Courtesy of NZ Motor Caravan Association
Can I help prevent water pollution?
Once you are aware of how water pollution is caused, you can make sure your actions don't contribute to the pollution. Below are some everyday substances that can cause serious damage if disposed of incorrectly.
Grey waste water Grey water contains many of the following things which can be very harmful to our aquatic habitats. Your 'little bit of soapy water', when added to many other people's 'little bit', adds up to a destructive amount.
Never dispose of grey water into streams, lakes, rivers or beaches. Only ever dispose of grey water onto land if you have specific instructions from the property owner and never on land where it could easily reach water. The best place for grey water disposal is a proper sewerage system (not a stormwater drain!).
Foodstuffs & Drink As they decay and rot in a body of water, they use up its reserves of oxygen, suffocating the creatures that live in it.
Cleaning Agents Detergents, disinfectants and degreasers all cause harm to aquatic plants and animals through poisoning, burning and irritating their sensitive membranes and tissues. Even those claiming to be 'bio-degradable' or 'environmentally friendly' can be toxic to fish and remove oxygen from a water body as they are broken down.
Ammonia & Chlorine Found in many household cleaning substances, both are highly toxic to aquatic life.
Bacteria and Disease These are found in very high levels in grey water, just from people showering or washing hands etc. Public health is at risk, as only a tiny amount of human faecal matter is needed to cause pollution – there are millions of micro-organisms in every gram.
Infectious viruses and parasites can survive for several months in water, including giardia, hepatitis A, cryptosporidium and gastroenteritis-causing viruses. Skin diseases can also be spread.
Oil & Grease One litre of oil can contaminate one million litres of drinking water and cover 100 m2 of water, oiling birds and creating a barrier preventing essential oxygen and sunlight from getting into the water.
Oil and grease from animal and vegetable fats in your grey water are just as guilty of this as used waste oils.
Always use drip trays when transferring or draining oil and other liquids, and wipe up small drips and spills. Used waste oil can be recycled at Transfer Stations or your local Service Station.
Suspended solids Any kind of suspended solids in your waste water can smother an aquatic habitat, blocking sunlight and oxygen and choking the creatures that live there.
Toilet chemical Some common toilet chemicals still contain formaldehyde – a poisonous carcinogenic substance banned in some countries.
Other toilet chemicals may not contain formaldehyde, but they can still contain strong chemicals and may be very high in ammonia – making them toxic to aquatic life (and your equipment!).
While there are several 'safe, biodegradable' products available in NZ, no toilet chemicals are designed to be disposed of in the natural environment, but in proper sewerage systems in the right quantities.
Black waste water Black waste water is any waste water containing sewage.
Black waste contains high levels of bacteria and disease, toilet chemical, ammonia and suspended solids. This page tells you how damaging all those components are to public health and the environment.
Black waste is also very high in phosphates, nitrates and other nutrients that promote the uncontrolled growth of plant and bacteria populations within the aquatic environment. Waterways can be choked off with weeds or depleted of oxygen by unnaturally high populations of micro-organisms.
Don't ever dispose of black waste into water! The only safe place for black waste is in a proper sewerage system.
Other substances Other substances that you need to dispose of correctly and with care, making sure they can't enter water, include the following:
Fuels & Solvents can damage fish gills so they can't breathe, as well as poisoning animals and burning plants. They contain cancer-causing agents that accumulate in fish and shellfish and they can be a major explosion hazard, especially in pipes. Heavier components accumulate in the bed sediments of a water body.
Paints, Dyes & Inks can be poisonous to creatures that come in contact with them. They also prevent light from entering the water, making it difficult for plants to get the energy they need to live and for animals to find food.
Corrosives including battery acid, vinegar, some cleaning compounds, acetic acid and cement wastes. The degree of corrosiveness in liquids is measured in pH units. These range from 1 to 14, with 7 being neutral. Levels of pH outside the range 6-9 damage sensitive tissues such as eyes, gills and skin, make it impossible for juvenile creatures to survive and burn or kill mature fish, plants and insects.
Heavy Metals such as lead (for example, in old paint), zinc, copper, cadmium, nickel and mercury inhibit plant growth and poison aquatic creatures by accumulating in their bodies. Metals do not break down in the environment. They build up through the food chain and accumulate in the bed sediments of a water body.
Even a very small quantity of a pollutant, or just one accidental discharge, can drastically alter the quality of a stream. Fish, insects and plant life can be killed, habitats destroyed and the affected stream can take many years to recover.
You may think that your little bit of waste can't harm the environment. But when combined with that of a million others it contributes to a massive amount of pollution that happens every day. The added effects of this cause serious damage to our environment and must be prevented. Dispose of waste appropriately, and never allow your waste water to flow or be washed down a stormwater drain.
It is illegal to cause pollution. There are substantial penalties, including instant fines and imprisonment
Always use a dump station or proper sewerage system to dispose of black and grey waste. Never dispose of black or grey waste into water!