
is flushed away without being drunk. Toilets are a major consumer of water,
and washing machines, showers and baths, and outside taps used for car and
garden maintenance also use up a high proportion. Very little is actually consumed
by the people who live in the homes or work in the businesses.
Some rural territorial authorities have expressed concern about whether it is necessary to treat all household water. In rural areas, they say, the majority of water treated to drinking water standards is used on farms. Many are asking whether it make sense to spend a lot of money purifying the water when it is then used to wash cow faeces off milking-shed floors. One solution that has been proposed is that local authorities supply water to homes without the same degree of treatment but provide residents with high-quality filters for taps that are used for drinking and cooking water.
Sustainable systems for water supply and waste disposal are essential for community health and well-being.
Waste water
Having passed through our city and town homes the water is then piped through the sewers to treatment plants where it goes through a number of treatment processes to remove solids, pollutants, and odorous compounds, and greatly reduce the number of potentially disease-causing micro-organisms. This treated water is then discharged onto land or into estuaries or the ocean. With individual consumption quantities and population numbers continuing to increase, the amount of water needing to be treated and discharged is rising every year. Questions that local authorities face include how much of this treated water could be reused where drinking quality is not required.
In rural areas, the population is spread out over a vaster area of land, and it may be unfeasible to have an integrated sewer system to carry away waste water. In these areas it is far more practical to use septic tanks, waste water treatment ponds and other methods to dispose of this water. However, for human safety and in order to keep water ways clean, councils still need to manage waste–water disposal, since often it contains effluent or chemicals and other byproducts that can be harmful to the environment. They do this by setting standards for waste water disposal systems, issuing permits, managing quantities, and conducting inspections.
Stormwater
Rain water needs to go somewhere. In rural and green areas, it is naturally
absorbed into the ground.
But in developed areas, rain that runs off roofs, roads and other areas such
as car parks and playing courts needs to be drained away and piped back into
natural streams and estuaries. It is important that regional authorities ensure
that this water is not contaminated. There have been a number of publicity
campaigns to stop people discharging contaminated water into storm water drains.
Regional authorities for large developed areas such as Auckland face particular concerns. Growth and urbanisation increase the volume of stormwater run-off, and this leads to contaminants and other sediments running into our streams and harbours, thus causing increased erosion and pollution. (Floods and erosion are also major concerns for regional councils. See page 48.)
Air
Air quality is a responsibility of regional councils. Poor air quality can seriously affect our health. Air pollution particularly affects our heart and lungs, and can cause cancer. A recent report to the Ministry of Transport by health experts around the country estimates that air pollution causes at least 486 premature deaths per year in the Auckland Region; 58 percent of these (253) are due to motor vehicle emissions.
As well as premature deaths, air pollution is known to cause sickness
and hospitalisation. Air
pollution particularly affects people with heart disease, respiratory disease,
asthma and bronchitis.
There are several types of air pollution that regional authorities particularly
need to manage:
- PM10
- carbon monoxide
- nitrogen dioxide,
PM10 pollution
This is caused by tiny particles, less than 10 microns in diameter, that are produced by combustion and are suspended in the air. The concentrations of these are very high during the winter months – particularly on still days when they are not dispersed by the wind – in places such as Christchurch, which is located on a very flat plain and has a high rate of solid-fuel-burner (wood and coal fires) use for home heating. Under these conditions high numbers of small particles are readily inhaled and lodge in the lower lung, causing a range of health problems.
An independent study by the University of Otago has shown that particulate pollution contributes to up to 70 deaths a year from respiratory problems. This and overseas work have shown a clear relationship with increased incidence of asthma, allergies and other conditions. Children and the elderly have been shown to be especially at risk.
Clean and pure, our right to enjoy it today, our responsibility to preserve it for the future.
Nitrogen dioxide
Nitrogen dioxide (NO2) is also produced by cars and can irritate the lungs, increase the susceptibility and severity of asthma and lower resistance to infections such as the flu. It can also affect plant growth and health and can significantly degrade visibility because it contributes to the formation of brown hazes and smog.
Regional authorities and councils manage air pollution by monitoring how and where it happens and then working to reduce it at source. For instance, in Christchurch residents are not allowed to light an outside fire without a permit from 1st May until 31st August. In Auckland, there have been major publicity campaigns to induce motorists to regularly tune their cars so that they are fuel efficient and don’t produce as many pollutants. One memorable campaign was ‘0800 Smokey’. This ran for 15 weeks and encouraged motorists to ‘dob in’ smokey vehicles. 43,000 calls were made during this time, dobbing in over 23,000 different vehicles. The worst vehicle was reported 67 times!
Carbon monoxide (CO)
This form of pollution is produced mainly by cars and trucks. In densely urban areas such as Auckland this is a particular concern. There are 650,000 vehicles in the Auckland Region travelling about 8,000,000,000 kilometres every year – that’s eight thousand million kilometres! This produces thousands of tonnes of toxic air pollutants. The amount of CO produced is greater when cars’ engines are not working efficiently or are idling. So when the traffic is congested more pollutants are being pumped into the air.
www.mfe.govt.nz
www.4million.govt.nz